Robin Colbourne

Jon, Having just come across this thread, I read through it and saw you mentioned issues with overheating preventing various configurations of engine and engine features. Given that Lasers are so popular in scale models, have you considered doing a liquid cooled Laser with, say a Perry (vibration driven) pump to circulate the coolant to a remote radiator? With telemetry being all the rage these days, the pilot could open up a restrictor valve if the engine started getting to hot, or you could have a fully automated closed loop control system in the model. As petrols run hotter, it might be an help there if you're going that way, and those inline twins become more viable as well. There was a twin engined scale control line model with liquid cooling back in the 60s or 70s, but I can't find a description of it at the moment.

Engine thrust line is important on powered gliders, otherwise as Daren Graham says, you get large trim changes between full power and idle/glide. If the engine is up on a pylon, you need up thrust, whilst on a nose mounted engine you need downthrust as the engine is well below the polyhedral wing. In the Rookie Major video, you can see how there is no significant upthrust on the pylon mounted engine, which explains the quite alarming dive immediately after launch. fortunately the pilot catches this in time with a fistful of up elevator. If you can pick up a copy of the old Radio Modeller book 'Radio Control Soaring' by Dave Hughes there is a lot of info on powered gliders and trimming them. **LINK** With regard to the engine choice, you can always choose a slightly heavier grade of balsa for the tail surfaces which will balance out the slightly heavier engine if you go with the .15.   Edited By Robin Colbourne on 18/12/2015 02:24:05

I go with IanN, contrasting dayglow colours top and bottom are good. A dayglow orange strip wrapped around the leading edge from root to tip helps too when the model is coming towards you on approach. Plummet's suggestion of dark underneath (against the sky) and light on top (against ground and trees) are good too. Whilst a dark colour may be good against the sky, its not so good against the background of trees on the approach on that last flight of the day (the one when you realize you should have landed earlier or not taken off at all...). The RAF sponsored some research into increasing visibility to try and stop Air Cadet aircraft banging into each other (its reprinted here on a German glider manufacturer's website): **LINK**

These ads rely on the watcher 'joining the dots' to get the subliminal message. i.e., Bold washing powder is good for removing blood from children's clothes...

Hi Ian I ran an adult education course for a couple of years in which I taught 45 people to build and fly. In addition I used to give one to one lessons using a buddy box, so I got to fly a great many HiBoys as well as just about every other trainer that was around at the time. If you really want to build a model, you could look on the likes of Gumtree, Ebay and Preloved to see what unstarted kits are on offer. You might pick something up for a song. As others have said, the Hiboy was heavy, so a less than perfect landing would break the saddles holding the noseleg which would result in it getting torn out, and usually a broken prop too. If you could get the softer Micromold saddle clamps they stood up better than the SLEC ones supplied in the kit. The Mk1 HiBoy (identified by the longer tank cover and steeper windcreen) had its main gear too far back, so would need incredible distances to get airborne as built. I found some people could cope with a four channel model straight away, whereas others, generally the 50 year olds upward, were better off with a three channel model with rudder/elevator/thottle. A few models of the period that really stood out for the period were: MFA Yamamoto 3 Channel - Superb model for older fliers, rubber banded on main gear, steerable noseleg, all sheet balsa fuselage and tail surfaces and a strong foam veneered wing. Don't fly in a strong wind though as the flat bottom wing doesn't penetrate that well. DB Tyro One pupil built one of these and flew it from take off to landing (albeit in flat calm conditions) on only his second go with an R/C model. He was a retired British Airways Concorde engineer, o it was a beautifully prepared model, but even so.. . DB Mascot - Nice model, but the one I flew had a vicious flick inot a spin if you stalled it. It might may have been just that one though. Precedent Flyboy - Incredibly difficult on the ground, Once in the air it was ok, but needed more fin area. Cambria Instructor - Nice tough model available as for a 20 or a 40, mine chugged around on an OS20 four stroke. Thunder Tiger Trainer - Flew nicely The Mk 2 had some interesting features to help it go together quickly. Irvine Tutor/Boomerang/Arising Star All these type models are good trainers but can be a bit delicate if you cartwheel them. Expect to split the covering, and get some splits in the ribs. They are ok if you don't mind a model with a few patches on it or are happy to buy new wings and tails as spares. There is a lot to be said for starting with a two channel glider which you can practice gliding into some long grass from a hand launch. Once you get the hang of the flare and landing, it won't be a big deal when you move on to landing your power model. There is also as others have said, a lot to be gained by starting with a tough electric powered foam model, which you can learn to fly on without worrying about cantankerous engines and covering damage on every flight. One thing I would say, the bigger the model, the slower it appears in the air, and that is a big help when learning, so your brain can keep up with what it is doing. Good luck!       Edited By Robin Colbourne on 17/12/2015 13:38:55 Edited By Robin Colbourne on 17/12/2015 13:59:01

Plenty of good advice already (pin holes in fuel pipes, leaky needle valve assenblies etc.) but a few more things to check: Is the clunk sucking itself on to the back of the tank? A saw slot across the end of the clunk can prevent this, otherwise shorten the clunk tube 6 to 8mm. If the model has come to a stop suddenly or been stored on its nose, the clunk can find its way to the front of the tank and get stuck there. When the model accelerates forward, the fuel goes to the back of the tank and the clunk is sucking in air. One model died every time just after it rotated into the air on takeoff. Tried everything, eventually a new plug cured it, I still don't know why. If you have a pressure pipe going to the tank from the silencer, sometimes you can get a blockage in this, causing the engine to lean and die. Try flying it with out the cowl. Air flow through cowls is often not the direction or rate you would think. The engine may be heating up faster than cooling air can cool it. As well as a ground run, get someone to hold the model vertically nose up with the engine running (making sure no one is inline with the prop arc just in case a blade comes off), now go from idle to full power, hold it there for 10 seconds or so, back to idle and repeat a few times. If it dies its far too lean (or has another cause of fuel starvation), if the exhaust has less smoke in it at full power than lower down the range, its getting a bit leaner, and the increase in rpm in the air the others mentioned may be the final straw. After a running at low revs for a while, fuel may build up in the crankcase, hence the need to go to full throttle and back a few times to clear this. With an inverted installation, the tank centre line needs to be on the same level as the centre line of the main needle.   Edited By Robin Colbourne on 06/12/2015 18:58:41

Bob Cotsford wrote: ..and I really hate drivers who overlap spaces in car parks with their panzer wagons so I have to squeeze my Mondeo in and end up chipping my door paint What, like this? Edited By Robin Colbourne on 27/12/2014 21:39:56

Age:  46 1. IC Sport  2.  Slope Soarers  3.  Electric Helicopters  First proper model:  Veron Classic towline glider when aged 9, then saved up for my first (secondhand) set of Fleet R/C gear which I bought at age 11.  First R/C model:  Bowman's Simpleton glider.

When I was working a contract at Airbus in Filton I joined the Bristol Radio Controlled Model Aircraft Club which flies near Thornbury.  They are a very friendly club with a nice site remote from houses.  They will want you to do your 'A' test before you can fly solo, but that isn't too onerous, and they generally prefer you not to fly alone.  The club flies IC, electric and helicopters.  It isn't really suitable for towline gliders.  One of the club members is one of the country's foremost scale builders, and there are others who fly jets and aerobatic models.  They have club nights at a hall in Thornbury and informal gatherings at a local pub in a nearby village.  Here is the club's website:  http://84.18.207.67/~ac/ Denzil, who is the club chairman is a really nice chap, and I had the pleasure of helping him learn to fly whilst I was there.  Good luck and happy flying.  Robin

Hi Stephen,   I go along with Bert, I'm also pretty sure your model is a Bobcat.  As Bert said these were built by a chap called Bob (surprise,surprise) who used them for giving instruction at Chobham Common in Surrey, and possibly other nearby sites in the mid 90s, and sold quite a few of them to his pupils.  I didn't know his surname.   They are a pretty good basic trainer and from the looks of the fin and wing, he may have evolved it from an MFA Yamamoto.     I gave instruction to several people who bought them, and was always a bit concerned about the potential for damage to the fuselage from the wing twisting in a cartwheel, but I don''t recall seeing one get broken this way.  Generally, like the Yamamoto, they were very robust.   Most of the ones I saw had a wide tailwheel undercarriage which was a bit soft, and resulted in some interesting takeoff runs.  Your tricycle undercarriage may be better behaved.   I hope you get a lot of flying out of yours.  It sounds as if the wing incidence may be wrong (packing required under trailing edge), or the engine needs down thrust.  My first successful R/C model, which was a 3ch Yamamoto, did exactly the same thing.  I think I 'cured' mine in the short term with bags of down elevator trim.    You may get on better with a smaller engine in it, as that wing section generates loads of lift when dragged along by a 0.40 size engine.  A 0.25 should be more than adequate. Best wishes   Robin

Hi Stephen,   I''m pretty sure your model is a Bobcat.  These were built by a chap called Bob (surprise,surprise) who used them for giving instruction at Chobham Common in Surrey, and possibly other nearby sites in the mid 90s, and sold quite a few of them to his pupils.  I don''t know his surname.   They are a pretty good basic trainer and from the looks of the fin and wing, he may have evolved it from an MFA Yamamoto.     I was always a bit concerned about damage from the wing twisting in a cartwheel, but I don''t recall seeing one get broken this way.  Generally, like the Yamamoto, they were very robust.   Most of the ones I saw had a wide tailwheel undercarriage which was a bit soft, and resulted in some interesting takeoff runs.  Your tricycle undercarriage may be better behaved.   I hope you get a lot of flying out of yours!   Best wishes   Robin    

Hi all, Thanks for the responses, I've been away without internet access for a few days so missed your replies.   So it did make the news after all.  Well done BBC! The Royal Aeronautical Society at Farnborough put on a lecture comparing Samuel Cody and A V Roe which was very informative.  John Bunting, Yes, Jim is my Dad.  He spent a couple of years in the early fifties, rebuilding Aeronca 100 G-AEWU at RAE Farnborough, only to have the Bessonneau hangar in which she was being kept, collapse on top of her when the snow covering the hangar turned to slush.  Evidently th hangar wasn't fitted with the snow poles it should have had.  Dad had flown the Aeronca to various rallies and around Northern France before she was destroyed.  I'm glad to hear you got a flight in her.  Dad is still a member of the Aeronca Association.  He last flew in one when Nick Chittenden took him up in his C3, G-AEFT, at Popham.  If you have any pictures of G-AEWU, I would be very grateful of copies and would cover all expenses.  Cheers,  Robin

100 Years ago today, Samuel Franklin Cody made the first aeroplane flight in this country, on the site of what is now the airfield at Farnborough.   Given the number of people who have since worked in this country's aircraft industry and the revenue it has generated for the country's coffers, who agrees that there doesn't seem like a lot of recognition of this event? Is this because: Samuel Cody was an American citizen at the time?Meddling ill-informed politicians have since scuppered most of the aircraft industry and are collectively too embarrassed to think about it?Aeroplanes are no longer politically correct, and are just regarded as weapons of war and pollution generators? Something else? What do you think?  Robin P.S.  I did go to Farnborough today and see the interesting, but fairly meagre flypast and the wonderful Cody Flyer replica.

"Wot?"  "Not another model, dear!" "But I won this one; honestly!!!  Can you please stop hitting me with that fuselage now?"  "For Chris' sake, I don't know what all the Foss is about...  Will I ever trainer to appreciate them?"

If you were a regular at the Sandown Park shows in the late 70s and early 80s, you couldn't have failed to see these big control liners flying combat and aerobatics.  They were tough .40 powered birds and it looked as if the same ones came back year after year, just a bit more oil soaked on each occasion.  They had a jet fighter-ish profile fuselage about 3ft long of 1/2" balsa, foam wings of about 4ft span, and what I think were wooden tail surfaces.  The wings were usually covered in garish wrapping paper. I have trawled the internet trying to find a picture, so  can build something similar. What I would really  like are enough dimensions to get a close likeness, i.e. wing root & tip chord, wing section, nose length, wing to tail distance, tailplane span & chord &  elevator chord; and did they have flaps?  I noticed the Barton Model Club have some references to them on their forum, but no pictures that I can see.  Can anyone shed any light?    Thanks  Robin

I once heard a comment, that in the old days, children would knock on people's doors and run away.  These days its called, 'Parcelforce'....

Ernie's dead right!!!  We should get a free prescription for model stuff.  Healthier and far more effective than filling ourselves with 'happy  pills'.  We don't even need to get depressed by weather forecasts;  to a modeller there are only two sorts of weather, 'building' and 'flying'!  Seriously though, I reckon that regular flying can help stave off having to wear glasses, as model flying forces your eyes to focus on a distant object for lengthy periods, which is the perfect antidote to hours sitting in front of a computer screen.  If we are entering a recession, the positive side of it from a modelling point of view, is that many modellers may discover that there are ways to have fun without instant recourse to the credit card.   Dust off some of those old airframes and engines in the corners of the attic, maybe customise them a bit, and see what they will do with the flying skills you have learned since they last saw light of day. 

Air Combat.... I've just had an email from my brother Stephen, who lives in Canberra, Australia.  He has been flying an electric powered Catalina from a lake there, for the last few weeks.  Here is this morning's instalment: ' The trouble with these flying boats is that are very vulnerable in dog fights. I was flying along minding my own business when two 'Nazi' plovers came out of the Sun and attacked the 'Cat'. One managed to break the tailplane and the other managed to tip the model into a dive and as I was only about fifty feet up there was no room to recover. Unfortunately I was also in the middle of the lake. Luckily the model ended the right way up , so that I could taxi back to the shore. The fuselage was split open and I never found the broken piece of tailplane. I should be able to repair it fairly soon though.' Stephen He often got attacked on his hang glider by Australian magpies and various types of eagle.  Fortunately they would go for the nose of the glider where the birds thought its eyes were, and not the 'food' underneath. Their talons made a right mess of the hang glider though. Has anyone else had problems with the feathered 'airspace users'?

My brother, Stephen, who lives near Canberra, in Australia, has just bought one of the 1.4 metre span ready to fly Guanli Catalina/PBYs that are on eBay.  He has posted a video of the first flight here:  http://www.rcgroups.com/forums/showthread.php?t=917117  He said that it tended to pitch up a bit on the first flight, and that the tip float strut was a bit weak, hence the ground (water?) loops before take off.  This was the first flight, so I'm hoping for some better low and slow videos including a landing.   It is not totally scale, as the observation bubbles are a bit smaller than they should be, but it still captures the gorgeous look of the full-size Catalina.

I've loved the Curtiss P-40 ever since I first saw the Revell 1:32 scale Flying Tigers model.  This one looks gorgeous, and it flies.  What wouldn't I do to win this!

Furry?  Looks a real pussycat!