They are bizarre, but actually quite user friendly - get it about right and off they go. The Russians held the helicopter duration record for ages with one - in the '50's, 60's Russians and Brits and who else would build these things with built up wings and small diesel engines with central tanks.. and fly forever. Too much fun not to build one. It's a 1-1/2 - 2 hour build plus finishing touches. Run a Sure Start on pressure, solves the centrifugal fuel delivery nightmares. Depending what engine/tank arrangement you use, I've had examples where the engine had to be almost choking on fuel before I could let it go. Others needed only a minor offset. Helps when you take a couple of minutes to plan ahead on the fuel system..
Needs an LED strip and small LiPO at the hub.
I've built two-a small 020 sized one from Aeromodeller ca 1070 or 71 the 'chip chopper' by Eric Clutton (yes the same one who designed FRED, and known to you in the US as 'Dr Diesel'-this would not fly on a Pee Wee no matter what I did-set it rich and it leaned out and quit-set it lean and it richened up and quit.....I eventually replaced the Pee Wee with a G-Mark 03 and got it to fly-though the G-Mark had to be mounted with the cylinder canted inwards at 45 degrees-after that it proved particularly stable and reliable and would climb till it was out of sight-and autorotate down. A larger 049 version-from 'Model Builder' has not been successful-so far I've tried a Cox 'product engine', DC Wasp and PAW 55-all without success-and with all sorts of varied tank locations. I think a bladder is the only option for this one....obviously the larger you make them, the larger the rotation radius-and hence the more centrifugal force on the fuel. The small 010 sized one in this thread should give few problems in fuel feed with the 010 tank mount-but it still might require canting the motor...
A thought just strikes me-I don't think ANYONE has done an electric one yet......just think-a small brushless, a small Lipo-plus a motor run timer.......no more fuel feed issues.....who's going to be first? The pic shows the unsuccessful 049 McCutchen which I'll revisit one day...
ChrisM
'ffkiwi'
