Broken Futaba S9254

[derrill84]

I have a Raptor 50 V2 with a Hyper 50 running a head speed of 1950 rmp and an Aerospire Multigov Pro. Gy401 W/ 9254 servo and radix 95 mm Tail blades. My radio is JR XP7202. The single wire lead from the gyro (receiver sensitivity lead) is plugged in to the gear channel ch5. The gain is set to 84% as per the recommendations on Raptor Technique.

So here is the deal.
I was flying today the wind was about 10mph. In fast FF I was getting the odd tail kick, so I thought that the gain might be a little to high. I landed so I could adjust it and when it touched down very softly! it landed in a bit of a low spot, so my tail blades cut a littl more gras than usual but I didn’t think much of it. Made my adjustment and went to take off, as soon as the heli got light on the skids it began to spin. I shut her off and went back to check it out, the problem was simple the tail servo gears were broken. This heli has never been crashed or what I would consider a hard landing.

So my question is, can the servo gain be set high enough to brake the gears or was it the bit of grass cutting or a little of both. Your thoughts would be greatly appreciated.

Thanks Derrill

[DavidH]

My opinion you have the gain to high. IF that 84% is the actual gain of the gyro that is too high. Some radios 0-50% is the gain in one mode and 50-100% is the gain in the other mode.
For example 84% may actually be a gain of 32%. Since 84 is 16 less than a 100 and 16 X 2 =32%. If it is actually 84% gain, then that is too much.
I would think getting the tail blades in the grass broke the gears in the servo.

David

[BarracudaHockey]

JR is 50 to 100 is heading hold so he's in the 34x2 or 68 percent gain range. Though its probably a bit higher than that since the mapping between Futaba and JR are not linear.

[derrill84]

Thank you for the info. I will play with lower gain settings and try to keep the blades out of the Grass.

Derrill