I have a 3D printer and it runs really well. I learnt a trick to zero it’s Z-axis which I’ve been applying to my Maslow I think worth sharing.
When replacing stock, or generally trying to stay accurate, I slide a sheet of paper under my sled; you should be able to wiggle it around if the bit is not hitting it. Slowly lower the bit until it bites the paper, then raise .1mm at a time till you get the wiggle back - it’s a feel thing, try it you’ll see.
Primitive, but works well for me