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My name is Peter Cabrol and I am 80 years old. I have been involved in the radio control of models since the end of 1959. It came about in this way. At that time I was working as a draughtsman in a small engineering company located at Weybridge, Surrey. A gentleman named G. Honnest Redlich came into the office and we started to chat; the Ford Motor Company were interested in radio controlling one of their tractors and had approached FVRDE (Fighting Vehicles Research and Development Establishment) at Chobham. Our company had carried out a certain amount of development work for FVRDE and they had suggested that Ford should contact our company. George was one of the true pioneers of radio control of models of all types. During our chat he mentioned he was having great difficulty in having parts made. When asked what type of parts, he listed the following - transmitter and receiver cases, servos, relays and reed units. Quantities envisaged were of the order of 100. A fellow draughtsman by the name of Donald Lincoln was very interested and we arranged a meeting with George to discuss the possibility of Don and myself going into a partnership to manufacture the parts. Don was very well qualified to make the cases being an ex Vickers Armstrong Toolmaker's Apprentice. At the meeting George agreed to give us an order with guaranteed payment on receipt of the goods with the proviso that they reach the required standard. Don and I found a small workshop in West Byfleet and we started work. At that time we were both married with new houses and mortgages so this was quite a gamble. I am happy to say George was satisfied with our efforts so Don and I formed a company called C & L Developments, i.e., Cabrol & Lincoln. After manufacturing George's parts, who had now been trading as REP (Radio & Electronic Products) for over a year, it soon became apparent that there was a need for a reliable multi-channel servo, so I sat down and designed the Climax Servomite. This servo had a linear push/pull output. We used the company's two initials C & L and turned it into Climax. Initially it was to be switched by relays in the receiver but later we transistorised it so that it was driven directly from the reed bank which reduced the weight and size of the Rx and improved reliability. This servo weighed about 1.5 ozs and was powered by a German manufactured motor made by R. Marx Luder. To improve reliability it was possible to mount either three or four on a fibre glass printed circuit with four anti-vibration mounts in each corner. Connecting leads for each servo were soldered directly into the printed circuit and one multi-channel plug inserted on the end of the PC carried all the connections to the Rx. Three servos were used for a six-channel system (picture below) and four servos gave a trimmable elevator facility by the simple addition of a trim bar fitted across the outputs of the two servos located at one end of the PC. One servo self-centered as usual with no input from the Rx and the other had the self-centering removed so that its output position was trimmable in the same way as the throttle control. All that was then necessary was to fix the connection to the elevator to the trim bar. For the full house ten-channel system a further servo could be plugged into the PC for aileron control. This servo could be mounted on a special plate which gave a push /pull output to drive the ailerons in each wing.
At this point, as sales of the Servomite were going quite well, I thought it was about time I learnt to fly using our own products. A Veron Robot kit together with a 2.5 cc glow motor was purchased. For the radio, a ten channel reed system from a new manufacturer called RCS (Radio Control Specialists). This company were ordering Servomites and to reciprocate an order was placed for their system. Three Servomites were installed for rudder, elevevator and throttle control.
I taught myself to fly by going to Epsom Downs and later to Chobham Common. The Robot was an excellent trainer and I managed to keep it in one piece. Later I joined the Esher MAC, later to become The Elmbridge MAC, famous for running the Model Symposium at Sandown Park. The Esher Club were allowed to fly at Fairoaks Aerodrome at Chobham which was a big improvement over Chobham Common. By this time I had become proficient at flying and decided to go for a full house installation. A new wing for the Robot was built with a slightly increased wingspan, reduced dihedral and ailerons. Power was increased by installing a Merco 35. I was now able to do reasonable axial rolls and trim the Robot to fly inverted. I wrote an article on these modifications to the Robot and sent it to Tony Dowdeswell, editor of the RCM&E magazine. This was duly published. Some while after this I received a call from Phil Smith, the designer of all of the kits manufactured by Model Aircraft Bournemouth. He wanted to see it fly so I invited him down to Fairoaks one Wednesday afternoon for a demonstration. I think he was impressed because he mentioned a very important customer of Veron's would be giving me a call. About a week later I had this call from a gentleman called Rafat who was in charge of the Iranian Civil Aviation Club. He would like a demonstration; this was duly arranged for the following Wednesday. On the designated Wednesday a well dressed gentleman arrived at Fairoaks and announced himslf as Mr Rafat. After a chat I flew for ten minutes and made a reasonable landing. He asked would I like to go to Iran with Mr Phil Smith for fourteen days and fly for the Shah's birthday celebrations, all expenses paid.
It was now September 1964 and the Company had been in business for approximately four years. We had found some premises in Weybridge which had the potential to be developed. The staff had increased by taking on two young lads to help with assembly. We had also designed and manufactured three additional servos. 1. The Musclemite which had a rotary output and was powered by a larger motor. This was encased in aluminium. 2. The Aquamite which had the same mechanism as the Musclemite but was encased in nylon with a rubber seal on the output shaft and connecting leads. This made it water repellant and was used for boats. 3. The Unimite. This was designed for simple single-channel sequential radio control and had a rotary output. I discussed Mr Rafat's request with Don and he said why not go as it would be good publicity for the company. Three weeks later Phil and I were on an aeroplane bound for Teheran with models and all necessary equipment in the hold. We arrived at Mehrabad, the main airport for Teheran, and were transported to a very nice hotel with views over the surrounding mountains. There have been reports of this trip in the modelling press in the past so I won't go over it again except to say that it was a unique experience. However there are two events that stick in my mind.
First; The events on the day of the main birthday celebrations were held in a large stadium. The main stand in which the royal family were to be seated had a canopy over the top to keep out the sun, etc. We were to launch a model from the top of this canopy. We chose the Mini Concord for safety reasons as a larger model would be dangerous if interference caused a loss of control. The view from the top of the canopy was marvellous. When the time came for us to fly, I launched the Mini Concord out over the stadium. Phil immediately mentioned that he was having problems controlling it. Single channel models were normally trimmed to fly in a large circle with occasional blips of opposite rudder to turn it in the other direction. The Mini Concord flew serenely on, flew under the canopy and over the heads of the royal family etc. and out the other side! When it arrived at the right-hand side of the stadium, Phil regained control, cut the motor and with a few blips of opposite rudder, landed it in the centre of the stadium to thunderous applause. Phil and I often wonder what the consequences would have been if it had flown a few feet lower.
Second; On the last day the Shah decreed that Mehrabad be closed for one hour and that all incoming/outgoing flights go on hold so his subjects could come and watch the flying. I started with the Concord and followed it with the Robot. As soon as one landed, Phil refuelled it and so on until the hour was up. I can truly say that I was knackered when it was over. I am happy to say that nothing was broken and all the parked aircraft were missed. You must remember that this was the first time that I had ever flown before such a vast crowd. The only other flying was in front of the royal family, etc., on a military aerodrome which was far less daunting. Incidentally the Concord had never been flown before arriving in Teheran.
On returning, the manufacture of servos continued but the orders from George were beginning to tail off due to other manufacturers' entry into the market. However we did start to receive orders for work outside of the model trade and over the next few years this began to grow. In 1968 we produced our first digital system and this was shown to the public at the 1969 Sandown Symposium. Don and I had a review of our business and we came to the conclusion that because of the entry of Japan into the model market and the Americans already in production for their home market, a huge injection of capital would be required to manufacture to the required standard. The likelihood of finding an investor with sufficient capital was small and if we did manage to find such a person he or she would require control of the business. This we were not prepared to do. Thus came the end of the manufacture of Climax equipment. As the business grew I stopped flying due to the lack of spare time and it was not until 1995 that I came back into the hobby. This came about in rather an odd way. We lived in Dockenfield, a small village in Surrey, in an old cottage with twelve acres of land. One Sunday I heard the sound of model IC engines being run. The sound came from a field on the other side of the road adjacent to the river. The Fleet & District MAC had permission to fly once a month. This aroused my interest and I joined the club and the BMFA. I mowed a patch in the centre of our field and looked around for a three-channel trainer and some radio gear. Being a Fleet Club member and nationalistic by nature, I bought a Fleet 6 channel PCM system, an Irvine 25 glow motor and a Yamamoto trainer. Having built the airframe and installed the equipment, the C of G and the radio range was checked. All was OK so I took off. It promptly tried to loop itself and I managed to get it back on the ground in one piece. The CG was again checked and it was as shown on the plan. After considerable thought it became blatently obvious, the wing section was a Clark Y and the CG was for a symmetrical section at 33% from the leading edge. The kit manufacturer also made a four-channel model with ailerons and a semi-symmetrical wing section and had not modified the drawing. I thought that this oversight was disgusting. Many new flyers to the hobby must have broken their models because of this problem. In 1996 the Fleet club appointed me Chairman; I was able to retrieve their flying field which was lost when the farmer stopped farming on the land owned by the MOD. The site is now fully licenced by Fleet Council and rented from the MOD. I gave up the Chairmanship in the year 2000 when I moved to our home in Oakhanger, Hants. During that period I also edited a quarterly newsletter. Peter Mc Dermott was also a member of the Fleet Club and I made several videos of his remarkable scale models. He could never have produced them without the support of his wife Kathy who was also his mechanic at events. During the period of fourteen years at Dockenfield I built several models apart from the Yamamoto. Aerobatics have always been an interest so I built two of Frank Van Den Bergh's Vertigo 2s, a design from 1967, used in the early world aerobatic championships with success. Then there was a Saphir 40 built from a kit and a Desire 40 built from a plan. My only effort at a scale model was a semi-scale Chipmunk powered by a Lazer 70 four stroke. An excellent motor. It was fitted with flaps and was a superb flyer. I am still great friends with Phil Smith and he gave me the plans and the fuselage bits for a Concord. I built this up with a slightly reduced span and fitted flaps. This again, like all Phil's models, flys really well. With the flaps lowered, I can literally stop it in the air in a slight breeze. I still have it and fly it occasionally to bring back memories.
Another good friend was Derek Olly of Fleet Radio Control who died in March 2006. All these friends were younger than me which makes me think how fortunate I am to still be here. Chris was a true pioneer of early radio control having built all the radio himself in the early days and designed his famous Uproar. In the year 2000 we sold Abbotts Farm in Dockenfield to my eldest son Paul and bought a semi-detached house in Oakhanger, Hants, from my youngest son Stephen who also had five acres of land behind the houses. Abbotts Farm was becoming difficult work-wise and the move was sensible. This village is all one could wish for with a marvellous community of friendly people. All my life I have flown Mode 1 with the transmitters located in a tray hung from my neck. Obviously a throwback from the early reed days when steering was done with the right hand and pitch controlled by the left. Disaster struck in September 2006 when I started to notice a lack of feeling between my thumb and first finger in both hands. It got so bad that I could not feel the sticks so had to stop flying. The problem was diagnosed as the Carpal Tunnel Syndrome where the channel for the nerves to the thumb and first finger become impeded where they pass through the wrist. This required an operation in each wrist, the last of which occurred in Sept 2007. I was warned that due to my age I might not recover completely. I am pleased to say that some of the feeling has returned and I am learning to fly with my thumbs on top of the sticks with the Tx supported by a neck strap. Needless to say my confidence has been severely dented. To relieve the burden of carrying heavy field boxes I have turned to electric power. With the advent of Lipo batteries this is now a practical proposition. Tomorrow (13th September) Betty and I are going down to see Phil and Joyce Smith for a lunch. Phil is coming up to his 92nd birthday. He too has taken up electric flying. What a remarkable man! Best wishes to you all. |
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PLANCK
The Brief :
Initial
Design :
Considering the pros and cons of Correx, I decided to omit the profile fuselage and utilise a box section. Similarly there was no real requirement for intermediate wing ribs so I retained only the tip and root ribs. Correx is fairly weak until formed into a section. Also it works easier cutting and folding along or perpendicular to the flutes. Angles in between are a pain. Planck 2 emerged. Time to start cutting.
New sheet of Correx to all major parts cut out in around 15 minutes.
Experimenting with
wing sections I soon discovered that I could achieve a decent curved aerofoil
as opposed to the angular F117 Stealth Fighter shape I had originally
envisaged. The spar required lamination to gain strength. Preparation
for bonding Correx involves cleaning with Meths and lamination involves
double sided tape. The spar was to be built in port and starboard lengths
with the centre open to accomodate the bellcrank. Bamboo skewers fit perfectly
into the flutes and are very stiff.
Unfortunately it's
a real pain trying to mount a bellcrank in amongst circular section skewers.
Good old weapons grade balsa to the rescue. It is not common to use the
spar to mount the bellcrank but with additional structure to cope with
the big hole in the middle it seems to work. Additionally the spar in
the Correx wing contributes less to the lateral stiffness than a conventional
built up wing. It could be argued that its main job is merely to keep
the upper and lower surfaces a respectable distance apart to create an
aerofoil. Note thin ply lining as denser material to bear the bellcranck
pivot bolt. This bolt is carried above and below the spar to act as a
locator when installing the spar into the wing.
Lights, camera, action.......well
lights at least. 3 mm ultra-bright LEDs provide the illumination. Using
a source voltage of nominally 5V I will have to wire them all in parallel
with one current limiting resistor per LED. Again the spar comes in useful
for purposes other than structural - the LEDs are mounted along the neutral
axis, three facing forward and two facing aft per wing half.
Next the wing ribs.
The ones at each tip simply cap the wing with the inboard one doing the
additional job of supporting the lead-out guides. I'm not really sure
whether I need centre section ribs but as they are made from Depron there
is almost no weight penalty. For additional strength and bracing I have
added gussets.
Wing assembly is
rather unconventional due to the decision to use Correx. Even well scored
to form the leading edge it is still a little springy. Additionally it
proved very difficult to properly locate and square the spar and ribs
so I decided to assemble these separately using the drawing as a guide,
then wrap the Correx around this. The extended bellcrank pivot bolt comes
in really useful here to locate the spar and retain it in position. Shoe
Goo was used as it is a clear adhesive that seems to get a good grip on
Correx. On the Mugis I used Evostick Contact but this is near beige in
colour and shows through translucent materials. I also needed a lot of
clamps and a few strips of wood to close off the trailing edge. I'm not
sure what aerofoil section the wing is ..... let's call it ES001.
Next for the LEDs
is the tail. They are mounted differently here by being inserted into
the flutes of the Correx. This allows for a very slimline installation
with no additional structure required to support them. The effect is a
bright shaft of light along the flute with greatly diffused light in the
flutes on either side. The tailplane has an integral elevator, hinged
by slitting the Correx on one side. The tailplane is stiffened by insertion
of a bamboo skewer at the leading edge. Note the change of tailfin to
rectangular - more in the spirit of a plank.
Keeping within the
SPAD spirit of this model, the fuselage is merely a parallel sided box
section. Keen-eyed viewers will spot that it has five sides, the extra
one being a double layer at the underside. This serves a few purposes
: additional strength at low weight penalty, maximum contact area for
adhesive to tie it all together and double door security for the access
hatches. The small cutouts marked are to take tabs in the formers. Small
area adhesive joints in Correx offer little security; additionally Correx
is flexible, which the liteply to be used for the formers is not, so a
tab and slot system offers good strength and could even be used dry.
Having stated earlier
that Correx is best used along or across the flutes at 90 degrees, and
originally intending to have an angular aerofoil section (like a Jedelsky
wing) I have now had to cut curved apertures in the fuselage sides to
take the wing. The fuselage/wing joint will not be the prettiest I have
ever made. I also faced the problem of trying to slide the wing through
the fuselage with the elevator pushrod in the way. After consideration
of various options - forward and aft fuselage sections joined by skewers,
port and starboard fuselage halves joined by tape, etc. - I eventually
decided on the simplest solution, a slot for the pushrod and a bit of
flexing of the Correx. I have also cut the access hatches at this stage.
Note also the additional slots for tail surfaces and wing/battery cradle.The
second picture shows the collection of Correx parts prior to final assembly.
Aforesaid cradle.
Again a part of the structure having to earn its keep by being multifunctional.
Firstly it gives rigidity to the fuselage which, being a four sided shape
has no inherent rigidity. Formers F2 and F3 provide the cross sectional
rigidity and are connected structurally by the plate which provides the
longitudinal rigidity. F2 and F3 are also used to mount fuselage LEDs
whilst the plate forms the upper part of the battery compartment. The
plan is also to mount one half of the Velcro tape for the battery on the
underside of the plate. The wing position is cut to be clear of the plate.
Motor: Emax
CF2812 1534kVA 16A brushless The motor, ESC and prop combination work well in my Multiplex Twinstar. The ESC is a bit on the heavy and large side but has thus far not burst into flames like it's predecessor. The ESC will also be enclosed so a higher than necessary rating should cope. Of particular interest and very rare in these parts is the timer. It is produced by Jean-Marie Piednoir in France and weighs less than a flea's testicle. It is specifically for the control line market but its origins can be traced to the free flight world where the days of the burning dethermaliser fuse or clockwork timer may be numbered. It's programming parameters are:
All this is done
by sequences of button pushing on its one and only button. Damned clever
these Continentals. Ironically it can ony be purchased via Bob Selman
Designs in the States so it is well travelled. It plugs into the ESC where
you would normally have the receiver.
Well it ain't pretty,
but it was never meant to be admired during daylight hours.
This model was really
meant to be a creature of the night so here you see it in all its "fairground"
glory.
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Peter Cabrol's Story
It
was whilst living at Dockenfield I met several flyers from the past. Probably
the most famous was Chris Olsen and his lifelong friend Stewart Uwins.
We would meet up for an occasional pub lunch and they both came to Dockenfield
for a fly-in on two occasions. I have videos of them flying. Sadly they
are no longer with us, Chris having died in October 2001 and Stewart in
July 2006. [Picture,
left, shows Stewart Uwins, Peter C and Chris Olsen taken in 1987 at Peter's
home in Dockenfield. Two Uproars and Peter's Saphir.]
