Tail Drive... slipped?????

[Hotshot Charlie]

Hey guys and gals,

While flying yesterday, I took my Hawk Sport up and was doing some fast piro's and when I stopped, it sounded like my tail drive slipped. Sort of like on a Raptor when a belt slips. It was a brief sound and didn't seem to affect the heli for the rest of the flight.

The question is, What should I look for to fix this? or Do you think I might have stripped a gear?

[DavidH]

Rob,
If the tail drive wire does not have a flat spot on it where the set screw contacts it. Then I suggest taking the wire out and grind a small flat spot at each end. This should help the set screw contact it better and keep it from slipping.

David

[Hotshot Charlie]

Hi David,

Yes, I filed a flat spot in the wire when I put the beast together. I also just got thru checking the gear mesh and all teeth seem fine, no hurt teeth on main gear or tail drive gear. There seems to be a little play between the two gears, but I really don't think there is too much.

The piro I was doing was pretty fast so maybe I just overloaded the little beast.

[rstacy]

Hotshot,
It may have been the pinion jumping on the main gear.
I have had this happen under the same conditions that you mention.
It makes a rachet sound when it happens.
Check the teeth on the main gear a little closer and see if they show signs of jumping.
If you do it enough it will clean the teeth right off.

[Hotshot Charlie]

Hey Ray,

Yes, I think that is what happened. I don't see any sign of the teeth being damaged, yet.... hehehee :wink:

Is there anything you can do to tighten that meshing up? Or do I just need to stay away from the high speed piro's?

[rstacy]

I dont know if changing the mesh is the answer.
This problem is not unique to the Hawk and started when we found HH gyros and high speed servos. It has been solved a couple of different ways.
A front bearing support for the pinion or a stronger main gear would be my first choices.
Neither of which is easily done on the Hawk.
I suspect the best answer is to lighten up on the high speed piros!

[Hotshot Charlie]

Who me.... lighten up???? hehehehee :mrgreen:

Thanks Ray !