Tempest Crown Gear Problem?

[loewermx]

Ok Guys, I need some help.

Yesterday I stripped ANOTHER crown gear. It made it about half a flight and I heard something grinding so I landed to check it out. The crown gear was being eaten away by the tail pinion. Before I flew it everything checked out OK and there is no binding in the geartrain at all. Am I missing something? I have a very small amout of freeplay in the mesh like it is supposed to be.

Any advice would help as I am somewhat frustrated.

Thanks
Scott

[Clintstone]

Check the pinion and see if it is smooth. I have heard of a very few getting by without having a smooth finish and I have also seen a few get lock-tight on them, check the pinion and I would bet this will be the problem. What gyro are you flying?

[loewermx]

Thanks Clint, I am using a 601/9251 and 105 MAH blades. Would it be good to use a different pinion for a faster tail?

[Shannon Davis]

Check the backlash around the whole gear. It could be out of true-- or the mount could be out of true. Is the pinion tight on the shaft????

[Spitfire_mk5]

Check the pinion: a defective one cost me half a tempest!

Teeth should be round and not feel sharp at all -- the one I had the teath were square and sharp.

[Clintstone]

I like the stock gear as I run my Extreme , Stock out of the box because it is the first Heli where I have had the luxury of not changing a thing to get the performance I needed. I would check the pinion close and it would be easy to change. If there is any question on it just call me @ 912-682-4434. I don't try to act as if I know everything but I know people who do.............. :wink:

[loewermx]

I did notice that the teeth on the pinion do come to a point, not sharp but a point. So I am assuming that this would need to be replaced. Anything else cause this problem? While I have it apart I am going to taka apart the tailbox to check the gears and make sure the bearings in the boom are OK.

I am going to have a New Tempest if this goes on much longer. All this with only 14 flights. :(

[DavidH]

Scott,
Does the pinion have a dull nasty looking finish to it?
If it does, then take your dremel and a wire wheel in the dremel and polish the pinion. There may be a few that slipped thru that did not get polished correctly.
I take a wire wheel and dremel and polish all my pinions before I install them.

David

[loewermx]

Yes, it is dull and nasty, Should I get a new one and polish it or just polish the one I have?

[DavidH]

Just polish the one you have. Like I mentioned, take a dremel with a wire wheel and polish it. I have done a few this way and it makes a difference in how the crown gear wears.

David

[Shannon Davis]

Watch out for the little Dremel wires. They really suck when stuck in your eye. :cry: