I had just moved into my new workshop. Being motivated to do something, but not really knowing what to do, nor having the material at hand for anything of consequence, I came up with a slightly crazy idea: Why not build a linear axis out of materials from the local hardware store?
Here's what I came up with using nothing but aluminium sheet, an aluminium rod, a threaded rod, screws, nuts, and some standard tools:
Didn't work. Way too flimsy. No matter, on to version 2:
Those may well be the worst of their kind, but the second one works: