Hawk21

My Feedback: (7)

Hi,
I am having a problem with the tail on my mx400, the servo moves the tail freely both sides, when I applied
power at certain moment the servo cant move the tail. The gyro is a 401 and the servo is a futaba 9650. I tried a new 401 gyro and a hitec 5084 and still the same. I am running out of ideas for fixing this.

dragus359

My Feedback: (1)

Had the same problem a while ago with my Axe 400.  I don't know if the MX400 is torque tube or belt-driven, but since my Axe 400 is belt-driven, I will assume that the MX400 is too. When this happened to me it was because one of my belt pulleys wore out.  On the Axe 400, the pulley gears are composed of two parts threaded together & the thread for the pulley gear located in the frame striped  over time which caused my belt to lose traction at higher RPMs. I simply replaced the gear and the problem went away. Hope this helps!

Hawk21

My Feedback: (7)

I had the t/r drive shaft pulley stripped. I replaced it. Now is the servo that when i spool up and go
in a hover it cant move the tail, on the ground without power i am able to move the tail. I already
check all the mixes and nothing is on.

dragus359

My Feedback: (1)

Ah, well I'm not sure as to what the issue is then. By default I would think it was the gyro, but you already checked that. Beyond this, I can't offer more than what would amount to pure speculation, so your guess is as good as mine. I'm sorry I couldn't be of more help.

Hawk21

My Feedback: (7)

Problem solve. The mx 400 upgrade T/B holder (red ones) were replaced for some TREX 450 T/B holder. The counterweight on the blade holders really make a difference witch the MX 400 did not have.

here is a video of what is happening with the upgrade blade holders
http://www.youtube.com/watch?v=G9CdNZLd3_w