New scratch built finished
04-03-2011, 05:45 PM
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New scratch built finished
I posted about connectors last week, I got EC3.
The plane shown is my own design. it is simmilar to somethng I made when I was 14. Back then one used a Cox .047 and "standard" size servos. I think I was flying 27 MHz. It did fly and provided lots of summertime fun.
This one uses a 375 size electric that draws about 11 amps. The battery is a 3c 1800 Ah lipo. The weight came out at 2# 2 oz. The wing area is 425 sq inches. That gives a wing loading of only 8.8 oz./sq foot. The airfoil is midway bwtween a clark y and a semisymetrical. It is 20% thick and the leading edge is pretty blunt. It has about 9* of dehedrial.
I flew it today. It was tail heavy but still very flyable. The motor has pleanty of power. I moved the CG foreward a bit and added some down thrust. I think it will be close to right next time. It is was easy to fly stable, slow and bleeds airspeed. Perfect for a trainer, IMHO.
As is my 6-year old son was able to fly it a bit on a buddy box. I am looking foreward to getting it dialed in and letting him fly it on a calm day. I think he'll catch on fast.
Thanks for the help on the motor selection and batery connector help.
The plane shown is my own design. it is simmilar to somethng I made when I was 14. Back then one used a Cox .047 and "standard" size servos. I think I was flying 27 MHz. It did fly and provided lots of summertime fun.
This one uses a 375 size electric that draws about 11 amps. The battery is a 3c 1800 Ah lipo. The weight came out at 2# 2 oz. The wing area is 425 sq inches. That gives a wing loading of only 8.8 oz./sq foot. The airfoil is midway bwtween a clark y and a semisymetrical. It is 20% thick and the leading edge is pretty blunt. It has about 9* of dehedrial.
I flew it today. It was tail heavy but still very flyable. The motor has pleanty of power. I moved the CG foreward a bit and added some down thrust. I think it will be close to right next time. It is was easy to fly stable, slow and bleeds airspeed. Perfect for a trainer, IMHO.
As is my 6-year old son was able to fly it a bit on a buddy box. I am looking foreward to getting it dialed in and letting him fly it on a calm day. I think he'll catch on fast.
Thanks for the help on the motor selection and batery connector help.
04-18-2011, 04:28 PM
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RE: New scratch built finished
Thank you.
I have about 20 flights on it now. It does to some odd things. Despite lots of down thrust it always pitches up at full speed. I can't figure that except that the airfoil I made has that property. Second, it does not self stabalize for roll. I have a bunch of dehedrial and it still eventually begins a death spiral. It is nothing that a tap on the rudder won't fix but it is annoying. I am thinking of a thinner airfoil and extra dehedrial on the outtermost 1/3 of the wing, like old timer free flight types.
It does fly for a really long time. It maintains altitude at 1/2 speed, about 2 amps. That is fun, it might be able to go 20-30 minuets on an 1800 mah battery. Boring but interesting.
I have about 20 flights on it now. It does to some odd things. Despite lots of down thrust it always pitches up at full speed. I can't figure that except that the airfoil I made has that property. Second, it does not self stabalize for roll. I have a bunch of dehedrial and it still eventually begins a death spiral. It is nothing that a tap on the rudder won't fix but it is annoying. I am thinking of a thinner airfoil and extra dehedrial on the outtermost 1/3 of the wing, like old timer free flight types.
It does fly for a really long time. It maintains altitude at 1/2 speed, about 2 amps. That is fun, it might be able to go 20-30 minuets on an 1800 mah battery. Boring but interesting.
