Trackball restoration

[Trimoor]

I got a imperial 3" trackball from that creepy pinball/arcade store for $10.

Only a few light scratches on the ball, and smooth bearings.

The problem is, when I try to spin it fast, the ball "jumps" up off the bearings, making it stop.

Any idea how to fix this?

Oh, and I had the idea of putting the ball in a rock tumbler to smooth it out.  Is this a good idea?

And, the ball is white, but has been yellowed partially.  What will fix this?  Rock tumbling?

[SirPeale]

DO NOT tumble that ball, you'll destroy it.  For the yellowing, you might try a degreaser and let it soak, maybe a bleach solution even.  

As for the jumping, is it mounted yet?  If not, that's why.  You're trying to hold it with a hand and give it a spin, and the whole unit will move.  Unless there's something wrong with what's holding the rollers in place.

[Trimoor]

it's not mounted.  it only jumps when spun on the x-axis, not y.
The rollers are fine, the ball is lifting off of them.

I don't see how mounting will help.  It already has a ring around it to keep it from falling out, but it seems to be too high.

[SirPeale]

It's kind of hard to explain.  The ring just keeps it from falling out (or from someone from taking the ball out)  When you're hitting it like that, you're pushing it off the rollers, just enough to cause that problem.

When it's mounted to a firm surface, you're putting downward pressure on the ball, not side to side pressure.  You *can* still do it when it's mounted, but that's with slap shots like you've been giving it.

[RandyT]

Something's not washing here.  The ball shouldn't be able to "jump" off the roller.  

The only way the ball can get enough of a "foothold" to start climbing is if the bearing or the shaft have resistance in them.  

Either that, or there is enough of a flat or damaged area on the ball or rollers to get a "chatter" going that eventually causes the ball to bounce high enough to hit the retaining ring.

Betson sells a rebuild kit it it's the bearings or the shafts.  You can also get a replacement 3" ball if necessary.  

Oh, and I agree with Peale on the tumbling.....don't  If you think you have problems now ......

RandyT