One way bearing going south?

[Dan MacKay]

Hi guys,

Does anyone have a clue as to what might be causing a rather loud ratching sound that come from my heli when it is just spooling up at low rpm? The tail blades studder and stop then start again accompanying this rather unnerving sound. The main rotors seem to be unaffected and this stops when I get up to 500 rpm or so. The belt is tight, no binding and moves smoothly when manipulated by hand. The belt appears to be have no damage so I am a bit at a loss. I woud assume that if the one way was going that the head would be affect as well. Any guesses?

Thanks,

Dan

[rcmike]

I had a similar problem with mine. The white belt drive gear had became loose on the mainshaft and was rocking back and forth on the main shaft bolt. Basically it caused the belt to be loose, then tight, then loose again. I changed it and the problem went away.

[BarracudaHockey]

The common problem is the red tail gear pin is coming out and rubbing the inside of the case because the set screw in the end of the tail shaft has backed out. Its worth splitting the case to inspect it.

Also look at the belt, the leading edges of the teeth should be a nice sharp trapezoid, if they are rounded off it can cause problems.

[Dan MacKay]

Thanks guys. I have the Mavrikk all metal tail and the custom metal gear. It was cold out at the time this happened and I followed the advice of tighening up the belt (even more than I had) and it flew fine today without a hiccup. I did remember to losen the tail boom supports this time so perhaps that had something to do with it as well.

Dan