This is a parallel shifter that I made for my self to do static and mechanic problems at school.

The parts are made to be press fitted together, so there is no need for glue. You will need to use a pair of slip joint pliers or something to fit the parts together though. But when that is done, it will not come apart again. In my experience the parallel shifter is much easier to use when there is some friction in the joints, so I've made the tolerances pretty tight.

Mix and match colors to maximize math-fun!

I've made the model fully parametric in both Fusion 360 and in Solidworks, so feel free to modify this in any way you want, for whatever purpose you want.