electric flight uk - British Electric Flight Association



electric flight uk - British Electric Flight Association
ISSUE No. 73 SUMMER 2003
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
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!
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
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 .................................
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.
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
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
BEFA Committee 2003/4
Robert Mahoney
123 Lane End Road, High Wycombe, Bucks. HP12 4HF
EMail: [email protected]
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]
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]
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.
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!
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.
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.
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.
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
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
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
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.
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.
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,
SO15 7NG
Tel: 07973 627738
Email address:
[email protected]
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
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]
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
See www.hobby-lobby.com for
more info about these products.
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).
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.
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.
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.
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.
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.
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
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:
Speed 600 8.4V (no flux ring)
Kontronik SUN 3000
8 x CP-1300 SCR
Kavan 8” x 6”
23A (static)
Hitec HFS 04MI
2x Graupner C241
Hitec HS-81
Flying Wt.
39" (100 cm)
1.9 sq.ft. (274 sq. in. or 17.7 dm2)
33.5oz. (950 g)
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.
167 Duffield Road, Derby. DE22 1AJ
Telephone: 01332 601693
[email protected]
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.
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
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.
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.
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.
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..
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.
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.
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
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
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
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
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
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.
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)
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.)
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!
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
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.
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.
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
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.
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.
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.
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.
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.
Electric World
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.
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”.
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
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
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
than the original kit!
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
the third run, he was “right on the money”, and dropped the big spherical “Highball”
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
“Pull-Up, Pull Up!”, Tony Major’s “Whitwell”climbs away from another go!
Encore! The Nyhuis Lancaster drops the bomb early on the victory flight
Tony Major’s “Whitwell” over the Dam
The Lancaster climbs away as the bomb splashes down - The Dam is about to blow!
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.
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
Tony Hyhuis receiving the “Barnes Wallis Trophy” from Kit Wallis (no relation)
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.
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!
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.
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
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
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
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.
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
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)
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
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.
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
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
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
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
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
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:
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.
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.
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
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
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).
BEFA League event at Leamington Spa. ElectroSlot / E400 league
event. For info contact Dave Perrett at [email protected]
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
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
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]
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.
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]
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
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
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.
West Calder Aeromodellers fly-in. Tarmac & grass runways.
Snacks available. Free entry. SAA/BMFA insurance required. 10am
to 5pm, all welcome. More details at www.modelclub.org
September 2003 (continued)
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]
BEFA League event at York. ElectroSlot / E400 league event. For
more details contact Dave Perrett at [email protected]
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.
BEFA League event at Pillerton Hersey. ElectroSlot / E400 league
event. More info from Dave Perrett at [email protected]
November 2003
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
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
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.
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.
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 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.
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.
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
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.
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.
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
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)
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.
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).
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
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
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
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
Speed 1 Pulse / Pk
Det 4-8 cells ........................................... £27.00
Speed Ex Digital
as above with discharge ...................... £55.00
Simprop 25 cell .................................... £100.00
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
8x4 ................... £6.00
11x8 ................. £9.00
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.
‘Sports Electric’ Helpline - Phone / Fax: (01227) 771331 - E-mail: [email protected]
Now online at - www.fanfare.f9.co.uk