electric flight uk - British Electric Flight Association
Transcription
electric flight uk - British Electric Flight Association
ELECTRIC FLIGHT U.K. ISSUE No. 73 SUMMER 2003 THE MAGAZINE OF THE BRITISH ELECTRIC FLIGHT ASSOCIATION http://www.ezonemag.com Visit the E-Zone on-line magazine – the best source of information for the electric flyer on the web today! Monthly columns covering nearly all aspects of electric flight Reviews on the hottest new aircraft and conversions Pictures of reader’s projects from all over the globe Showcase of manufacturers’ electric offerings Join the E-flight mailing list and converse with hundreds of electric flyers from around the world Four years of articles archived on-line Classified ads Links to numerous other electric internet sites Best of all – it’s free! Be sure to stop in! http://www.ezonemag.com Electric Flight - U.K. Issue 73 - Summer 2003 "To Encourage and Further all Aspects of Electric Model Flight in the British Isles and Elsewhere" - B.E.F.A. Constitution CONTENTS BEFA Committee 2002/3 ......................... 4 Chairman's Chatter ................................. 5 Current Lines ......................................... 6 Lead-Acid Battery Safety ....................... 7 New-2-U ................................................. 8 Readers' Models .................................. 14 Fun with a B-29 .................................... 28 Sudden ‘ush! ....................................... 34 Flying in Indy ....................................... 36 BMFA SF Nationals Application Form . 40 BMFA Northern Area Indoor Fly-In ..... 42 A Zagi-FiXX ......................................... Wizard Prang! ....................................... Maxi AXI .............................................. TLC from your TLO .............................. BEFA League 2003 ............................... Event Calendar ..................................... For Sale / Wanted ................................. New to Electric Flight? Start Here ........ BEFA Sales ........................................... Advertisers Index ................................. 43 48 59 66 70 72 75 76 78 78 Cover Photo: The cover photograph is David Chinery’s Sukhoi SU31, powered by the new larger AXI 4120-14 brushless motor. The motor and it’s use are discussed by David in his article “Maxi AXI” on page 59. NEXT ISSUE. The copy date for the Autumn 2003 issue is 1st September 2003, with the magazine due for publication by 1st October 2003. DISCLAIMER B.E.F.A. and Electric Flight U.K. wish to point out that the content, techniques and opinions expressed in this magazine are those of the individual authors and do not necessarily represent the views of either the Editor of this magazine or B.E.F.A. and its committee. All reasonable care is taken in the preparation and compilation of the magazine, but B.E.F.A. and its committee cannot be held liable for any error or omission in the content of this magazine or any subsequent damage or loss arising howsoever caused. To allow proper appreciation of the photographs used, colour copies of them will be posted on the B.E.F.A. website after publication of this magazine. If you can, check them out at www.befa.org.uk E.F.-U.K. 3 BEFA Committee 2003/4 Chairman Robert Mahoney 123 Lane End Road, High Wycombe, Bucks. HP12 4HF EMail: [email protected] Secretary Peter Turner 37 Church Street, Horsley, Derbyshire. DE21 5BQ Email: [email protected] Membership Secretary David Andrews 2 Gainsborough Road, Kibworth Harcourt, Leicester. LE8 0SG Email: [email protected] Treasurer Bob Smith 1 Lynwood Avenue, Tollesby, Middlesborough, Cleveland. TS5 7PD Email: [email protected] Editor EF-UK Jan Bassett 111 Plantagenet Chase, Yeovil, Somerset. BA20 2PR Tel. 01935 472743, E-mail: [email protected] EF-UK Printer Brian Boughton 'Red Roofs', Vicarage Road, Thetford, Norfolk. IP24 2LH Events Co-ordinator Terry Stuckey 31 Dysart Avenue, Kingston-upon-Thames, Surrey. KT2 5QZ Email: [email protected] Competition Secretary David Beavor 34 Chestnut Close, Brampton, Huntingdon, Cambs. Midlands Representative Roger Winsor 14 Butler Gardens, Market Harborough, Leics. LE16 9LY Email: [email protected] Northern Representative Bob Smith, details as Treasurer Southern Representative Dave Chinery 251 Station Road, Hayes, Middx. UB3 4JD Email: [email protected] South West Representative Jan Bassett, details as Editor EF-UK Indoor & Free-Flight Rep. Gordon Tarling 87 Cowley Mill Road, Uxbridge, Middx. UB8 2QD Email: [email protected] Technical Liaison Officer Alan Bedingham 17 Highcliffe Close, Wickford, Essex. SS11 8JZ Email: [email protected] Public Relations Officer Dave Perrett 10 High Lees, Sharnford, Leicester. LE10 3PW Tel: 01455 272297, Email: [email protected] Webmaster Jan Bassett, details as Editor EF-UK - (www.befa.org.uk) Safety Adviser Stan Rose Tel: 01636 525029, Email: [email protected] Please enclose an SAE with all correspondence to the committee. 4 E.F.-U.K. Chairman’s Chatter Welcome to issue No 73, I hope by now those with internet access will have seen the new item on our wed site front page! It's called RECENT NEWS, and we hope to update daily or when there is urgent news that cannot wait for our magazine. One of the items on Recent News is the as from 2004 BEFA will require all flyers that attend BEFA Fly-ins to hold an "A" in any fixed wing disciplines (electric helicopter pilots must have an "A" helicopter certificate). Why I here you all say? Well have you been to a fly-in recently? Safety in the pits has gone to pot; the same has happened on the flight line, I could go on. No one seems to give a damn - well the BEFA committee do. If this improves the standard of airmanship we can hold off implementing the "B" for fly-ins for some time. The committee has also deemed that the E400 models will have Graupner Speed 400 motors only, label not too be removed. All voltages can be used; the only modification allowed will be changes to timing - NO TAKING APART (as now). This change will stop flyers using other motors that look like a Mabuchi 380/400 motors, but not based on them, e.g. Johnson. This change is not being introduced this year. Remember E400 was started as a NOVICE event. I repeat the offer below - as to date no one has come forward to be tested! Perhaps you will now! After the discussion at the TWS, and receiving e-mails and letters re the electric thermal "A" and "B" tests. (Some members thought that the tests had not been approved by the BMFA) I have now received the approval from the BMFA and Terry Rounce the Chairman of the Achievement Scheme Review Committee for our members to take the test at this year's fly-ins. But we must follow the rules set out below. 1. If you are a country member of the BMFA i.e. not a member of an affiliated club, all you have to do is ask myself or other silent flights examiner's in BEFA for you too take either an "A" or "B" at one of our fly-ins. 2. If you are a member of an affiliated club, the examiner would have to have a letter from either your club Chairman or Secretary saying that it's OK for you too take the tests away from your club environment. Remember these are for electric thermal type of aircraft only! By the way we are not asking for everyone to have an "A" or "B" at our fly-ins this year! If you are a SF Chief Examiner and would like to help us please get in touch with me ASAP. If you wish to email me, will you please use this new address as I am going away from Hotmail due to spam - [email protected] That's all for now so KEEP THE WATTS UP! E.F.-U.K. 5 Current Lines from the Editor Firstly an update on the unknown that was model submitted by Dick Godden and featured in the last issue. I received three responses, from John Jackson, John Price and Mike Pirie, who all think it is a Voodoo. The Voodoo is a design by Arthur Searl that was published in Radio Modeller in around 1973/4. It was described as a tailless 69½" span slope soarer for 2 function RC. The plan is still available from Nexus and can be bought on-line at www.modelflying.co.uk. In the centre pages is an application form for the BMFA Silent Flight Nationals taking place at The Wetlands Wildfowl Reserve, Nr Retford on 23rd to 25th August. If you don’t want to remove the page, photocopies are acceptable. As I feared might happen, the number of articles and information for the magazine have much reduced. Putting this issue together was more challenging than any of the previous issues. Having run around, twisting writers arms and the like, I have ended up with a few bits left over for the next issue. The bottom line is that if you want EF-UK to continue, it is imperative that articles, etc., are forthcoming. The magazine doesn’t write itself, and I have enough to do just compiling each issue. With the fly-in season just started, hopefully I’ll see a lot of you around the BEFA events. I also hope that someone will submit an article on each of the electric flight events. Looking further forward, to the building season, it would be nice to have information submitted on your next project. I would like to extend my thanks to all the contributors to this and previous issues and hope that they can contribute more in the future. 6 E.F.-U.K. Lead-Acid Battery Safety by David Andrews An important part of electric flying has to be safety, either with the use of NiCds, and other types of batteries, including storing and charging them. The photograph below must come under the category of “misuse during charging”. This car battery (yes it was complete at one point) was being charged overnight in the usual way, with two crocodile clips on the terminals. It was outside in the open, but still fitted to the car. Next morning the bonnet was depressed slightly to open the safety catch. This must have caused a spark which ignited the Hydrogen gas given off during charging this type of battery.. The resulting explosion brought the neighbours out; the car did a runner never to be seen again; and it blew a bulge into the car bonnet which was the talking point for a week. On the serious side, this could have easily been a fatal accident, with the bonnet absorbing the blast (they made Cortina bonnets very strong). Imagine if it had exploded when disconnecting a crocodile clip with the charger turned on (your face might only be a couple of foot (60cm) away). Please make sure you never charge your batteries in an enclosed space (e.g. flight box or closed cupboard), allowing any gas produced to escape. Never short circuit the terminals. Finally ensure that the charger is turn off before disconnecting the charging leads (this is an essential safety measure for lead acid batteries). These are basic rules, but it is very easy to forget as I did, or just to get complacent. E.F.-U.K. 7 New-2-U A Brief Round-up of New Items of Interest Left is the new Astro Micro Box designed to fit the tiny Astro 010 brushless motor. The gearbox weighs a mere 1/2 ounce (14g) and fits all Astro 010 motors. The gear ratio is 3.3:1 and it spins propellers from 8” x 6” to 10” x 7” on 8 to 10 NiMH cells (or 2 to 3 lithium polymer cells). The gearbox is mounted to the motor with two screws as shown and is mounted to the model with a single nut (not shown) on the threaded barrel of the bearing housing immediately behind propeller. It is available now as part number 709 and priced at $34.95 (approx. £22). Also now available are “Zero Loss” connectors with 3-pins for Brushless Motors. They are not polarised, which allows the motor direction to be reversed by simply reversing the connector. These are designed to handle wire up to 13 AWG (1.83mm diameter). Available as part number 521 and priced at $9.95 (approx. £6) the pair. AERC (Advanced Electric Radio Control, www.aerc.com) have introduced a Speed 400 Yak - 9. The kit has many laser cut parts; including the wing skins and ailerons. Therefore very little cutting and fitting is required by the builder. The moulded plastic parts include a cowl with gun troughs moulded in, a clear canopy with framing moulded in, a pair of exhaust stacks, a pair of gun blisters, and we even include a moulded pilot. The kit also includes a full colour cockpit insert with a detailed instrument panel and side panels for that finishing touch. The kit is very lightweight but plenty strong enough to support brushless set-ups. Span 31” (78.7cm), Wing Area 170.5 sq. in. (11 dm2), Weight 15 to 18 oz. (425 510g). The model as shown is 15.8 oz. (448g) with 6v Speed 400 motor, 7 cell 600 NiCds, GWS Rx, 20A ESC & 2 Hitec HS-50 servos. The kit is $74.95 +P&P 8 E.F.-U.K. Also recently available from AERC is their F-4 Phantom kit. The Phantom is designed to be powered by 2 GWS EDF-50 fan units, clearly shown in the photograph on the left. It requires a radio with elevon mixing (or a separate elevon mixer).. As can be seen from the “skeleton” shot the structure is laser cut and very light. Wing Span: 21.75 in (55cm) Wing Area: 143 in² (9.2dm2) The kit includes all wood needed to complete the kit, formed canopy and nose cone, ducting material, foam wings, full-zized plans and construction manual. The kit is $64.95 + Shipping. Check out the AERC website at www.aerc.com for more information. GWS have been at it again, with yet more new models. First up is the BN2, which will be available in a range of propeller of EDF versions. The version shown left is the propeller version, which has 2 EDP-100 motors, 5.0” x 4.3” propellers and 6 or 7 cells between 400 and 800 mAh. It is designed for 3 to 4 channel radio control with 2 to 3 servos. It has a wing span of 36.6” (93cm), a wing area of 208.5 sq.in. (13.5dm2) and a flying weight of 13 to 15 oz. (370 - 430g ). The EDF version is almost idenitcal but uese 2 EDF-50A fans. Unusually, it is approximately 1 oz. (25g) lighter. Prices have not yet been set. E.F.-U.K. 9 The second new model is a lightweight version of the F4-U Corsair. Despite being light at under 12.7 to 14.8 oz. (360 to 420g), it has a span of 35.5” (90cm) and a wing area of 233 sq.in.. (15dm 2 ) and uses 4 channel radio control. Again a couple of power variants will be available. The low power & lighter version uses the GWS EPS-350C unit driving a 10” x 8” propeller and 6 to 7 cells between 270 and 600 mAh. The higher power options uses a EPS-400C unit driving a 7” x 3½” propeller on 6 to 7 cells of 400 to 600 mAh. Price and final specification still to be determined. Next is a small F3A pattern ship called Formosa, shown in a low inverted pass. It has a span of 35.4” (90cm), a wing are of 256 sq.in. (16.5dm2) and a weight of 12.7 to 14.8 oz. (360 to 420g). This also uses three EPS-350C power unit driving a 9” x 5” or 9” x 7” propeller on 7 or 8 cells in this case. Again 4 channel radio is required. Again price and availability to be decided. The final offering is a scale model of the DC-3 (or C-47 if you fancy). This will be available in 2 versions using either a pair of EDP-100 or EDP-300 units. Both will use either 6 or 7 cells between 400 and 600 mAh. The span is 43.5” (110cm), area 212 sq.in (13.7dm2) and flying weight from 13.6 to 18.3 oz. (385 to 465g). Control can be 3 or 4 channels with 2 to 3 servos and micro equipment. Price TBC. 10 E.F.-U.K. A User-Friendly Guide to the Super Nova Charger Andrew Gibbs has created a 28-page user-friendly guide in a handy A5 size, for owners of the Ripmax Super Nova Charger. Andrews says that the guide was created is response to the many modellers who purchased the charger, but reported difficulty in getting the best out of it. The guide is clearly written and easy to understand. It includes a flow chart, which makes it easy to program the charger and navigate around its menu system. First users of the guide say their experience of using the charger has been transformed by the guide. The guide also contains a number of safety precautions and tips about cell charging and battery connections that will be useful for the inexperienced in electric flight. The Super Nova user guide is priced at £6.00 and is available from: SMC (01903 207525), Flitehook (02380 861541) or direct (post free) from the writer by sending a cheque made payable to Andrew Gibbs to: Andrew Gibbs, 1 Atherley Court, Hill Lane, Southampton SO15 7NG Tel: 07973 627738 Email address: [email protected] E.F.-U.K. 11 Left, from BMJR models, is the Baby Phoenix-PF (PF stands for Park Flyer). It is based on the 1949 free-flight design by Frank Ehling. The BMJR kit is true to the original design except for the fuselage being 1/ 4" (6 mm) wider to accommodate electric power and micro RC. This 35” (89 cm) span model may be flown in lazy circles as a Park Flyer or climb and do some thermal hunting. The kit price is $33 +P&P. The original design has 61 laser cut parts, and this kit should be same. On the right is the “Flash-E”, inspired by the old Comet Phantom Flash rubber model. It incorporates classic plan form features such as the tapered wing and semi-elliptical tail surfaces. As designed, with a wing span of 44" (112cm) and around 5½oz./sq.ft. (17 g/dm2), it was intended to be a small motor park- flyer. However, it has proven to be a pretty good soarer and an excellent float plane as well. The kit price is $38 +P&P has laser cut parts, full size plans, a complete hardware package including a pull-pull control system, and detailed building notes by the designer. The BMJR recommended power system for these park-flyers is their EPU-3 unit, which looks like a GWS Carbon brushed motor with 3.5:1 BB gearbox and a GWS 6” x 5” propeller. With this set-up they suggest 7 cells. For more information on these products check out their website at www.bmjrmodels.com, email [email protected] 12 E.F.-U.K. Two new models from Hobby Lobby that are expected to be available on 31 Jul 03. Top is the Cobra EPP aerobatic ARF model with a span of 30¾” (78cm), 203 sq.in. (13.1dm2) and flying weight of 11 oz. (310g). Included with airplane are a Pot 3B power system with a specially timed Speed 300 motor, 5:1 gearbox, 9.5” x 4.7” folding propeller and Potensky 8A speed control pre-wired to the motor. Illustrated instructions, hardware with light foam wheels, steerable tail wheel included. Wildly aerobatic in flight, converts in 30 seconds to float plane with the addition of POT007F floats (see bottom photo). Rudder, Elevator, Throttle, Aileron controls. Price will be $129, which seems extremely good for the contents. In a similar vein is the Eagle Fun-Flyer, which is produced in white EPP and has a 35½” (90cm) span and 12 oz. (340g) flying weight. The wing area is not given, but must be around 250 sq.in. (16dm2). The power system and kit contents are the same as for the Cobra above, and the price will be $139. Available are the same time will be these 18½” (47cm) long, 1¾” (4.4cm) wide and 17/8” (4.8cm) high pre-cut EPP foam floats, designed for the "Cobra" and "Eagle", but would be suitable for similar sized models. The kit includes all hardware & instructions. They can be built in an hour, and conversion from wheels to floats takes only 30s. The price of the floats kit will be £23.40. See www.hobby-lobby.com for more info about these products. E.F.-U.K. 13 Readers' Models Your chance to show the members your model(s). Another shot of Rich Flinchbaugh’s “Royal Gull” shown a few of issues ago, this time held by Alexandra. I think the flying surface could be described as challenging! Michael Carella of Connecticut USA holding his Grandfather’s (Rich Flinchbaugh) “Dreamboat”. Span 42” (107cm), powered by a Mega ACn 16/15/5 motor, 7” x 4” propeller, Castle Creations Phoenix 25 controller and 8 Sanyo 4/5AR Twicell NiMH 1700 Cells. Weight 34.5 oz. (980g) and 17.3 oz./sq.ft. (52.8g/dm2). 14 E.F.-U.K. Above is Bernie Winter and his Hangar Rat from the Model Flyer plan. It has a wing area of 350 sq. in. (22.6dm2) and weighs a mere 7 oz. (200g) giving a light wing loading of 2.9 oz./sq.ft. (8.85g/dm2). Below is a FlexiFlyer Rogallo (plan available from the Editor). Both use equipment originally fitted to Pico-Sticks. Bernie’s garden has an effective flying area 90 ft by 30 ft (27m by 9m), which is made more restrictive by flowering shrubs and trees. Bernie says the Hangar Rat has just got the edge over the FlexiFlyer for gentle landings and handling, but both fly well in this small space. E.F.-U.K. 15 Above: Anthony Hill’s attractive 1/4 scale RAF SE5a with a span of 80” (203 cm) and an all-up-weight of 18 lb. (8.2 kg). Powered by an Astro 60 with Superbox (2.75:1) on 32 cells and driving a 22” x 14” propeller producing 1kW. Below is a Flair Bristol F2B fighter (yet to fly), again from Anthony Hill. The span is 76” (193 cm) with an all-up-weight of 10½ lb. (4.8 kg). Power is from an Actro 12-5 brushless motor with 12½” x 6” propeller on 16 cells producing 600W. 16 E.F.-U.K. Above is another Anthony Hill model, a Henschel 129B. It is powered by 2 x 480 motors driving 6” x 4” propellers and runs on 7 cells. Below: is the final submission from Anthony Hill. This is a 1/3 scale Druine D31 Turbulent. Anthony stated the all-up-weight as 13 lb. (5.9 kg) but didn’t give the span, however, the scale makes it 86” (218 cm). It is powered by a direct drive Astro 60 fitted with a 16” x 8” propeller and running on 24 cells. E.F.-U.K. 17 Above is John Anderson’s “Spartan”, which has won several vintage competitions over the last few years including the Hayes Fly-In in May this year. It is powered by an Atomic Force (540) buggy motor with 3:1 Master Airscrew gearbox driving a 10” x 6” propeller running on 7 RC 2000's. 18 E.F.-U.K. Above and left are two photographs from a friend of John Anderson in Tasmania. The Hawk has a Mega 16/15/5 motor and goes like stink, whilst the other 2 have standard Speed 400's. All three models shown are from free plans in UK magazines. E.F.-U.K. 19 This is a Grumman Wildcat built by Rob Ireland from a plan by JP Neate. At 1/12 scale he hasn't gone mad with modifications this time. It is of course converted from i/c to direct drive electric, and the rather chunky wing profile was changed to Clark Y. The power set-up at the moment is drawing an excessive, and inefficient, 23A static from 8 x CP-1300 cells, but it gives a very respectable 88W/lb. input. After 4 flights, the performance can be described as authoritative! As well as being fast, it is also perfectly stable when slowed down, and fully justifies the months 20 E.F.-U.K. spent building and finishing it. The battery tray is designed for a 7 or 8 cell pack of Sub-C NiCds, so when “propped” more suitably the flying time should increase from 4 to about 7 minutes. This will ideally be at a power loading of 60W/lb. The subject modelled is a General Motors built FM-2. It left the military for civilian life in 1957, when it became a crop sprayer. After a crash in 1958, the damaged airframe eventually became owned by the Yankee Air Corps by 1981, being restored and flying again by 1987, now under the ownership of the Confederate Air Force. This particular aircraft took part in the US Navy's celebration of the 50th anniversary of VJ-Day, when in August 1995 it launched from the deck of the nuclear-powered carrier USS Carl Vinson. Model Stats: Motor ESC Battery Propeller Current Speed 600 8.4V (no flux ring) Kontronik SUN 3000 8 x CP-1300 SCR Kavan 8” x 6” 23A (static) Rx Ailerons Elevator Hitec HFS 04MI 2x Graupner C241 Hitec HS-81 Wingspan Area Flying Wt. 39" (100 cm) 1.9 sq.ft. (274 sq. in. or 17.7 dm2) 33.5oz. (950 g) E.F.-U.K. 21 This is Bill Macleod’s Hercules, which he bought as a finished model and repainted. The wing span is 72” (183cm) and it has a wing area of 504 sq.in (32.5dm2). It is powered by 4 Speed 400 7.2 V motors with white Günther propellers. The battery pack is either 7 RC-3000HV NiMH cells giving 15 minutes or 12 RC-2000 cells giving 12 minutes. The thick black lead represents am air-air refuelling hose. 22 E.F.-U.K. uzzflight 167 Duffield Road, Derby. DE22 1AJ Telephone: 01332 601693 Email: [email protected] Website: www.buzzflight.co.uk Hummingbird the definitive control-line trainer - ideal for youngsters Deluxe Kit - complete with motor, propeller, prop. adapter, spinner, wheels, balsa, u/c wire, control-line / power wire, on-off switch, battery connectors, sundries, building instructions & full-size plan, bellcrank and control handle. The only other items needed are the covering and a 12v 7AH battery. £39.99 + £2.50 P&P. Standard Kit - contains balsa, u/c wire, control-line / power wire, on-off switch, battery connectors, sundries, building instructions & full-size plan, bellcrank and control handle. Again the covering and a 12v 7AH battery are not included. £24.99 + £2.50 P&P. Plans & Instructions - £7.99 including P&P, add £5.99 for control-line / power wire and switch. Please contact us for Overseas prices. Please make cheques payable to Buzzflight and allow 14 days for delivery. E.F.-U.K. 23 A number of models from Ivan Goodchild complete the Readers’ Models section this issue. This page features his 1/10th scale A-10 Warthog. It is scratch built using fibreglass and balsa, spans 66” (167cm), has a wing area of 5.5 sq.ft. (~800 sq.in or 51.5dm2) and an all-up-weight of 11 lbs. (5kg). It has 2 Hacker B50-12S brushless motors in WeMoTec Midi-Fans on 10 cells per motor. Throttle control is by two 75A opto-controllers. This gives a thrust to weight ratio of 56%, which is reasonable. It has ailerons, flaps, airbrake, rudder, elevator, retracts and bomb 24 E.F.-U.K. This a Stearman built by Ivan from a kit. The span is 48” (122 cm), the wing area is approx. 720 sq.in. (46.5 dm2) and the flying weight 7 lbs. (3.2kg). It is powered by a Kontronik BL400-33 brushless motor with 4.2:1 gearbox, driving a 12” x 8” propeller at 7200 rpm. A 10-cell pack of 3000mAh cells and a 40A opto-controller complete the power train. This set-up draws around 33A static and gives flights of 8 to 10 minutes. The radio equipment is 4-channel with ailerons (2 servos), rudder, elevator and motor control. E.F.-U.K. 25 This is Ivan Goodchild’s “Mystic” built from the kit. The span is 78” (198 cm), the wing area 1010 sq. in (65.3 dm2) with a flying weight of 10 lbs. (4.5 kg). The motor is a Kontronik BL600-18 brushless with a 4.2:1 concentric gearbox. The motor and 22-cell 3000mAh battery are connected by a 50A opto-controller. An Aeronaut 12” x 8” folding propeller causes 35A to be pulled (static) giving over 90W/lb. Flight times are stated as 8 to 10 minutes. 26 E.F.-U.K. The final model (this issue) from Ivan Goodchild is his 1/4 scale SIG Cub, which is balsa construction and “tex” fabric covered. The wing span is 108” (2.75m) and the wing area is a huge 13.5 sq.ft (1944 sq.in or 125dm2). The weight is 16 lb. (7.3kg) giving a wing loading of 28.4 oz./sq.ft, which is good for a large model. A Hacker B50-12XL brushless motor, 6.7:1 gearbox, 75A optobrushless- controller and 22 cells provide the power. The battery stowage an be seen on the photograph on the left. These drive an 18” x 10” propeller and draw about 32A. The flight time is 10 to 15 minutes. Next issue: An article on Ivan Goodchild’s huge 1/10th scale, 12’ (3.66m) span, scratch-built B-17 bomber. E.F.-U.K. 27 This the Editor’s AFF Alpha-Jet, which has a span of 35½” (90cm) and a wing area of 287 sq.in. (18.5 dm2) and weighs 27½ oz. (890g). It is powered by a WeMoTec 480 Mini-fan with a Graupner Speed 480 Race motor, a Jeti JES 500 controller and 8 Sanyo CP-1700 cells. It draws 15.5A static and the typical flight time is around 6½ minutes of aerobatics. A little more power would be nice, but it’s OK.. 28 E.F.-U.K. This is another of the Editor’s models, but it hasn’t flown yet. It is a Multiplex Kranich with a span of 112 in (2.85m) and a wing area of 850 sq.in. (55dm2). With 6 servos, a 700mAh Rx pack and 12 Sanyo RC-2000 cells it weighs 7 lb. 7¼ oz. (3.38kg). Power is through a Hacker 70-3P Opto brushless controller to a Hacker B50-9S motor with 6.7:1 gearbox and RFM 14.5” x 10” propeller. This combination pulls 60.5A static at 11.6V giving 700W which is 94 W/lb. E.F.-U.K. 29 Fun with a B-29 or, if two is good will four be better? by Mike Smallridge As a fairly recent convert to the electric “power model” (as opposed to powered gliders), I have been tempted to put finger to keyboard to describe my experiences with a B-29 from Titanic Airlines via Gordon Tarling. My previous model was a Twin Star, which was (and still is) the most successful model that I have ever had. I almost said ever built, but I can hardly claim to have built it. Despite being about as aerodynamic as the box it came in, it is stable, elegant, as aerobatic as I need and glides better than some gliders that I have known. Add to this flight times of 18 minutes of gentle flying or 10 to 12 minutes of aerobatics on 8 by 3000 NiMH and I was convinced of the advantages of multi’s. My logic went that if two motors are good would not four be better. Well read on. In response to some dropped hints Santa Claus left me a large box for Christmas 2000. Initial inspection of the contents revealed four enormous sections of fuselage made from foam, hot wire cut inside and out and skinned with 1 mm balsa. The adhesive attaching the balsa to the foam was green and appeared to be epoxy. The wings were the normal foam core covered with balsa and the green glue and the tail parts were sheet balsa. Engine cowls and the hemispherical nose were plastic mouldings. The plan was a much reduced sketch with some areas enlarged where more detail was required, but gave only the vaguest details of where the flight pack, receiver, speed controller or servos were to go and no details at all as to how they were to be fitted in position. The written instructions were excellent having been translated by Ian Tunstall. Construction I decided to begin with the fuselage and soon realised that all was not right. The four sections of the fuselage comprised of left and right sides of the front parallel part and left and right sides of the rear tapered part. The problem was that either the balsa skin or the glue had shrunk and the parts that should have been semicircular were partly flattened. They could be squeezed to the correct shape, but would not stay there. My solution was to cut several lengthwise grooves with a saw, fill the grooves with white glue and secure the fuselage sections in the correct shape with rubber bands. The fuselage sections then fitted together more or less as they should, but there must have been some weight penalty. I made up and fitted a plate of thin ply to hold the servos for the rudder and the 30 E.F.-U.K. elevator and they hang batlike from the top of the inner fuselage. To keep the weight down as much as possible I used Hitec HS-50 servos. A balsa push rod worked the elevator and a closed loop system was arranged for the rudder using steel fishing trace. The servos are behind the wing cut out and so I had to make a small hole in the bottom of the fuselage to reach the servo arm screws. This hole also helps to get a little air over the speedo and the battery. The wing is held to the fuselage by two 6 mm steel bolts with large plastic heads that would not look out of place in an Ikea flat-pack. These bolts screw into two alloy tubes placed sideways across the fuselage. I cable tied the Rx to the rear cross-tube and the speed controller to the front tube. I left the flight pack position until last to adjust the C of G. The front of the fuselage foam was faced with a ring of Liteply and a similar ring stiffened the back of the plastic hemispherical nose. The model can be built with several control options. They include rudder and elevator; aileron and elevator; or aileron, elevator and rudder plus of course motors. I think it would be a brave pilot who attempted to fly this model without ailerons and so I went for the full house. The instructions give detailed dimensions for cutting servo recesses in the underside of the wings and there are grooves in the foam cores to route the aileron cables out to the servos. After cutting servo recesses I realised that the groves missed Mike with his B-29 E.F.-U.K. 31 the recesses by about an inch! OK, I should have checked the direction the groves were taking by inserting a stiff piece of wire into the groves and working out where they were going. But I didn’t. I therefore had to gouge out another channel under the balsa skin to route the aileron wires from the channels to the servos. The servos, Hitec HS-50s again, were fixed in place with silicone sealant. The motor cables live in a channel in the foam behind the leading edge and I soldered a 15A fuse in the positive wire inside each cowling. Motor mountings consist of three pieces of thin ply in a channel section in which the motors are located by means of sticky tape! This sounds rather feeble, but has proved more than adequate. The motor mounts are fitted to the leading edge by cutting slots in the wing and the ply mounts simply glued in. Part of the mounting is set to line up with the bottom of the wing to set the correct down thrust. Because I did not like the thought of the motor mounts tearing themselves out and damaging the wing, I cut several lightening holes/ weak spots in the ply. Again, I probably could have been braver and cut more away, for the mountings have proved more than strong enough. The motors themselves were 7.2v Speed 400, wired in parallel and fitted with Graupner 7” x 4” propellers as recommended in the instructions. Also recommended is the use of a 7 or 8 cell 1700mAh flight pack. As 2400mAh packs were by now available I fitted one of these. The speed controller was a 40A Fleet unit with BEC. A note in the instructions says that this set-up should need “half to one third throttle”; this was a little optimistic. The alternative set-up is for 6v Speed 280 motors with 5” x 2” propellers. Mike preparing to launch 32 E.F.-U.K. I feel that this set-up would not be powerful enough. With the motors mounted on the wing I turned my attention the plastic engine cowls. These are vacuum formed and the top and bottom half of each cowl has to be cut out from its sheet of plastic. As with the fuselage sections the cowl halves were not semicircular but worse they were not long enough to cover the motor mounts. Either the ply mounting and the motor would stick out of the front or the slots in the wing where the ply sections fit would show at the back. After some head scratching I craved some new cowls from solid in white foam. These simply push over the motor mounts and are lighter than the plastic mouldings. The wings were then set up at the correct dihedral and joined with the GRP bandage included in the kit. There is a choice of angles, about scale for use with ailerons, or increased for rudder/elevator. Once this had set the leading edge had to be trimmed back to fit in the gap in the lower fuselage and the motor cables routed out and fitted with connectors. The whole model was given two coats of sanding sealer followed by a coat of Balsaloc and covered with aluminium Litespan. The Litespan sheets had previously been treated to a coat of Balsaloc as well. Instructions with the Litespan say that the silvery side should be applied outwards. However, although there is a slight difference in colour between the sides, I could not decide which was “silvery”. Anyway it has stuck perfectly. The foam cowls and the plastic nose cone were painted with water based acrylic paint from an art shop and is a very close match to the Litespan. The next job was balancing. The instructions give the range of CofG and it seemed sensible to start at the furthest forward point. I discovered that the power pack had to be partly over the wing to obtain the correct CofG and so I constructed a foam battery box to hang the flight pack from the roof inside the fuselage. The back of the battery was resting on top of the wing, which seemed OK. A thin ply plate stopped the battery from moving forwards and a block of foam stopped it from going backwards. Decoration took the form of U.S. markings, cut from Fablon, as was the cockpit glazing and the name on the nose is Letteraset These really brought the model to life. Two of the black “windows” in the nose are cut out to feed cooling air into the fuselage. I set the control movements as recommended except for arranging the ailerons to more up than down. The suggested rudder movement sounded rather excessive at +/- 40mm (it is 50mm for the non-aileron version) and flying has proved this to be so. I decided that I had better weigh the model and was rather surprised to find it weighed nearly 5lbs, giving a wing loading of 20oz/sq ft. The instructions mention 13oz/sq ft, which must apply to the PSS version without motors or flight battery. Anyway, I had to fly the thing sooner or later and so on Boxing Day 2001 (I am a E.F.-U.K. 33 slow builder and a slower typist) it was off to the field. A gentle fling around with the Twin-Star to get in any eye that I might possess, and I could delay no longer. To allow solo hand launching I glued a block of pink foam about an inch square to the underside of the wing and with the under wing panel left off, this makes launching easy. Also the new nose cone made from white foam was lighter than the original plastic. The snag was that the repairs had increased the weight and the wing loading was now a hefty 23.5oz/sq ft What a difference! The model now climbs away from the launch with ease. The rate of climb could never be called fast but it is probably a lot better than scale. Handling is still rather twitchy with the model tending to over-bank in turns, possibly due to the small amount of dihedral, but you can look away for an instant to check for other models. Flight times are about four minutes but feel longer! The model looks stunning in flight, especially as it is turning on to finals or on a low (or not so low) pass. Landings are still tricky however. I have never managed to land yet without bending at least two motor shafts. At least they are easy to bend back again! So, success at last! Was it worth it? Of course it was. Would I build another B-29. Well I don’t know about that. While writing this, the thought occurred to me that there might be other B-29s out there, with other owners who may have had either better or worse experiences with this model. My E-Mail is at the end of these ramblings. Perhaps we should form a B-29 owners club. With the help of a friendly weight lifter the beast was away and climbing steeply. Rather too steeply actually. With the stick against the front stop I could just maintain level flight. I did not dare reduce power and was trying to co-ordinate the rudder and ailerons properly so I had to struggle for what seemed an age to gain some height before sparing a hand to trim fully nose-down. This helped a bit but the model was seriously tail-heavy and did not seem too stable in roll either. I was now feeling brave enough to reduce power slightly and this seemed to improve the handling. The important thing was to get the model down, preferably in one piece and especially without hitting anyone or anything. I must have done a circuit, but I don’t remember it, but suddenly the model was on finals and flopped rather heavily on to the strip. The only damage was a wing mounting tube pulled loose, three bent motor shafts and the thin ply plate, designed to let the battery escape through the front door, had done just that. Once I had stopped shaking the next thing to do was check the CofG. It was, as I thought, at the forward end of the range. Obviously it would have to come forward some more - I moved it forward 10 mm. Also I had realised that the use of the rudder was actually slowing the model down in flight and later flights have shown that use of the rudder is almost unnecessary. The next trip to the patch was both better and worse. For some reason I had the field to myself and was going to have to launch the beast myself. Now hand 34 E.F.-U.K. The B-29 climbs away, very realistic appearance launching a 5lb low wing model sounds tricky but perhaps more by luck than judgement it climbed away perfectly. It was obvious however that the CofG was still not right. The rest of the flight was uneventful and the landing caused no damage at all. I felt that the tail-heaviness was controllable and decided to try again. I should have gone home then! After recharging the battery I launched the model again. My hand slipped on the lower fuselage and my mighty heave became a feeble throw. The model staggered a few yards but there was never any doubt. One of those pointed wing tips stalled and the B-29 rolled into the ground. I hardly dared to look at the result. The fuselage was broken in two over the wing cutout, the battery had taken the quick route out and the plastic nose cone was shattered, but, I suppose, it could have been much worse. Repairs took a week or more and it was at this time that I discovered that with the battery moved forwards once more it could now be placed in front of the wing and also on the bottom of the fuselage thus lowering the CofG as well as moving it forwards. The CofG is now an inch forward of the position shown on the plan. I also took the time to think carefully about the rest of the model. Now I know that ideally you should make adjustments one at a time, but as well as the battery repositioning, I reduced the angle of the wing under the fuselage with about 4 mm of packing over the leading edge and adjusted the ailerons to give about 3 mm of wash-out to the wing-tips. E.F.-U.K. 35 Sudden ‘ush! by David Chinery My Grandson Jake continues to have undeserved “adventures” with his learning process; this time his Pico-Jet just went “dead” whilst in flight. The nearly-new model fell “out of control“ into the long grass, fortunately without serious damage, but what was the problem? Tests at home with a “slave” Rx NiCd showed the radio was still functioning, so the BEC supply from the speed controller was obviously the culprit! Jake’s Pico-Jet uses the standard Multiplex Rondo speed controller mounted directly to the back of the motor. I tried removing the motor from its foam “bed” to get at the controller, but it was stuck fast, and I didn’t want to disturb this critical joint unnecessarily. Instead, I carefully cut down the sides of the foam upper fuselage/ fin moulding and gained access that way. As I removed the top of the model, I noticed something rattling around in the bottom of the fuselage recess. It was the voltage regulator chip from the speed controller, which had become completely detached (see photo). A few minutes work with a small soldering iron had the chip back in place, and the model was functional again. A chip off the old block! Multiplex Rondo ESC with the BEC chip complettely detached (shown on elevon) 36 E.F.-U.K. These chips are cantilevered off the three legs, their only support, as they otherwise hang in mid-air to allow maximum access for cooling. There was originally very little solder on the legs of the chip and matching pins on the small circular PCB, so I made sure I built up good strong blobs of solder when refitting it. BEC voltage regulstor chip soldered firmly back in place. I would recommend that anyone building a Pico-Jet, or any other model using this type of controller, should check the security of these solder joints before “burying” the speed controller inside the model. Jake’s model was easily repairable after the crash, but the episode hasn’t done much for his flying confidence. In different circumstances, the model might have been a write-off! I wonder if we would have received a refund from the manufacturers? (Editor: As warrantees normally exclude incidental damage, it is probable that no compensation would be forthcoming for the model. If negligence can be proven legal proceedings might result in compensation, but the timescales are protracted. The vast majority of the cooling effort from this type of regulator is from the metal heatsink. Therefore, it would be a very good idea if the plastic body of the regulator were bonded to the circuit board with a suitable adhesive.) Postscript Since I originally wrote the above, another clubmate has had a similar problem, this time only one of the three legs of the chip separated, but the model crashed on its first flight and the owner is highly dischuffed with Multiplex! E.F.-U.K. 37 Flying in Indy by Rom Muryn I have recently been seconded to work at Indianapolis and have taken the opportunity to get involved with the local flying folk. My first impression was that there were not many model shops over here and I was right, I have found two and am aware that a third exists. The shops are much the same as aver the rest of USA and pretty similar to those in the UK. Most folk use the mail and web as a first source. What has struck me is the number of flying clubs. There seems to be one on every corner of the city, but all seem to be favouring the wet form of flying. However I discovered by accident that things are in fact rosier if I look. I discovered that indoor flying was starting up in town. The indoor golf dome was apparently available from 8-10 at night. Local club members just can see from the picture that its quite a size, probably 80 feet by at least 300 feet. The sides are soft and the only real obstacles are the golf balls and the truck driving around collecting them. GWS got is making a fortune over here, there must have been a dozen Tiger Moths in the dome and it was easily the most A view down the Golf Dome 38 E.F.-U.K. The Golf Dome “Pits” area - impressive popular model. Close behind was the GWS Slow Stick, this too was common and being bigger was more amenable for modification. There were many home builds and light kit builds. A couple of light models were seen from Herr Engineering the StarLite shown only weighed 5 oz. (140g) and flew really well. The Herr Engineering StarLite a 36” (91cm) indoor or park flyer with laser cut & strip balsa and hardware pack. Normally 3 to 4 oz. (85 to 115g) and 261 sq. in. gives a low wing-loading. 5 mins from 7 x 50 mAh pack or over an hour with a 9v Lithium pack. E.F.-U.K. 39 A Mini Laser 3D, a small & manoeuvrable Park Flyer. This is a kit from Laser BV of Belgium. Wing span 31½ in (80 cm), wing area 278 sq.in. (17.9 dm2), weight 16 oz. (450g). The kit requires 4-channel radio (4 micro servos), 11A speed controller, 7-cell 500 mAh battery pack, covering material and glue. It is powered by a 300 motor with 3.75:1 gearbox. More details from www.lasermodels.com or [email protected] A small unknown delta that has an extremely light structure with balsa strip ribs and Depron fins. The span is approximately “ (cm) and powered by a GWS EDF-50. 40 E.F.-U.K. E.F.-U.K. 41 BMFA Northern Area Indoor Fly-In 23rd March 2003 at Harrogate by John Thompson (PRO Northern Area BMFA) Despite the calm sunny conditions outside twelve flyers turned up with an assortment of models for this second event at the Army College. There had been some concern that the Iraqi conflict would cause entry problems, but my contact at Jarvis Construction had smoothed the pathway superbly and we all enjoyed an afternoon at this excellent venue. Near the end we were able to take advantage of the whole 50 x 35m hall and this opened up the possibilities even further. Four Tiggies were airborne together at one point. Und-Nu's are showing increased popularity with IFO's on the wane. Doug Potter caused a lot of interest with his Pusher version of a sort-of Und-Nu, and it flew surprisingly well after a hand launch. A mod has now been done to the UC to improve take off. Several foam Scale park flyers were found to be too fast for indoor. It is hoped to make this a monthly event in the winter so watch out for it in the various events calendars 44 E.F.-U.K. A Zagi-FiXX by Rom Muryn & Jan Bassett After attending the indoor flying in Indianapolis, pangs for flying drove to purchase madness. I really wanted the Zagi-FiXX from Trick RC, however, a phone call to them was helpful but they don’t sell to the public any more. I have a Zagi imported some 5 years ago before they became the huge hit they are now and I wanted the latest. The full kits were $150 but I just wanted the wings. Through sheer luck I was in Milwaukee and the local model shop was able to sell me a set of wings for $69. The FiXX is made of a very different material to just the plain foam of the original Zagi. Whilst it is still foam-like it has a shiny finish with the flashing exhibiting a latex quality. The upper surface is white, with the underside (including the outside of the fins) being red. The inner material seems more crumbly than most foam, rather like Polyurethane in a dry mix. Time will tell if its good. The completd Zagi-FiXX The design itself is dead sexy. Swoops and curves all over the place. I am an engineer by trade and impressed with the design considerations put into place. More than just a moment has been spent in designing this model. It is based around the ubiquitous GWS motor found in the Lite-Stick. To start a short stick is used both as a motor mount but also as a locking tool for assembly. The mouldings are also arranged to provide engine mount support. The design and installation provides good cooling for the motor and battery. E.F.-U.K. 45 The equipment layout of the Zagi FiXX. The battery needed to be at the front of the equipment tray to achieve the recommended CofG position. The top surface of the wings each have a moulded servo well designed for the excellent Hitec HS-55 servos. The servos fit beautifully and even the lead length has been allowed for. As can be seen on the photograph above, Zagi “Z” decals are also supplied to cover the servos once installed. To sum the Zagi-FiXX up, assembly is a doddle. In assembling the FiXX, It is obviously that the model is very specifically designed around a particular configuration of equipment. I have costed the equipment supplied in the full kit and must say that the price of $130 is excellent. With the model completed, it was necessary to wait for the wind to drop before the test flight could be completed. I asked a the member of the Indianapolis West RC Club, to make the test flight. With the test flight completed without problems, although the wind was still a little strong. At this point Jan takes over the story. Rom offered me free accommodation in Indianapolis (Indy) so I decided that I would take him up on his offer. Rom’s Zagi-FiXX was completed and test flown just prior to my visit, so the opportunity was there to get some “stick time” in The BMFA insurance doesn’t cover flying in the USA or Canada. However, all that is necessary is to contact the BMFA and they will provide a cover note, free of charge, for the duration of the visit. My first impressions of the FiXX were good as it seemed to be quite robust and amazing light. The quality of the mouldings was excellent with the join between the wing panels an extremely close fit. 46 E.F.-U.K. On past experience and the Trick RC website, I estimated that the maximum current the GWS motor would pull would be around 2A in this configuration. I wondered whether the massive 16W power supplied by the GWS motor would really be sufficient to power this 40” (100cm) model weighing about 10 oz. (285g). If you calculate the power to weight ratio, 16W provides only about 25W/lb. As it had been test flown, I knew it flew, but would it be possible to throttle back and achieve a good flight time. A trip a few moments down the road and we were a bit of parkland alongside the Union Football Center. As can be seen by the photograph the area is large with a nice, pretty flat, grass surface. Rom with his Zagi FiXX in the grounds of the Union Football Center. For my first flight on this lightweight model, the wind was a little strong at around 10 mph. As the wind was steady, I decided that it would be OK to fly and away she went. I was instantly impressed with the authority of the model, which certainly didn’t lack power. I found that the model would maintain height with the throttle stick in a central position, which should allow nice long flights. As the wind strength was increasing the flight was cut short after about 13 minutes, pretty good in this wind. One thing that was fairly obvious is that the model was a little unstable in yaw. This was manifested by the model “fish-tailing” around the sky. Whilst, this wasn’t a real problem it is unnecessary. E.F.-U.K. 47 The fin extensions fitted to the FiXX to improve the lateral stability. The model as set-up had excessive control throws which made it a little twitchy and it would stall out with full up elevator. Reducing the throws made the model much nicer to fly, but retained the ability to roll and loop (from a shallow dive). With the control throws reduced the model became much more docile and allowed Rom to do some flying. One criticism of the kit is that the instructions make no mention of the recommended control throws. Rom and I discussed the yaw stability and we decided that a little modification was in order. Hunting for material a foam egg-box was found that was about the same thickness as the FiXXs' fins. I traced the fin shape onto a piece of paper, and then sat down to determine the shape of the fin extensions. The size was limited by the flat area available on the egg-box lid, at least it was from a dozen eggs. I wanted to retain flowing lines and have a real liking for the design of the Rutan ARES. The fin extensions were therefore made with a sweeping trailing edge as can be seen in the photograph. Using in the largest area possible gave around an additional 5 sq. in. per fin. The weight increase is negligible, and no change to the CofG position was perceived. The slight increase in the weight will require more lift, but if the model flies straight the drag could actually be reduced and an overall increase in flight time. As with all things like this, the proof is in the flying. It was pretty obvious the "fish-tailing" was much reduced and hardly noticeable. I think that this modification is well worthwhile as the benefits much out way the drawbacks. 48 E.F.-U.K. During the time I was in Indy I had 8 flights, totalling just over 2 hours. An average flight time of over 15 minutes is pretty impressive for any model, but especially for one at the small end of the scale. The weather conditions varied from almost flat calm up to about 15 mph with moderate turbulence. The FiXX coped with all these conditions, but was not so nice to fly in turbulent conditions. I would recommend the FiXX as a model, but suggest that 10 mph is about the sensible wind limit. The instructions and kit and very good, with the exception of the lack of control throw recommendations. Below is an extract from the manual, showing a couple of the step by step instructions. The standard kit (left) contains the model, motor, gearbox, propeller, 5A ESC, 8-cell 370 mAh NiMH battery and a complete hardware pack. In the USA the kit retails for $130 (~£80), which is reasonable value considering the contents. They also make a number of enhanced kits with Radio equipment and/ or charger. Which of these kits will be introduced to the UK remains to be seen. E.F.-U.K. 49 Electric World Championships by Bob Smith Most members of BEFA know that there are two well established categories for World Championships which are based on electric powered flight. These are for F5B (multi-task electric gliders) and F5D (electric pylon racing). CIAM, the Commission for International AeroModelling, is the part of the FAI which is responsible for the organisation of World Championships, and allocates all of the championships National Organisations on a bi-annual basis. In recent years the F5 championships have been held in Germany 1998, USA 2000, and Switzerland 2002. We are delighted to confirm that the 2004 Championships will be held in the UK. Under the auspices of the BMFA, a group of individuals from various aspects of electric flight in the UK prepared and submitted a successful bid to CIAM, as a result of which the Championships will be held for the first time in this country. The dates chosen are 9th to 15th August 2004 and the location is the Knavesmire in York. The Knavesmire is a racecourse close to the centre of York and many of you may have attended the annual electric fly-ins organised there by the Ebor club. If you have done so you will know that it consists of a large area of flat, well maintained grass pasture, ideal for such an event. If you have a good memory you may remember that a highly successful F3B World Championships were held there back in 1983 so that there is some history to the location. Those of us who are on the organising committee feel that the site is an excellent one and that the reputation of York as one of this countries premier tourist attractions will help to ensure a good turn-out of International Competitors and spectators. Event planning is making good progress even though we have a full year in front of us. The BEFA Committee was involved (through me) in all of the initial preparation of the bid and will, in due course, turn it’s commitment into a more pragmatic participation. The main requirement will be manpower and we hope our members will be amongst the first to volunteer to help at the appropriate time. The intention is to turn this event into a showpiece of electric model flight in the UK and show the rest of the world that this country can organise and stage an event which will stand comparison with the best. This will be the result of lots of hard work by everyone involved at all levels. All we need is to transfer the enthusiasm we all possess for electric flight into the preparation and running of this World Championships and it will be the success we are aiming for. 50 E.F.-U.K. The following is a paragraph from the CIAM submission. “The Organising Committee believes that World Championships are an opportunity for all involved to participate to the best of their ability in a friendly, fair, and enjoyable atmosphere. The competition organisation must be efficient and effective but the supporting features of the event need to encourage competitors, supporters, and visitors to appreciate the pleasure of involvement in model flying to the highest international standards. The location of the event in York, a renowned centre of tourism, and the provision of on-site camping/caravan facilities with additional nearby lowcost accommodation will help to create the right environment. The committee will build on this and other features of the proposal to foster the ideal ambiance.” The current calendar and timetable are: Friday 6th August Arrival date plus initial registration Saturday 7th August International Open F5B, F5D registration/processing Sunday 8th August International Open F5D, F5B registration/processing Monday 9th August Opening ceremony, Official practice day & briefings Tuesday 10th to Friday 13th August F5B / F5D / F5B World Championship rounds Saturday 14th August Spare day (plus tours) Saturday evening Banquet and Prize Giving Sunday 15th August Electric Flight Festival There is a website at http://ewc2004.users.btopenworld.com Competitor liaison and enquiries will be welcomed by the Communications Officer, George Shering, email [email protected] The official contact and information source is: British Model Flying Association, 31 St Andrews Rd, Leicester, LE2 8RE. UK Telephone: 0116-244-0028, or Fax: 0116-244-0645 Email: [email protected] As they say “watch this space”. E.F.-U.K. 51 Wizard Prang! by David Chinery The Dam Busters commemoration at Brooklands was very successful, in spite of an unpromising weather forecast. A blustery southerly wind made flying tricky, but the rain held off until the event was over. The event was open to electric and IC models, and about a dozen actually flew in the competition. The Models The competition encompassed three classes, the premier of which was Scale, which had three entries, all Lancasters, from Tony Nyhuis, John Ranson, and an IC powered example by veteran modeller Eric Faulkner, who sold me my first-ever proportional radio (RCS Tetraplex analogue) in the nineteen-sixties. Tony Nyhuis entered his “big” Lancaster, which was flown on the day by “bombardier” Dave Stevens. Tony’s Dam Busters conversion allowed for scaletype backwards rotation of the bomb before release. John Ranson’s Lancasters are better known for dropping “Grand Slam” bombs, but one was converted to “Operation Upkeep” standard especially for the day. Technical problems prevented the third IC powered Lancaster from flying. Preparing the “Lake” at Brooklands 52 E.F.-U.K. The “innsrds” of the Nyhuis model, The white rubber band at the left of shot is to spin up the bomb before release There were also classes for non-scale IC and electric “open” models. I will mention the electric entry first, as there was only one, a Pico-Jet masquerading as a Vulcan, modified to drop a single golf-ball. I was staggered to see that not a single Multiplex “Cargo” (bomb doors as standard) was entered in the competition! The IC class had several entries, notably the semi-scale “Whitwells” of Tony Major and Mark Stannard. A pastiche of Armstrong Whitworth Whitley and Vickers Wellington bombers, these models are about six foot span, and are powered by twin, very well-sorted four-stroke engines. Normally used for toffee-bombing, their conversion to Dam Busting was apparently quite straightforward. A bright yellow IC twin was entered by John Bransgrove, featuring a “magazine” of four or five “bombs” to allow several attempts per flight. Several other models were entered in the IC Open class, notably Jack Rogerson’s converted “shovel”. The Dam The target for the day was an 18-foot foam “dam”, complete with towers, arranged at the end of a “lake” formed by tarpaulin draped over drainpipe frames to raise the edges. After aligning these with respect to the wind and the safety distance from the crowd line, the lake was filled by courtesy of the Brooklands Fire Brigade. In order to score the accuracy of bomb drops, linear scales were arranged at the E.F.-U.K. 53 John Ranson’s Lancaster had correct cylindrical bomb, but incorrect Squadron letters side of the “lake”, in front of, and behind the dam, to measure the linear error. To add an altitude aspect to the scoring, a vertical reference was used, models passing below the sight-line scoring only a single “error” figure, while passes above it had their error score doubled. The winner would be the model with the lowest final error score. To make things more interesting for the paying spectators, who had made the trek from the Brooklands Museum at the other end of the site, pyrotechnics were placed to detonate when impacts occurred during the competition. Water “bombs” were placed just beyond the lake, as detonations in the lake itself might have blown holes in the tarpaulin! To complement any impacts behind the dam, different pyrotechnics were placed upwind of the dam. As a final touch, more explosives were placed inside the dam itself, ready for the Grand Finale. The Flying Despite the blustery wind, competitors were eager to take the air to practise bombing runs, as soon as the “lake” had been filled and the area declared clear. First up was John Bransgrove with his “yellow peril” which had ample power and enough “density” to ignore the gusty conditions. He made several passes, using his magazine of bombs to good effect. The “Whitwells” soon followed, and the other entrants got into the act. Unfortunately, the Pico Jet was hit by a gust of wind on its practise flight, and ended up in more pieces than the original kit! 54 E.F.-U.K. Before the competition proper, we were entertained by some different models, flown from the main Tarmac runway. The first was a big IC-powered ducted-fan TSR-2, which appeared really demanding to fly, with its tiny wing area. Even the 500 metre runway was a bit tight for the landing, but it alighted successfully. In the apparent absence of wheel-brakes, it ran right to the end and had to be “ground-looped” to stop it hitting the tyre barrier! A turbine-powered tailless model also flew successfully, however its short undercarriage wheelbase caused some amusing but possibly damaging “bunny hops” on the landing roll-out. Whilst on the subject of turbine models, a non-flying exhibit in the pits was a large Harrier airframe, incomplete and awaiting installation of a two-spool turbine, fully rotating nozzles, and hot gas puffer-jets to make it fly. This impressive project is expected to weigh 80lb (35kg) ready to fly, and has been worked on for many years by Tom Stone, a narrow-boat builder from Bromley Hayes, near Lichfield. I hope he succeeds! The Competition With the “lake” clear, and the pyrotechnics armed and ready, the signal was given for the bombing runs to start. In view of the weather conditions, Tony Nyhuis had declined to make any practise runs earlier, so when the big Lancaster took the air it was for the first time at the venue. Guest pilot Dave Stevens took the model up and made a couple of dummy runs over the lake for limited practise. On John Ranson’s Lancaster over the Dam E.F.-U.K. 55 the third run, he was “right on the money”, and dropped the big spherical “Highball” bomb. It scored a direct hit, right in the middle of the dam, and the impact was rewarded by a “water bomb” explosion. This zero-error score would be impossible for any of the other competitors to beat, but several later came close. Being over the sightline for bombing height, Tony’s score was doubled, but twice zero is still zero! The competition allowed three drops per entry, so despite it being impossible to improve on the first score, the big Lancaster was landed for a quick reload and another flight on the same battery charge. Unfortunately, the left main-wheel hit a hole on touchdown, ripping the entire retract unit out of the model, and leaving the big “Lanc” resting on a wing-tip and tail-fin base. Whilst the big model was taken away for repairs, the “Whitwells” had a go, scoring moderately with their golf-balls. Some passes were very low, in spite of the turbulence at low level, see photos. “Unders” and “overs” were accompanied by the appropriate bangs and attendant water splashes or puffs of smoke. John Ranson’s smaller, but still large, Lancaster was flown, dropping a more appropriate cylindrical “Upkeep” weapon, but the drop accuracy was less good and he had no chance of even equalling the best scores. There seemed to be a delay in the bomb release mechanism, as most of the drops were well “over”. The remaining, non-scale entries had their goes, then it was time to tot up the results. “Pull-Up, Pull Up!”, Tony Major’s “Whitwell”climbs away from another go! 56 E.F.-U.K. Encore! The Nyhuis Lancaster drops the bomb early on the victory flight Tony Major’s “Whitwell” over the Dam E.F.-U.K. 57 The Lancaster climbs away as the bomb splashes down - The Dam is about to blow! A Tony Nyhuis’ “Lanc” before the “Encore” flight, is that tail already a little wonky? Joyn Bransombe’s”Yellow Peril” and Tom Stone’s big Harrier in the background. 58 E.F.-U.K. The Results From the start of the competition, it was obvious that Tony Nyhuis’ Lancaster’s first and only drop would be the outright winner. He was presented with the specially-made Barnes Wallis Trophy, representing an “Upkeep” weapon splashing down (see photo). John Ranson came a very creditable second in the Scale class. The Open IC class winner was Mark Stannard, flying one of the “Whitwells”, with Tony Major and John Bransgrove coming equal second with “Whitwell “TB-T” and The “Barnes Wallis Trophy”, awarded to Tony Nyhuis for Dave Stephen’s direct hit E.F.-U.K. 59 Tony Hyhuis receiving the “Barnes Wallis Trophy” from Kit Wallis (no relation) 60 E.F.-U.K. the “Yellow Peril”. There was no Open Electric competitor left after the crash of the Pico-Jet. The Finale – Nearly Too Final! With the competition over, it was time for the newly-repaired winning model to “take a bow”. The model was taken off again by Dave Stevens, and flown round to line up with the dam. Flying this time a little higher, about 20 feet, the model approached the dam and the bomb dropped. As it impacted, a little short this time (no-one is perfect), the dam was “blown”. This was quite spectacular, as pieces of the dam reached the height of the model and only just behind it! This was captured on at least one lot of film, although my own shot had been taken an instant earlier as the bomb was dropped. The model was climbed away from the dam, and turned round for a diving pass in front of the crowd. Immediately, shouts of alarm came from observers, as all was visibly not well with the model. The tailplane appeared loose in “roll”, and was not aligned with the wing. Once the pilot realised the situation, the model was slowed down and positioned for an immediate landing, keeping as far from the crowd as possible. It touched down OK, but as the tail dropped, the entire tailplane assembly, including the tail-wheel, detached from the model, which nosed-over gently due to removal of the weight in the tail. Thankfully, no serious damage was done. The cause of the problem probably included several factors. After the first landing, the model came to rest on its port wing-tip, allowing the bottom of the port fin to touch the ground. The tail assembly is attached by screws into captive nuts in the middle of long, narrow cross-pieces in the rear fuselage. These are amply strong for all normal loads, but the twisting force caused by the fin resting on the ground appears to have cracked the cross-members at the midpoint where the captive nuts were inserted. This weakness was not identified during the repairs to the port main leg unit, and the model was flown without more investigations. The final pieces of the jigsaw occurred over the dam. The flight up to the point of bomb impact appeared normal, but when the dam was “blown” two mechanisms could have triggered the failure of the weakened structure. Either the tailplane was hit by a piece of the dam, or the pressure-wave from the blast “shocked” the tail and caused the crosspieces to start to fail at their midpoint. This allowed the tail assembly to become loose in “roll”, at which point the problem became apparent to all observers. Mercifully, the close fit of the short piece of lower fuselage under and integral with the tailplane prevented the tail incidence or yaw angle changing much, so control and stability were retained. E.F.-U.K. 61 However, if more “up” elevator had been applied, the weakened and bent crossmembers could have failed completely, allowing the tail to detach from the model! If this had happened, Tony would have needed a VERY large bin-bag to take the model home in! Debrief The Dam Busters event was very successful in spite of the weather conditions and being held on a Saturday. This event was a one-off, so I won’t say that I will be going again next year; will I see you in 2013 instead? However, the venue could be good for a BEFA Fly-In sometime in the future, so watch this space! Victory parade! Left to Right: Mark Stannard, Tony Major, Tony Hyhuis (kneeling), John Bransgrove, Kit Wallis and John Ranson. 62 E.F.-U.K. Maxi AXI by Dave Chinery In addition to the existing selection of smaller motors, like the 2814 and 2820 ranges, Model Motors have produced a new larger size AXI “out-runner” motor, the 4120. Intended for 14 to 20 cells, these new motors are available in two winds, the hotter 14-wind and the torquier 18-wind. Diameter 49.6mm (about 2”) and 61.1mm (2.5”) long, the motors weigh 12oz. (320g). With 650 rpm per volt, the 12 to 16-cell 14-wind will turn a 14” x 7” propeller at about 9000 rpm on 14 cells with an efficiency of about 85%. The 16 to 20-cell, 18-wind motor is 510 rpm per volt, turning a 13” x 11” propeller at about the same speed on 18 cells, with a marginally higher efficiency. These motors will be ideal for converting the hordes of 0.40 to 0.60-size ARTF and kit models that are on offer these days, and they deserve to be very popular, considering their very affordable prices. An amusing touch is the label fitted to the rotating "can" reminding absent-minded installers that "This part rotates!". I bet someone would otherwise try and mount the motor in a clamp or tube and wonder why the shaft wouldn't go round! The Model Motors AXI 4120/18 out-runner motor from Puffin Models E.F.-U.K. 63 The frront mouting arrangement of 4 x M4 holes at 30 mm centres and 6 mm shaft The rear end showing the separated coils for air cooling 64 E.F.-U.K. The word from Eastern Europe is that, eventually, longer versions, the 4128 series, may become available for up to 30 cells. The new 4120 motors, together with the full Model Motors range of smaller AXI and brushed motors, are available in the UK from Puffin Models, of Bristol, phone 01454 314139 Fax 01454 316953 or see their website at www.puffinmodels.com Got one! I have my hot sticky fingers on one of the first 4120s in the UK (see photos), which is now fitted in my Sukhoi 31 to replace the geared Aveox set-up. Running on 14 cells, I am using a 14-wind version, connected to the new high voltage Model Motors controller, the 5024-3 Opto 8 to 24-cell 50A controller. A 70A version, the 7024, is also available for use with other motors (the AXIs are limited to less than 50A). The 4120-14 motor swings the same 14” x 7” APC electric propeller as the geared set-up, but at higher RPMs (see below). Sukhoi it and see! Fitting the AXI to the Sukhoi raised several issues. Fitted with the Aveox set-up, the balance point was marginal, the model being neutrally stable in pitch. The model had to be flown all the time in pitch, and a loop required only a “kick” of up elevator to start it. The elevator was neutralised going round the loop, then a “kick” of down was needed to level out! Steady inverted flight required slight “up” elevator! Once The motor and controller around £185 + P&P from Puffin Models E.F.-U.K. 65 accustomed to this effect, the model was tolerable to fly, but a little too exciting at times! This nervous behaviour was in spite of the motor mount being moved forward over an inch from its original position, and fitting a big 700mAh Rx NiCd to the motor mount. There was no scope for the usual solution of moving the main NiCd packs forward due to constraints in the NiCd compartment. If nothing else changed, the AXI set-up would be lighter in the nose, making the model potentially tail-heavy, so I needed to do more than just change over the motors and controllers. Although I could have fitted the AXI to the existing mount by opening –out some of the holes in the front plate, I decided to make a new 4mm ply motor mount. This allowed me to extend the nose by another ½” or so, getting the motor weight further forward. The AXI 4120/18 motor direct-drives an APC 14” x 7” electric propeller at 39A static on 14 cells. I was further helped in this by the short, fat, shape of the “out-runner” AXI compared to the long, narrow Aveox and in-line gearbox. This, in itself, moved the motor centre of gravity forward by at least ½” (13 mm). The power and sensor wires of the Aveox set-up were rather rigid, making the “natural” position for the motor controller axially in-line behind the motor. This placed it in the “fuel tank bay” behind the firewall. The flexible leads of the AXI motor and controller allowed me to fit it on top of the motor mount, in the voluminous space of the Sukhoi’s radial cowl (see photos). Although not expected to be a problem, cooling of the controller would be improved over the rather “buried” position of the Aveox unit. The large cockpit of the Sukhoi looks rather bare without a pilot, so a latex one was acquired at Sandown. In anticipation of the slight extra weight behind the CG, the receiver was moved from underneath the cockpit floor to a position above the main NiCd packs over the wing LE. Whilst this is theoretically less ideal from the viewpoint of separating the receiver and the power electrics, in practise it seems to be no problem with a good-quality Rx. 66 E.F.-U.K. Motor and controller mounted in the Sukhoi 31 The cumulative effect of these changes more than offset the difference in motor weight, so the model ended up a little lighter and better balanced as well. It’s a breeze! The model is fitted with the same 14” x 7” APC electric propeller that was used for the previous Aveox set-up. Incidentally, this size of propeller was also used initially to fly my big 71”, 11lb. (180 cm, 5 kg) P-47 (on a geared Aveox 1412-2Y and 21 cells) so it is not lacking in thrust! Model Motors recommend using folding propellers to protect the motor shafts, but the slim APC electric propeller will flex or break long before the 6 mm shaft of the AXI gets bent. Static testing showed the motor draws 39A static on 14 cells, well within the 55A maximum quoted for the motor. The testing was done indoors due to bad weather, and the thrust appeared to be very good; the airflow rearranged the contents of my garage for me! Power play! Wanting to test the model in time for the Bickley fly-in the following week, I had to brave the traditional windy Sandown weekend weather. This made testing more demanding than it might have been, however the model flew well with no mishaps. With everything checked-out, the model was lined-up into the 20-knot breeze and the throttle opened. After a 10ft (3 m) ground roll, the wheels were off the ground E.F.-U.K. 67 and the 6.5lb (3 kg) model rotated into a 45-degree climb, alarming, except that the model was accelerating all the way. Frantic re-trimming of the elevator stabilised the climb angle at about 45 degrees, until a few seconds later power was reduced and the model levelled-off at 200ft (60 m). A few circuits at half to three-quarter throttle allowed the trims to be finetuned, then it was time to have some fun! There was loads of power at full-throttle, with no discernible deceleration of the model going up loops, the speed over the top positively encouraging the scale practise of closing the throttle on the downward part. My normal technique for stall-turns had to be modified. Previously, I had left full power on until the model had yawed round and was coming down (technically a Chandelle). The extra power of the new set-up required me to dip the throttle to slow the model when going vertically up, then apply a burst of power to kick the model round with rudder over the top. Even my favourite Lomcevak manoeuvre required this dip in power when ascending vertically, or it was uncertain whether the model would stop going up at all! With all the power available, a lot of time was spent at part-throttle, and the first flight (on 2400mAh NiCds) was cut short at five minutes only as a precaution in the prevailing weather conditions. A second flight allowed exploration of some more aspects of the model. The Sukhoi 31 model (pictured before conversion) 68 E.F.-U.K. A highly unusual breakage of a servo plug limited the testing to two flights only, however, the rough air conditions made flying a bit of a chore, so I wasn’t too disappointed. As I write this, I have yet to discover if the model will actually prop-hang, and work on some new manoeuvres such as rolling loops. Running-out! Since the pioneering Actro out-runner motors first appeared on the market, numerous manufacturers such as Model Motors, Flyware, etc., have recognised and exploited the technical advantages of out-runners, and I think they will soon be the most popular motors for the more committed electric flyers. Whilst I cannot comment on the quality and performance of other makes, AXI motors, and the new 4120 in particular, offers a very high performance package at reasonable prices. For those modellers wishing to move up from simple seven-cell models, there is a huge variety of 0.40-size plans, kits and ARTFs available, with spans between 52” (130 cm) and 60” (150 cm). An AXI 4120-14 on 14 cells will power all of these admirably without the complications of gearboxes, etc., and at about half the price of “first generation” inrunner brushless set-ups, which mostly need gearing to give their best performance. The AXI 4120 14-turn and 18-turn motors and controllers are available from Puffin models (see above), retailing at £94.99 for the motor and £109.99 for the controller. Puffin presently (May 2003) offers a 10% discount for the combo, making the overall price £184.48 plus P&P. As I mentioned earlier, a larger 4128 motor is promised, for up to An underside view showing the narrow carbon undercarriage and NiCd compartment E.F.-U.K. 69 TLC from your TLO by Alan Bedingham This time I want to talk about some of the rules of thumb I use to help me get to the right battery / motor / propeller combination for an electric aeroplane to be successful. Don’t get me wrong, I didn’t invent them, other, more qualified people than me thought them up, I just use them! I had a question from Mike Rollason that shows how they can help. I am in the process of building a Ford Tri-Motor from a plan. The spec for the model is as follows: Wing span 74 in. (188 cm), Weight approx 5 lbs. (2.3kg) Wing area approx. 6 sq.ft. (864 sq.in. or 56dm2) The original power unit recommended was for 1 off 40 four stroke. I would like to fit three electric motors so could you suggest a suitable power train. This could be either brushed to keep down costs but if necessary I am prepared to invest in brushless motors (i.e. AXI). If we go the brushed route I will have to use in line gearbox due to lack of space. Also if you could indicate what battery packs and controllers I would need to complete this project. The first point is that Mike is asking the wrong question! It’s not the motors that are important, it’s the battery. If you think about it, the battery in an electric plane is the real source of power, motors just convert this power into thrust via the propellers. The first job then is to try to estimate how big a battery this project will need, then we can look at choosing suitable motors and propellers to convert this into thrust. Based on a three view I’ve got (see right) , a 74 in. span Ford Trimotor will have a wing area of about 850 sq. in. The first rule of thumb is that sport and scale models will need one 2000-2400 mAh size cell for every 50 sq. in. of wing area. (Aerobatic or high speed, agile models will need one cell for 70 E.F.-U.K. every 35 sq. in of wing area.) This isn't hard and fast, but it will get you close. In this case we're talking 17 cells. Note that I haven't mention NiMH cells which can now go up to 3300 mAh in Sub-C size - the reason is that they have a similar ability to source current as Sub-C size NiCds, so the rule holds good for them as well, you'll just fly for longer. Another rule of thumb is that you need around 50W/lb input power for sport and scale models and as much as you can get for fast or aerobatic models! Taking Mike's estimate of 5 lb, we're going to need around 250W of input power. We can convert this to a battery pack size by assuming that each cell can deliver 1 Volt and 30 Amps, i.e. 30W. Why 30A? Well, a 2400 mAh cell is, looking at it another way, a 144 Amp minute cell. 30A is just over 4½ minutes of full power which will give us an easy 7 to 9 minutes of flight time with use of the throttle, plenty enough. 250W converts to eight cells! This is obviously wrong, no aeroplane designed for a 40 four stroke will fly on eight cells! I think we need to assume that the 5 lb is empty weight and add on another three pounds for the motors and battery. The wing loading is still eminently reasonable at 22 oz./sq. ft., so no worries there. Now we're talking 400W (just over half a horsepower) which is much more likely for a 40 four stroke. 400W is around 14 cells, which leads on to another rule of thumb I use when thinking of a glow conversion -- the 'Rule of a Thousand'. Take the displacement of the engine the aeroplane is designed for in cubic inches and multiply it by a thousand to get an estimate of how many Watts input you'll need. A .10 cu.in. engine then equates to 100W, a .25 cu.in. engine equates to 250W, a .40 cu.in. engine equates to 400W and so on. This one tends to under estimate a little, but it all balances out in the end because most glow powered models use propellers that don't run the engine at anywhere near their maximum power and an electric model can generally use a propeller that is bigger and more efficient. So, after all this head scratching, we're talking about using 14 - 17 cells for this aeroplane. I like to have some power in reserve for those days when the grass is a bit long and wet, so I would plump for a compromise of 16 cells which will allow the use of two 8 cell packs in series, which you might already have anyway for other aeroplanes. I've long since given up using 7 cell packs, I've found that the small weight increase of going to 8 cells is more than made up for in performance. The next task is to choose the motors and propellers - at last! My 3-view shows the scale propellers for the Ford Tri-motor to be surprisingly small at around 7½” diameter, so anything around 7 or 8” would be alright. Now to find some motors. Their choice is highly dependant on whether they're running in parallel or series. Take the parallel case first, each motor would see the full 16 cell battery voltage but would only need to take a third of the current, i.e. 10A. I can't think of many E.F.-U.K. 71 motors that would do this, generally high voltage motors are designed for aeroplanes that use only one motor and so tend to be big and heavy. One exception is the AXI 2814/10 which is reasonably small and light but three of them (and three controllers) would be a bit on the expensive side. If we look at three motors in series it would mean that each motor would see a third of the battery pack (five and a third cells) and the full 30A current. Actually, I should point out that this would be a whole lot simpler if we were talking about a twin or a four motor aircraft. A twin using 16 cells would be easy, 8-cell motors that could stand 30A are easily found! A 4-motor with the 4 motors connected in series-parallel so that each motor sees 8 cells and 15A would be just as easy. A 3-engine 'plane is not quite so simple. Right, we're looking for a motor that will draw around 30A from 5 cells while turning a propeller in the 7 to 8 inch range. Sounds like a direct drive buggy motor to me! Now I turn to that invaluable aid for this job - ElectriCalc. It saves me all the grief of poring through manufacturers catalogues trying to find the right motor. Feeding these numbers in and trying a few readily available motors I get one that looks hopeful, the Graupner 600 Race 7.2V #6370. This will turn an APC 7” x 4” at 26A A Ford Tri-Motor suspended in mid-air above one of the halls of the Smithsonian Air & Space Museum, Washington DC 72 E.F.-U.K. or an 8” x 4” at 33A, which is just about where we want to be. A 17-turn buggy motor gives very similar numbers. I think what I'd do is to buy one 17-turn buggy motor and try it on 5 cells and a 7” x 4” (and maybe an 8” x 4” as well), if the current looks good, I'd go and get the other two. If the current is too low, go down a turn, too high, go up a turn. Most car racing shops sell the armatures separately, so this wouldn't be an expensive process. Did I mention that you need an Ammeter that will read up to 40A? Don't even think about this sort of experimental model without one, I'd be lost without my Astro Whattmeter, but you can get a 40A meter for around £15 if funds are tight. The money you save in burnt out motors and controllers will pay for it in no time. The speed controller would need to handle 16 cells and 30A with very little cooling because it will be inside the fuselage, I think it would be a good idea to go for at least a 50A rating here There is another factor here to worry about, as I found out the hard way! Apparently, motors with three to five poles on the armature (buggy motors are all three pole), when run in series, are electrically noisy and can make speed controllers heat up more than you'd expect at low to mid throttle settings. It's all to do with recirculating currents in the drive and brake FETs causing them to get hot, another reason (other than potentially poor cooling) to use a generous rating. Note that speed controllers for 16 cells and 50A will almost certainly not have BEC, so a separate flight pack battery will be needed. I've found that a 4-cell 270mAh NiCd pack is easily enough capacity for a days' flying, even with a 6-servo aeroplane, and only weighs around 2 oz. Don't forget, you won't be spending ages with the radio on starting engines and fiddling with needle valves, just switch on and fly. Do remember to charge it though! That's Mikes aeroplane sorted using some quite simple rules of thumb, but please note that they just get you in the right area, you may well need to experiment further, particularly with propellers. To summarise my recommendations: Battery Pack: Motors: Propellers: Controller: Receiver pack: 16 Sub-C cells 3 x 17-turn Buggy Motors (direct drive) 7” x 4” or 8” x 4” 16-cell minimum, 50A 4-cell, 270mAh NiCd Luckily, these are the cheapest part of the aeroplane, so there's no excuse not buy handful of various sizes to try. You wouldn't believe the difference an inch each way on diameter or pitch can make to the performance of your 'plane. The same goes for the actual type of propeller, my current favourites are the APC Electric ones, admittedly they're fragile in a nose over, but they seem to give the best performance of any I've tried. E.F.-U.K. 73 BEFA League 2003 by Dave Perrett As many of you will know, BEFA runs League competitions for Electroslot gliders in two classes, one for Speed 400 type motors and the second for any motor. Both classes are limited to a maximum of seven cells and the aim is it fly for twelve minutes and land close to a spot for maximum points. The motor can be run for up to one and a half minutes for E400, and one minute for the open class . E400 is flown over three rounds and the open class over five, but in the latter class the battery may not be recharged. (All the rules are on the BEFA and BMFA web-sites). Three events have been flown this year so far:1. Pillerton Hersey, 27th April. John Lewthwaite kindly provided us with a field but, despite running the event a week later than last year, the weather was again bad with a strong, near gale force wind. Rather than cancel the event, as at the two previous April meetings at Pillerton, it was decided to run the open class. Once airborne most models just about coped. Landing was a different matter and most of us were happy to put the model down safely anywhere in the field. Despite that one or two did score landing points including one maximum from Bob West. Given the weather, or perhaps because of it, we had two mid-airs, One was between Steve Mettam and Tony Brindle, and the second between Bob West and Trevor Wain. Steve and Trevor were both put out for the remainder of the competition. The conditions were such that the E400 class had to be cancelled 2. Billesden, Leicester, 18th May. Arriving at Billesden it looked as though it might be a washout with rain and threatening cloud. However it did eventually clear but once again it was very windy not helped by the fact that this field, although ideal, is fairly elevated by comparison with the surrounding countryside. However a few people elected to fly the open class and several managed to pick up landing points (including some maximums) aided by the fact that Billesden is less turbulent than Pillerton. In the third round I fell foul of modern speed controllers. I failed to reconnect my battery, realised when the start was called and then connected the battery with the receiver and transmitter switched on. The result-Nothing!! I should have turned both off before connecting the battery. When I realised this and got the motor to run I was outside the ten second start time. I aborted the flight and scored nothing for the round. Only later did I appreciate I could have flown in the remaining slot time and would have lost only the few seconds between the end of the start time and when I got my motor to start. Ah well, we live and learn!! The moral seems to be fly if you can and sort out your score afterwards. This does provide of course that your timer keeps proper account of all the times. Once again the 400 class was scrubbed. 3. a decent day and we were able to run both classes. 74Leamington, 1st June. At last E.F.-U.K. This was a relief to newcomer Mick Barnett, who had attended both our previous meetings with his E400 model. Our only problem was raising the school caretaker to open the toilets! Conditions were such that most slots were capable of being flown to a maximum and landings became important. Timekeepers had to keep an eye out for full size aircraft from an air show at the nearby Bagington Airport but apart from a few pleasure flights we saw little off it. I think all of us enjoyed the outing. The top three in each event so far are shown below:- For those of you familiar with World Superbike Racing Tony Brindle seems to be in the same position as Neil Hodgson is in that championship. Certainly he is the one to beat-but time may tell. There are five more events still to be run . A number of newcomers have joined us to enjoy the fun – why not you? Stan Rose prepares his ESlot model for another round E.F.-U.K. 75 Electric Flight Calendar If you would like details of your event to appear in these pages please send full details to the Editor EF-UK, contact details on page 4. For last minute info check out the events list on the BEFA website at www.befa.org.uk Dates, times and, even, locations of events can change at the last minute. You are strongly advised to check on events with the given contacts before setting out on your journey to any event. You are asked to please check with the organisers of non-BEFA events for their qualification requirements before the event. All BEFA flying events require proof of BMFA or equivalent insurance to fly. Additionally, all models must have been satisfactorily test flown prior to the BEFA event to fly - NO TEST FLIGHTS ON THE DAY. The BEFA has not yet set minimum qualifications to fly at our events, i.e. no BMFA certificates are required to fly. Currently all that is expected of pilots is a reasonable level of flying competency. July 2003 20th Grand Electric Fly-In at Pontefract Park (off J 32 M62) presented by BMFA Northern Area with Pontefract & District Aeromodellers. 10am to 5pm. Low key events for Scale (Flying), Sport, Vintage, AULD, & Helicopters (if numbers allow). Pilots £2 per event, spectators free. Proof of BMFA insurance essential. All frequencies. Raffle. Free boot sale. Traders by prior appointment only. Sorry no camping. For details see http://www.pandasclub.fsnet.co.uk/ or contact John Thompson on email [email protected] or telephone 01924 515595 (reasonable hours please). 27th BEFA League event at Leamington Spa. ElectroSlot / E400 league event. For info contact Dave Perrett at [email protected] 27th Bath SpaRCS All Electric Fly-in at RAF Colerne Wiltshire. Airfield site with grass and Tarmac runways. No competitions. Proof of BMFA insurance required. Regret no facilities for spectators. Pilots brief 1000. Contact Bob Partington Tel 01225 891441 or [email protected] August 2003 3rd 76 BEFA Fly-In at Woburn Abbey. This event will include Scale and All-Up-Last-Down competitions. BEFA members can gain free admission to the site by presenting their membership cards at the entrance. Pilots' briefing will be held at 10am and it is essential than E.F.-U.K. all pilots are in attendance. A map of the area can be obtained from www.streetmap.co.uk by entering OS grid reference 496549,232722. For more information contact Jan Bassett on 01935 472743 or [email protected] 10th BEFA Fly-In at Leamington Spa. The site is the North Leamington School, with entry being from the end of Park Road. If you have an internet connection you can get a map from www.streetmap.co.uk by entering the OS grid coordinates 432050,267640. For more information contact Roger Winsor at [email protected] In an effort to increase the visibility and accessibility of the E400 competition, an E400 event will be held during this fly-in instead of the All-Up-Last-Down. The event will not form part of the BEFA E400 League, but prizes will be awarded on the day. In addition the usual Scale competition will be held. 16th/17th Greenacres Fun Fly at Walsall Airport. Cost per frequency £2.50. The usual arrangements for camping, trade, etc. For further information contact Andrew Moult on telephone 01922 724311 or email [email protected] or alternatively Peter Hubbard, on 07754 058872 or email [email protected] 17th BEFA East Anglia Fly-In hosted by the Phoenix MFC, Lowestoft. All electric flyers with BMFA insurance are welcome. Fun flying with the addition of Scale, All-Up-Last-Down & Vintage competitions. Even frequencies only. Barbecue / liquid refreshments available. Pilots entrance fee of £2.00. Location at Pakefield, Lowestoft, Suffolk. For further info contact Tom Taylor, 01493-668555 or email [email protected]. Additional info and location map available at the Phoenix MFC web site at www.phoenix-mfc.freeserve.co.uk 31st Furness Model Aircraft Society annual Electric Fly-in beginning at 10am. The venue will be the Rakesmoor Lane flying site at Barrow-in-Furness, Cumbria. Entry fee will be £4 per modeller. Proof of insurance is required on the day. Further details from Gary Knight, 12 Dale Street, Askam-in-Furness, Cumbria. LA16 7DH. Tel. 01229 467447 or email [email protected] September 2003 7th Open Electric Day at North London RCMFC, Baldock. Entry £5 on the day. No Free-Flight. Limited Trade welcome by prior appointment only. Proof of insurance essential. Food & drink available. For more details call John Raines on 01462 893059. 7th West Calder Aeromodellers fly-in. Tarmac & grass runways. Snacks available. Free entry. SAA/BMFA insurance required. 10am E.F.-U.K. 77 to 5pm, all welcome. More details at www.modelclub.org September 2003 (continued) 13th The Northern Area BMFA presents the Annual Pudsey Swap Meet and Indoor Free Flight event. Pudsey Civic Hall, near Leeds. Doors open 8.30am. Tables £3 each, admission £1. Flying starts 1pm. Classes for: Small Scale; ARTF Butterfly; Foam 200 & Civic / mini Gyminie Cricket; Dart; and Hamster. Charge will be £1 per class entered (Juniors free). Details Gordon Warburton 0113 2852947 or Northern Area Website (http://members.aol.com/bmfanorth/) or email [email protected] 14th BEFA League event at York. ElectroSlot / E400 league event. For more details contact Dave Perrett at [email protected] 21st Pillerton Hersey fly-in courtesy of John Lewthwaite, including an All-Up-Last-Down competition. Contact John Lewthwaite for more information on telephone 01789 740 688. 28th BEFA League event at Pillerton Hersey. ElectroSlot / E400 league event. More info from Dave Perrett at [email protected] November 2003 2nd BEFA Technical Workshop at the Royal Centre, Royal Leamington Spa. The usual Traders Fair and technical presentations. The Bring & Buy stand will also be present. Note: All items deposited on the Bring & Buy are left at the risk of the seller. March 2004 BEFA 2004 AGM at the Royal Centre, Royal Leamington Spa. It has been decided to extend the duration of the Traders Fair this time. The doors will open for Traders at 8am and for the public at 9am. The AGM itself will also be delayed until 2pm to give 1½ hours additional trading before the meeting. Trading can continue right through the AGM, the only proviso is that we vacate the centre by 5pm at the latest. The Bring & Buy stand will also be present and trading between 9am and 1.30pm. Note: All items deposited on the Bring & Buy are left at the risk of the seller. Please note that the BEFA Committee has decided that, from the first fly-in in 2004, it will be introducing a requirement for all pilots to have a minimum of an ‘A’ certificate. This requirement is introduced due to the ever increasing pressure to improve safety at events with public attendance. For more details contact the Chairman, details on page 4. If you have an electric-flight event that you want publicised send the details to the 78 E.F.-U.K. FOR SALE / WANTED Member's Sales & Wants For Sale by Rob Ireland a Model Designs BRISTOL BLENHEIM (60” span). Finished (stand off scale) as 1st British built aircraft (No. 160) to be supplied to the Yugoslavian Air Force (Predominantly silver, with Yugoslavian markings). Almost ready to fly and complete with servos (ailerons (2 x HS-80), rudder (HS300), elevator (HS-81)), 2 x Speed 400 7.2V, 3:1 gearboxes, 10 cell Sanyo 2000SCR pack and Schulze 35be controller. Requires props and receiver to fly - £150. Contact Rob Ireland (Northants) on 01327 352609 (evenings). For Sale by Eric Cable, the following motors which are boxed and unflown. Contact Eric on telephone 01935 478974 (Yeovil). • Plettenberg HP 200/20/12 motor - £75 • Astro 05 FAI, 6 turn motor, geared 2.2:1 - £95 • LRP Super 400 - £25 Wanted by the Editor (contact details on page 4) any of the following: • • • • • • General or Technical Articles. Product Reviews. New products. Electric Flight Event write-ups. Hints and Tips. Photographs of your models (with dimensions, equipment installed and flight performance please). • New items of interest for inclusion in this magazine. • Photograph prints (6” x 4” or larger please) supplied will be returned if you supply a return address, unless you specify otherwise. • Digital photographs should be at least 1000 pixels wide, in colour and uncompressed wherever possible. Requests for inclusion in the For Sale & Wanted pages can be made by email, post or by telephone, to the Editor using the contact details on page 4. Entries can also be submitted on-line from the For Sale & Wanted page on the BEFA website at www.befa.org.uk If you wish to have pictures included with your for sale or wanted entry, post photographs, or email graphic files, to the Editor. Graphic files should be in colour and uncompressed were possible. Adverts will be included in both E.F.-U.K. and on the BEFA Website unless instructed otherwise. E.F.-U.K. 79 New to ELECTRIC FLIGHT? START HERE . . . . . You may be taking up Electric Flight for the first time, you may be converting from another discipline. Whatever your situation, help and advice is available. BEFA has prepared an information sheet which details further sources of information which you may find useful when just joining the hobby. To receive a copy, please send a Stamped Addressed Envelope (SAE) to Robert Mahoney, address on page 4. BEGINNER'S GUIDE A Beginner’s Guide to Electric Flight is available, which explains many of the 'Mysteries' of Electrics’ and will, hopefully, set you off on the right foot. Please send £3.00, per copy required, to The Editor of EF-UK at the address on page 4. Please add £1.00 extra for overseas postage and remit in Sterling, cheques payable to BEFA. TECHNICAL HELP SERVICE Technical help is now available again for the use of all members. We regret that no telephone service is available, but all questions in writing (or email) will be answered by our new Technical Liaison Officer (TLO). Please refer your queries to our TLO, to the postal or email address on page 4. Please ensure that you include an SAE for a reply. CONNECTIONS SERVICE Requests are frequently received from members who wish to be put in contact with other members living in the same area. The easiest method of doing this is to place a free 'wanted' advert in the classified section of this magazine. Alternatively, a request may be made IN WRITING to the Membership Secretary who is allowed to divulge such information to members ONLY. Please supply as much information about your location as possible and please remember to include an SAE for your reply. B.E.F.A. MEMBERSHIP Membership of the Association is open to all members of the BMFA. Those who are not members of our national controlling body may only subscribe to EF-UK with no other benefits of membership. Overseas members are very welcome and will be classed as full members if they belong to their own national controlling body. CONTACT For full details, please send an SAE to the Membership Secretary (address on page 4) requesting a membership application form. Those with Internet access may visit the B.E.F.A. website at http://www.befa.org.uk, where you will find all the membership application form & information you should require. 80 E.F.-U.K. MAIL ORDER MODEL SUPPLY GOLD PLUGS Ideal for Speed 400/600 2mm plug 75p; cuts into two giving one plug/socket 2mm solder socket 43p. 2mm plug and a 2mm socket £1.15 Lightweight 2mm plug and socket 55p; Max 15A motor current draw Spares. 2mm light plug 40p. 2mm light socket 20p Pack of red/black shrink: 3.2mm or 4.8mm 50p GOLD PLUGS 600 or larger motor 4mm plug 90p; cuts into plug/socket. Very low resistance 4mm hollow plug and a separate 4mm solder socket £1.15 Spares. 4mm hollow plug 85p. 4mm solder socket 43p Lightweight 4mm plug and socket 75p; Max motor current 35A suggested Spares. 4mm light plug 55p. 4mm light socket 25p Pack of red/black shrink: 6.4mm £1.25: 4.8mm 75p Providing that you bear in mind the suggested amp ratings all the 2mm and 4mm plugs are interchangeable. All fit any of the same size. EXTRA FLEXIBLE WIRE. 0.5mm2, 129 strands, Max 10A, 35p/metre Red or Black or White. Park Flyers etc. or servo extensions. EXTRA FLEXIBLE WIRE Supplied in packs of 1 metre of red and 1 metre of black, i.e. 2 metres of wire 0.75mm2, 196 strands; ideal for weight saving, Max 15A, £1.00/pack 1.00mm2, 258 strands; ideal for weight saving for speed 400, Max 19A, £1.40/pack 1.50mm2, 378 strands; ideal for speed 400, £2.00/pack 4mm2, 1036 strands; £3.50/pack SILICONE INSULATED WIRE. Pack of 1 metre of red and 1 metre of black 1.5mm2, 378 strands. £2.50 2.5mm2, 651 strands. £3.00 All wire can be cut off the roll, in longer lengths if required. CELL HEATSHRINK metre lengths 25mm 50p; suits single AAA or AA cells or any same size 48mm 75p; suits single sub C cells/sticks or packs of dumpy 600 65mm 85p; suits 1700 or 2000 packs, also RC oblong sticks etc. 94mm 95p; suits double deck packs (1700 etc.) All sizes layflat width, supplied in clear. 48mm available in opaque blue also. WIRE HEATSHRINK metre lengths 1.6mm 50p; 2.4mm 60p; 9.5mm £1.00. Black only 3.2mm 75p; 4.8mm 80p; 6.4mm 95p. All in red or black. ALL ORDERS PLUS POSTAGE: 60p UK; £1.10 Europe; £1.70 World M. E. DONKIN, 37 WYDALE ROAD, OSBALDWICK, YORK, YO10 3PG Tel/Fax 01904 414738. Mobile 0771 202 8329. E-mail: [email protected] or [email protected] All messages - an attempt will be made to contact you. (I work shifts) E.F.-U.K. 81 B.E.F.A. Sales BEFA Round, Coloured Rub-down Decals - 50p each EF-UK Back Issues - No's 38, 40, 41, 44, 52, 53, 55 to 63 (inclusive) at £1.00 each for BEFA members, or £2.00 each to non-members. Issues 64 to 72 are also available to BEFA members at £3.00 each, or £5.00 each to non-members. These prices include UK P&P, overseas rates on application. Please Note these are the ONLY back issues now available. EF-UK Index. A comprehensive index of EF-UK from issue 28 to 59 is available by sending a £1 coin to cover copying and postage cost. Binders:- are available to hold eight issues of Electric Flight U.K. Produced in dark blue with gold lettering on the spine, these cost £4.50 each including U.K. postage. Please add £1 for European postage and £2 for Worldwide postage. Sweat Shirts & Tee-Shirts: Stock of these is now almost all gone - please contact Robert Mahoney regarding remaining stock, sizes and prices. Please send all orders to Robert Mahoney at the address on page 4. PLEASE REMIT IN STERLING ONLY, WITH ALL CHEQUES MADE PAYABLE TO B.E.F.A. Advertisers Index BEFA Sales .................................................................. 82 Buzzflight .................................................................... 23 E-Zone ...............................................Inside Front Cover Fanfare ............................................... Inside Back Cover For Sale / Wanted ........................................................ 79 ImporTekniK ............................................................... 41 Mail Order Model Supply............................................ 81 New-2-U ........................................................................ 8 Traplet ............................................. Outside Back Cover EF-UK advertising rates are £25 per cover (inside or outside), £20 per full page, £10 per half page, all per issue. Contact the Editor for more details (see page 4). 82 E.F.-U.K. – MAIL ORDER – SPORTS ELECTRIC FLIGHT FANS AND GEARBOXES www.fanfare.f9.co.uk GEARBOXES FANS Morley ‘Jet Elec’ Fan .............................. £15.00 Adaptors for 480 & 410 motors .............. £3.00 WeMoTec Micro-Fan (280/300/330) ..... £14.00 WeMoTec Mini-Fan (400/480) ............... £28.00 WeMoTec Midi-Fan (540/ 600/930) ....... £38.00 MOTORS WEP Turbo 10 ........................................ £55.00 Speed 500 E Race ................................. £13.00 Speed 600 8.4v BB SP .......................... £15.00 Speed 600 8.4v Race ............................ £18.00 Speed 650 9.6v BB Race ...................... £33.00 Speed 700 ............................ £14.00 to £22.00 Speed 700 Neodym ............................... £38.00 RE 380 / Rocket 400 ................................ £5.00 Speed 480 PB .. £14.00 BB ................ £21.00 Pro 400 ............... £5.00 Pro 480 HS .... £6.00 Master Airscrew 2.5, 3, 3.5:1 ............... £16.00 MP Jet Planetary 3.33 & 3.8:1 - 400’s ... £25.00 MP Jet Planetary 3.33 & 3.8:1 - 480’s ... £40.00 MP Jet Planetary 3.33 & 3.8:1 - 5/600’s £50.00 Mini Olympus ....... £8.00 Olympus ...... £12.00 MOTORS / GEARBOXES MFA Rocket 2.5:1 N.I.L. with 600 .......... £21.00 Speed 400 FG3 ..................................... £17.00 SpeedGear 400 4:1 Inline ...................... £37.00 SpeedGear 480 3.45:1 .......................... £55.00 SpeedGear 600 2.8:1 ............................ £52.00 SpeedGear 700 2.7:1 9.6v .................... £70.00 SpeedGear 700 Neo .............................. £90.00 Mini-Olympus & RE380 .......................... £12.00 Olympus & 540 ...................................... £19.00 Jamara 600 2.9:1 ................................... £24.00 Jamara 650 2.9:1 ................................... £26.00 MAXCIM BRUSHLESS Max Neo 13Y 1430 rpm/v ................... £160.00 Max Neo 13D 2470 rpm/v .................... £160.00 Maxu 35D, 21 Cell Controller ............... £140.00 Maxu 35C, 25 Cell Controller ............... £180.00 Superbox 1.6 to 4.28:1 ......................... £50.00 Monsterbox 4 to 6.8:1 .......................... £60.00 Motor Mount ........................................... £12.00 CHARGERS Speed 1 Pulse / Pk Det 4-8 cells ........................................... £27.00 Speed Ex Digital as above with discharge ...................... £55.00 Simprop 25 cell .................................... £100.00 PROPS M.A. Folding 12x8 ............... £14.00 15x12 ............. £15.25 M.A. Wood Electric 10x6/10x8 ........ £4.00 11x7/11x9 ........ £4.25 12x8/12x10 ...... £4.50 13x8/13x10 ...... £5.00 Carbon Folders 7x4 ................... £6.00 (Perkins) 8x4 ................... £6.00 11x8 ................. £9.00 Slimprops 8x4, 8x6, 9x6 ........... £3.50 APC Electric 5½” - 12” dia ....... £3 to £4 (full range available) 13 ” - 20” dia. .... £5 to £15 Selection of Graupner & Aeronaut folding & fixed props. Wheels, Wire, Servos, Fuses, Caps, Powerpole, 4mm & 2mm gold conns. FANFARE • 18 HILLSIDE ROAD • TANKERTON • WHITSTABLE • KENT • CT5 3EX ‘Sports Electric’ Helpline - Phone / Fax: (01227) 771331 - E-mail: [email protected] Now online at - www.fanfare.f9.co.uk