I am not sure if this will pique your interest but I find kinetic sand tables really fascinating. Sisyphus came up with it first and there have been a number of open source implementations in due course. One way is to implement it using a scara arm mechanism but they have the problem of load weight in the case of long arms.

I came across this design that rethinks the design using an elegant rack and pinion arm but still needs a belt that may go out of calibration over time. This looks to be improved further using [two, concentric rings] (frew.io/work/sisyphish) but this design is not available to explore/copy.

I have no idea about 3D designing, but I would love to create a table one day: something that will not need constant adjustment. If you get around to taking this up, I would love to see what design improvements you can come up with.