Assimilation Process trackball

[waynestewart]

I have out my Kensington and Assimilation Process (AP) trackballs.

The Kensington trackball works fine but the AP trackball has a tracking issue. After a bit of cleaning tracking was good in one direction. If I move the rollers manually it works well. I swapped the roller assembly and now it’s good in the other direction. It appears that the rubber roller is slipping on the trackball. I was thinking about sanding the rubber roller to increase grip but that’s a one off thing. So before I try that I thought I’d see if anyone had any suggestions.

 

[adespoton]

Shrink tubing over the roller?

The problem is, if you abrade it you’re making it smaller and more uneven.

 

[joevt]

Need a closer look at the rubber roller. Is it a rubber o-ring around a plastic cylinder that has a groove for the o-ring? If so, replace the o-ring. If not, 3D print a replacement rubber roller? Or 3D print a plastic cylinder with a groove for an o-ring?
But before that, search for "rejuvenate rubber". I have no experience with any of that though.

 

[waynestewart]

The rubber roller is solid rubber, no O-ring. It does have a spring that presses the roller against the ball. It wasn't moving in either direction at first. I stretched the springs a little and one direction started working normally but not the other.
I doesn't have o-rings but maybe I'll try adding a couple.

 

[Joopmac]

I have two of these. The Colour of the ball always seems strange

 

[waynestewart]

I have two of these. The Colour of the ball always seems strange

Feels like the ball needs retrobrighting. Fortunately when Kensington acquired them, they changed the trackball colour.

 

[waynestewart]

Success. I tried an O-ring that was a good fit but there wasn't enough clearance between the roller and the circuit board. Then I stretched a really tiny O-ring with a 2mm center over a tapered dowel and was able to get it on with just enough clearance.