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Old Sep 08, 2007, 02:11 PM
boffin99 is offline
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Peterborough, England
Joined Apr 2006
24 Posts
Hi guys,

This appears to be a very well subscribed thread full of most interesting and innovative designs. I thought you may appreciate my own efforts. These are electric, canard and free flight. Yes, I let them go and let them do as they wish……..

Rezenebe : This is a Jim Fullarton design and I decided to go for broke and set it up with a GWS EDF50 ducted fan as it had been sitting on the shelf far too long and I wanted to see if I could tame a ducted fan for free flight. Power was by a 250 mah single cell LiPo and timed using a simple MOSFET timer. This is the only model that I launch upwards as if I get the launch angle wrong, the model just nods away until it reaches an equilibrium. It is a heavy weather Ebenezer and is very stable in pitch and yaw , far more than any conventional model that I own. It is also very quick , which is no surprise as the motor runs at > 3amps static……most impressive for a 12mm brushed budget motor. The model is no lightweight at 88gms and I get 8-10 30 sec runs before the battery needs pumping up. The wing loading on this model assures me that there is only a 1% chance of it being grabbed by a thermal. If it does then I make another as the model cost is only some £20.

Cekoadon : I built this from photographs on Colin Hutchinson’s website. IMHO it is the ugliest model I have ever seen with the strangest aerodynamic layout. It had to be built and was. I wish I could say that it flew off the board but it did not. It suffered undamped , unstable roll oscillations which were eventually corrected with increased foreplane area, dihedral, revised CoG and reduced decalage. This model should not fly, yet it does and very handsomely. It has a RobotBirds power train comprising ann HCS 40Watt outrunner and a budget Tower Pro ESC driven by a 3 cell 450 mah LiPo . The power taken by the motor and the motor run time is controlled by a PIC chip based FlytProf controller. The model weighs 160 gm and gives me 10-12 30 second flights before I need to charge the battery. The FlytProf system gives me a DT facility which I use to crack the rudder over to spin the model in. So far it has behaved itself and not tried to escape......but it will, it is of French heritage and has a mind of its own! (TIC).

There is something special about a canard , the way it sits in the air and the quite unexpected yaw and pitch stability offered by these two models. I will continue with their development and will post if there is any interest?

Regards Ian (UK)
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Last edited by boffin99; Sep 09, 2007 at 05:37 AM.
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