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Old 08-27-2007, 12:54 PM
gpontis gpontis is offline
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Join Date: Jul 2007
State: Calif
City: Palomar Park
Country: USA
Posts: 7
Excessive head speed on VE, need setup advice

Voyager E, Feigao 540S-10 with 17t pinion, 3S LiPo, G410T with HS-5925MG

I have been flying this heli at a basic level using a HiMax 3200 KV motor and 15t pinion. After a crash I was trying to figure out what went wrong and was led to low head speed. Sure enough, it was only 1410 RPM. I also measured the battery current at 25A while pinned down with full up collective. So I purchased and installed this Feigao motor. It is a good size for this heli in terms of size and fit.

While playing with pitch and throttle curves, I had the bird pretty well reved up on the ground, and before lift-off one of the tail grip screws let loose. It was broken clean off right where it exits the aluminum tail hub. I replaced the now bent shaft and hub but did not have extra 2x10mm screws to reinstall the TR grips and blades. I tested the main rotor RPM with the skids pinned down. As best I could tell, it was able to rev the head to 2000 RPM or more. I am not sure exactly what the pitch was in this condition, but it was at least 5 degrees up and probably closer to 7-8. I am thinking that this is excessive for a stock head and wood blades, and was probably the cause of the TR self-destruct. It would also explain the strong climb performance that this bird has now. I might add that I had to reduce the gyro gain to compensate for the increased tail rotor speed. Makes sense in retrospect but I did not anticipate it.

So here's what surprises me. This motor is rated at 3524 KV, well under the 39xx KV for the popular hacker motor. I would have guessed that this one and the Hacker are of comparable torque, and did not expect to get this kind of headspeed. Did I misjudge the motor/battery combination or were the measurement conditions inappropriate ?

Once I get the right pinion in there, are there any suggestions for pitch and throttle curves for normal mode ? I have the mechanical setup as per the VE manual.

Thanks,
George
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