How to keep pinion from falling off?

[ReV:-O]

Hi guys,

I have a converted Hyper 8 running on 6s. It uses Mod1 gears and as a result, there is a fair amount of vibration between the pinion gear and the spur.

My problem is, the pinion keeps sliding down the shaft and falling off. At the moment i'm using removable thread lock to keep the grub screw in place. I'm worried that if I use non-removable thread lock, it will still slide off but I wont be able to get the grub screw out.

Any thoughts or experiences?


Cheers for any help!

[ClodMaxx]

do you have a flat spot ground on the motor shaft? this is essential - they won't budge after that. and, a good hex driver to really torque it down. i never use threadlock on my pinions - they all stay.

[ReV:-O]

Yes it's placed on a CC 2200 motor which has a flat spot, and I screw it down as tight as possible without stripping out the screw.

I never had a problem with the pinion coming off my E-Revo, but that was Mod0.8 gears and didn't have to withstand nearly as much vibration as it is now, with Mod1.

[nitrostarter]

I had a problem like this, I used blue loctite on the shaft and the grub screw.

[lincpimp]

"How to keep pinion from falling off?"

Duct tape and welds. Maybe use some glue too. And a screw. Plus you could put something very heavy on it. Like Uranus. That is heavy.

[whitrzac]

use a new set screw, loctite on both the shaft and screw...

if all else fails use a SLIGHT amount of red on the shaft...

[BrianG]

Like ClodMaxx, I would ensure the motor shaft has a flat spot. Without a flat spot, you are relying on simply grub screw friction. But if it does slip, it will heat up the screw pretty quick and loosen whatever locktite you put on it.

I actually use a flat spot on the motor shaft and blue locktite just to be sure. From experience, it sucks to hunt around for the pinion if it does happen to fall off.

[PBO]

The brand of pinion makes a difference also...

Use the techniques above with RCM pinions & the problems magically go away

[ReV:-O]

Thanks for the replies guys.

I'm using a HPI Savage Flux pinion, as all the other pinions had the wrong shape teeth (including the RCM one) which made a very loud grinding sound (see my other thread).

Anyway, I'm using blue locktite which I believe is the removable one. I never thought of putting locktite on the shaft itself, i might have to try that.

I don't really wanna weld it on, because then it would be very hard to get off!

[ClodMaxx]

one other thing that you probably know already, but it can't hurt to reiterate: if you're using loctite, make sure you give it at least 24 hours to cure/fully dry. anything less than that, and you risk it having the same holding properties of milk.

[BrianG]

Originally Posted by ClodMaxx

one other thing that you probably know already, but it can't hurt to reiterate: if you're using loctite, make sure you give it at least 24 hours to cure/fully dry. anything less than that, and you risk it having the same holding properties of milk.

Yep, and it probably helps to clean most of the old stuff off.

[suicideneil]

Blue loctite on the shaft and grubscrew ftw- never had an issue myself using that technique ( allow to dry overnight is important too yeah ).

One other option is to drill or grind a little dimple onto the shaft in the right place ( on the flat spot ), then re-attach the pinion and tighten the grubscrew down into that dimple- that'll stop the pinion wondering along the shaft ( use blue threadloc too ofcourse ).

[ReV:-O]

yeah i think i'll try drilling the flat spot, that should help.

Cheers

[George16]

I also grind the tip of the setscrew to make it really flat. Flat on flat works wonders .

[scarletboa]

Originally Posted by George16

I also grind the tip of the setscrew to make it really flat. Flat on flat works wonders .

i heard somewhere that you're not supposed to do that for some reason.