Bearings falling out of rhino plates

[bfk]

I noticed that after running our Rhino drivetrain around for a little while that the bearing supporting the drive shaft on the outer plate has slipped along the shaft and was no longer giving any support. The bearing could be easily pushed in and out with finger pressure. The flange is on the inside so the bearing ran along the shaft rather than fall to the floor. Looking more closely we saw that the bearings on the inner plate were also very loose. This happens on at least three of the four rhinos we have.
For the drive shaft we can add spacers and there's always Loctite, but has anyone else seen this?

[Jon Stratis]

Typically flanges bearings will ONLY guarantee the bearing won't move in one direction. Even if you have a tight press fit on the bearing, it will loosen up over time. So, it's important to make sure you constrain your bearings in the other direction as well! This can often be done with spacers - we keep some 1/2" ID PVC pipe on hand to cut to the proper length when needed. It can also be done with shaft collars, or if you have a lathe you can cut a groove and use an E clip. In fact, we're using all 3 of these methods on our robot this year!

[dradel]

Yes I posted about that in another thread here, and even talked to Andy about it. We put a hex collar on the shaft rather than a spacer.

[FrankJ]

I suspect you missed something during assembly. The bearings should be retained one way or another so they do not float out. The direction they are inserted is often important.

[dradel]

They didn't miss anything. Bearing is supposed to be "press fit" but the hole in plates are not quite press fit

[techhelpbb]

Would a drop of 'LockTite sleeve retaining compound' help close the distance in the bearing press fit?

I've used that before on slightly worn, or shafts designed to be undersized for plating but were not plated, to hold things in place.

Better to have the plate machined properly but in a pinch...

[Sunshine]

We occasionally drill a small hole next to bearings and screw in a sheet metal screw so head just touched the bearing.

[hrench]

Originally Posted by Jon Stratis

if you have a lathe you can cut a groove and use an E clip.

You can also cut an e-ring groove with a hacksaw.

[Matt C]

Originally Posted by FrankJ

I suspect you missed something during assembly. The bearings should be retained one way or another so they do not float out. The direction they are inserted is often important.

Likely nothing was missed. I noted the surprising lack of spacer/retention for the flanged bearing on the outer plates(when oriented with the flange inside). This confirms my suspicion though that a spacer should be added.

[FrankJ]

As you observed, the light press will not retain the bearing. It might be worthwhile to ask AndyMark. They are very supportive of their products.

[cadandcookies]

Originally Posted by FrankJ

As you observed, the light press will not retain the bearing. It might be worthwhile to ask AndyMark. They are very supportive of their products.

It's pretty much always worth contacting FRC suppliers before you start posting on Chief Delphi when you have issues with their products-- I've found them to be almost universally highly responsive and helpful.