electric flight uk - British Electric Flight Association

ELECTRIC FLIGHT U.K.
ISSUE No. 66 AUTUMN 2001
THE MAGAZINE OF THE
BRITISH ELECTRIC
FLIGHT ASSOCIATION
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Electric Flight - U.K.
Issue 66 - Autumn 2001
"To Encourage and Further all Aspects of Electric Model Flight in
the British Isles and Elsewhere" - B.E.F.A. Constitution
CONTENTS
BEFA Committee Addresses ................. 4
Chairman's Chatter ............................... 5
EF-UK Colour Photographs .................. 5
Current Lines ......................................... 6
New-2-U ................................................ 7
Channel 64 - A Problem? ...................... 9
Readers' Models .................................. 13
The Airco D.H.2 - Part 1 ..................... 19
Electric Powered Gliders - Part 4 ........ 22
BEFA at Middle Wallop 2001 ............. 29
A Haggle of Hackers ........................... 46
Park Flying .......................................... 52
Electroslot at Middle Wallop .............. 56
Beginners Start Here ........................... 64
For Sale ................................................ 65
Event Calendar .................................... 67
BEFA Sales .......................................... 70
Advertisers Index ................................ 70
Cover Photo: A shot of an extremely nice Focke Wulf 190 taken during the
BEFA Festival of Flight at Middle Wallop on 24 June 2001. Unfortunately as the
model had not been flown prior to the event, it could not be flown. Unfortunately
no further information on the model was available.
NEXT ISSUE. The copy date for the Winter 2001 issue is 20 November 2001,
with the magazine due for publication by 10 January 2002.
DISCLAIMER
B.E.F.A. and Electric Flight U.K. wish to point out that the content, techniques
and opinions expressed in this magazine are those of the individual authors and
do not necessarily represent the views of either the Editor of this magazine or
B.E.F.A. and its committee. All reasonable care is taken in the preparation and
compilation of the magazine, but B.E.F.A. and its committee cannot be held liable
for any error or omission in the content of this magazine or any subsequent
damage or loss arising howsoever caused.
E.F.-U.K.
3
BEFA Committee 2001
Chairman
Robert Mahoney
123 Lane End Road, High Wycombe, Bucks. HP12 4HF
E-Mail: [email protected]
Secretary
Bob Smith
1 Lynwood Avenue, Tollesby, Middlesbrough, Cleveland. TS5 7PD
Tel. 01642 823197, E-Mail: [email protected]
Membership Secretary
Robert Mahoney, details as Chairman.
Treasurer
Roger Winsor
14 Butler Gardens, Market Harborough, Leics. LE16 9LY
Editor EF-UK
Jan Bassett
111 Plantagenet Chase, Yeovil, Somerset. BA20 2PR
Tel. 01935 472743, E-mail: [email protected]
Assistant Editor EF-UK
John Brinkler
15 Hollands Way, Warnham, Horsham, RH12 3RH
Tel. 01403 257752, E-mail: [email protected]
Production Editor
Brian Boughton
'Red Roofs', Vicarage Road, Thetford, Norfolk. IP24 2LH
Events Co-ordinator
Terry Stuckey
31 Dysart Avenue, Kingston-upon-Thames, Surrey. KT2 5QZ
Competition Secretary
David Beavor
34 Chestnut Close, Brampton, Huntingdon, Cambs.
Midlands Representative
Roger Winsor, details as Treasurer
Northern Representative
Bob Smith, details as Secretary.
Southern Representative
Dave Chinery
251 Station Road, Hayes, Middx. UB3 4JD
South West Representative Jan Bassett, details as Editor EF-UK
Indoor & Free-Flight Rep.
Gordon Tarling
87 Cowley Mill Road, Uxbridge, Middx. UB8 2QD
E-mail: [email protected]
Technical Liaison Officer
Robin Andrew
143 Coventry Road, Coleshill, Birmingham. B46 3EX
E-mail: [email protected]
Public Relations Officer
Position Vacant
Safety Officer
Jan Bassett, details as Editor EF-UK.
Webmaster
Jan Bassett, details as Editor EF-UK.
Please enclose an SAE with all correspondence to the committee.
Further Membership information is on page 66.
4
E.F.-U.K.
Chairman’s Chatter
Welcome to issue No 66 of Electric Flight UK. This years flying season seems too
have flown by, or is it my age! I am sorry that this years Woburn Abbey fly-in did
not happen, this was beyond our control, we will try to get this event back on for
next years calendar.
BMFA has now issued the paper work to silent flight examiners for the NEW A
& B tests. It’s now up to you to obtain them, as we have done the ground work;
it’s up to you to do the air work! In fact I can see that at future fly-in the person
or club running the fly-in, could insist on them! It has been enforced at Old
Warden for two years with great results. Is this why, that only two of us turned
up for the BEFA Scale competition at Old Warden, or is it the word competition
that you are afraid of.
Please remember that the Tech. Workshop is not to far away, so get your tickets
from Gordon Tarling ASAP (his address is on page 4). Well that’s all for now so
keep it safe.
Keep the Watts Up
Robert Mahoney
E.F.-U.K. Colour Photographs
Association members may remember that for our Millennium edition we did
include some colour photographs. With the exception of that and our cover we
have not found it financially viable to move from our current black & white to a
full colour magazine.
At the last meeting the Committee discussed this matter and although we were
forced to accept that the financial situation had not improved, a suggestion was
made which may make colour photographs available to the membership at no
additional cost. The proposal is to publish the photographs associated with articles
in black & white in the magazine as we now do, but to also publish the same
photographs on our website in full colour. Those members who have access to
the website could then view the colour versions of the photographs whilst reading
the articles or could even print out the colour shots to slip into the magazine.
This does have an implication for contributors in that the photographs they
submit with their articles are made available to the association for publication
in both the magazine and on the internet (in terms of any copyright limitations).
We hope to be able to trial this procedure in the near future so it will be worth
your while to regularly checkout the website. (http://www.befa.org.uk)
E.F.-U.K.
5
Current Lines
from the Editor
The time between my first issue and this, my second, seems to have flown by.
The next BEFA event is the Annual Technical Workshop, to be held at the
Royal Centre, Leamington Spa on 11 November 2001. If you plan to come an
save a few pennies, get your ticket before the event. More details are on page 66.
The timescale for publication of the next issue has been extended to allow for a
Christmas break. If you do want to submit something, please ensure it reaches
me by 20 November 2001. An ideal opportunity would be to hand it to me at the
Technical Workshop (I’ll be there, somewhere).
In response to the requests for articles and Member’s model, I am happy to report
that a number of new contributors have come forward. Infact, it wasn’t possible
to fit everything received in this issue and a number of things have been held
over to the next issue. I am extremely grateful for these contributions to EFUK, as without them I would not find it possible to produce the magazine. Despite
the great response, the plea remains the same - EF-UK needs you (well your
models and articles anyway).
Indoor flying is becoming much more popular and I have completed 2 new models
for this Winter and included pictures below. The Pico-Stick is a kit by GWS,
which retails art under £20 and includes motor, gearbox, propeller and lots of
hardware (more items than you need). The FlexiFlyer is a Ron Fikes design and
can be seen on-line at http://www.geocities.com/srfikes2001/FlexiFlyer. I would
like to include more information on indoor models and would be especially
grateful for any contributions on this subject.
If you do have anything, please let me know so it can be included.
Jan
GWS Pico-Stick
6
FlexiFlyer by Ron Fikes
E.F.-U.K.
New-2-U
A Brief Round-up of New Items of Interest
Improved Mini IFO
The specifications of the Mini IFO (Indoor Flying Object) have changed with the
new kit introduced in August 2001. The main carbon rods of the structure have
been thickened to make the whole airframe more stiff. The previous Mini IFO
structure had a tendency to bend slightly during extreme aerobatic manoeuvres,
however the new stiffer structure is more predictable and precise in its flying
characteristics.
The Mini IFO is still 62 cm (25”) wingspan and to provide the urge you can use
either a GWS motor/gearbox or a Faulhaber coreless motor/gearbox, and 7 or 8
cell battery pack. The aerobatic performance is spectacular with both set-ups.
The Mini IFO can be obtained in different forms – the “Combo” Deal includes
the kit, motor, gearbox, propeller and speed controller, and is just £59.69. The
“Ready-To-Fly” (RTF) version with all motor and electrics and servos installed
is £148.99 (“just add battery and receiver to fly”). For more information, see
their website at www.IFO.com
The Mini IFO and IFO are distributed in Europe by ANSA Products Ltd. All
ANSA products are now available in any good local UK Model Shop. If any
difficulty contact ANSA Products on 01633-843000, fax 01633-243222 or email
[email protected]
E.F.-U.K.
7
The Mouse is the equivalent of a
“Pattern” aerobatic plane for indoor
flying or any small space. It is very
precise & accurate to fly, and will suit all
people who aspire to be aerobatic pilots.
The Mouse has a unique design concept
– a circular wing, with “tailerons”
mounted directly to servo horns at the
back and the motor/gearbox mounted on
the front of the wing. It is made entirely from carbon fibre tube & purpose-made
fibre-glass parts, a superb and comprehensive kit. The cost is just £63.99 for
ARTF, and only £33.99 for the kit. It has excellent aerobatic performance using
the GWS Carbon brush motor/gearbox with GWS 10x4.7 orange prop, a GWS
2A speed controller, and an 8 cell-pack of 180 mAh NiCd cells (from ANSA).
Alternatively use a Faulhaber coreless motor / carbon propeller and high
frequency speed controller for ultimate performance.
The famous Stubenfliege is one of the
best & most elegant indoor flying
aeroplanes in the world. It will fly in
any tiny indoor space, and outdoors on
a calm day. Indoor experts say “this is
the most relaxing aeroplane to fly in
the very smallest space”. Designer,
Stefan Dolch, flies the Stubenfliege
in his office at work. To see a
Stubenfliege fly is sheer delight. It
glides forward, slides noiselessly into
the air and floats around at walking pace. It can also be flown faster and will do
aerobatics – loops and rolls, bunts and sharp banks. The tailerons give very
positive control. It is made from spiral-wound carbon tube and purpose made
fibre glass parts - and there is a unique (patented) method for producing an
airfoil section in the wing. The Stubenfliege is supplied as ARTF (airframe
ready-built) for £95.99, or as a kit for £65.99. It flies very well with the low cost
GWS motor/gearbox/propeller/speed controller system, or alternatively use the
superb Faulhaber coreless motor / carbon propeller combination.
All ANSA products are now available in any good local UK Model Shop. In
difficulty contact ANSA Products direct on telephone 01633-843000, Fax 01633243222 or email [email protected]. Website: www.IFO.com
8
E.F.-U.K.
Channel 64 – A Problem?
by Gordon Tarling
Over the years, I am sure that some of you have lost models due to ‘interference’.
By that, I mean in circumstances which are not easily explained by equipment
failure, pilot error or many other possible causes. What I am referring to, in
particular, is a model which has been flown previously without problems, but
which suddenly starts ‘misbehaving’ during a flight, leading to the inevitable
crash. Needless to say, on subsequent examination, all the equipment is found to
be working properly.
Personally, I have experienced several such heart-breaking crashes over the last
five or ten years and have normally put it down to being ‘one of those things’.
During one year, in particular, I can recall three or four such crashes inside a
period of a couple of months. At times, I had my suspicions about the cause(s)
but have never been able to point my finger at any one thing and say for certain
‘that was the it’. However, the one thing that all of the crashes appeared to have
in common was that I was using channel 64 at the time. For a while, I moved to
other channels and the problem seemed to go away. However, for whatever reason,
I started using 64 again (I couldn’t tell you why!) and for a time, things seemed
to be OK, but then problems started appearing again.
Late last year, I only just got away with avoiding a bad crash of my Atlanta II
model at our local field - it had been flying quite normally and suddenly started
violent glitching as I started my landing approach - I just managed to maintain
control and land it safely. My brand-new Jim Ryan Corsair was test-flown at our
local field one Sunday this year by John Palmer, display pilot extraordinaire,
without a single glitch being evident. The following Sunday, at the same field,
with no other transmitters operating at the time, I had several violent glitches
during the first flight, culminating in an uncontrollable last glitch on approach
which led to a rather hard crash. Needless to say, the model ended up badly
damaged.
If any of this story, so far, is beginning to sound familiar to you, then read on there’s more to come!
Inevitably, such a crash of one of your favourite models dents one’s confidence,
but it also led me to start thinking if there really could be some problem with
either my radio gear (transmitter) or some sort of deliberate interference on
channel 64. I managed to rule out my transmitter - it was only a couple of years
old, hasn’t seen what I would call a lot of use and, furthermore, managed to cope
quite well with many of my models which weren’t on channel 64. I still wasn’t
entirely convinced, however, about a definite channel 64 problem, because my
E.F.-U.K.
9
RFB Fantrainer had been flying for two or three years on channel 64 without a
single glitch being recorded on the glitch counter with which it was fitted.
I began to make enquiries about my ‘problem’, one person in particular actually
told me about a ‘channel 64 problem’ that he had heard of and that he would
send me some information that had come to light. The e-mail which he sent
showed that a channel 64 problem was suspected around the Greater London
area, where many similar incidents to mine had been recorded. However, the
problem wasn’t confined exclusively to the London area because a club in
Aberdeen had banned the use of channel 64 altogether at its flying field! The
evidence was mounting!
Further e-mailed discussions with several correspondents revealed that there
may be a problem being caused on certain channels ‘by the military’ but I really
couldn’t believe that the military would be deliberately transmitting on our
exclusive frequencies. I had even taken to listening in to the R/C channels with
my scanner at various times but can honestly say that I never heard anything
untoward on any of them.
By now, it was becoming clear to me that there was more to this than meets the
eye, so I resolved to try to get to the bottom of the problem. One of my e-mail
correspondents pipped me to the post slightly by firing off an e-mail to the BMFA
about the possible problem, only to receive this response directly from Dave
McQue of the Joint Radio Control Users Committee. I reproduce it here, word
for word so that you may read it in its entirety and fully digest the implications“With a single conversion RX, the Xtal local oscillator is at
the Channel frequency minus the Intermediate frequency of
0.455 MHz so for Chan 64 at 35.040 MHz the RX Xtal is on
34.585 MHz. Unfortunately a signal on 34.130 MHz will also
produce the I.F. of 0.455 MHz. That is the image frequency
which happens to be in a military frequency band. With a
dual conversion RX the first I.F. is at 10.7 MHz so the image
frequency for the same channel is at 13.640 MHz which far
enough removed for the input tuned circuits at 35 MHz to
reject.
I found the problem with the Midland Soaring Society at
their hill near Kineton north of Banbury. They now use dual
conversion RXs for weekday operations.”
Regards
Dave
10
E.F.-U.K.
I have to say that after reading that statement, the light suddenly came on! Let
me explain a little more. Channel 64’s actual transmitted frequency is
35.040MHz. Although the receiver crystal may be similarly marked, the ACTUAL
frequency at which the receiver operates (single conversion) is 455kHz (normally)
below 35.040MHz - i.e. 34.585MHz. The transmitted frequency beats with this
lower frequency in the mixer stage of the receiver to produce the difference
frequency of 455kHz which can then be filtered and further refined before being
decoded and passed to the servos. This normally works fine in practice and we
enjoy the benefit of a secure (?) radio link with our models.
Now consider what happens in the receiver if a transmitter were to start
transmitting on 34.130MHz. This is clearly outside of our allocated radio control
band and is actually IN the frequency band allocated to military use. The
difference between the transmitted 34.130MHz and the 34.585MHz crystal in
our receiver is, lo and behold, 455kHz!!! Thus, the wrong transmission may
easily pass through all the carefully designed filtering stages in our receiver and
get through to the servos, although the pulse train will probably not be correct
to operate the servos properly.
Has the light come on yet? A transmitted frequency outside of our band, yet
still on a legal frequency (for that user) will cause signals of some kind to pass
clean through our receivers to reach the servos! It is no good listening on channel
64 for this interference - nothing will ever be heard! All of my own models which
had been on channel 64 had been using single conversion receivers except for
my Fantrainer, which used dual conversion!
You will now probably be asking ‘how does this affect me?’ and ‘what can I do
about it?’. Although I have no proof (yet) that this problem exists country-wide,
I am personally convinced that there is a potential problem in areas where the
military might be operating nearby. Please do NOT assume that because you fly
near a built-up area that you are safe - YOU ARE NOT! Apart from the obvious
Army, Navy and Air Force bases and operational areas around the country, don’t
forget about your local Territorial Army base, just around the corner! We simply
don’t know which frequencies the military will be using in what areas and at
what times.
The whole problem can be simply overcome by the use of a dual conversion
receiver. These have a first initial stage of conversion which operates at around
10 MHz difference in frequency and thus should not be affected at all. OK, OK,
I can hear you all saying now - ‘but a dual conversion receiver costs more money
and is physically larger’. Well, as far as I am concerned, ALL of MY models are
worth the extra asking price for the dual conversion receiver - can you honestly
say that it isn’t worth paying out another £20 or £30 to be sure that your model
won’t fall victim to the problem? As for size, there are too many models already
E.F.-U.K.
11
being flown on suitably undersized single conversion receivers which are designed
more for indoor and park flyers than the types of models in which they are being
used. Small dual conversion receivers DO exist and they should, ideally, be used
in whichever models into which they will fit.
Don’t assume that use of PCM will solve the problem either - many of the lower
cost PCM receivers are single conversion types and will be as affected as a non
PCM receiver - the difference being that the PCM’s servo response will slow
down as the interference is experienced, culminating in the infamous ‘PCM
Lockout’ if the situation becomes too bad. Other, newer, types of receiver such as
the Multiplex IPD will also be susceptible if of the single conversion type.
If you don’t want to change receivers in your models, then I can only suggest
that you maintain a close watch on the problem and if unusual glitches or crashes
start to occur, then you will have to consider what steps will need to be taken. If
you intend to monitor the frequencies with a scanner or monitor, then make
sure that you are monitoring the right frequencies - i.e. 34MHz! Undoubtedly,
there will be those people out there who have always flown on channel 64 and
have never had a single hint of the problem. All I can say is that you have been
lucky so far!
Another thing to consider is that the problem may not just be confined to channel
64. Several correspondents have mentioned that channel 65 also appears to be
affected and, frankly, I think we should assume (until we can prove otherwise)
that any of our channels could be affected.
One does have to ask why our national body, the BMFA, have not chosen to
inform us of this problem before now? One can only surmise that it was lack of
concrete information which was holding them back. After all, the proof of such
a problem appears to be hard to obtain. However, I personally feel that this
problem has been around for longer than anyone cares to admit - I can’t imagine
that the military have only just started using those frequencies of 34MHz.
Maybe, by the time that you read this, we will have seen an official statement
from our national body, together with a promise of a permanent resolution. In
the meantime, we will attempt to keep all our members informed of any
developments and would request that any information which you may have about
the problem be submitted directly to myself and to the BMFA if you consider it
appropriate.
12
E.F.-U.K.
Readers' Models
Your chance to show the members.
A bumper Reader' Models this time with such a variety to suit most tastes.
The first two models are own designs submitted by Robin Fowler. Both models feature
home built retracting undercarriages using readily available materials and using the
most basic metalwork skills. All three wheels are operated from a single SuperTec
S136L servo which has a torque of 8kg/cm.what your doing.
The first is his de Havilland DH-104 Devon, which is 67" (1.7m) span with a wing area
of 439 sq in (28.3dm2). The flying weight is 4lb 13oz (2.2kg) giving a wing loading of
25.3 oz/sq ft (77g/dm2). It is powered by 2 "Buggy" motors direct drive to MA 8" x 6"
propellers. He says it normally flies on 7 x 1700mAh cells, but he is currently using 8
cells. He says that despite the high wing loading, she flies like a dream. This was the
first electric model that Robin had fitted retracting undercarriage or flaps to.
E.F.-U.K.
13
Robin's second models is a 100" (2.5m) span Liberator, designed for 500 or 540
standard (and cheap) motors on Olympus belt-drives and 11" x 8" propellers. He says
the slow flying speed and rumbling belts enhance the scale impression in the air. He
hopes the lovely noise makes up for the lack of scale detail, which is a feature of his
models. The wing area is 800 sq in (51.6dm2) and it has a flying weight of 9lb (4.1kg),
giving a wing loading of 25.9 oz/sq ft (79g/dm2). The Liberator is fitted with split flaps
as the full size, but the travel is limited to 45°. He also says the Liberator is a good
magnet for admiring comments, even if only such as "I didn't think it was going to get
fast enough to get off the grass"!
14
E.F.-U.K.
Above is a GAF Nomad built by Rob Ireland from a plan. It is 60" (1.5m) span, the wing
area is 495 sq in (31.9dm2) and it weighs 4lb 8oz (2kg). It is powered by Graupner
Speed 480 7.2v motors (2) fitted with Graupner Super 6" x 4" propellers, running on 8
Sanyo RC2400 cells and draws 22A (measured static). As only 1/2 throttle is required to
fly, the flight time is 8 minutes with a reserve remaining.
Below is a Multiplex Pico-Cub (yes really) built by Richard Haywood. Span 45.6"
(1160mm), area 439 sq in (28.3dm2) and the flying weight is 1lb 9½oz (725g). The
weight is increased due to the tissue covering, the paint finish and the struts. The
supplied 400 motor has fitted the upgrade of gearbox and Günther 17½cm x 16cm
propeller. The battery is a 8-cell 1300mAh NiMH pack, which gives flights of over 12
minutes even with the increased weight. Rob says he is going to buy another Pico-Cub
to fit the recently available floats set.
E.F.-U.K.
15
The 2 pictures on this page were submitted by Eric Leadley. They are the work of Will
(Ralph) Scarlet from York, who is new to be the hobby, but loves to experiment with
flying wings. As he can't fly them yet, Eric flies them for him.
The on the right in the above picture is powered by an Astro 05 FAI motor on 8 RC2400
cells and a 7" x 4" pusher propeller. It flies extremely well, but needs at least 1/2
throttle or it drops a wing.
The model on the left (above) is 5ft (1.5m) span powered by 6 K&P fans. These are
wired in 2 sets of 2 motors in series, running from 8 x 1250mAh cells. They give ample
power and sound great in the air. Below is the installation of the fans.
16
E.F.-U.K.
The two photographs on this page of an enlarged (1.4x) Black Magic suitably modified
to electric power by Colin Boast. It is 84" (2.1m) span and has a wing area of 6.4 sq ft
(59.5dm2). It is fitted with a geared Astro 40, a 15" x 8" propeller and power is supplied
by 18 x 2000 cells. Static ground testing measured a thrust of 80oz (22N), drawing 26A.
The flying weight is 9lb 4oz (4.2kg), giving a wing loading of 23.1 oz/sq in (70.6g/dm2),
which is quite reasonable.
Colin says he simplified the original (complicated) tailplane, but retained the ability to
remove it for transport. To facilitate more graceful turns, he reduced the dihedral and
fitted ailerons. Based on past experience of a similar model, he lengthened the nose to
ease installation of the electrics. He covered the model in Fibafilm. The result is a
delightfully relaxing model to fly, with a short take-off from grass and is also flyable on
a breezy day, when others might be grounded.
E.F.-U.K.
17
Another model by Colin Boast, a Partenavia P-68 Victor this time based on the
Radiomodeller plan. Powered by 2 Graupner Speed 650BB motors with Olympus drives,
14" x 7" propellers & 16 x 2000 cells. As Colin flies from grass, the wheel spats were
not added. He said it is a very pleasant model to fly, with a satisfying, authentic buzz
from the twin belt reducers. Span 79" (2m), wing area 5.5 sq ft (51dm2) and flying
weight 9lb 13oz (4.45kg). Thrust is 84oz (23N), drawing 28A.
The Editor’s Little Tiny built from the Todd Long kit. The motor is a Faulhaber DC1717
coreless motor with Faulhaber 11.8:1 gearbox. The propeller in the photograph is a
Braun 26cm x 16cm carbon, but the model is normally flown with a WES carbon 26cm x
12cm propeller. For duration a 3 cell LiMn02 780mAh battery is used (45 min motor
run), but a 10-cell Sanyo 50mAh pack is used for increased power. Span is 24” with an
area of 220 sq.in. The model was being flown without wheels, but it didn’t prevent ROG.
18
E.F.-U.K.
The Airco D.H.2 - part 1
by Jan Bassett
What to do with a spare Astro 40 with Superbox when you something scale, but
a little more unusual to put it in. I looked around for inspiration and couldn’t
really see anything that I liked. Then I saw the free plan issued with Flying Scale
Models, January / February 2001 - an Airco D.H.2. This was 1/9th scale giving a
span of about 37” and using a speed 400 motor.
The prototype Airco D.H.2
Due to the significant size change, an enlarged plan would be used for the outline
only and the structure completely redesigned within it. A suitable size seemed to
be 1/6th scale, but that would mean multiple enlargement and several pieces of
paper. The largest I could get on a single page was a increase of 41% (from A1 to
A0 paper). This would give me a scale of 1/6.38, which seemed OK. I therefore set
about evaluating the options.
The original was 28ft.3in. span, a wing area of 249sq.ft., a maximum weight of
1547lbs and a maximum of 110HP motor. Scaling span and area is simple and
gives 53.1” and 6.11sq.ft. (or 881sq in) respectively.
I like to use the Wing Cube Loading (WCL) for scaling weight, which is:
The full size’s wing loading is (1547lbs x 16oz.) / 249sq.ft. = 99.4oz/sq.ft., giving
a WCL of 99.4 / √249 = 6.3. This figure can be evaluated using the table below.
E.F.-U.K.
19
The figure of 6.3 obtained is extremely low, but not untypical of early biplanes.
My target is to equal this figure with the model. As we know the wing area and
required WCL, we can transpose the equation to determine the wing loading and
then weight.
Thus, the required Wing Loading = 6.3 x Ö6.11 = 15.6oz./sq.ft., giving a flying
weight of 15.6oz/sq.ft. * 6.11sq.ft. = 95oz.
The next calculation is the power loading and I use the factors derived by Bob
Boucher in his article “Understanding Scale Speed”. This can be viewed online
on the Astro Flight site at http://www.astroflight.com/scalespeed.html. Bob derives
an equation for scale power for a model:
Therefore for my D.H.2, the power needs to be 110HP / (6.38)3.5 = 0.167HP or
125W. This gives a power to weight ratio of only 21W/lb, which is really low.
However, the original was extremely underpowered so it is probably correct.
Having said that, I still want to have about 50W/lb to be comfortable so I intend
to have at least. 300W available.
I want to use a scale 4 bladed wooden propeller to improve the static looks. The
full size diameter is exactly 8ft, giving a scale size of almost exactly 15in. Using
ElectriCalc, I decided that for 14 cells a pitch of around 12in would be reasonable
for the speed range envisaged.
I emailed EAT Propellers (http://www.props2000.freeserve.co.uk/) with a scanned
picture of the blade shape and my dimensional requirements, and with 2 days I
had a finished propeller in my hand & I duly sent the cheque by return of post.
What a superb service. The top section of the supplied propeller is shown below.
I reversed the direction of motor rotation and retimed it to suit and bolted on the
propeller - now to test it. The aircraft weight was adjusted depending on the
weight of the pack hence the W/lb. variations. The results were:
20
E.F.-U.K.
As the wing covering will be translucent, as was the original, I want the wing
construction to be visually very similar to the full size. The full size has a very
thin wing section, which I couldn’t identify. I decided that an 8% thick Clark Y
section would fit the bill as there is a lot of wing area. Spar and rib spacing
would also have to be at scale positions and intervals. On the full size the ribs are
stronger where attachments (booms & struts) are to be made and my ribs would
need to be 1/16” thick and 1/8” thick.
First snag - it’s a biplane, and therefore we need lots of ribs. As the wing is
constant chord - well to the trailing edge apar anyway, I made the ribs using the
traditional sandwich method. I then used a second set of templates for the trailing
edge of the centre section. Below is a completed wing panel set of ribs, not quite
a quarter of those required.
The wing tips were laminated from 3 layers of soft balsa around a former of pins.
These parts were assembled into 4 wing panels. Despite making the leading edge
riblets, they haven’t been fitted yet as early aircraft didn’t have them. The
diagonal cross bracing has also yet to be fitted. One right wing panel is shown
below with a picture of the original wing structure from Windsock Datafile 48.
That’s all I’ve got time for at the moment, but there will be more next time.
E.F.-U.K.
21
Electric powered gliders
by Bob Smith
This is part 4 of a series of articles which has been running in EFUK over recent
editions. The first three articles covered an introduction to electric gliders, models
for beginners/converts, and competition/hot ships. This final instalment will deal
not with the models but with the technical aspects of flying them. There has
already been a fair amount of technical material spread through the previous
articles but this edition’s content will pull it all together in hopefully a more
logical presentation. The comments I will make are not, of course, restricted to
electric gliders alone but will be relevant to many other aspects of electric flight.
I will, however, concentrate upon those aspects which relate to this kind of model
in particular.
General factors
Although I have used the single term “electric glider” for this series of articles,
those who have read all of them will realise that I have actually covered many
quite different types of models. It would be unwise to suggest that the technology
of a beginners ARTF glider is the same as that of a 28 cell F5B model, but there
are similarities. All of the models have a power train which will consist of a
power pack, a controller, a motor, and almost certainly a folding propeller.
They will all have a receiver and servos. They may have a gearbox and they may
have a receiver battery. The modeller will require certain ancillary equipment,
primarily his transmitter, a 12 volt source battery and a charger, possibly
additional battery packs, and in the ultimate he might choose to fit one of the
latest gadgets, an in flight variometer. The beginner may well be dealing with an
ARTF package which will include some of these components but even here he
might be advised to upgrade or replace some items.
As a general principle we have to accept that normal commercial rules will apply.
As the quality and sophistication of a component increases, so does it’s price. In
everyday terms “you get what you pay for”. You may know what you need,
specification wise, but you also know what you can afford. Only when there are
several units which satisfy your specification and your budget will you need to
make a choice. Many people advise you to “get the best you can afford”, and
there is a lot of sense in this. You do, however, need to think of the overall picture
and try to obtain a balanced set of components. There is little point in fitting a
cheap gearbox to an expensive and powerful brushless motor.
I intend to work through the various components in turn so let me begin by
looking at the power train again.
22
E.F.-U.K.
A typical Motor / Gearbox combination
The motor may be a ferrite (such as the ubiquitous Speed 400, 500, 600 etc),
cobalt or neodymn brushed (such as the Astro series and the Mega range) or a
brushless motor (Kontronic, Hacker, Plettenberg, Ultra, Aveox, etc.) and may be
sensored or sensorless.
The range of motors specifically for electric flight is enormous and this does
make choice more difficult. If the model is from a kit or a plan then there will be
a recommendation with regard to the motor but there is no reason why you
cannot substitute one of your own choice. Apart from the cost factor which I
have already mentioned, the two areas you would need to consider in choosing
would be the size of the motor, weight and dimensions (including the gearbox if
using one), and the power output. The model will have limited space available in
the nose so you must be sure that
1) the motor/gearbox you choose will physically fit into the nose leaving
enough room for the other components, and
2) the weight is not going to make it impossible to obtain the correct
position for the C of G.
The power output involves several additional factors. First and foremost there is
the performance you wish to achieve and with an electric glider this is normally
rate of climb (although duration of flight will also be involved). The rate of climb
depends upon the number of cells, the size of the propeller, and the rpm at which
it is driven. This last factor is a function of the current drawn and you need to
take account of motor limitations (usually based upon maximum temperature
E.F.-U.K.
23
increase in use) and controller limitations. Of course you can overdo the power
and fitting an F5B system into a lightweight built-up airframe will result in
instant destruction. It is possible to perform a set of complex calculations to
resolve this problem but the more usual approach is to use a combination of
computer software (Electricalc or Motocalc) with test flying (trial and error?).
I have expressed my opinion on the use of gearboxes in electric gliders before but
I will take this opportunity to stress it. For a relatively slow flying model like a
glider the rate of climb will be better with a larger propeller than with a smaller
one at the same current.
A particular model may climb at 100 metres per minute with an 8” diameter
direct drive propeller pulling 25 amps. If the motor has a gearbox added so that
it can drive a 12” diameter propeller at the same 25 amps then the rate of climb
might easily rise to 150 metres per minute. The improved performance is simply
the result of improved propeller efficiency so it always makes sense to take
advantage of this. There are exceptions of course and these are usually with
models which have a faster flying speed such as hot ships and F5B models. Even
here however, many of the current F5B models are beginning to use geared
systems.
Speed Controllers
There was a time when electric gliders used electronic (or even mechanical)
switches to control the motor but not now. The availability of reasonably priced
electronic controllers means that the basic proportional throttle function is easily
obtained. These units are starting to get very small, most have programmable
functions, and they are usually available with a BEC (battery elimination circuit).
You must match the controller to the motor, both for type (brushed, brushless,
sensorless) and for specification (cell count and current).
Most units are specified with a continuous current value and a higher short
term value (say for short 20 second bursts). Again heat is the limiting value and
it is always useful to arrange for cooling air to flow over the motor, controller,
and battery pack. Some of the most advanced controllers do have a lot of options,
(some even interface with a PC to allow complex programmes to be set up) and I
suspect that these would be counter-productive if you were not experienced in
electric flight systems.
Apart from this limitation these units are now virtually foolproof. Do choose a
unit which has a brake facility as the large diameter propellers we tend to use
are sometimes reluctant to fold on the glide and a free spinning propeller is a
very efficient airbrake. Not what you need when you are trying to extend the
glide time of the model.
24
E.F.-U.K.
A Schulze controller for brushed motors.
Propellers
Most of the major manufacturers now produce a range of moulded folding
propellers suitable for any application. The price is dependant on the quality
and materials involved and they are available complete with hubs or yokes, and
spinners. The arrangements for fixing to the motor/gearbox shaft can vary but I
prefer the collet type since I believe they are more secure and give a truer locking
position.
In most cases you can also purchase the blades separately as a pair. This is useful
if you already have a suitable yoke/spinner but also if you have an accident and
damage one or both blades.
The propeller is one component of an electric glider which does a lot of work,
especially with powerful motors, so it is wise to regularly check them for security
and damage. Always replace a damaged blade!! A blade may have very slight
damage which you may not think to be a problem, but it is simply not worth any
risk to the model, yourself or to third parties.
Replace the damaged unit before you even run the motor, let alone fly the model.
I have already mentioned the determination of propeller size (diameter and pitch)
as part of the drive train design process, but it is perhaps the least understood
element of the train and therefore most likely to be determined on a trial and
error basis.
E.F.-U.K.
25
A typical set of high-quality folding propeller blades.
Battery Packs
The power pack is the heart of any electric model. The decisions you need to
make include the size and type of cells, the number of cells, and the format. The
most common cell size is the sub-C (1700, 2000, and 2400 NCR) NiCd cell but
you should be aware of alternatives. The E400 type models use both A (500AR)
and AA cells, situations where large cell counts are required in limited space can
use 2/3 sub-C (1250CR), and the larger full C (3000CR) cells have greater capacity
for limited cell counts.
In all cases the number in the battery code refers to the nominal capacity in
mAh, and the letters cover the size and charge type. We generally abuse our
batteries in that we charge and discharge them at rates which are far beyond the
manufacturers recommendations. For this reason it is always best to obtain the
best quality of cell you can afford, and my own recommendation is for Sanyo
type R (fast charge) cells. The chemistry of re-chargeable batteries is developing
very quickly at the present time, and the environmental pressures are away from
the Cadmium based technologies. Nickel metal hydride cells are not far behind
NiCds (may even be better in some categories), and Lithium metal/Lithium oxide
are rapidly advancing.
All battery packs for electric gliders will involve a number of cells electrically
combined in series to act as a pack. Such packs can be purchased ready-made
with welded intercell connections, or can be home made with soldered joints.
26
E.F.-U.K.
Individual cells and the pack as a whole are generally insulated with plastic heatshrink sleeving and various formats are available to fit the required number of
cells into the available space.
A typical 7 cell Sub-C flight pack of Sanyo RC-2400 NiCd cells
The connection of the battery to the rest of the drive train requires cables and
connectors. The cables should be silicon sleeved and multistrand for flexibility,
and should have minimum resistance by being as short as conveniently possible,
as large a conductive cross-section as possible, and using the best possible
connectors. I would only recommend either gold-plated sleeve fitting (4, 3.5 or
2mm diameters) or the colour coded Power Pole type.
I should also mention the availability of matched and “zapped” cells and packs.
These offer increased capacity/performance in some situations but it may be
difficult to justify their increased cost for sport flying. They are commercially
available but not normally considered as a suitable process for home assembly.
Battery charging.
Like controllers, most modern battery charger units are sophisticated electronic
units which the modeller will purchase and use, hopefully without problems.
They are intended to be foolproof, and in this respect the manufacturers are
largely successful. Most operate from a 12 volt DC supply (there are some mains
operated bench units available) and this is logical since you will most probably
wish to recharge your batteries at the flying field. You can use your car battery
to supply the 12 volts but a days flying can flatten this and make starting the car
for the journey home problematic. It is best to use a separate 12 volt lead-acid
battery and the best types are not typical car batteries but are classified as “leisure
batteries” with a capacity of 50 to 100 Ah.
E.F.-U.K.
27
One of the latest Schulze Field Chargers
Suitable chargers are available at costs from around £25 up to £200 plus, and, as
usual, the better ones are more expensive. Even the basic units should include
an automatic full-charge cut-off (delta peak detection) but then the cost increases
as the features available become more sophisticated.
The kind of features you might look for would include two or more charging
outlets, increasing cell counts (basic is 4-8 cells only), variable charging current,
LCD display for programming and capacity recording, selection of cell types
(NiCd, NiMH, Lead acid, Li Ion etc), and cell cycling programmes. In the most
sophisticated (and Most Expensive) units, you might look for a discharging facility,
complex balancing and testing programmes, and even an interface with a PC for
data recording.
As you will see, the technology of electric gliders can be quite complex but please
remember that it is all about flying a model. Choose the level of technology which
you are comfortable with and which will enable you to enjoy flying your electric
glider, and concentrate on waiting for the gentle breeze, blue sky, and fluffy white
clouds above every thermal.
28
E.F.-U.K.
BEFA FESTIVAL OF FLIGHT
Middle Wallop 23rd and 24th June 2001
by John Brinkler
What a weekend! Both days were gloriously sunny with a 10 to 15 mph breeze on
the Saturday and a very light wind on the Sunday.
As usual the Electroslot competitions took place on the Saturday, but for a change
this year fun-flying would also take place on the Saturday. The Electroslot flight
line was some 500m from the general flying area and had their own allocated
frequencies so this enabled flying to take place at both sites simultaneously. Now
I’ll omit any further mention of Electroslot here as I have covered this in a
separate article later in this issue of the magazine.
For those of you who have never visited Middle Wallop it is a grass military
airfield sitting on the top of Salisbury plain in Wiltshire and being quite high
above sea level it is normally exposed to the prevailing wind, but not this weekend!.
The flying area allocated to us gives us a huge unobstructed flying site with
adjacent parking at the edge of the field. On the site there is also the Museum of
Army Flying with its own restaurant and other facilities, being open to us during
both days. There is also an area available next to the Museum for overnight
camping which some flyers took advantage of.
However it’s the planes and flying you want to read about and that came in
abundance especially on the Sunday, but even so there were never any queues
for the frequency pegs. Apart from the fun flying Sunday also featured an AllUp-Last-Down competition and informal Scale and Vintage competitions for
planes which flew on the day – no hangar queens here!
I’ll cover the competitions first and follow the results with photographs and
descriptions of the winning models and then I’ll feature some of the many other
models I saw and photographed over the two days. If I have missed you and your
model out this time catch me and pose at one of the next meetings!
The Festival of Flight was the first meeting I have covered for the magazine and
there were so many wonderful planes I had a heck of a job catching up with
everyone.
Now what amazed me was how happy everyone was to pass on details of their
models; there’s no secrecy in electric flight circles just fun, friendliness and
openness. If you didn’t visit this year make a mental note to look out for next
years event and determine to attend! You’ll enjoy it.
E.F.-U.K.
29
Two photo’s showing some of the entries for the informal scale & vintage competitions.
The scale competition results were as follows:
1st David Theunissen with his Boeing Stearman PT17
2nd Mike Payne with his Miles Sparrowhawk
3rd Bob Mahoney with his Ryan
30
E.F.-U.K.
David Theunissen’s Boeing Stearman PT17. Scratch built to 1/5th scale it has a
wingspan of 73”. The fuselage is moulded from fibreglass from a plug made by David.
The rest of the model is of built up construction. The wing has scale rib tapes with 1mm
serrations. David also turned up a plug for the 7 cylinder Continental engine which was
then moulded in fibreglass.
The AUW of the model is 18.5lbs and it is powered by a direct drive Actro 40/5 which
turns its 16”x8” prop at 7000 rpm and draws 40A static from its power supply of 30
CR3000 C size Sanyo NiCds. A typical flight will last 6 minutes and the model flies
beautifully just like the full size one which I frequently see from my club flying site when
the local aged rocker Dave Gilmour of Pink Floyd takes it up for a spin
(well actually no just a couple of loops and rolls usually).
E.F.-U.K.
31
Mike Payne’s Miles Sparrowhawk. Built to 1/5th scale it has a wingspan of 66” and was
featured as an EFI plan last year. The model is powered by an Ultra 1800/5 on 20
NiCds driving a 14.5”x8” Aeronaut prop through a Graupner 2.09:1 belt drive. The
AUW is 3.2kgs and a typical flight is 8 minutes. The photo of the front of the fuselage
with the cowl off shows the motor installation and the 20 cells in 2 packs of 10 in a slide
above the wing and in front of the cockpit. Also shown in the photo is Mike Payne’s 56
inch span low winged Yellow Lark. This is powered by a Plettenberg brushed 290/20/8
on 10 cells turning a 12x7 prop through a 2.4:1 gearbox.
32
E.F.-U.K.
Bob Mahoney’s Ryan. This is an ARTF kit from K and W in the Philippines, it is 1/5th
scale with a wingspan of 112”. The model is powered by an Aveox 1415/2Y turning a
17”x8” prop through a Planeta 3.7:1 gearbox. The static current on its 21 Sanyo 2400
cells is approx 38A giving 7500 rpm at the prop. The AUW is 24lbs 9 ozs and the model
flies typically for 6 minutes and even features the originals scale long run take off and
landing characteristics! The input power to weight ratio is approximately 30 watts per
pound - amazing to see how little power you need for scale flight when you match the
right prop to the plane and motor/gearbox combination. Just as well Bob’s a big strong
fellow to carry this little plane!
E.F.-U.K.
33
The Vintage competition results were as follows:
1st David Theunissen with his Dragonfly
2nd Angie Piacentini with his Junior 60
David Theunissen’s 84” span Dragonfly which was an original 1938 design. The model
is powered by an Astro 40 running on 20 Sanyo 2400 NiCds and turning an 11”x7¾”
prop through an 1.63:1 Astro gearbox. The AUW of the model is 9.75 lbs and a typical
flight lasts 9+ minutes.
At lunchtime on Sunday an All-Up-Last-Down competition was run. Only a small
entry of 8 pilots took part, with the other pilots taking a break. For this event
there are no restrictions on either plane cells or motor…..
The start of the AULD competition with a simultaneous launch of the models.
34
E.F.-U.K.
Concentrating hard after 1 hour with 3 pilots left in the fray.
After 1hr there were 3 planes left, so limbos (below an imaginary 10ft bar) were
called to speed up cell depletion. After 1hr 25mins Alan Bedingham landed last!
The AULD competition results were as follows:
1st Alan Bedingham with his own design model
2nd Chris Pegg with an FVK Simply The Best
3rd Norman Childs with his own design Dog E2
Alan Bedingham with his winning own design 2.5m span glider
E.F.-U.K.
35
Alan Bedingham is powered by 8 Sanyo NiMH cells to a 3.1:1 geared Hurricane
650 motor turning a 12”x10” prop. The model is fitted with air brakes for getting
out of lift and still had about 1.5 minutes (out of 9 minutes available) power left
in its battery on landing.
Chris Pegg’s 2nd place Simply the best 1.8m glider was powered by an Astro 020
geared brushless motor turning an 11”x8” Graupner CAM prop. The battery
used was an 8 cell pack of 1100 SAFT pen-cells.
Norman Child’s third placed DOG E2 is featured in the Electroslot article later
in the magazine.
That ends the competition elements of the weekend and the following photos
show some of the many pilots and planes which took part in the fun-fly over the
weekend.
Brad York with his Parab’aile flying wing available from Marc Le Maitre in France.
It is a flex-wing design with a span of 47” that can be folded up for transport. Flying
weight is around 750g for the electric version, but it can be quickly converted to a
glider . This one is in typical colours of purple and black. It is supplied with a 6v Speed
400 and gearbox and the recommended battery is a 7-cell Sanyo KR-1400AE pack.
More information is available at www.zsysteme.com
36
E.F.-U.K.
Ian Burridge from the Middle Wallop flying
club (lucky fellow) with his Simprop Lift Off XS.
(this model replaces the Simprop Peppo a plane
of which I have many unfond tip stalling
memories - well, not too many really…….).
The model is powered by a direct drive CEM 05
turning a Graupner 8x4.5 CAM prop. Cells are
7 x 1900 mAh Sanyo NiCds and a typical flight
is 15 to 20 minutes.
Model is aerobatic and fast but also glides and
penetrates well and doesn’t appear too keen to
tip stall.
Michael Sykes from the Wealden (East Sussex) club with his X Models Falcon 2m glider.
The model is powered by a Lehner Brushless motor turning a RF 14”x10” prop through
a 6:1 gearbox. The motor draws 55A static giving a 2min 20sec motor run from the 8
Sanyo 2400 NiCds. The AUW is about 4.5lbs. The result is a model transformed into an
electric rocket with a 75 degree climb-out. The model features a glass and epoxy
covered balsa sheeted wing over an open built up structure which gives a light but
strong wing for fast climbing launches and aerobatics.
E.F.-U.K.
37
Gordon Tarling with his
GT Kits Bearcat finished
in the racing Bearcat
colour scheme.
The model is powered by
a 6v Speed 400 turning an
8”x5” Graupner prop
through a 1.8:1 gearbox.
Cells are 7 Sanyo 500AR.
Typical flight time is 4+
minutes.
Needless to say Gordon
has these kits for sale at
the eminently reasonable
price of £45.
Dennis Bannister with his
1/12th scale scratch built
Fournier RF4. The plane
is Dennis’s hack flying
model and is now 4 flying
years old.
The power comes from a
7.2v Speed 400 turning a
Robbe 6”x3½” folding
prop on 7 Overlander
1300 NiMH cells.
The AUW is 24 ozs and the
12 minute motor run gives
a 20+ minute flight.
38
E.F.-U.K.
Bob Corfield from Southampton with his 57” span P-51. The 6.5lb AUW model was
built from a Sailplane & Electric Modeler plan. The model is powered by a direct drive
Ultra 1300/12 turning a 12”x6” APC prop on 16 Sanyo 2000 NiCds. Static current
draw is 35A with a typical flight lasting 6+ minutes.
Dennis Bannister with his 1/12th
scale SE5. The model is scratch
built from hot wire cut foam and
has an AUW of only 4.1 ozs.
Power is from a GWS motor
geared 4.8:1 and turning a GWS
9”x4.7” slowfly prop on 7 x
110mah NiCds. The speed
controller and receiver are also
GWS components and the rudder and
elevator are controlled by 2 Naro servos.
Typical flight time is 5 minutes and the
plane is capable of flying in very light
winds so Sunday suited it fine.
E.F.-U.K.
39
Ken Nixon of the Nottingham RCS with his Ezee Pzee
built from a Paper Aviation kit (no longer available).
The plane is 84” span and has a wing area of 8.3 sq ft.
Power comes from a direct drive Hektoplett Brushless
370/A3 motor on 28 cells turning a 16”x10” prop.
AUW is 12.2lbs, power is more than adequate for a
brisk take off & climb out. Flight time is typically 6 to 8
minutes depending on the power used.
Harry Dove from South Dorset Soarers with his 112” scratch built Fournier RF4. Power
is from an Astro 40g turning a 15”x8” prop on 18 Sanyo 2000 NiCds & AUW is 10 lbs.
With an 8 minute motor run typical flights are about 12 to 15 mins. The plane can also
carry a camera on the port side of the fuselage behind the cowl (shown inset).
40
E.F.-U.K.
Don Sim and Barry Kerley from the Isle of Wight with a collection of their planes.
Included is a York Air Charter of 74” span powered by 4 parallel Speed 400 motors
geared 1.85:1 and turning 9”x6” props. 8 Sanyo 3000 NiMH cells provide the power.
The Salamander has a WeMoTec 480 fan powered by an AP 29 on 8 Sanyo 800AR cells.
The P-38 is powered by 2 Speed 400 direct drive motors fed from 7 Overlander 2250
NiMH cells. The Heinkel 219 UHU is powered by 2 Speed 400 geared motors on 7 cells.
Dave Theunissen and Trevor Hewson with their Boeing Stearman PT13 and PT17. The
PT13 has a 9cylinder Lycoming engine and the PT17 a 7 cylinder Continental engine.
Trevor’s Stearman PT13 is of
58” span and is powered by
a Graupner 700 driving a
14”x8” prop through a
Robbe Planeta 3.7:1 box.
The 14 Sanyo 1700 cells
give flights of 5½ minutes.
The model is of built up
construction and is covered
in Profilm.
Trevor had a flight in the full
size plane at Old Sarum for
his 50th birthday.
E.F.-U.K.
41
Kevin Saunders with his very impressive
JEPE F16.
The model and flight earned Kevin a
spontaneous round of applause from the
appreciative spectators on landing.
The model is powered by a Phillippe Noro
carbon cased brushless motor running on
14 Sanyo 2400 NiCds and weighs only
1.7kg.
The fuselage is a fibreglass moulding and
the wing is of balsa veneered foam with an
epoxy and glass cloth covering.
After bungee launch a typical fast and
aerobatic flight lasts 5 minutes.
The 1/20th scale Vulcan of Cyril Carr
from the Phoenix club Wareham.
Cyril’s Vulcan is 65” span and is
powered by two Ultra 930/6 brushed
motors driving two own
design fan units.
28 Sanyo 2000 cells
provide the fuel for the two
series wired motors.
The plane has an AUW of
10 lbs and is now in its 8th
flying year.
A typical flight lasts 6+
minutes.
42
E.F.-U.K.
Cyril Carr with his semi
scale 60” span BEDE 5.
The plane is powered by
an Ultra 930/6 running on
8 cells and turning an
Aeronaut 9½”x5” folding
propeller.
The plane is aerobatic and
very slippery and typically
flies for 6 minutes on its
2000 Sanyo NiCds.
With that depth of
fuselage knife edge flight
ought to be one of its
specialities.
Mike Sayer of the Coventry club with his 60” span Puppeteer which he built in 3
months from the Flair kit. With its 10 sq. ft. of wing area this 10 lb model is lightly
loaded and flies slowly and gracefully. Power is provided by a geared Aveox 1412/3Y
turning a 15”x8” prop on 24 cells. Flight times are usually of more than 8 minutes.
E.F.-U.K.
43
Mike Payne’s other Dragonfly this time a scale model of the De Havilland one. The
model weighs only 4 lbs and is powered by 2 direct drive Graupner 600 Eco motors fed
in parallel from 8 cells.
A few additional bits added by the Editor.
This a Lambert Monocoupe 90 (Park Air College Inc.) by Eric Mansfield. He has built
it with an extra bay in each wing to increase the wing area. This is not easily noticeable
& improves flying performance.
44
E.F.-U.K.
An extremely nice DC-3 Dakota in the Royal Aircraft Establishment livery.
Unfortunately, the other information was misplaced.
A number of traders normal attend on the Sunday, with the odds & sods that most
people are after. Shown in the foreground is Phoenix Model Products, with Fanfare and
other traders in the background.
E.F.-U.K.
45
A Haggle of Hackers
by Bob Smith
Sorry about the title but there seems to be a collective noun for almost everything
these days so I thought I would invent one just for this occasion. This report
stems from one of those offers one can’t refuse as they say. Several weeks back
John Brinkler, who is Assistant Editor of EFUK, asked me if I would be interested
in doing some tests on some Hacker motors which he owned but was not currently
using. I said yes please, and he produced two motors and a controller. Since I
already had a couple of my own motors and controllers, this gave me the
opportunity to test a series of motors from the same manufacturer and I thought
this would be of interest to our readers.
Introduction
If you are familiar with the Hacker range of aircraft motors you will know that
Rainer Hacker produces brushless sensorless motors in three basic groups, the
B20, the B40, and the B50 series. Each series is available with either long or
short cases and with or without gearboxes. The really unusual aspect of this
range of motors is the availability of different winds. The B50 range is produced
with winds from 4 to 26 (in all intermediate values), the B40 from 4 to 21, and
the B20 in 22,26,31.and 40 winds for the short case motor, and 12,15,18 and 26
for the long case.
You can obtain all of the technical dimensions etc. either from the original Hacker
website at www.hacker-motor.com or from the UK importer’s site (Gordon
Tarling) at http://homepage.ntlworld.com/gordon.tarling/index2.htm. Hacker does
not produce a range of speed controllers for these motors but he does recommend
the Schulze Future range and these are what I have used . They could be driven
by any of the other sensorless controllers available providing the parameters are
matched.
You will see from the photographs the combination of units which I was able to
include. These were an HBR 50 short case 15 wind with a 3.7 to 1 gearbox, an
HBR 40 long case 15 wind with a 4.4 to 1 gearbox, an HBR 40 short case 13 wind
with a 4.4 to 1 gearbox, and finally the tiny HBR 20 long case 26 wind with a 4 to
1 gearbox. The controllers were a Schulze Future 58bo, a Schulze Future 45be,
and a Schulze Future 18be. The tests were all static tests of the motors and
controllers on my standard test bench using appropriately sized packs of Sanyo
RC 2000s and taking current readings via an Astro Whattmeter. I have found in
the past that brushless motors are best driven via a controller rather than by
varying voltage so I simply used a receiver and transmitter link to vary the power
46
E.F.-U.K.
The four motors for comparison
The graphs were plotted from a low start point rather than zero thrust but in all
cases the upper end point represents full throttle operation. The two smaller
controllers are BEC but the 58bo is not and needed a receiver battery.
Propellers were chosen as typical of the sizes which might be used with gearboxes
and the cell counts were changed to suit the power loading. The results were all
plotted as graphs of current against static thrust. The B50 was one of the motors
loaned to me by John & he had indicated that he hoped to use it in an aerobatic
model. I therefore tested it with fixed propellers but the others were all folding.
The three Schulze controllers available for the tests
E.F.-U.K.
47
There is an interesting point linked to the B50 application and you will see in
photograph below that the motor is provided with a slip-on heat sink. In most
applications we use high powered motors in fairly short bursts of power and
with brushless motors we do not expect the motor to overheat. In an aerobatic
model however, the motor is run continuously at varying throttle throughout
the flight and the provision of the heat sink may be a wise precaution. This
would also apply to a large scale model.
The B50 complete with heatsink
Results and Graphs
I have given graphs for each of the motors but I have combined those for the two
B40 motors. I will comment on each graph in turn but leave you to reach your
own overall conclusions.
John originally expected the B50 motor to pull 40 amps at full throttle on the
APC 12” x 8” but the tests indicated only 30 amps. This would leave him with
the option of propping up (the 13” x 8” increases the current to 38 amps and
gives 10% more thrust) or he could increase the cell count to say 14 cells. In any
case this level of fine tuning is best carried out after the model has been flown
and the basic performance parameters established.
48
E.F.-U.K.
In the case of the two B40 motors the graphs give an indication of the very different
performance which two motors within the series can give. The 13S was chosen
with an electroslot model in mind, hence the use of 7 cells. The 15L is clearly
under utilised on 7 cells and so this motor was re-tested on 12 cells.
E.F.-U.K.
49
Under these conditions the motor is now showing how much power it is capable
of producing. Of course the load on 7 cells could have been increased by moving
to a much larger prop but it would have needed quite a diameter to get up to the
30 amp range.
The two Hacker B40s showing the different case length
50
E.F.-U.K.
The B20 was purchased for a duration model and intended to run on a small
propeller at low current. It is, in fact, ideally suited to this and the graph shows
the 9” x 4” RASA pulling only 3.5 amps at full throttle. Even when propped up
to the 11” x 8” the current only rises to 6amps.
Of course the motor is capable of working much harder but with the 4 to 1 gearbox
prop sizes should probably not be too large. The Schulze Future 18be controller
is rated for 6 to 10 cells so I repeated the tests with 10 cells and this increased the
current draw 10 amps on the 11” x 8”. Even so, the logic of using such a small
motor which is relatively expensive needs to carefully considered.
There are not many situations which justify such expense on what is a low power
motor. It is of course, very small and light, and like all brushless motors it is very
efficient, but I do feel that possible applications are limited.
E.F.-U.K.
51
PARK FLYING- A WHOLE NEW
WAY TO START THE DAY
by Brian Rawnsley
Having seen many adverts for “indoor / park-fly” type models I was tempted to
jump in and try this new mode of flight. Having not had the opportunity to see
one fly, in my minds eye I pictured a somewhat underpowered model, able to
stagger around at head height for a couple of minutes before expiring to the floor
and breaking its delicate little wings. Was I in for a surprise!
Jumping in with both feet, I ordered a GWS Pico-Stick, which looked like a good
“entry level” choice of kit. Additional items I purchased at the same time were a
Pico RX, 2 Pico servos and speed controller (all GWS), and a 250 mAh 7-cell
NiCd battery pack.
The Pico-Stick came as a complete kit with all necessary hardware- wheels, horns,
pushrods, even glue. It seemed good value at around £20 including the “deluxe”
motor, gearbox and propeller.
The GWS Pico-Stick
The Pico-Stick went together in a couple of evenings. The motor, plastic wing
mounts, servo tray, battery holder and pushrod guide all “slide fit” onto the square
“stick” fuselage. The only “mystery item” not covered in the instructions was
how to hinge the rudder and elevator. I accomplished this using clear vinyl tape
cut as a strip from the edge of the supplied “Iron Cross” transfer sheet. I left off
52
E.F.-U.K.
the “Iron Cross” transfers themselves, being concerned that they would add
unnecessary weight. I think the model looks pretty enough without them.
When complete, the Pico-Stick looks a bit like an overgrown Sleek-Streak. The
all-up weight is 190g (about 7 oz). This gives a wing loading of just 4 oz / sq. ft.
The first flight took place in a late summer evening. I walked over to my local
park with the model disassembled in a carrier bag. The takeoff was run-off-ground
from the cricket pitch. The Pico-Stick was airborne in a few yards, with little
tendency to swing its tail.
The first pleasant surprise was the power to weight ratio. The model has a very
positive rate of climb, and I continued to about 300ft altitude in a couple of
minutes. Later in the flight, another pleasant surprise, the very smooth and
precise motor speed control, allowing good height control during descent,
approach and landing.
I have flown the Pico-Stick over many sessions now, outdoors. My favourite
battery is an “Overlander” supplied 300mAh 7-cell Nickel Metal Hydride pack.
Another pleasant surprise, this pack gives a flight duration in still air of between
15 & 22 minutes! Not bad for a “sport” configuration model with undercarriage.
A close-up of the motor, gearbox, battery & RC installation.
E.F.-U.K.
53
To fly the Pico-Stick outdoors, I need calm weather, so I have found it really only
feasible to fly in the early morning or late evening, when the air is still.
What I do is watch the weather forecast, and when high pressure and calm weather
comes along I throw the Pico-Stick in the car, and fly it at a local park which I
pass on the way to work, arriving at about 8.00am. I use the cricket pitch as a
“strip” for takeoffs, landings and countless “touch-and-go’s”.
How about battery management? Well, for flying sessions on the way to work, I
have to be quick. Field charging is not an option, so I slow-charge the packs
overnight and arrive at the field with three fully charged packs in my pocket.
To assemble the Pico-Stick for flight, the wings “plug in” to a fuselage mount,
leaving a one-inch air-gap between the wings at the root. This must be highly
inefficient drag-wise, effectively giving twice the “tip-losses” of a normal wing.
Prior to flight, I always seal this gap with a couple of pieces of sellotape applied
“long ways”. This also serves as a positive means of attaching the wings, which
otherwise rely on the interference fit of the wing plug and sockets, which are
becoming less positive with age.
The Pico-Stick in it's element
54
E.F.-U.K.
I have not yet flown the Pico-Stick indoors, but find that by turning sharply
after takeoff and flying oblong circuits, I can keep it within a “box” contained by
the mown cricket pitch- probably about 30 yards by 20 yards. My only “gripe”
about the manoeuvrability is that rudder turns are not so positive during the
glide. I think a bit more dihedral would cure this.
Park obstructions such as football posts and trees are not really a problem due
to the manoeuvrability and its angle of climb. Flying high is sometimes preferable,
as low flying over parks tends to attract the attention of passing dogs!
So what next? Maybe sometime I will purchase a second kit for spare parts. I
have had a few “rough” landings without yet breaking anything, though I expect
breakages or “hangar rash” will set in eventually due to the high usage of the
model. I would like to fly in and out of a tennis court. I think this would be an
interesting “confined space” challenge, to build up my confidence to maybe try
indoor flight this winter.
So how do I now feel about “park flying?” Well it is certainly practical and fun.
Though limited to calm days, it opens up the possibility of flying on work days
instead of just weekends. I have had more “stick time” with this model than any
of my others this summer. I also like the peace and freshness of flying in the still
early-morning air. It’s a whole new way to start the day!
If you have any queries or comments, you can contact Brian via email at
[email protected]
A very close fly-by
E.F.-U.K.
55
ELECTROSLOT LEAGUE AT
THE FESTIVAL OF FLIGHT,
MIDDLE WALLOP
by John Brinkler
The Electroslot competition took place on the Saturday of the 2 day Festival of
Flight (23rd June 2001) in sunny conditions but with a steady 10 to 15 mph wind.
The flight line for the competition was some 500 metres from the fun flying and
separate frequencies were reserved for the competitors so that fun flying could
continue uninterrupted while the 5 rounds of each of the 2 competitions took
place.
I had my own agenda for wanting to observe the competition because I am
contemplating joining in next year if I manage to learn to fly my gliders properly
for the whole slot and to land within the landing area - like what the experts
do. It looked as if I would have much to learn…..
Firstly a brief resume of the main rules for the 2 competition classes:
ELECTROSLOT (E-SLOT)
5 rounds will be flown and charging is not permitted between rounds.
Slot duration is 12 minutes, which includes a maximum motor run of 1 minute.
Power source is limited to 7 cells.
Any type of motor is permitted.
There is a variable bonus for landing within the 10 m radius landing circle.
ELECTROSLOT 400 (E-400)
5 rounds will be flown, but charging is permitted between rounds.
Slot duration is 12 minutes which includes a maximum motor run of 1.5 minutes.
Power source is limited to 7 NiCd cells.
The motor type is restricted to 400 type (Mabuchi RS380) motors.
There is a variable bonus for landing within the 10m radius landing circle.
Now photographic and reporting duties (!) did not permit me to cover all the
rounds of the competitions so I can only report on the action and flying I was
privileged to see so if I missed the best bits the pilots can fill me in next time! The
easiest way to tell the story is I think to show you the photographs I took and to
put the comments round them and then to summarise the action at the end.
56
E.F.-U.K.
E-SLOT
The launch of the 3rd round of the E-Slot competition. Norman Childs and his Dog E2
glider in the foreground with Stan Rose and Ron Barns away from him.
Stan Rose from Newark with his FVK Electron. Model is of 2.5m span, powered by an
Aveox 1409/2Y turning a Graupner 15”x9.5” folding prop through a Kruse 3.05:1
gearbox. Power source is a 7-cell pack of Sanyo 3000 C size NiCds which weigh
E.F.-U.K.
57
Norman Childs from Thames Valley silent flyers with his own design Dog E2. The plane
is 2.7m span, has a built up wing with carbon tube leading edge. The wing section is the
fashionable MH32 with a single airbrake. Powered by a Purple Bull wet mag 540
through a Ripmax 4:1 gearbox, Norman uses Sanyo 2400 NiCds as his power source.
Bob Smith and his adapted 2.1m E-Slot model. Wing is from a West London Models
1.8m span Highlight and has a 300mm centre extension. The wing section is S4083
which is a quite fast flying undercambered section with a tendency to tuck under in a
dive if up elevator is not applied in time. The fuselage is that from an unknown Hobby
Model glider that Bob picked up from an exhibition in Germany. Power comes from a
Kontronik brushless 480/33 fitted with a Maxon 4.3:1 Planetary gearbox and driving a
16”x10” Aeronaut prop. Bob uses 7 Panasonic 3000 NiMH cells, which weigh 440g.
58
E.F.-U.K.
The servo installation in the tail end of the fuselage of Bob Smith’s E-Slot model –
eliminates long servo linkages and gives positive control of rudder/elevator.
Bob Smith’s E-Slot model achieving a spot landing. The model has no air brakes so
relies on the skill of the pilot to stop it in the landing area by using a wing tip as a
ground brake.
E.F.-U.K.
59
Each competitor had a timekeeper equipped with 2 or 3 stopwatches. This timekeeper
had 3 stopwatches – the 1st shows remaining slot time, the 2nd shows motor run time used
& the 3rd the flight time. Nimble dexterity is required to operate all 3 simultaneously at
the launch. The competitor calls out the start & stop points of his motor runs.
2 or 3 climbs to height followed by a glide seemed to use up the 1 minute’s power.
It was noticeable that most competitors could not fly out the full slot, probably
because there was not much thermal activity. It was also noticeable that those
competitors who had been flying gliders for years were more successful in finding
what thermal activity there was & therefore achieving longer flight times.
Dave Perrett’s 2.25m span Silent Dream from FVK models. The model has flaperons for
roll control & braked landing. Power is from a Kontronik 500W brushless geared power
system turning a Graupner 14”x9½” CAM folding prop. Dave uses 7 Panasonic NiMH.
60
E.F.-U.K.
E-400
Dave Chinery’s Simply The Best from FVK models.
The construction of this model ( which I think is built in the Ukraine) has to be
seen to be believed – it owes much to free flight developments and technology.
The fuselage is an epoxy glass cloth and Kevlar moulding, the wings are of built
up construction using a Kevlar D-box and carbon and Kevlar reinforced spar.
The ribs are balsa with carbon cappings and the trailing edge is a carbon strip.
These wings are incredibly stiff and light and use the S4083 undercambered and
thin (8%) wing section. Typical weight of a 1.5m span model as supplied by FVK
is around 180/190grams and in flying condition for use in E-400 is between 500g
and 570g. A light model climbs faster on the limited power available in this class
and will also glide longer provided it can cope with the wind. These models do
not like a wind speed much over 12/15mph.
Dave’s own model uses the 1.5m polyhedral 3 part wing – there is also available
an 1.8m wing in either polyhedral form or straight centre section and single
dihedral outer wing sections. Power is from a 6v Speed 400 turning a RASA
12”x13” carbon prop through a Cosmotech 4.5:1 gearbox. 7 Sanyo 500AR NiCd
cells provide the power source.
Bob Smith and Dave Perrett also used 1.5m span Simply the Best models. Dave
used the same power set up as Dave Chinery but Bob used a Maxon 4.4:1 gearbox.
The Maxon gearbox seems to be more efficient than the Cosmotech but there is
a weight penalty to pay for the Maxon gearbox is, at nearly 50g some 25g heavier
than the Cosmotech. Climb quicker and higher on the Maxon or glide longer on
E.F.-U.K.
61
the Cosmotech – that is the choice. Have a look also at the RASA 12”x13” prop if
you get the chance. It is moulded from carbon & has a thin undercambered blade
section & typically at launch will be turning at 3300 rpm. The prop complete
with centre & spinner weighs around 18g. The motor typically draws 10A static
so there is more than adequate power available in the 500 mAh cells for the 1½
minute run time (Remember cells are recharged between rounds if wanted).
Norman Child’s unashamedly low tech own design E-400 model Dog E1.
It has a span of 2m and uses an E193 section. The fuselage is built from 1½ sheets of
3mm balsa. Its AUW is approximately 700g, i.e. more than 150g heavier than the high
tech Simply the Best models it was competing against.
Power is supplied by a 6v Speed 400 turning an Aeronaut 12”x”8 prop through a
Jamara 3:1 open gearbox (shown inset). Note the rubber band round the prop blades to
ensure the blades close properly when gliding.
62
E.F.-U.K.
Norman and Dave Chinery were unfortunate to collide (the gliders that is) on
their landing approach Dave’s Simply the best crashed into the long grass with a
crushed leading edge at the collision point but Norman’s Dog E1 continued on
to land unscathed.
And now the results:
ELECTROSLOT
1st
2nd
3rd
Bob Smith
Dave Perrett
Norman Childs
ELECTROSLOT 400
1st
2nd
3rd
Norman Childs
Dave Perrett
Bob Smith
Well the contest was fascinating with the same competitors reversing their
positions in the two classes. I thought you would need brakes in E-Slot to land
precisely and the winner proved they were unnecessary and I thought you would
need to have a light high tech plane to succeed in E-400 and again the winner
proved you didn’t.
So what did I learn:
Practise at gliding and landing improves your chances;
The first shall be last and the last shall be first and the second shall maintain
his position:
A wing tip makes a good brake in order to achieve maximum landing points:
If you can’t beat’em knock’em out of the air.
See you all next year.
E.F.-U.K.
63
NEW TO ELECTRIC FLIGHT?
START HERE . . . . .
You may be taking up Electric Flight for the first time, you may be converting from
another discipline. Whatever your situation, help and advice is available.
BEFA has prepared an information sheet which details further sources of information
which you may find useful when just joining the hobby. To receive a copy, please send a
Stamped Addressed Envelope (SAE) to Robert Mahoney, address on page 4.
BEGINNER'S GUIDE
A Beginner’s Guide to Electric Flight is available, which explains many of the 'Mysteries'
of Electrics’ and will, hopefully, set you off on the right foot. Please send £3.00, per copy
required, to The Editor of EF-UK at the address on page 4. Please add £1.00 extra for
overseas postage and remit in Sterling, cheques payable to BEFA.
TECHNICAL HELP SERVICE
The Technical help service is now available again for the use of all members. We regret
that no telephone service is available, but all questions in writing (or e-mail) will be
answered by our new Technical Liaison Officer. Please refer your queries to our Technical
Liaison Officer, to the postal or email address on page 4. Please ensure that you include
an SAE for a reply.
CONNECTIONS SERVICE
Requests are frequently received from members who wish to be put in contact with
other members living in the same area. The easiest method of doing this is to place a
free 'wanted' advert in the classified section of this magazine. Alternatively, a request
may be made IN WRITING to the Membership Secretary who is allowed to divulge such
information to members ONLY. Please supply as much information about your location
as possible and please remember to include an SAE for your reply.
B.E.F.A. MEMBERSHIP
Membership of the Association is open to all members of the BMFA. Those who are not
members of our national controlling body may only subscribe to EF-UK with no other
benefits of membership. Overseas members are very welcome and will be classed as full
members if they belong to their own national controlling body.
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
7B.E.F.A. website at http://www.befa.org.uk, where you will find all the membership
application form & information you should require.
64
E.F.-U.K.
FOR SALE
Member's Sales & Wants
For Sale by Pete Barrow, a Kruse Synchro 2500 Duo gearbox. Any reasonable
price considered. Contact Pete at [email protected] or on telephone him
on 07946-657385.
For Sale by Gordon Tarling, an X-Models 'Little Star' glider. Complete with
AP29BB motor with Kruse 'Introgear' gearbox, Aeronaut 10 x 6 Folding Propeller,
Micro-Star 20BEC Motor controller, Futaba 3 channel receiver, 2 x JR341 servos
and 7 x 1000SCR battery pack. Little flown and all in excellent condition. Readyto-fly at £220 o.n.o. Contact Gordon Tarling - [email protected]
For Sale by Stan Rose. Contact him on e-mail [email protected] or
telephone 01636 525029.
· FVK "Silent Dream" electric glider, new & never flown, complete with 4
Graupner wing servos, total cost £260 accept £195, buyer collects.
· Kruse Intro-Gear 750 Gearbox, 3.05:1 ratio, rated up to 800 Watts, brand
new and unopened cost £65 accept £55.
For Sale by Neil Stainton, telephone him on 01926 314011 or e-mail Neil at
[email protected]
· Aveox 1406/2Y brushless motor, new in box, £75.
· Aveox L160C 100A competition brushless motor controller, £110.
· Velkom Whistler 48" span all moulded hot-liner ARTF, £79
· Velkom 2020 Neodym S400 size motor, £45
· Hitec CG317 peak detect charger, 7 cell, 3.4A, £10
· Toytronix Balloon Craft 2000 blimp, including 3 channel IR control, £48
· Sanyo 120mAh cells, £1.50 each or 6 for £8.00.
For Sale - Electric beginners outfit with brand new electro tutor kit, only rear
wing & fin built, complete with electric power train (motor, gearbox, batteries &
speed controller). Brand new unused JR XP652 computer radio set, which is
fully NiCd and comlpete with 4 servos. CSM v9.1 RC aeroplane & helicopter
simulator for PC with interface cable to suit the JR radio set. A truly complete
beginners outfit, all superb condition, genuine reason for sale. Worth around
£425, all brand new, price :- £250. Contact Tony Bryan at email address
[email protected] or telephone on 01455 446701 and leave a message
if unavailable.
E.F.-U.K.
65
For Sale by Eric Cable, telephone 01935-478974 (Yeovil)
· GRAUPNER 'SILENTIUS' 86" Span glider with Futaba servos and
Graupner spoilers, operated by centre servo in 3-piece wing. Model is
finished, covered but unflown - £70.
· Suitable Motor, 3:1 M.A. gearbox & speed controller, all as new - £22 ea.
· MG Gearboxes in ratios 3.23:1 and 5.11:1 as new, unflown - £22 ea.
· Graupner Speed 600 motor & Aeronaut 2.33:1 gearbox, little used - £25
· Johnson 600 motor, unused - £8.
Wanted by Steve Foster, an electric ducted fan, motor and speed controller.
Preferably around a 90mm fan unit. E-mail him at [email protected], or
telephone 01384-271155 home or 07966-144140 mobile.
Wanted - a hand-launch glider model (or just wing), doesn't have to be in perfect
condition, preferably 1.8m span and a Simply the Best, Highlight or Carbon Dlite. Call Neil Stainton on 01926 314011 or e-mail [email protected]
Wanted - a 4 channel radio gear with servos, batteries, charger etc. Any
information ring 01825 872752 East Sussex and ask for Chris.
Wanted by the Editor.
• Articles
• Photographs, and
• New items of interest for inclusion in this magazine.
• We are interested in anything related to Electric Flight.
• All photographs submitted will be returned after publication.
• Please send any information to the Editor, address on page 4.
Requests for inclusion on these pages can be made in writing, or by phone, to the
Editor (details on page 4). Alternatively, on-line requests can be submitted via
the For Sale & Wanted page on the BEFA website (www.befa.org.uk). Requests
submitted will be included in both lists unless instructed otherwise.
66
E.F.-U.K.
ELECTRIC FLIGHT CALENDAR
If you would like details of your event to appear in these pages, please send full
details directly to Jan Bassett at the address on page 4.
Dates, times and, even, locations of events can all change at the last minute. You
are strongly advised to check details with the given contacts before setting out
on a long journey to any 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 BEFA event to fly. Please check with the organisers of the other
events for their requirements.
October 2001
From 5th
Indoor Flying resumes at the Westlands Sports Hall, Winterstoke
Road, Weston-Super-Mare with meetings every Friday from
October to December. Flying from 8pm to 10pm. For further
information contact Dr. Allan Levi on telephone 01633 843000 or
email [email protected]
November 2001
11th
BEFA Technical Workshop at the Royal Centre, Leamington Spa.
This will include the usual technical presentations, traders fair and
bring & buy stall. Unfortunately, the details of the talks is not
available at this time.
Entrance is £6 for advance tickets or £8 on the door.
Advance tickets can only be purchased from:
Gordon Tarling
87 Cowley Mill Road
Uxbridge
Middx
UB8 2QD.
Please make cheques payable to BEFA and include an SAE
for return of the ticket(s).
It is intended to get transcripts of the presentations made this year.
They can then be published in EF-UK for reference, and for those
who couldn’t make it on the day.
E.F.-U.K.
67
Next Issue
Hopefully in the next issue we should have the following items:
• Details of the BMFA ‘A’ and ‘B’ thermal soaring certificates.
• A hovercraft design for the winter.
• A high current measurement technique.
• A report on the Leamington Spa fly-in.
• A report on indoor flying at Weston-Super-Mare.
• A mini report from the Bath SpaRCS electric fly-in.
• DIY Brushless Motors - The LRK way.
• A review of the Ron Fikes designed FlexiFlyer.
• BEFA electroslot and E400 final results.
JLR RATPAC
Mail Order Model Supply Advert as last issue
the universal, geared speed reducer for electric motors
SPECIFICATION:
MOTOR OPTIONS:
STANDARD RATIOS:
WEIGHT:
POWER:
MOUNTING:
SPEED 600/500/400 and 480 RACE, singly or paired
3.2:1, 4:1, 4.8:1
54g
Tested up to 350 Watts
Mounting holes included in the gearbox flange
RATPAC GEARBOX is available in any standard ratio (3.2:1 4:1 4.8:1), for single or twin Speed 600/
500/400 or 480 RACE motors. Please quote ratio and motor with order.
Single motor RATPAC / S - £30.50. Twin motors RATPAC / T - £33.25. P & P on gearboxes - £1.00
WISKERR - 1910’s period monoplane. For Ratpac 3.2:1, S600, 7 - 10 cells. 59” span.
BUILDING PLAN - £6.00 Post & Packing - £1.50 (rolled plan) £0.75 (folded plan)
PIPER CUB - the modellers’ favourite. For Ratpac 3.2:1, S400 6v, 7 - 10 cells, 54” span.
BUILDING PLAN - £6.00 Post & Packing - £1.50 (rolled plan) £0.75 (folded plan)
(Some Ratpac/S pre-production gearboxes available for £19.00 + £1.00 p&p)
Your Special Requirements Catered For
For Further Details, please send an S.A.E. to
Robert Ireland (JLR Developments) 39 Highfields, Towcester, Northants. NN12 6EY
68
E.F.-U.K.
MAIL ORDER MODEL SUPPLY
GOLD PLUGS Ideal for Speed 400/600
2mm plug 75p; cuts into two giving one plug/socket
2mm solder socket 43p. 2mm plug and a 2mm socket £1.15
Lightweight 2mm plug and socket 55p; Max 15A motor current draw
Spares. 2mm light plug 40p. 2mm light socket 20p
Pack of red/black shrink: 3.2mm or 4.8mm 50p
GOLD PLUGS 600 or larger motor
4mm plug 90p; cuts into plug/socket. Very low resistance
4mm hollow plug and a separate 4mm solder socket £1.15
Spares. 4mm hollow plug 85p. 4mm solder socket 43p
Lightweight 4mm plug and socket 75p; Max motor current 35A suggested
Spares. 4mm light plug 55p. 4mm light socket 25p
Pack of red/black shrink: 6.4mm £1.25: 4.8mm 75p
Providing that you bear in mind the suggested amp ratings all the 2mm and 4mm plugs
are interchangeable. All fit any of the same size.
EXTRA FLEXIBLE WIRE. 0.5mm2, 129 strands, Max 10A, 35p/metre
Red or Black or White. Park Flyers etc. or servo extensions.
EXTRA FLEXIBLE WIRE
Supplied in packs of 1 metre of red and 1 metre of black, i.e. 2 metres of wire
0.75mm2, 196 strands; ideal for weight saving, Max 15A, £1.00/pack
1.00mm2, 258 strands; ideal for weight saving for speed 400, Max 19A, £1.40/pack
1.50mm2, 378 strands; ideal for speed 400, £2.00/pack
4mm2, 1036 strands; £3.50/pack
SILICONE INSULATED WIRE. Pack of 1 metre of red and 1 metre of black
1.5mm2, 378 strands. £2.50
2.5mm2, 651 strands. £3.00
All wire can be cut off the roll, in longer lengths if required.
CELL HEATSHRINK metre lengths
25mm 50p; suits single AAA or AA cells or any same size
48mm 75p; suits single sub C cells/sticks or packs of dumpy 600
65mm 85p; suits 1700 or 2000 packs, also RC oblong sticks etc.
94mm 95p; suits double deck packs (1700 etc.)
All sizes layflat width, supplied in clear. 48mm available in opaque blue also.
WIRE HEATSHRINK metre lengths
1.6mm 50p; 2.4mm 60p; 9.5mm £1.00. Black only
3.2mm 75p; 4.8mm 80p; 6.4mm 95p. All in red or black.
ALL ORDERS PLUS POSTAGE: 60p UK; £1.10 Europe; £1.70 World
M. E. DONKIN, 37 WYDALE ROAD, OSBALDWICK, YORK, YO10 3PG
Tel/Fax 01904 414738. Mobile 0771 202 8329.
E-mail: [email protected] or [email protected]
All messages - an attempt will be made to contact you. (I work shifts)
Computer faxes must send start signal before my fax will respond!
E.F.-U.K.
69
B.E.F.A. Sales
BEFA Round, Coloured Rub-down Decals - 50p each
'BEFA 2000' Millennium Decals - £1.00 each
Back Issues of EF-UK - No's 38, 39, 40, 41, 43, 44, 47, 48, 49, 51, 52, 53, 54, 55,
56, 57, 58, 59, 60, 62, 63, 64 and 65 at £1.00 each (inc. P&P) for BEFA members
ONLY. Non-members, £2.00 per copy. Please Note these are the ONLY back
issues still 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:- Binders are now available to hold eight issues of Electric Flight U.K.
Produced in dark blue with gold lettering on the spine, these cost £4.50 each
including U.K. postage. Please add £1 for European postage and £2 for Worldwide
postage.
Sweat Shirts & Tee-Shirts: Stock of these is now almost all gone - please
contact Robert Mahoney regarding remaining stock, sizes and prices.
Please send all orders to Robert Mahoney at the address on page 4.
PLEASE REMIT IN STERLING ONLY,
WITH ALL CHEQUES MADE PAYABLE TO BEFA.
Advertisers Index
ANSA Products ............................................................. 8
BEFA Sales .................................................................. 70
E-Zone .............................................. Inside Front Cover
Fanfare ............................................... Inside Back Cover
JLR Developments ...................................................... 68
Mail Order Model Supply............................................ 69
Traplet ............................................. Outside Back Cover
70
E.F.-U.K.
– MAIL ORDER –
SPORTS ELECTRIC FLIGHT
FANS AND GEARBOXES
GEARBOXES
FANS
Morley ‘Jet Elec’ Fan ............................... £15.00
Adaptors for
480 & 410 motors ..................................... £3.00
WeMoTec MiniFan 480 .......................... £28.00
MidiFan for 540’s, 600’s 930’s ................ £38.00
Master Airscrew 2.5, 3, 3.5:1 ..................
Superbox ................................................
TAB Inline 2.65 540/600’s ......................
TAB Inline 2.08 & 3.05 480’s ..............
TAB Inline 2.1 700’s ..............................
Mini Olympus ....... £8.00 Olympus .......
MOTORS
WEP Turbo 10 ....................................... £55.00
Speed 500 E Race .................................. £14.00
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 .............................................. £22.00
Neodym ..................................... £38.00
RE 380 / Rocket 400 ................................ £4.50
Speed 480 PB ... £14.00 BB ................ £19.00
Pro 400 ................ £5.00 Pro 480 .......... £6.00
£16.00
£40.00
£40.00
£40.00
£50.00
£12.00
MOTORS
MFA 2.5:1 N.I.L. with 540 .......................
Speed 400 FG3 ......................................
SpeedGear 400 4:1 Inline .......................
SpeedGear 480 3.45:1 ............................
SpeedGear 500 2.8:1 ..............................
SpeedGear 600 2.8:1 ..............................
SpeedGear 700 2.7:1 9.6v ......................
SpeedGear 700 Neo ...............................
Mini-Olympus & RE380 ..........................
Olympus & 540 .......................................
Robbe 410/35/45 ....................................
£21.00
£17.00
£32.00
£46.00
£40.00
£41.00
£60.00
£78.00
£12.00
£19.00
£36.00
MAXCIM BRUSHLESS
PROPS
Max Neo 13Y 1430 rpm/v ...................... £160.00
Max Neo 13D 2470 rpm/v ..................... £160.00
21 Cell Controller .................................. £140.00
25 Cell Controller .................................. £180.00
Superbox 1.6 to 4.28:1 ........................... £35.00
Monsterbox 4 to 6.8:1 ............................ £50.00
Motor Mount ........................................... £12.00
CHARGERS
Speed 1 Pulse / Pk
Det 4-8 cells ........................................... £25.00
Speed Ex Digital
as above with discharge .......................... £55.00
Simprop 25 cell ..................................... £100.00
M.A. Folding
12x8 ................ £12.50
15x12 .............. £13.50
M.A. Wood Electric
10x6/10x8 .......... £3.75
11x7/11x9 .......... £4.00
12x8/12x10 ........ £4.25
13x8/13x10 ........ £4.50
Carbon Folders
7x4 .................... £6.00
8x4.5 ................. £6.00
11x8 .................. £9.00
Slimprops 8x4, 8x6, 9x5, 9x6 ................. £3.50
Selection of Graupner & Aeronaut
folding & fixed props.
Wheels, Wire, Servos, Fuses, Caps,
Powerpole, 4mm & 2mm gold conns.
FANFARE • 18 HILLSIDE ROAD • TANKERTON • WHITSTABLE • KENT • CT5 3EX
‘Sports Electric’ Helpline - Phone / Fax: (01227) 771331 - E-mail: [email protected]