View Full Version : Main shaft vertical free play

02-19-2009, 09:12 AM
I've got a little under a millimeter of vertical free play on my main shaft.

I'm inclined to eliminate it by adjusting the little collar that holds the main shaft in place.

But when I pull the shaft all the way up, where it would be if I moved the collar down, the main gear is only about half-engaged with the drive gear on the motor.

So far, I haven't been able to get comfortable with this, and I don't see any obvious way to adjust the vertical position of the motor or the drive gear.

So I'm wondering -- what are you guys doing about this?

--Al Evans

02-19-2009, 09:23 AM
Adjust the height of the pinion on the motor, bearing in mind that when in flight, gravity will pull the shaft up (or rather pull the rest of the heli down) as far as it can go anyway.

A little vertical free play is fine.

02-21-2009, 01:03 PM

Check that the main shaft collar is the right way up, the protruding bit of it should face down, you can also do the Swash plate modification, use a small length of spring form the flint of a small BIC lighter, put it under the swash plate to keep it form moving around as much, do not put too much tension so it does not bind up the head, use about 8 turns or 1mm.