gear noise...

[celt]

A heads up fellas,

Pretty much completed the chassis portion of the TRX-4 kit. Something to make critical note of.

I've been building / racing RC kits for almost 30 years, so not my first rodeo. I could not for the life of me, determine what was causing this awful sound in the gearbox. I was very, very careful in building the gearboxes.

Turns out: it's quite simple and easy to remedy.

Even those who have the RTR's, should make sure your pinion is getting full bite on the spur gear (make sure pinion and spur is aligned). Too far South and the pinion rubs on the gear cover. Too far North and you simply don't have enough gear mesh.

Here's the deal...

The set screw that came with the kit pinion is a 3x4mm - it sticks out beyond the valley of the pinion mesh. So every revolution, with the pinion and spur almost perfectly aligned, the set screw makes this nasty grind on the Southern edge of the spur gear. It starts to turn that edge of the spur into dust, and makes that awful noise.

The simple fix? Install a 3x3mm (rather than 3x4mm) set screw that does not protrude beyond the edge of the setscrew threaded hole.

Nothing rubs...all I hear is the normal gears going through their reduction.

I can provide some pics if I'm not making sense. If your rig is making an odd noise that just doesn't seem right, this might be the issue.

[Stewdog]

Thanks for the heads up celt! I did center my RTR pinion on the spur when I got it, but will double check to make sure there's no rubbing going on.
Fellow Madison RC guy! Are you in Madison, WI? If so, are there any good crawling/trailing spots that you like to run at?

[celt]

Originally Posted by Stewdog

Thanks for the heads up celt! I did center my RTR pinion on the spur when I got it, but will double check to make sure there's no rubbing going on.
Fellow Madison RC guy! Are you in Madison, WI? If so, are there any good crawling/trailing spots that you like to run at?

Yup, Madison, Wi...

I've been a racer for years, in Madison and Milwaukee. New to the crawling thing - looking for something more chill.

So, not sure about good spots. I know there is a Madison crawlers group, but we should find some places...

[willygee]

[QUOTE=celt;5806379]A heads up fellas,

Pretty much completed the chassis portion of the TRX-4 kit. Something to make critical note of.

I've been building / racing RC kits for almost 30 years, so not my first rodeo. I could not for the life of me, determine what was causing this awful sound in the gearbox. I was very, very careful in building the gearboxes.

Turns out: it's quite simple and easy to remedy.

Even those who have the RTR's, should make sure your pinion is getting full bite on the spur gear (make sure pinion and spur is aligned). Too far South and the pinion rubs on the gear cover. Too far North and you simply don't have enough gear mesh.

Here's the deal...

The set screw that came with the kit pinion is a 3x4mm - it sticks out beyond the valley of the pinion mesh. So every revolution, with the pinion and spur almost perfectly aligned, the set screw makes this nasty grind on the Southern edge of the spur gear. It starts to turn that edge of the spur into dust, and makes that awful noise.

The simple fix? Install a 3x3mm (rather than 3x4mm) set screw that does not protrude beyond the edge of the setscrew threaded hole.

Nothing rubs...all I hear is the normal gears going through their reduction.

I can provide some pics if I'm not making sense. If your rig is making an odd noise that just doesn't seem right, this might be the issue.

I too installed the short set screw..i also used the d holes for the motor mesh as c were too tight.