Low motor speed
#1
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Low motor speed
I bought a park pilot from Tower Hobbies for my 9 yr old girl so she would have something to fly when she goes with me to the field. I normally fly glow. but I thought electric would be fun to try. Ok here is the problem. I bought the plane with motor and battery. I elected to use my spare fataba radio so she could get use to a 4 channel radio if she should want to move up to a glow trainer. So I bought the mini servos and Great Planes mini reciever and short Fataba crystal to go with my transmitter. Everything works like it should but the motor is not going fast enough. The battery is fully charged and seems to work properly, but when I bypass the motor without the radio it runs a lot faster. Can't get enough speed to fly. It flys slowly to the ground, can't get any lift. I am sure the motor is not running fast enough. Am I missing something. Please help. She wants to fly. This was a Christmas present we put together and the weather is getting better. Thanks
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RE: Low motor speed
To me it is criminal that Tower can sell a plane like that - a direct drive 280 motor with a 5" prop, running on 6 NiMh cells surely CANNOT produce [I'm guessing here] more than 3oz thrust! I didn't even know that anyone used 6 NiMh cells for ANYTHING.
Edit: Unfortunately this educated guess was close to the mark - I put the numbers into MotoCalc - 2.3A, 10W and 2.6oz thrust!!!!]. Since rule of thumb says you need ~40W/lb for a trainer type plane to fly, and/or a 1:2 thrust to weight ratio - there is no way this aircraft can hope to reach those criteria.
I can't think of a perfect solution - ideally you want a geared 300 motor in there, but perhaps a Mega MIG 280 motor [direct drive] would be a possibility - according to H-L on 6v @ 6A it can produce 7oz of thrust with a 6x4 prop. That's a great improvement.
Cheers, Phil
Edit: Unfortunately this educated guess was close to the mark - I put the numbers into MotoCalc - 2.3A, 10W and 2.6oz thrust!!!!]. Since rule of thumb says you need ~40W/lb for a trainer type plane to fly, and/or a 1:2 thrust to weight ratio - there is no way this aircraft can hope to reach those criteria.
I can't think of a perfect solution - ideally you want a geared 300 motor in there, but perhaps a Mega MIG 280 motor [direct drive] would be a possibility - according to H-L on 6v @ 6A it can produce 7oz of thrust with a 6x4 prop. That's a great improvement.
Cheers, Phil
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RE: Low motor speed
Thanks for the info Doc, but since the motor runs faster if I bypass the transmitter, could there be some quick fix on the transmitter or adjustment on the transmitter to obtain more speed. Its a 4 channel Fataba and you can slide the slide adjuster beside the throttle knob up all the way and gain a little but the throttle does not begin to turn the prop untill I am about half way up on the throttle.
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RE: Low motor speed
Certainly sounds like a problem with the end points on the throttle - what ESC do you have? Most better ESC's (e.g. Castle Creations) automatically adjust for the full throttle range. Someone out here must know what to do - I haven't a clue where to begin, since I've been spoilt by using Pixie and Phoenix ESCs.
If all else fails buy your girl a $35 Slow Stick - THAT would be perfect!
Cheers, Phil
If all else fails buy your girl a $35 Slow Stick - THAT would be perfect!
Cheers, Phil
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RE: Low motor speed
Can't tell what kind of speed control. I bought a Great Planes mini reciever to use. Any way, to get the plane airborne I put the throttle on the rudder channel and the rudder on the aileron channel and elevator on the elevator channel. It will fly and easy to control I just have to use the rudder control and hold it to the left and it has plento of power now. But training my 9 yr daughter to fly leaves a little inconsistancy between this set up and my trainer she is going to fly. Thanks for the help. I may contact Tower Hobbies and find out what the deal is on the speed control.
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RE: Low motor speed
Are you using an electronic speed control? It sounds like your plugging the motor directly into a receiver channel. You did not mention an ESC. You only mentioned buying a receiver. You could be trying to run the motor on 5 volt servo pulses.
OK, I just read the add for the plane. It says it includes a speed control.
I second the Slow Stick recommendation. I love to fly mine. I learned on it with no help except from this forum.
OK, I just read the add for the plane. It says it includes a speed control.
I second the Slow Stick recommendation. I love to fly mine. I learned on it with no help except from this forum.
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RE: Low motor speed
If your radio happens to have ATV (adjustable travel volume) or EPA (end point adjustment), make sure these are set to the maximum on the throttle channel. Most simple 4-channel transmitters don't have these adjustments, though.
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RE: Low motor speed
Thanks for the input guys. I sent a little note to Fataba and for now I will fly the thing with the throttle on the rudder channel. I really don't want to sink any more money in this airplane. I just finished building a Profile 38 and have too much $ in both planes already. Once again thanks and this web site is great.