US Digital Shaft Encoder and VersaChassis Hex Shaft

[Sohaib]

It'd be a lot easier if you told us what resources your team has access to. From the looks of it, it doesn't seem you have a lathe. Would you happen to have a 3D printer?

[tr6scott]

A little "goop" works too.
it is a little less sticky than hot melt glue, better option to get it apart if needed.

Drill and tap it, put a shoulder bolt in it, with a little locktight, cut the head off it, and use the surgical tube coupling method, with zip ties.

If your mechanism has significant momentum, and the you get encoder bouncing values when you stop due to the surgical tube twisting, change out the surgical tube with 1/4" high pressure fuel line. We needed to do this last year on our elevator. We have used this method for years in the past with surgical tube, last year was the first we saw and issue with bounce, when changing directions, stopping, etc.

[Chris is me]

Just wrap the encoder shaft in a little painters tape or scotch tape until it's a press fit. Single side is fine, you're not trying to fasten anything just increasing the OD until it goes in smooth. There's basically no torque transmitted to worry about so this is totally fine. Don't worry about doing anything more robust than that.

[CLAMPS]

I suggest you use a set of clamps.