Encoder codewheel slipping on CIMple shaft

[billbo911]

While assembling our KOP CIMple box tranny's today, we attempted to install the encoders to them. When it came time to install the codewheels, we found that they just slipped on with no force required. In fact, they also spun freely on the shaft. We are not sure if it is a problem with the shaft or the disk. We will be contacting both AndyMark and US Digital to see if they are aware of this issue.

Is anyone else experiencing this issue? I can't imagine we got the only two bad sets in all of FIRST.

[SuperBK]

We had this happen a couple of years ago. We had to gently compress the codewheel where it grips on the shaft, so that it fits snugly on the shaft. I think we used a vice to carefully compress a little, test and repeat.
Brian

[Alan Anderson]

Sometimes the manufacturing tolerances conspire to make the disks very loose. I've also encountered problems in the other direction before, where the encoder disk wouldn't fit without applying uncomfortably high pressure.

A few years ago I think there was a semi-official document from AndyMark showing how to use a pair of pliers to carefully squeeze the plastic and make it fit a bit more snugly.

[JesseK]

This happened with our SuperShifters this year. We're re-using the (unmodified, COTS) SuperShifters we purchased in 2008, yet putting new encoders on them. In 2008 we didn't have a problem at all; this year we had to squeeze one of the encoders a bit. It works fine now though.

[billbo911]

Originally Posted by Alan Anderson

Sometimes the manufacturing tolerances conspire to make the disks very loose. I've also encountered problems in the other direction before, where the encoder disk wouldn't fit without applying uncomfortably high pressure.

A few years ago I think there was a semi-official document from AndyMark showing how to use a pair of pliers to carefully squeeze the plastic and make it fit a bit more snugly.

I found this statement on AndyMark today after reading your suggestion.

Installation tip
If the encoder wheel slides loosely onto the 1/4" shaft, then follow this procedure to make the inside diameter of the encoder wheel collet to be slightly smaller:

Use a medium-sized pair of pliars and gently squeeze the collet portion of the encoder wheel. This is the longer protruding part of the encoder wheel with the parallel slits in the body. If you gently squeeze the sides together, equally, in 2 or 3 different locations, you can make the inside diameter of the encoder wheel slightly smaller. Then, the wheel will fit on the new shaft.