Booklet Format - British Electric Flight Association - ef

ELECTRIC FLIGHT U.K.
ISSUE No. 89 SUMMER 2007
THE MA
GAZINE OF THE
MAG
BRITISH ELECTRIC
FLIGHT ASSOCIA
TION
ASSOCIATION
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1
– MAIL ORDER –
SPORTS ELECTRIC FLIGHT
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WeMoTec Midi-Fan (540/ 600/930) ....... £38.00
MOTORS
MPJet Brushless motors; 9 motors; outrunners,
inrunners & geared; 280 to 700 .... £40.00 to £58.00
WEP Turbo 10 ....................................... £55.00
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Speed 600 8.4v BB SP .......................... £17.00
Speed 600 8.4v Race ............................ £22.00
RE 380 / Rocket 400 ................................ £5.00
Speed 480 BB ........................................ £21.00
Pro 400 .................................................... £5.00
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Pro 480 HS BB ......................................... £8.00
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MOTORS / GEARBOXES
Speed 400 FG3 ..................................... £17.00
SpeedGear 400 4:1 Inline ...................... £38.00
SpeedGear 480 3.45:1 .......................... £55.00
SpeedGear 600 2.8:1 ............................ £51.50
SpeedGear 700 2.7:1 9.6v .................... £70.00
SpeedGear 700 Neo .............................. £92.00
Mini-Olympus & RE380 .......................... £12.00
Olympus & 540 ...................................... £19.00
Jamara 600 2.9:1 ................................... £24.00
Jamara 650 2.9:1 ................................... £26.00
PROPS
M.A. Folding
M.A. Wood Electric
CHARGERS
Speed 1 Pulse / Pk
Det 4-8 cells ........................................... £27.00
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Maxu 35D, 21 Cell Controller ............... £140.00
Maxu 35C, 25 Cell Controller ............... £180.00
Superbox 1.6 to 4.28:1 ......................... £50.00
Monsterbox 4 to 6.8:1 .......................... £60.00
Motor Mount ........................................... £12.00
Master Airscrew - 2.5, 3, 3.5:1 ............................. £16.00
MP Jet Planetary - 3.33 & 3.8:1 - 400 / Pro 480 ...... £28.00
MP Jet Planetary - 3.33 & 3.8:1 - Speed 480 ........ £28.00
MP Jet Planetary - 3.33 & 3.8:1 - 540 / 600 ............ £28.00
MP Jet Plastic BB - 4 & 5:1 - 280 / 300 ...................... £8.00
MP Jet Plastic BB - 3, 3.5 & 4:1 - 400 / Pro 480 ......... £8.00
MP Jet Plastic BB - 2.33, 3.5 & 4:1 - Speed 480 ..... £10.00
MP Jet Plastic BB - 1.75, 2.33 & 2.8:1 - 540 / 600 .. £15.00
Mini Olympus ............................................ £8.00
Olympus ................................................. £12.00
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Regular columns and HOT NEW PRODUCT reviews in all areas of RC
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7x4 .................... £6.00
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YEARS of articles archived
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2
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63
B.E.F.A. Sales
BEFA Round, Coloured Rub-down Decals - Ultra-thin & light - 50p each
EF-UK Back Issues - Issues 71 to 73 and 75 to 85 are available to BEFA members at £3.00 each,
or £5.00 each to non-members. These prices include UK P&P, overseas rates on application.
Reprints of earlier issues may be available to special order at slightly higher cost, contact the Editor
for details (see page 4).
EF-UK Index. A comprehensive index of EF-UK, from issue 28 to date, is available by sending
a £1 coin to cover copying and postage cost.
Binders:- are available to hold 8 to 12 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.
Please send all orders to The Editor of EF-UK at the address on page 4.
Sweat Shirts & Tee-Shirts: Stock of these is now almost all gone - please contact Robert Mahoney
regarding remaining stock, sizes and prices.
PLEASE REMIT IN STERLING ONLY,
WITH ALL CHEQUES MADE PAYABLE TO B.E.F.A.
Advertisers Index
BEFA Sales ....................................................................................... 60
Fanfare .................................................................. Inside Back Cover
For Sale / Wanted ............................................................................ 57
New-2-U ............................................................................................ 41
RC Groups / E-Zone .........................................Inside Front Cover
Traplet ................................................................ Outside Back Cover
EF-UK advertising rates are £25 per inside or outside cover page,
£20 per full page, £10 per half page, all per issue.
Contact the EF-UK Editor for more details (see page 4).
62
E.F.-U.K.
Electric Flight - U.K.
Issue 89 - SUMMER 2007
"To Encourage and Further all Aspects of Electric Model Flight in
the British Isles and Elsewhere" - B.E.F.A. Constitution
CONTENTS
BEFA Committee 2006/7 ......................... 4
Chairman's Chatter ................................ 5
Minutes of BEFA Committee Meeting ........ 6
The Flight of the Challenger .................. 10
Spread Spectrum ............................. 14
Three into One .................................... 20
Middle Wallop BEFA Electric Fly-in ......... 25
Member’s Planes .................................. 34
TLC from your TLO .............................. 35
Blade Helicopter ................................. 38
New-2-U ............................................. 41
Members’ Letters .................................. 50
Electric Flight Calendar ......................... 53
For Sale / Wanted ................................ 57
Wanted by the Editor ............................ 58
New to Electric Flight? Start Here ........... 59
BEFA Sales .......................................... 60
Advertisers Index ................................. 61
Cover Photo: Taken by Robert Mahoney: Neil Jarvis at the BEFA International
Electric Fly-in Weekend. Details of his plane are as follows: RD Jets El Bandito built
from kit. DS 51 Fan unit. Hacker B50 13XL motor. 9S 4000 TP. Pro Lite cells. Hacker
77 OPTO esc. AUW around 8lb. 1600W. 51A. Flight times of around 7-8 mins.
9 servos. Air retracts with time delayed nose gear door
Next Issue: The copy date for the Autumn 2007 issue is 30 August 2007 with the
magazine due for publication by 30 September 2007.
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 information in this magazine is copyright of the authors. Any request to use information
from this magazine is to be made to the editor (contact details overleaf).
All reasonable care is taken in the preparation and compilation of the magazine, but B.E.F.A. and
its committee cannot be held liable for any error or omission in the content of this magazine or
any subsequent damage or loss arising howsoever caused.
To allow proper appreciation of the photographs used, colour copies of them will be
posted on the B.E.F.A. website after publication of this magazine. If you can, check
them out at www.befa.org.uk
3
E.F.-U.K.
BEFA Committee 2006/7
Chairman
Robert Mahoney
123 Lane End Road, High Wycombe, Bucks. HP12 4HF
Email: robert@rlmahoney.co.uk
Secretary
Webmaster
South West Representative
Jan Bassett
111 Plantagenet Chase, Yeovil, Somerset BA20 2PR
Tel. 01935 472 743
Email: sec@befa.ef-uk.net or webster@befa.ef-uk.net
Treasurer
Membership Secretary
Northern Representative
Bob Smith
1 Lynwood Avenue, Tollesby, Middlesborough, Cleveland. TS5 7PD
Email: bob.smith007@ntlworld.com
EF-UK Editor
Jill Day
6 Starboard Walk, Littlehampton, West Sussex, BN17 6QL
Email: editor@befa.ef-uk.net
Events Co-ordinator
Terry Stuckey
31 Dysart Avenue, Kingston-upon-Thames, Surrey. KT2 5QZ
Email: terrystuckey@blueyonder.co.uk
Midlands Representative
Roger Winsor
14 Butler Gardens, Market Harborough, Leics. LE16 9LY
Email: Rogerwinsor7@aol.com
Welfare Officer
Southern Representative
Dave Chinery
251 Station Road, Hayes, Middx. UB3 4JD
Email: DavidDchinery@aol.com
Indoor & Free-Flight Rep.
Gordon Tarling
87 Cowley Mill Road, Uxbridge, Middx. UB8 2QD
Email: gordon.tarling@ntlworld.com
Technical Liaison Officer
Alan Bedingham
17 Highcliffe Close, Wickford, Essex. SS11 8JZ
Email: bbba18333@blueyonder.co.uk
Public Relations Officer
John Thompson
19 Park Avenue, Liversedge, West Yorks, WF15 7EQ
Tel. 01924 515 595
Email: johnty99@ntlworld.com
Safety Adviser
David Beavor
34 Chestnut Close, Brampton, Huntingdon, Cambs., PE28 4TP
Email: wbeavor@connectfree.co.uk
Please enclose an SAE with all correspondence to the committee.
4
E.F.-U.K.
New to ELECTRIC FLIGHT?
START HERE . . . . .
You may be taking up Electric Flight for the first time or 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 (S.A.E.) 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 should be made payable to BEFA.
TECHNICAL HELP SERVICE
Technical help is now available again for the use of all members. We regret that no telephone
service is available, but all questions in writing (or email) will be answered by our Technical Liaison
Officer (TLO). Please refer your queries to our TLO, to the postal or email address on page 4. If
sent by post, please ensure that you include an S.A.E. 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
S.A.E. for your reply.
B.E.F.A. MEMBERSHIP
Membership of the Association is open to all. Those who are not members of BMFA (our
national controlling body) will have a subscription to EF-UK membership with none of the other
benefits. Overseas members are very welcome and will be classed as full members if they belong to
their own national controlling body.
CONTACT
For full details, please send an S.A.E. to the Membership Secretary (address on page 4) requesting
a membership application form. Those with Internet access may visit the B.E.F.A. website at
www.befa.org.uk where you will find all the membership information you should require and a
application form.
E.F.-U.K.
61
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Chairman’s Chatter
Welcome to our first internet issue of
Electric Flight UK. For those who did not
attend the AGM this year, and
unfortunately many didn’t, it was decided
that to save money we would try a web
based magazine. This was reluctantly
agreed to after a great deal of discussion,
with particular regard to our current
financial situation. However, if you know of
any members who cannot download a PDF
file, please let me know, as I will be able to
print a few for them.
On your behalf I would like the thank Brian
Broughton and family for looking after us
over the years with respect to the printing
of our magazine, they have done a grand
job.
I was very sorry that the weather was
terrible for our Middle Wallop event. I did
ask for our normal sunny weekend but I
think we were overlooked this year. We did
however, have some flying on the Sunday,
with wind speed around 20 mph; there are
photographs elsewhere in this issue.
I was going to
award two
trophies at
Middle Wallop,
but due to the
weather, and
the long
distance of
travel, the
recipients informed me that they would not
be able to make it.
The trophies were the QFI, and the Exide
and Drydex, won by JePe and John Ranson
respectfully. A photograph of the trophys
and a keepsake tankard, which have now
been received, is also elsewhere in the
magazine.
I hope too see you all at the Technical
Workshop in November, but please note
that it will be at a new venue in Kenilworth.
Keep the watts up and safe flying
Sadly, it has not been a good two months
for flying, but regardless of this the BEFA
International Electric Fly-in Weekend held
at Middle Wallop was more of a success
than could possibly have been hoped for.
You will find some super photographs to
prove it, which begin on page 25. Well
done Robert Mahoney, for the
photographs, and for not letting the
weather and the terrorists beat you!
As always there are the regular
contributions, and this issue is no
exception. We have a very interesting
‘New-2-U section’ on page 41 and of
course the ‘TLC from your TLO’ article on
page 35. I am
sure you all
appreciate the
amount of work
and time that
goes into
preparing these
items.
And of course
the very important articles that members
take the trouble to send, they are
particularly welcome, so please keep them
coming.
No more rain dances please!
Robert Mahoney
Current Lines
6
Jill Day
E.F.-U.K.
Wanted by the Editor
any of the following (see page 4 for contact details):
•
General / Technical Articles.
•
Hints & Tips.
•
New Product notifications.
•
Product Reviews.
•
Photographs of your models.
•
Electric Flight Event Reports.
•
Any other item of interest to electric model aircraft flyers.
Please send colour Digital photos or photographic prints (6” x 4” or
bigger) to the editor. If possible, please do not send inkjet prints as too
much quality is lost during the printing and scanning process.
If you have no way to email or write the files to a CD, please contact the
Editor for other options.
Photographic prints supplied will be returned, unless specified otherwise
(as long as you give a return address).
Digital photos should be sent at the highest resolution possible, in
colour, and preferably uncompressed. Where compression is
unavoidable the camera should ideally be set to the lowest compression
possible and at the maximum resolution. Digital photographs can be
emailed to the Editor at editor@befa.ef-uk.net
Readers always like to know what equipment is fitted to models so they
know what combinations work well (or not so well). Therefore please
include as many details of the models in the photographs as possible,
but ideally at least wing span, wing area, motor(s), gearbox(es),
propeller(s) or fan(s), battery pack(s) used & the flight performance.
Where articles are produced on a word processor package, please send
an electronic copy - it make the Editors job much easier and quicker.
Ideal formats are Microsoft Word (any version), Works word processor,
WordPad or Notepad. Other formats can be accommodated, but please
contact the Editor first.
E.F.-U.K.
59
FOR SALE / WANTED
Information for members
BEFA Committee Meeting at the BMFA HQ
held on 14th April 2007
Member's Sales & Wants
Present: Robert Mahoney (RM), Bob Smith (BS), Dave Beavor (DB),
Alan Bedingham (AB), Dave Chinery (DC), Terry Stuckey (TS) &
Jan Bassett (JB).
FOR SALE
Contact Jim Horne HORNEGb@aol.com or phone 01388 819 638 Co Durham A FVK
RIVAL 2.8m span, fitted with a Kontronik 480 brushless with 5:1 gearbox, Hacker 70A ESC,
six new servos, Schulze 8 channel receiver, Carbon propeller & spinner, and comes with a
3300mAh flight battery. £450-00 or vno or swap - what have you got?
1.
APOLOGIES FOR ABSENSE
Apologies were received from Jill Day (JD)
2.
MINUTES OF THE LAST MEETING
The minutes were agreed as a true record of the meeting.
Contact Jim Horne HORNEGb@aol.com or phone 01388 819 638 WeMoTec Midi-fan
fitted with an Aveox 36/24/2 sensorless brushless motor Price £70
...and WANTED
Contact Dave Chinery: daviddchinery@aol.com or phone 0208 573 4687Dave is trying to
find a pair of William’s Brothers, 6" diameter, vintage style wheels (faired-over spokes).
Not necessarily new but must be in good condition. Fair price paid. Money waiting!
Contact Ray J Donno (Exeter): rd018b4702@blueyonder.co.uk or phone 01392 666 912
Ray is after Maxcim N32-13Y motors, Maxcim 35C-25NB controllers and Maxcim motor
mounts.
3.
MATTERS ARISING
a. Action 71.1. JB had now converted 24 issues into PDF
documents and posted them to the members area of the
website. The latest version is presented in 2 versions; the first
for viewing on the screen and the second to allow printing as a
booklet. Action complete.
b. Action 71.2. JB stated that the warning signs had not been
made yet, but would be completed before the Middle Wallop flyin. Action ongoing.
71.2 – JB
c.
Action 71.4. AB reported that he is still looking for
alternative methods of providing useful data, action ongoing.
71.4 – AB
d. Action 72.1. BS had recommended an increase of £1,
which had been rejected by the membership in favour of ceasing
the magazine and maintaining the membership as is. Action
complete.
e. Action 72.2. JB had circulated the 200W/kg again, but still
had received no additional comments, action complete. RM
stated that the rules would be sent to the BMFA for consideration
of the safety issues that have been raised. It was agreed that TS
would remain the BEFA representative for the SFTC.
f.
Action 72.3. Comments had been received on the BMFA
handbook and are to be sent to the BMFA for review.
58
E.F.-U.K.
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7
4. OFFICER’S REPORTS
a. Chairman – RM reported the sad news that Roger Bedford
had died on 29 Mar 07 after a protracted illness, his
immeasurable contribution to model aviation and especially
electric flight will be greatly missed.
b. Secretary – JB stated that the AGM minutes had been
issued and were available in the committee area of the BEFA
Website.
Treasurer & Membership Secretary – BS stated that the
c.
membership now stands at approx. 100 members and that he
had been drawing the removal of the printed magazine to those
renewing
d.
Editor – JD was unable to make the meeting.
e.
Safety Advisor – DB stated that there was nothing to report.
CASTLE HOWARD NORTH YORKSHIRE
Following the successful event last year we are pleased to announce, by
kind permission of the Hon Simon Howard, another ‘Stately Fly-In’ for
BMFA/LMA Members, organised by the BMFA Northern Area.
Saturday Sept 15th general ‘off the peg’ flying minimum ‘A’ certificate.
Sunday Sept 16th morning ‘off the peg’ again,
afternoon a Flying Display by invitation only.
Andy Symons ; 01924 400953 or 07976 548010 (reasonable hours
please) or nabmfa@ddmac.fsnet.co.uk for pre-booking. A nominal charge
will be levied. Camping available
www.castlehoward.co.uk or 01653 648444 for details
f.
Welfare Officer – DC stated there were no welfare issues
at present.
g.
Event Co-ordinator – TS had no comments to make.
h.
Technical Liaison Officer – AB stated that he had received
permission from the South African Soaring Association to reprint
an article on 2.4 GHz radio control, which should forwarded in
time for the next EF-UK.
i.
Public Relations Officer – The PRO post currently
unoccupied, however, Keith Day is considering taking on this
role.
j.
Indoor & Free Flight Representative – GT could not be at
the meeting, but there was nothing to report.
Area Representatives – The area representatives present
k.
had nothing additional to report. The possibility of having
representatives for Northern Ireland and Scotland was raised.
This was considered a good idea provided they are virtual
representatives and not required to attend the committee
meetings.
8
E.F.-U.K.
Hayes/BMFA London Area
Silent Flight Open Competition Day
Sunday September 2 2007
For full details see meeting for June 3 on page 50
Open to all BMFA members
NOT a fly-in!
RC Carrier Deck and Pico Pylon competitions
(to existing published rules)
A small charge will be made for each entry,
up to three per class per flyer.
Flyers, helpers and observers only
Entrants and Hayes Club members may sport-fly off the peg between rounds if
time allows
Photo: Robin Andrew
Traders are not expected
E.F.-U.K.
57
30 BMFA 200W/Kg eSoaring League
event at Billesdon, Leicestershire, see the
website or
Contact: Dave Perrett
Email: d.l.perrett@btinternet.com
for more information via website.
November
4 BEFA Technical Workshop 2007 at the
Spa Centre, Royal Leamington Spa,
Warks.More details to follow.
2008
February
24 BEFA Annual General Meeting 2008
5. AGM FEEDBACK
a.
The AGM proceeded fairly smoothly after the initial
concerns that the meeting might not be quorate. It was agreed
that JB should consider whether a change to the quorum
requirements should be proposed at the next AGM. 73.1 – JB
at the Spa Centre, Royal Leamington Spa,
Warks.
November
16 BEFA Technical Workshop 2008 at the
b.
It was recommended that some form of Proxy Voting be
considered, and JB agreed to look at the options and report
back to the October meeting.
73.2 – JB
Spa Centre, Royal Leamington Spa, Warks.
c.
Over 100 members attended the Traders’ Fair, but only 26
remained for the AGM itself. Considerable discussion took
place on how we can get members to stay for the AGM. One
suggestion was to hold the AGM meeting mid morning, which
would allow trading before and after the AGM. The Committee
were requested to think of any other potential options for
discussion at the next committee meeting.
If you have an electric flight event you want to have
included, please send an email giving the details to
webmaster@befa.ef-uk.net
d.
It was agreed, as an incentive to increase trader
attendance, that all traders attending the AGM or Technical
Workshop would be given a free one-page advert in EF-UK.
e.
The cost of renting the Royal Spa centre is continuously
increasing. It was agreed that possible alternative venues should
be investigated
73.3 – RM + BS
f.
It was also suggested that some of the committee could sit
and answer questions in a “Watts you problem?” style panel. For
this to work a laptop with ElectriCalc and/or MotoCalc would be
required. This to be given more consideration at the next
committee meeting.
g.
6.
It was also suggested we discontinue the raffle at the AGM.
EVENTS 07
a.
The Middle Wallop weekend is to be held on 30 Jun and 1
Jul 07 and RM stated that arrangements are well in hand.
Photo: Keith Day
Flying on the South Downs - Ripmax Spitfire
56
E.F.-U.K.
b.
Discussion took place as to whether a Portaloo could be
provided near the flying patch, RM agreed to investigate.
73.4 – RM
E.F.-U.K.
9
7.
SFTC MATTERS
a. Apparently the SFTC had decided that the 200 W/kg rules
would replace the ESlot and E400 competitions at the BMFA
Nationals. The Committee agreed that if this were the case, the
BEFA Trophy would not be awarded the winner of a 200 W/kg
event due to the safety concerns.
b. Discussion took place over the possibility of becoming an
Electric Flight Technical Committee. The rationale for this
suggestion was to provide a more formal footing for maintaining
Electric Flight Safety, which is hampered at the moment by only
being a Specialist Body. RM Agreed to discuss this with the
BMFA HQ to find out the method for achieving this.
73.5 – RM
c.
RM requested copies of Technical Council meeting
agendas be sent to him.
8.
BEFA WEBSITE
a. Concern was expressed over there being a single login for
the members’ area, and possible misuse that might arise from it.
JB agreed to look at increased security options and processes,
RM agreed to assist.
73.6 – JB + RM
b. It was agreed that the minutes of committee meetings
would only be published in EF-UK once agreed at the
subsequent meeting. The same would apply to the minutes of
the AGM expect approval would be at the next committee
meeting rather than next the AGM.
9.
ANY OTHER BUSINESS
RM reported that 2.4 GHz radio systems are potentially affected
by Wireless Network systems, which could be a problem with
sites in urban areas. Additionally the installation of the receiver
(due to the very short antennae) can be problematic in all carbon
fuselages.
10. DATE OF NEXT MEETING – The next meeting will be at the
BMFA HQ on Saturday 16 Jun 07, starting at 10am.
10
E.F.-U.K.
12 BMFA 200W/Kg eSoaring League
9 BMAC Electric Fly-in
event at Billesdon, Leicestershire, see the
website or
Contact: Neil Stainton for more
information.
Basingstoke Hampshire. Free Entrance,
Free Parking, Free to Fly, BBQ and
refreshments available, Chemical loo,
Trophy’s and prizes from our sponsors
FlightPower and Deluxe Materials for the
“Peoples Choice” models. Friendly
atmosphere, Large well kept field just off
tarmac road, Good parking, Lots of large
and cutting edge models expected. Site
Opens 09:00am, Pilots Briefing 10:00am
Flying Starts 10:10am, Fly until Dusk.
Pilots must bring proof of insurance and
have a minimum of a “A Cert”. For more
details see website.
19 Woodspring Wings MAC E-Fly near
Yatton, South Bristol (10 minutes drive
from Junction 20 of the M5). No entry fee
for registered pilots. Entrance £5 per car.
For details and registration for
E-mail : Bob Everitt. See more information
on the club website at
www.woodspringwings.co.uk
26 BMFA 200W/Kg eSoaring League
event at the BMFA Nationals, see the
website to contact Mike Proctor for more
information.
September
2 Hayes/BMFA London Area Silent Flight
Open Competition Day.
Open to all BMFA members.
Note: This is NOT a fly-in it is a
competition day!
RC Carrier Deck and Pico Pylon
competitions (to existing published rules).
Flyers, helpers and observers only. Main
details as for June 3rd except for traders
not being expected. £2 entry fee for each
competition entry (up to 3 per flyer in each
class) Entrants and Hayes Club members
may sport-fly off the peg between rounds
if time allows.
Contact: Dave Chinery 0208 573 4687 or
Email: DavidDchinery@aol.com
9 BMFA 200W/Kg eSoaring League event
at Wetlands, Nottinghamshire, see the
website or contact Mike Proctor for more
information via website.
15-16 Aspach Electric Flight Meeting,
Aspach, Germany.
15-16 ‘Stately Fly-In’ for BMFA/LMA
Members at Castle Howard, organised by
the BMFA Northern Area. Saturday Sept
15th general ‘off the peg’ flying minimum
‘A’ certificate. Sunday Sept 16th morning
‘off the peg’ again, afternoon a Flying
Display by invitation only.
Contact: Andy Symons 01924 400 953 or
07976 548 010 (reasonable hours please) or
Email: nabmfa@ddmac.fsnet.co.uk for prebooking. A nominal charge will be levied.
Camping available
www.castlehoward.co.uk or 01653 648 444
for details.
16 Pillerton Hersey Electric Fly-in.
Proof of insurance is required. Come and
join in the fun.
Contact: John Lewthwaite 01789 740 688
for details.
E.F.-U.K.
55
Electric Flight Calendar
If you would like details of your event to appear in these pages please send full details to
the Editor EF-UK, contact details on page 4. Please bear in mind that this magazine is
quarterly so ensure that the details are sent in good time.
The Flight of the Challenger
by Bob Boucher
An epic poem describing the flight of the
Solar Challenger and its historic Channel crossing
For last minute information on events please check out the events list on the BEFA
website www.befa.org.uk. Dates, times and, even locations of events can change at the
last minute. You are strongly advised to check on events with the given contacts before
setting out on your journey to any event.
Paul wanted an airplane to fly by the sun
He asked Bob of Astro, well could it be
done
All BEFA flying events require proof of BMFA (or equivalent) insurance and an ‘A’
Certificate to fly. For fixed wing models, any of the fixed wing ‘A’ certificates are
acceptable. For helicopters, a helicopter ‘A’ certificate is required.
Yes, Bob had the panels and motors and
stuff
But as for the power it wasn’t enough
All flying models must have been satisfactorily flown at least twice since build or repair
before flying at a BEFA event.
Now Brian’s too heavy, your idea’s not
sound
We’ll need a small pilot to get off the
ground
NO TEST FLIGHTS ON THE DAY
Standing Events
22 PANDAS Grand Electric Fly In at the
1st Sunday of every month - The
Brighouse Vintage MAC have been using
the small airfield at Tockwith, near
Wetherby, Yorkshire for several years,
but have recently had noise problems. The
field is now all electric & any BMFA
Member is invited to fly there on the 1st
Sunday in each month from 10 - 5pm for a
small fee. Do not be put off by ‘Vintage’
they fly anything! There is a concrete
runway available and details of the site
can be obtained
Contact : Derek Haviour 01422 204 472
PANDAS Club, Pontefract Racecourse, J32
M62. Includes BBQ & Modeller’s Boot
Sale.
Contact: Trevor Jones on 01924 835 256,
Tony Waite on 0113 286 6373 or
see www.pandasaero.co.uk
July
22 BATH SpaRCS All Electric Fly-In at
RAF Colerne Wiltshire. Airfield site with
both grass and tarmac runways. No
competitions. Proof of BMFA insurance
required. Regret no facilities for
spectators. Pilots briefing at 1000.
Contact: Bob Partington on 01225 891 441
or by email see website
54
29 BMFA 200W/Kg eSoaring League
event at Wetlands, Nottinghamshire, see
the website or
Contact: Mike Proctor for more
information via website.
August
5 BMFA 200W/Kg eSoaring non-league
event at Bartletts Farm, Essex, see the
website or
Contact: Brian Austin for more
information via website (may be promoted
to a league event if other events are
scrubbed).
E.F.-U.K.
He covered the bones with a mylar most
thin
Then he turned up the heat to tighten the
skin
The motor’s installed, the wires connected
She’s ready to fly, or so we suspected
With Marshall aboard and the crew at the
ready
It flew and it flew but not very steady
My twelve year old Marshall, he’s small
and he’s light
But don’t tell his mother, she might die of
fright
We’ll just finish Penguin, put panel on top
She’ll fly and she’ll fly and never will stop
So off the old Simi, to Ray and his crew
The men are assembled, there’s much work
to do
Now Morgan the boss was a prince of a
bloke
Who mostly drank water but sometimes
drank Coke
We all came to Ray with our cares and our
woes
Then he’d yell and he’d scream and he’d
stomp on our toes
Ray fashioned the spars from a Kevlar all
brown
Then whacked them and thumped them and
pronounced them sound
Then all of a sudden, as quick as a flash
Down came the Penguin in a terrible crash
The Structure was broken and lay in the
dirt
Young Marshall was stunned but not
really hurt
So back to old Simi all night and all day
We all worked long hours for overtime pay
The Penguin repaired now in Bakersfield
town
had a new pilot, miss Janice of Brown
Janice flew Penguin after Marshall’s
demise
For scores of furlongs under Gossamer
skies
The Penguin had earned a new place in the
Sun
Challenger was next for the tasks yet
undone
The Challenger was by a committee
conceived
By Solar Apostles one cold winter’s eve
E.F.-U.K.
11
But solar apostles have a strange little
quirk
They love to do preaching, they hate to do
work
So back to Ray Morgan and his Gossamer
crew
The ball’s in his court, there’s much work
to do
The lines were laid out with chalk marks on
the floor
Till tempers were strained and muscles
were sore
Yes Challenger grew from those seeds that
were sown
But it twisted and turned with a mind of its
own
Peter the Wizard of air and its movements
Studied and studied a host of
improvements
Lissaman fashioned an airfoil inverted
It flew very well, but looked quite
perverted
She climbed up our ladder to lengthen her
fall
through wing and through tail and finally
through wall
She bounced like a ball, her pride was
unhurt
But the wall of our shop was now rubble
and dirt
The party was over, the plane put away
Then off to the desert to try the next day
Now out in the desert at first rays of light
Challenger waited, was everything right?
Small Droplets of sweat formed on Dick
Woodward’s brow
He was told it would fly, but he couldn’t
see how
This time last year I had just retired. A major event that happened, almost at the
same time, as a move down to Littlehampton. Not usually a healthy combination of
events, but for my wife and I, it has proved to be a great success.
Over the last year I have rekindled my interest in flying model airplanes…and
converted to electric flight! By joining local clubs, and receiving this magazine, I
have been able to learn a great deal over the last few months and have met up with
some super people, who have been more than generous, in sharing their knowledge,
and teaching me new skills.
One Sunday morning recently, we were strolling along by the sea, when I heard a
familiar sound. We looked over to the grass area and saw a chap flying an electric
helicopter. It was a Mini Titan, which flew like a dream. Of course we went over to
have a look and a chat with him. For a change I had my camera with me (I never
usually have it with me when there is a good photo opportunity!) and was able to
take some pictures, as you can see.
Keith Day
Paul gave him the odds; they were seven
to one
Yes all that was needed was maximum sun
It’s top was all flat, and it’s belly was bent
Would it carry Ptacek from Pointoise to
Kent?
Over at Astro, Bob’s crew had not rested
Thousands of solar cells all had been
tested
Wired together three gross to the string
Then taken to Simi and glued to the wing
A short take off run then she started to
climb
An illusion in motion and all quite sublime
The Challenger looked like a dream in the
air
As she soared and she sailed with a
gossamer flair
Then the motor fell silent, the plane had to
land
Out in the mesquite on a small patch of
sand
The motor was tested, it really put out
Jim got excited, Bob started to shout
This Astro Motor has the power and balls
To fly from old Simi to Niagara Falls
The Challenger’s ready, they called in the
press
But too many came, what a heck of a mess
12
Wanda came first, the queen of the focus
She’s long of the tongue and wide of the
tokus
Down in the desert, the Challenger
plopped
Our stock with Dupont had suddenly
dropped
E.F.-U.K.
E.F.-U.K.
53
But England the country of silk and
brocade
was also the country of maximum shade
We tried it again with a new cooling fan
The motor just loved it, it ran and it ran
Letter to the Chairm
an
BEFA Middle Wal
lop International
Electric Fly-in Wee
kend
Thanks for the tro
phy! Did I win it fo
r drinking beer or
about the inscriptio
flying? I was won
n: BEFA I know, bu
dering
t what is QFI, is th
an annual prize? I
is the magazine? Is
am very proud to ha
it
ve won it but I wou
about the origin of
ld like to know mor
the trophy. Thanks
e
for shipping and I
soon. Next time I
hope we meet agai
will not respond to
n
links warning of ba
d weather!
Regards
Jean-Paul Schlösse
r
Letter to the Chairman
BEFA Middle Wallop International Electric Fly-in Weekend
Thank you for the tankard which I received yesterday. I was honoured to be
presented with it. It is also good to note that the 109 is still in one piece after over
100 flights.
It was a shame that the weather for Middle Wallop was so poor at the weekend,
but I understand that you all did get some flying in. Well done for that. I had
entered the Hornet in for a BMFA scale competition the previous weekend and got
completely soaked, as did the model.
Look forward to seeing you all another time.
Please thank the other members of the BEFA Committee.
John Ranson
Oh! No! cried Jack Comney in frantic
despair
While pieces of Propeller flew through the
air
Paul gave us the odds and snatched up
our money
T’was seven to three the day would be
sunny
It’s nothing, it’s nothing Ray Morgan did
yell
With only one blade, it still will fly swell
More odds were given on the wind and its
course
We prayed and we argued until we were
hoarse
But Jan was more prudent and did not
show fright
The challenger wounded did safely alight
For thirty three days our whole crew had
to wait
Till brotherly love was now turning to hate
She tried it again and within the next week
But the farthest she got was Pecacho Peak
At last Woodwards Folly was placed in its
box
and carefully trundled by road to the
docks
She landed in desert, she landed in dale
She frightened coyote, she flattened out
snail
The sun in the winter is cold and is low
The Cells won’t put out and the motor’s
too slow
The crew called it quits, then they hauled it
away
The waited for summer and sunshine all
day
Then finally summer arrived in a flash
And off to old England went crew in a
dash
E.F.-U.K.
On most every morning from seven to nine
A service was held at Saint Hillary’s Shrine
We prayed for the weather, we prayed for
the wind
We prayed for the day the flight could
begin
Jan headed for Phoenix, a tail breeze a
blowing
A cold winter wind with a promise of
snowing
They waited around for the summer anew
While budget expired and bucks were but
few
Best regards
52
Then all went to Tucson to make the long
flight
From Tucson to Phoenix if things went all
right
A long drive through France where fortune
awaited
Where sunshine, pilot, and plane would be
mated
Next morning was perfect, the sky it was
clear
The wind had abated, the moment was
here
With Ptacek aboard and strapped in his
place
Just a hint of excitement shown in his face
Ray wheeled her about, with her back to
the sun
The motor was started, the flight had
begun
13
E.F.-U.K.
Higher and higher in a sun drenched sky
Ptacek and Challenger away did fly
Yes, quiet and clean and never polluting
America’s Pride and well worth saluting
While over in England, four hours away
The ground crew was praying, let this be
the day
That day is history, but I still recall
That pride in achievement that’s shared by
us all
Two miles above France on that beautiful
day
Ptacek and Challenger were having their
say
Printed by kind permission of ‘Astrobob’
(Bob Boucher)
Photo: Keith Day
Flying on the South Downs
14
E.F.-U.K.
Members’ Letters
Please send your letters to the Editor
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E.F.-U.K.
51
Spread Spectrum
by Brian Mulder
I
The Actronic 45 HD bec ESC with fan blown cooling
irrespective of load and voltage). All of these
variations are accessed through a series of
jumpers at one end of the unit. The controller
is 50 x 32 x 21 mm and weighs 68 gms
(including wires). It is obviously larger than
a typical controller but not excessively so.
b) The Kontronik Power Jazz.
This controller is something of a brute. It is
84 x 51 x 35 mm and weighs 220 gms (including
wires). It does, however, handle up to a
continuous 120 amps (200 amp for 15sec
burst) and 13 to 63 volts (18 to 45 NiCd/NiMH
cells, 5 to 15 S Lithium). The controller does
not have BEC and is therefore opto-coupled
to the receiver but you do need an additional
battery for the receiver/servos. It has the full
range of programmable options which are set
by means of the Kontronik Progcard.
Kontronik claim that this unit is virtually
indestructible and is 100% waterproof with
total reverse polarity protection. It really is
an impressive specification for a unit which
maintains the Kontronik reputation for
design and development at the highest level.
t has been labelled the Holy Grail of
Radio Control and on the verge of
dawning in a new era. Well, actually
this new era has already arrived, as the
technology has already been around for a
while in the form of the Spektrum DX6 RC
Radio system. Those that have purchased
these radio sets swear by them while
others are not convinced that these
systems can live up to the expectations.
And quite frankly, the expectations are
high.
Imagine no frequency control and
interference- free operation. You simply
arrive at the field and turn on your
transmitter. No trip to the pegboard is
required!
*
Now as the DX6 Spectrum system has been
around for a while already, why has it not
made more of an impact, considering this it
is being regarded as the Holy Grail of RC?
The Spektrum Radio is in fact an older
generation of a JR radio transmitter with
limited features. Spektrum purchase these
radios directly from JR, add the RF circuitry
and supply their own receivers. Up to now,
the main problem with these sets is the
limited output power (10 mW or so), which
allows for relatively short-range operation.
As a result, the Spektrum radio system is
more suited to the park flier and helicopter
markets.
The Kontronik Power Jazz Brushless Sensorless Controller with Fan Cooling
50
E.F.-U.K.
Spektrum DX-6
Some modellers have even gone to the
extent of actually purchasing a Spektrum
Radio, stripping it down and moving the
required bits and pieces to a computer
radio such as a JR-9X. RC Groups has this
whole operation detailed in a thread.
Now for people to go to this sort of trouble
says something . . . it tells us that this
technology is required in a more elaborate
radio . . . and modules don’t exist to satisfy
the spread spectrum requirement. Tim
Drew of Xtreme Power Systems identified
this need, and developed the Xtremelink
module system.
For the more serious modeller though, the
features of the radio itself are too limited.
The Xtremelink web page provides
specifications that look amazingly
E.F.-U.K.
15
impressive. From a ground range of more
than 1 km to more than 5 or 6 km in the air,
plus telemetry downlink, is simply
breathtaking. There is a whole host of
other features and well worth visiting the
site and having a read.
Now, amazing as the specifications may be,
the system has got to be 100% reliable,
with no glitching or loss of signal, to be of
any use for Radio Control applications.
When news of this system hit RC Forum
sites, all kinds of speculation arose as to
whether the system could in fact live up to
these expectations. What was also quickly
noticed was that the Xtremelink used only
operation with a single receiver just does
not appear to be easily achieved.
Standard Futaba Tx Module (left) and
SS Tx module (note tiny aerial)
Standard Futaba Rx
compared with
Xtremelink Rx
Other interesting observations regarding
the Xtremelink is the tiny aerial on the back
of the Tx module.
When holding the Transmitter in your
hands, the signal is going to be radiated
mainly in front of you. This may not be
too much of a problem, but for glider
pilots, who sometimes have a plane
directly overhead, signal loss could occur,
depending on how you position yourself.
a single receiver, unlike the Spektrum,
which uses two in a system.
I will explain the use of two receivers a
little later, but as a result of public
scepticism, the planned launch date
(October 2006) was delayed to allow for
more testing. In fact, at the time of writing
this article, the launch date is still not
known which might indicate that the
Xtremelink cannot live up to the
expectations just yet. Even the designers
of the Spektrum radio expressed concern
about the claims on Xtremelink based on
there own experience. Bulletproof
The receiver too cannot simply be thrown
into any convenient space. More thought
needs to be given to the installation. The
reason for this is that the radio link no
longer works on any of the normal radio
bands. Instead, the licence- free ISM
(Industrial, Scientific and Medical) band at
2,4 GHz band is being used. So we are
jumping from 35 MHz to 2400 MHz. The
way radio waves behave at these two
frequencies are quite different from each
other and needs to be taken into account.
In fact, the biggest issue is that of
16
E.F.-U.K.
The Tornado Mounting Frame fitted with the Thumper 5055
Controllers for large models
a) The Actronic 45 HD bec brushless
sensorless controller.
This unit solves the problem of heat
generation in high power controllers by using
forced air cooling (a mini fan blowing air
through a heatsink) and this allows the unit
to include BEC even though it will handle up
to 45 amps from 6 to 45 volts (7 to 32 NiCd/
NiMH cells, 3 to 10 S Lithium). It has the
usual range of programmable features
including brake, undervoltage cut-off,
overtemperature cut-off, and can be operated
Items from Importeknik (Alan Fry)
in several modes. These include car mode
Contact: ImporTeknik, Alan Fry, 29
(with equal forward and reverse throttle
Braiswick, Colchester, Essex, CO4 5AU
ranges), normal mode (with zero to fullthrottle), and constant speed mode (max
Tel: 01206 852209
throttle produces constant motor speed
49
E.F.-U.K.
Tornado range of brushless speed
controllers. It may be used with larger power
supplies, up to 5S Li-pos or 16 Nimh/Nicad
cells, and loads up to 80 amps. The unit is
85 x 29 x 16 mm and weighs 55 gms, and is
programmable using the Tornado Protronic
programming card. This allows the user to
set the brake level, battery type, LiPo cutoff voltage, normal and reverse rotation,
start mode, timing, overload cut-off, and
frequency. A powerful and reliable controller.
Tornado Drive Reversing Adapter.
One of the problems with brushless
outrunners is that the normal format of
mounting the motor with the rotating bell
behind the mounting bulkhead is not easily
reversed to place the whole of the motor in
front of the bulkhead when the position of
the C of G requires this. With the smaller
motors it is sometimes possible to slide the
shaft through the motor to a new position
but this is not a solution with larger motors
because of the high torque levels involved.
Tornado have produced a solution for their
Thumper motors which involves fitting a
complete new prop shaft on to the rear face
of the body and the kit to achieve this is
available as an extra.
set of machined rods with end plates to
match the motor mounting screws which
forms a cage around the motor. Anodised a
bright orange, the frame is very sturdy and
will hold the motor securely and accurately.
Again a useful add-on to these motors.
Tornado Gold Opto Brushless controllers
and Protronic Programming Card.
Use of the larger motors in the Thumper range
does require a suitable controller. The ESC
needs to be able to handle the power
involved in terms of both current and voltage,
particularly with regard of part-throttle
operation when heat generation is a major
problem. These units operate at cell counts
which usually preclude BEC and can
therefore be Opto-coupled to the receiver,
minimising interference problems but
requiring a separate receiver/servo battery.
The Tornado Gold OPTO 80P ESC is one of
the latest additions to the already extensive
The Tornado Reverse Motor Fitting Kit
Tornado Mounting Frame.
If reversing a brushless outrunner does not
move the motor forward far enough to
achieve the correct position within a cowl
or to have the model C of G far enough
forward it may be necessary to extend the
motor mount beyond the front bulkhead. It
is possible to do this by building a frame of
plywood box panels but a stronger and more
The Tornado Gold Opto 80P ESC and
engineered solution is to use an aluminium
the Protronic Programming Card
mounting extension. The Tornado unit is a
48
E.F.-U.K.
meets required design specifications and is
suitable for market release.)
*
So how does Spread Spectrum work?
The History
Spread Spectrum originated in the form of
frequency hopping and it is not quite clear
as to who exactly pioneered the idea. It
seemed to originate from a number of
people. I checked the Wikipedia site and it
states . . .
reflected signals, which I will explain in a
while.
Now, whilst the modular approach is going
through the development phase, Spektrum
have released the new Spektrum DX7.
This radio is now defined as full range and
once again is based on a cheaper JR radio
with limited features. There is talk
however, that a JR-9303 (similar to 9X) will
be released in the near future. The snag
though, is that they are not module
upgrades, which is what the greater
majority of people want. It is really strange
that the Spektrum producers are missing
the boat on this issue. Whoever comes
out first with a working module system will
capture the world market in a huge way.
Why they insist on the full radio approach,
nobody knows. If Xtremelink can
“qualify” * their system, they will come up
trumps. However, Xtremelink progress has
gone somewhat quiet. (Latest News is that
Tim Drew has stated that he is waiting for
“plastics” — cases etc. Xtremelink System
is expected to be released in the near
future.)
( “Qualify” in electronic technology means
that the product has been fully tested,
Perhaps the earliest description of the
technique is in Nikola Tesla’s U.S. patent #
723188, 1903, the application for it
having been filed even earlier in July
1900. Tesla came up with the idea after
demonstrating the world’s first radiocontrolled submarine in 1898, when it
became apparent the radio signals
controlling the submarine needed to be
secure from “being disturbed, intercepted,
or interfered with in any way”. His
patented design is comprised of many
separate transmitter/receiver pairs of
differing carrier frequency (or other
exclusive characteristic), which are
alternately activated by an encoding
wheel in a predetermined order of
succession, duration, and combination.
Frequency hopping is also mentioned in
radio pioneer Johannes Zenneck’s book
Wireless Telegraphy (German, 1908,
English translation McGraw Hill, 1915),
although Zenneck himself states that
Telefunken had already tried it several
years earlier. Zenneck’s book was a
leading text of the time and it is likely that
many later engineers were aware of it. A
Polish army officer Leonard Danielewicz
came up with the idea in 1929. Several
other patents were taken out in the 1930s,
including one by Willem Broertjes
E.F.-U.K.
17
(Germany 1929, US patent # 1,869,695,
1932).
and the scheme fits within the SS
hyphenated description above.
During WWII the US Army Signal Corp
invented a communication system called
SIGSALY for communication between
Roosevelt and Churchill, which
incorporated spread spectrum, but due to
its top secret nature, SIGSALYs existence
did not become known until the 1980s.
*
What defines a modulation scheme as
being Spread Spectrum?
Spread Spectrum is a modulation technique
applied to a carrier signal. Our current 35/53
MHz carrier frequencies are Frequency
Modulated, but could in fact be modulated
via spread Spectrum signal if so desired.
This is not done though due to bandwidth
restrictions, which is a fundamental
requirement of SS. In fact, a transmission
can be called SS if the bandwidth used is
much larger than that needed for traditional
modulation schemes and that the
bandwidth is also independent of
modulation content.
Now imagine somebody comes along with a
standard 35 Tx operating on 35,050 MHz.
As your hopping transmitter jumps around,
it will eventually use the 35,050 channel and
the received signal will be corrupted. So
over the period it took to hop all channels, it
only encounted one bad interferer, which
results in a 95% reliable transmission.
Should a second and third interferer be
introduced, overall reliable reception
percentage starts to drop, but
communication is still maintained.
Now, should a second and third hopping
transmitter be used simultaneously over the
same frequency band, hitting each other’s
frequency is of a random nature and the ‘hit’
may last for a short enough period such that
it would not be noticed.
Getting the picture, are you?
One of the Tornado Large Diameter Shaft Propeller Adaptors
Let me try to explain all of this a little more
clearly. There are numerous SS systems
that exist, but we will look more closely at
two of them (Frequency hopping and Direct
Sequence) in order to get a better
understanding of how the system works.
Frequency Hopping
Imagine your Transmitter could hop
randomly between all the 35 Mhz channels .
. . from 35,000 to 35,500 and stay on each
channel for let’s say 0,25 seconds. The
receiver would be synchronized and follow
the transmitter from channel to channel. In
this example, you are using the whole band
18
I am sure you are!
Direct Sequence Spread Spectrum
The DSSS system is not nearly as simple
as the hopping concept. Early designs
were complex and required a lot of
hardware. As technology advanced, the
amount of hardware required became less
and is now at a stage where and entire
DSSS system is integrated into a single
microchip.
E.F.-U.K.
XOAR propellers.
Ideally suited to the range of Tornado
Thumper motors, this range of wooden
electric propellers covers 15 sizes between
10" x 5" and 24" x 10". Manufactured from
premium grade beech in Germany, these
propellers have a high quality natural clear
finish, are manually pre-balanced, and are
uniquely shaped for an accurate pitch giving
fast acceleration and high performance.
They are claimed to be the world’s lightest
range of electric propellers and have a predrilled centre hole which needs opening to
the required motor/gearbox/adapter shaft
diameter.
Tornado Prop Adapters.
Again matched to the Thumper range of
motors these well finished aluminium collet
style adapters are available in sizes up to
and including the 12 mm diameter shafts of
the 8085 and 80100 motors. Provided with a
domed cover to fit the locking nut they give
an attractive finish to the propeller assembly
and are ideally suited to large scale and
sports models. Accurately machined to
enable the largest diameters of propellers to
be operated safely and smoothly with
minimum vibration, these units are, like all
Tornado products, available at economic
prices and cover applications which are not
easily available elsewhere.
47
E.F.-U.K.
Trying to understand exactly how the
DSSS system works is not easy . . . and
probably even more difficult to explain.
correlation of the transmitted PN
sequence with the receiver’s assumed
sequence.
Nevertheless, let me try . . . Unlike a
frequency hopping system that has a
carrier frequency hopping amongst predefined frequencies at a fixed power level,
the DSSS system is like taking a fixed
carrier frequency and then squashing it
down so that it spreads out over a wide
band. The resulting signal appears like a
hump disappearing into the noise.
For de-spreading to work correctly, the
transmit and receive sequences must be
synchronized. This requires the receiver
to synchronize its sequence with the
transmitter’s sequence via some sort of
timing search process.
For a more technical description, I found
Wikipeda gives a reasonable explanation . .
Now as frequency goes up, the RF signal
starts to behave somewhat differently.
Where low frequencies tend to bend over
the curvature of the earth, high
frequencies want to go straight and hence
the term “line of sight” becomes
applicable.
Two of the Tornado Thumper Outrunner motors, the 4250 and the 5055
The Tornado Thumper 5055 fitted with a XOAR 13" x 7" Beech Electric Propeller
46
E.F.-U.K.
So what are the issues then?
As spread spectrum techniques require
significantly more bandwidth than what
has been allocated at our lower frequency,
SS is used at much higher frequencies
where much more space has been made
available. So we are no longer dealing with
35 MHz, but rather 2,4 and 5,8 GHz.
Put simply, direct-sequence spreadspectrum transmissions multiply the data
being transmitted by a “noise” signal.
This noise signal is a pseudo-random
sequence of 1 and -1 values, at a frequency
A major problem with radio gear at high
much higher than that of the original
signal, thereby spreading the energy of the GHz frequencies is Diversity. What
happens here is that a transmitted signal
original signal into a much wider band.
radiating in a different direction, can be
reflected off a distant object and arrive at
The resulting signal resembles, an audio
the receiver a little later than the signal that
recording of “static”, except that this
followed the direct path. So depending on
noise can be filtered out at the receiving
the timing of the two signals, they can
end to recover the original data, by again overlap (at a specific point in space) in a
multiplying the same pseudo-random
way that results in them cancelling each
sequence (PN sequence) to the received
other out. If the receiver is positioned at
signal (because 1 × 1 = 1, and -1 × -1 =
this point in space, no signal will be
1). This process, known as “dereceived. To prevent loss of signal
spreading”, mathematically constitutes a occurring when the received signals cancel
each other out, a second receiver can be
19
E.F.-U.K.
placed in another point in space that
would be outside the nulled area.
Other Issues
As stated, the 2,4 GHz ISM band has been
chosen for Spread spectrum RC. This
band however is extensively used by all
kinds of apparatus, from digital radio links
operating long distances between towers
to wireless networks around the home.
Everybody is climbing onto the wireless
bandwagon.
As the radio wavelength at 2,4 GHz is very
short, the second receiver need not be
mounted far away from the other in order
to receive a valid signal while the other is
situated within a null.
Spektrum identified that a nulling problem
existed and introduced the second receiver
to solve the problem. Xtremlink however
use only one receiver and claim that they
manipulate the transmitted pattern to
prevent nulling from occurring. It has also
been suggested that a moving aircraft will
fly through nulls and appear transparent.
And this is where a storm has been
brewing. Technical people (like myself)
refuse to believe the system will work
adequately based on radio frequency
principles and experience. The less
knowledgable who use the system with
some success don’t want to believe that
problems may exist as they have ‘proven’
that it does work. You then have a mudslinging match developing between the
two parties.
*
20
The 2,4 GHz band is quite wide and can
accommodate many channels. When the
system powers up, it will look for a ‘quiet’
spot to operate on. When other devices
transmit on that same band, the noise level
increases resulting in less than 100%
signal data getting through. As the
percentage goes down, system
performance slows (servos response could
be delayed) and is a clear sign that reliable
communication is being reduced. A total
lockout is possible as well. There have
been a number of reports of this
happening. I think it pretty much depends
on the RF activity in any specific area.
Flying a plane through a powerful RF beam
being radiated from a nearby tower might
not be a good idea.
That said however, a lot of people have
had good success and as a result, the
demand for Spread Spectrum systems is
growing. Time will tell how successful
Spread spectrum becomes, but the
conceptual idea will probably form the
basis of systems to come.
Orca LiPo Transmitter Battery.
This is a 3S 2600 mAh Lipo battery
designed to fit Futaba/JR transmitters. It is
a small and light unit (98mm x 23 mm x
30mm and 150 gms) and has excellent
capacity. It has been designed to operate
at continuous low current (which is the
kind of load created by a transmitter) and
is not suitable for use as a power-pack. It
connector and simply plugs into the
transmitter socket exactly as the original
Nickel battery does.
An interesting development, which takes
advantage of the higher energy density of
LiPo batteries.
Items from Overlander Technologies
Contact: Overlander Technologies, Unit 1,
Jesmond Dene Trading Estate, Forton, Nr
Lancaster, Lancs PR3 0AT
Tel: 01524 793328 website:
www.overlander.co.uk
Tornado Thumper Outrunner Motors
There are twelve motors in this range and
the manufacturer’s specifications are
included in the following table
(see Diagram below).
The ORCA Lithium Polymer
Transmitter battery
obviously needs to be charged using a
suitable LiPo charger/balancer and NOT
the normal charger supplied with the
transmitter, and should also be removed
from the transmitter for each charge. It is
fitted with a standard Futaba type
This is a wide range delivering up to 6 kW
of power and designed to operate large
diameter propellers at low to moderate
RPMs using high voltage and moderate
currents. The photograph shows two of
these motors, the 4250 and the 5055, and
they are typical of the design, quality, and
finish of the full range. These are fine
motors, well engineered, accurately
manufactured, and available at economic
prices. They have a full range of
supporting accessories.
Brian Mulder
E.F.-U.K.
E.F.-U.K.
45
* Input current: 5A DC
* Cooling fan
* Output Current: 0.5A - 2A (Adjustable)
* Auto-Cut off when battery cell fully
charges
* Auto Charging Current Adjustment at
Voltage Peak Region
The charger has JST-XH type ports for 2S
3S and 4S packs. Included are various
harnesses for various packs (charge only)
It also has the ability to charge 2 x 2S
packs at once!
A fantastic charger for the safe charging
and balancing of Lithium battery packs.
The ORCA 1 to 4S
Lithium Battery Balance Charger
44
Read-out screen of the ORCA Lithium Charger.
E.F.-U.K.
Three into One
by John Stennard
T
he correct name for this trio
of aircraft is ‘Three In
Formation’ and it was
designed by Dick Sarpolus and
published as a plan in the American
Quiet Flyer magazine. The concept
of linking a number of models
together and using one motor is
certainly not new but two things
appealed to me about this one.
Firstly it is electric powered, and
secondly the information with the
plan said, that it was capable of
Early stages and ready for the link up
mild aerobatics. Another attraction was
that 6mm Depron and is used for all of the
The biggest headache in the construction
construction. I always have a generous
was turning the tiny magazine plan into a
supply of this available for building my
full size version. One has to increase a
indoor 3D models. It uses carbon fibre
75mm (2.95ins) wingspan drawing to
tube to link the aircraft, and again I already
560mm (22ins). Luckily the three models
had plenty of this in stock.
are basically of identical size and shape,
with differences between the central model
I believe that most of the earlier linked
and outer models being concerned with
models were a ‘four ship’ unit, so
with three aircraft, this one is
different and makes for a lighter
structure. Obviously there is lots of
drag from all the tubes and wires,
so the airframe efficiency is
reduced. The designer describes it
as ‘an inefficient delta wing with a
bunch of holes in it’! He has
balanced it as a delta wing. To take
the place of the reflex trailing edge
the elevators are set up at an angle
of 20º. This in turn means that a
comparatively powerful motor is
required to haul the model(s)
around the sky.
The AXi Silver Line motor is ideal
E.F.-U.K.
21
the motor mount, and various ply
reinforcing pieces.
The model uses four servos which
are situated in the outer models.
They use the elevators and the
outer aileron. The central model
has no operating control surfaces,
but has the motor, Rx, ESC and
battery pack.
Once all the Depron parts had been
Another chance to use my Spektrum Rx gear
cut, using the first set as a template, I had
to decide what motor to use. The designer
If you are used to building with Depron,
had used an AXi 2212/20 with a GWS 9 x 5
this is a very easy model to construct. I
prop, but mentioned that more power
used 5mm CF rod for the crosswise linking
would be an advantage in aerobatic
struts, and solid 4mm rod for the forward
manoeuvres. So, I headed for Puffin
to rear struts.
Models to check out what John Emms
thought would be the most suitable Axi
Decorating three models at a go was going
motor. I felt at a weight of 542g (19oz), I
to be time consuming, so I decided to use
needed 100-150w from the motor, and the
the excellent ZIG POSTERMAN pens, and
ability to swing a larger prop if required.
keep the decoration to a minimum. In fact,
John suggested the Silver Line 2212/26
as can be seen by the photos the results
and this proved to be the right choice.
are very effective, and the models show up
well in the sky.
The radio gear was no problem, as I
wanted to use a Spectrum AR 6100 Rx, and
there was plenty of room for this.
Four HiTech HS-55 were chosen, as
their longer leads are useful, and I
fitted a 20A Astro Flight ESC.
Batteries were no problem, as I had
a selection of 3S 1200/1500/
1800mAh LiPo packs. There were
two choices for the wiring loom. I
could either make up leads or
modify standard extension leads. I
chose to do the latter, and used
four 1000mm leads cut and
soldered, to achieve the required
lengths.
5mm CF rods and some of the very long leads
22
E.F.-U.K.
voltage to two decimal places (3.76 etc.).
At a rate of about 2 seconds per reading it
scrolls through the cells in sequence and
will continue to do so as long as it is
plugged in. For 2S and 3S packs the unit
still scrolls through four readings but
indicates an error for cells not present (e.g.
a 2S pack might give readings of 3.82, 3.84,
err, err,). It draws minimal current from the
pack so can be left in place during a flight
allowing readings to be checked before
and after discharge. A very useful and
remarkably low cost unit.
“On a Wing & a Chair” Feature Length
DVD.
This is no ordinary modelling story, even
after setting aside the world record - this is
the tale of a highly unlikely friendship and
how two friends pushed themselves - and
their model aircraft - to the absolute limit.
Two lives, poles apart. A freak accident
brought them both together. This is the
story of two men - Nigel Hawes and Brian
Collins - who made an audacious attempt
at a world record and against all the odds
made it happen.
Brian Collins is the fella in the wheelchair paralysed from the waist down after a
horrific motorbike accident. He is the MD
of BRC HOBBIES; one of the largest and
fastest growing suppliers of electric flight
products in the country. His friend is Nigel
Hawes, world renowned model aircraft
journalist, designer and model maker.
Together they set themselves the task of
flying an electric powered model aircraft
across the English Channel.” In the end it
was more of a physical endurance battle
than piloting skills.....most people told us
we were crazy to attempt it and that we
didn’t stand a chance” This amazing
feature length DVD captures the full story.
ORCA Lithium Battery ‘Balance
Charger’ for 1-4S Packs 0.5-2A.
This new charger from Orca is full of
features to enable the safe charging of
Lithium battery packs. It not only charges
Lithium battery packs but also balances
them as it charges!
The clear LCD screen gives you a clear
indication of the status and voltage of
each cell within the pack.
Select from 500mA to 2 Amp charge rates!
(in 0.5A segments) the unit has auto cutoff when it is finished charging!
The Feature Length
“On a Wing and a Chair” DVD
SPECS
* Size 130x89x40mm
* Weight 219g
* Li-on/Li-Polymer Battery
* Input voltage 9-13v
E.F.-U.K.
43
New-2-U
A brief round-up of new items of interest
by Bob Smith
If you are a manufacturer, importer, or retailer who has something new
you wish to bring to the attention of the readers,
please send details to me at the address given on page 4
Items from BRC Hobbies
Contact: BRC Hobbies, P.O. Box 226,
Whickham, Newcastle upon Tyne, NE16
4WU
Tel: 01914887879
website: www.brchobbies.com
HiModel Lithium Battery Cell Voltage
Checker.
This tiny unit is ideal for keeping a check
on the balance of your Lipos. The health
42
and life of lipo packs is linked to the
avoidance of over (>4.2V) and under
(<3.0V) voltage in the individual cells of a
series pack and using this unit will allow
you to check that your charge and
discharge procedures are working
correctly. The checker works for 1 to 4S
packs and you will see from the photo that
the unit is plugged into the balancing lead
of a pack where it begins to read the
voltage of each cell in turn. The LED
display first indicates the cell being
checked (No 1, No 2, etc.) followed by the
The BRC HiModel Lithium Individual Cell Voltage Checker
E.F.-U.K.
For the initial flight, I fitted a 9 x 6
APC E prop with a 3S 1500 LiPo
pack. This was certainly one of the
most unorthodox models that I
have flown, so I was fairly
apprehensive before the first
launch, although the model ‘felt
right’. I need not have worried, as
following a gentle hand launch, the
model climbed away steadily, and
proved both exceptionally stable,
and easy to fly.
The extension leads are essential
What was obvious, was that I needed
more power, as although the model climbed
quite well, it would not loop, and the roll
was very ragged. For the second flight, I
switched to a 10 x 5 APC E, and this
immediately improved both the roll and
following a gentle dive, the model would
loop. The designer says that the model
does not glide well and power has to be
held on for landing. The best method of
landing is to slow up the model and try to
‘drop’ it onto the ground. On a slightly
faster landing the prop hit the ground and
broke off the motor mount. When I
replaced it, I included some
triangular balsa reinforcing behind
the mount. I then tried a folding
prop but the size I used did not
give enough thrust. The final and
most successful configuration was
to use a 3S 1800 LiPo pack and a 10
x 7 APC E prop. The model now
climbs steeply and is much more
lively, rolls very smoothly and can
loop from level flight. A
combination of a heavier pack
moved slightly further rearwards,
and the extra power from the larger
prop, have given the improvement.
The duration is now slightly
shorter but the model still flies well for 6-8
minutes.
Fellow fliers, arriving at the field, and
seeing the model in the air for the first time
at a distance, often fooled into thinking
E.F.-U.K.
Continued on page 24
HS-55 servos are ideal
23
are affected by the higher drag of the open
fuselage.
Top and bottom with different colour schemes
24
Away they go in perfect formation
E.F.-U.K.
I did have a little whoopsy outdoors in
that it was getting quite high and
accidently chopped the throttle causing a
tumble. Now I switch on at LOW TRIM on
the throttle and then fly with Full Trim so
the rotors never stop.The damage
consisted of bent shafts and slight damage
to the fuselage shells, so while I was at it I
fitted one of the alternative bodies, so it is
now resplendent in a blue and yellow
Police guise, not bad at £16.00. There is
also a Marine body with rockets which is
more expensive.
Spare parts are remarkably cheap
compared with some models, and an
instance is the Landing Skids which are
individual plug in units, while with some
models you have to buy the complete unit.
Everyone who has seen it have been very
impressed with the looks, performance,
and price, plus the 2.4Ghz radio means I
shall be able to take it abroad on Holiday.
John A. Thompson
E.F.-U.K.
41
Continued from page 22
the excellent Balancing Charger
with the mains adaptor. This takes
quite a long time, so probably is
as safe as they come.
that three independent models are
flying in formation. Initially, I used
dummy rotating props on the outer
models, but I felt the slightly
increased realism was not worth the
additional drag, so I removed them.
The TX is a simple 5 channel
single memory unit, looking
distinctly JR in origin and so has
good quality sticks, but no rate
switches. Binding has already
been done as they are test flow at
the factory.
My first flights were in my one car
garage and it performed very well
with a little trimming. Next was at
the Dewsbury Club meeting in the RAFA
Ballroom and then it really came into its
own, forward, back, sideways, it was
superbly controllable, and caused a lot of
interest from the members. Meanwhile
Shaun had suggested fitting the twin heat
sinks to the motors, very cheap, easily
done, and well worth the few pounds. The
body shell is a lightweight moulding in two
halves and is attached by two carbon rods
into rubber grommets. Later that week was
a calm day so it was tried outdoors with a
training UC and coped well, although the
slight breeze reacted with the UC causing
drift. Since then it has been flown
outdoors without the UC and coped even
better. It seems to me that the streamlined
shape helps, while the Llama/Twister types
Because of the model’s slightly
different flying characteristics, it is
best to have a flight plan in your
mind before each manoeuvre, as
sharp recoveries are not possible.
However, if flown with
consideration, this trio rewards you with
some great sights and the rods, although
more visible on photographs, tend be lost
in the background.
Formation flying was never this easy
Another success for a combination
of brushless, LiPo and Depron,
anything is possible!
This model has been great fun to
fly and I’m considering a smaller
indoor version.
John Stennard
Heading for a roll
These pilots are good!
More photos on page 30
40
E.F.-U.K.
E.F.-U.K.
25
Middle Wallop BEFA International Electric Fly-in Weekend
Photos by Robert Mahoney
Blade Helicopter
by John Thompson
Already being a fan of Spektrum
radio I was impressed when
clubmate Shaun brought a Blade
helicopter to one of our indoor
sessions at Garforth. It seemed
extremely good value for money at
£120, and flew very well, so a
mental note was made to look out
for the next delivery, as the few in
our local model shop were soon
snapped up.
Recently dropping the wife
shopping in Leeds I visited the
model shop at Crossgates just as
a pile of them had arrived. Luckily
I had just sold some bits on eBay, so had
an excuse to spend.
The packaging is impressive with
everything protected by a two piece foam
moulding, and even the 4 dry cell batteries
provided for the TX, yes only 4 cells,
though there is a charging socket on the
TX! The receiver seems to be the
AR6100 six channell with integral
controller and gyro. Everything is
provided, Model, TX, 12 volt
charger, mains adaptor,
instruction book, and DVD. The
latter is supposed to play on a
DVD or PC, but I could not get it
to work on either, even with the
three options for the PC.
However, this is not important, as
I have flown indoor mini copters
before.
better performance and I was not
disappointed.
The first thing was to read the
instructions, and everyone should do this
as it includes all the AMA safety
recommendations for model flying. The 2s
800 Lipo battery was then charged using
My main heli experience is with a
Hirobo Llama which I sold
recently as it became boring,
although it had taught me to
hover. The Blade promised a
The trophies were the QFI & the Exide and Drydex, won by JePe & John Ranson (see p 5)
26
E.F.-U.K.
39
E.F.-U.K.
Erratum
These numbers sound small until you do
the maths - at 50A a NiCd will drop it’s
voltage by 0.2V, a Nimh 0.25V and a Lipo
0.5V.
I feel I should point out some errors in
Peter Vivian’s article in the last issue on
battery basics to set the record straight.
He said that NiCd cells have the lowest C
rating, Nimh are higher and Lipo are the
highest. In fact the situation is just the
opposite. NiCd can source very high
currents, F5B flyers were regularly pulling
60C (150A) out of them. Nimh are not
quite as good, maybe 40C, because their
voltage drops more at high current than
NiCd. Lipo are the worst: I’ve seen some
rated at 30C for very short bursts of less
than 5s, but I wouldn’t want to run even
the best of them at more than 20C for short
burst of 10s or so. Running Lipos at 10C
will keep them cooler and they will live
longer.
This is all to do with something called
internal impedance. Yeah, I know, what’s
that? Well, if you’ve got something like a
Whatttmeter, and watch the battery
voltage as you rev up your motor, you’ll
see it drop off as the current increases.
This is because no cell is perfect and acts
as if it’s got a resistor in series with it. It’s
a pretty low value of resistance, normally
rated in mOhms (thousandths of an Ohm),
but it is there and has two effects, the first
is to cause the cell voltage to drop as more
current is drawn, the second is to act like
an electric fire and heat up the internals of
the cell.
Gordon Whitehead and his Lightning F1A
in 56 Sqn Firebirds colours, scratch-built
to my own design from balsa/ply. Span is
26in; weight 45oz; 4-channel REMA
controls Schuebeler DS30 fan unit with
Kontronik FUN480/42 and 3S lipos running
at about 550W. Regarding the batteries, I
designed the battery bay to take up to 3S
6000 Prolites, which despite being bulkier
12-18C batteries only weigh 3oz more than
The really nasty bit is the internal heating
effect, at 50A a NiCd will have to dissipate
10W, a Nimh 12.5W and a Lipo 25W. To
give you some idea of how much heat this
is, car sidelight bulbs are typically around
10W, it’s not something you’d want to
keep your finger on for very long! Given
that Lipos are much less tolerant of high
temperatures than NiCd or Nimh, you can
see why I think Peter has got it wrong.
My other concern is the diagram on page
16 showing NiCd cells connected in
parallel. This is fine for flight where you’re
discharging the packs in parallel, but it is a
problem for charging. The delta peak
circuit in your charger will trip out early if
you charge parallel connected NiCd or
Nimh packs, you must charge each pack
separately.
Parallel connection of cells is not a
problem for Lipos since the charging
algorithm is totally different and much
simpler, more like the way your car battery
charger works. A Lipo charger charges the
pack up to a fixed maximum voltage,
tapering off the current at the end of the
charge, giving parallel connected cells a
chance to ‘catch up’ with each other.
Don’t let the smoke out!
Typical values for good cells are NiCd at
4mOhm, Nimh at 5mOhm and Lipo at
10mOhm.
38
Alan Bedingham
E.F.-U.K.
E.F.-U.K.
27
the far lower capacity 30C+ Flightpower
EVO 3700s etc, yet provide better power
and far longer flights. Launch ramp is a
copy of Bob Partington’s Bob-sleigh, and
is the best ramp for low-tail designs as
there’s no risk of the tail catching the
ramp. The plane has had way over 100
flights now, and it’s loads fun to fly.
the motor wires in the wing (one twist per
inch) will help to cut down potential
interference problems with your radio.
Interference is going to be a problem with
all that wiring carrying high currents, just
try to get the receiver as far away as
possible from the battery and speed
controllers in the rear of the fuselage.
Don’t forget to label all the connectors
between wing and fuselage (three to each
motor) so that the right wire goes to the
right motor and the right way round if you
don’t want to become the ground loop
champion of the world.
Remember to program the speed
controllers identically, especially the
throttle throw and cut-off voltage. The
cut-off voltage settings in speed
controllers aren’t all that accurate, so make
sure you don’t run the battery(s) too low.
I use a countdown timer for all my flights
and set it to a conservative flight time to
make sure I don’t get near the low voltage
cut-off in flight, it’s even more important
with twins if you don’t want a brown
trouser moment. Make sure you’ve got
some air vents to the speed controllers,
they won’t get much cooling inside the
fuselage away from the high-speed airflow
of the propeller.
One other, not so obvious, point is to
enable the propeller brake. If you have the
propellers freewheeling at low throttle,
you’ll lose some aileron authority in turns.
What happens is that the high wing in a
turn is going faster than the low wing
because it’s got further to go, so the
propeller on that side spins faster and the
low wing propeller spins slower. The
faster spinning propeller causes more drag
than the slower one acting just like a
28
E.F.-U.K.
rudder, but against the direction of the
turn. Some ‘planes are more affected than
others, I had a four motor model that
behaved very strangely in turns at low
throttle until the penny dropped and I
realised what was going on.
I think it’s safer to use one battery,
suitably rated for the total current draw of
course, than separate batteries for each
motor. The logic behind this is that all the
motors will see the same voltage. Separate
batteries may not have identical
performance or you may forget to charge
one as much as the other. You could end
up with one motor having more power than
the other, or even cutting out when you
least expect it.
There’s no problem using Y leads to
connect the speed controllers to the
battery or the throttle plugs to the Rx. I
would suggest that, if you’re using speed
controllers with battery elimination
circuits, you let one controller do the job
of supplying the Rx and servos and pull
the red pin out of the throttle plug on the
others, or they could fight each other and
overheat.
Something I’ve often thought about, but
never tried, is to plug the two speed
controllers into separate channels on the
Rx and fiddle with the Tx mixers so that
they go up and down together with the
throttle and vary side to side with the
rudder. This would get over the problem
of no airflow over the rudder when taxying,
and could allow for some interesting yaw
manoeuvres in the air. Horizontal blenders
anyone? If you do it, please let us know!
E.F.-U.K.
37
TLC from your TLO
By Alan Bedingham
Wiring for Twins
I
’ve had some questions about the way
to wire up brushless motors for twin
motor ‘planes (or triple or quad) and I
think it’s worth talking about because
there are differences in the way you’d do
the job compared to brushed motors.
know that there are some speed controllers
out there that claim they can do it, but my
advice is - don’t.
The second is not to be tempted to put the
speed controllers out on the wings with
the motors and lengthen the battery wires
to reach a battery in the fuselage. Long
battery leads and brushless speed
controllers simply don’t mix. You may
have noticed a (usually blue) round thing
The first is that it’s not a good idea to try
on the battery end of your speed
to run more than one brushless motor from
controller. This is a capacitor to soak up
one speed controller. The reason is that
the big spikes of voltage and current that
the speed controller sends out pulses of
these busy little beasts pull out of the
current to the motor on start up (you just
battery when they’re running. Make the
knew there was a reason for all those
battery leads too long and the spikes get
beeps, didn’t you?) and looks at what’s
so big that the capacitor will blow followed
coming back to decide which way the
rapidly by smoke out of the speed
motor is to run. The poor little thing could
controller. The motor leads you can make
get terribly confused if there’s more than
as long as you like, in some industrial
one motor hanging off it and one of them
applications they’re 10m long! Twisting
may not start, or, worse, run backwards. I
36
E.F.-U.K.
Overlanders test airframe for motors
E.F.-U.K.
29
Member’s Planes
‘In the bin? No way, I enjoy building’
by Peter Vivian
The little 3-function Pinto in front, I built
simply as a Park Flyer for my
granddaughter – if only I could find the
definition of a Park Flyer, or even a Park.
Does anyone know where she can fly it in
the Fleet area?
The smaller Cub on the left, I built as
electric, with a Brushless BM2409-12 but I
have not tried to fly it yet.
...and finally Will Beaver with his Manta
Manta Details: Length: 40 3/8" (1025.5mm). Wingspan: 40 1/8" (1019mm). ESC: Jeti Master
77 opto. Motor: Hacker B50 - 14L. Fan: WeMoTec Midi Fan. Energy: 20 x. GP2200mAh.
Weight: 6lb ish
Photo: Keith Day
30
Flying on the South Downs - Ripmax Spitfire
E.F.-U.K.
The larger Cub, I built up with a 54 4stroke, it flew OK but nothing spectacular.
Experts said it was a bit underpowered, so
I fitted an RCV 60 and I was able to fit it
totally in-cowl, I hate sticky-out cylinders.
More oomph but still not aerobatic - just
as well, I am no flyer. However, I then
converted it to electric, or tried to, with an
AXI 4120/14. Yes, it became airborne, but
only just on full throttle, and had to be
hot-landed. So now I intend to carry out
some experiments, AXI versus RCV,
measuring at a fixed rpm, the thrust with a
range of props of different diameters and
pitches. Actually, not quite that simple, the
RCV runs at half the ‘normal’ revs.
Therefore, do I put a gearbox on the AXI
or experiment at matched forward speeds rpm x pitch - and hence compare forward
speed with thrust? I know static thrust is
no direct measure of thrust in flight but it
must be comparable? Anyway, a
comparison of theoretical forward speed
against thrust and for electric current
drawn (hence Watts), will be interesting -
to me anyway. And if the RCV comes out
markedly superior, I shall ask for
suggestions for an alternative motor.
The large Cessna 182 is a different animal,
and doesn’t really belong in an electric
magazine. I built it with an RCV 90 and
built heavy. It is not quite finished but I
doubt it will fly. With an 82" span, 18 lbs
weight (50% high!), 44 oz/sq ft wing
loading - who can calculate for me prop
diameter, pitch and speed which may lift
this creation? Given such a calculation,
who can tell me if there is such a thing as
an electric motor which will do the job? Or,
shall I just put the whole thing in a glass
case in my workshop? Or, in the bin?
Actually, bin no way. I enjoy building,
especially this, and if it cannot fly, well, I
will settle for enjoyment.
Peter Vivian
Photograph page 33
E.F.-U.K.
35
Photo: John Stennard
Photo: Peter Vivian
Above: Climbing away easily
Below: Tight banking turns look nice
(article page 20)
Photo: Dave Chinery
34
Tom Lambert and his Roco M used in the Carrier Competitions
E.F.-U.K.
Photo: John Stennard
E.F.-U.K.
31
Photo: Malcolm Mackendrick
Malcolm Mackendrick
Photo: Dave Chinery
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lco
a
:M
oto
Ph
k
ric
d
n
cke
Ma
and his Demoiselle
Photo: Dave Chinery
Dave Chinery’s Vermonte Belle which won the first season’s Carrier Competitions
32
E.F.-U.K.
Photo: Malcolm Mackendrick
E.F.-U.K.
33