Assembly is rather straight forward, the parts stack one on top of the other as in the solidworks assembly. The sliders can either be glued, pinned or screwed down in order to secure part 2 to part 1. The base ring ended up being useless as there is no way of putting it on without breaking something... oh well. If you really wanted, you could cut the ring in two and insert the halves seperately, but I found that the interference fit held

The parts are all dimensioned exactly, so you will have to sand them more or less depending on your printer's resolution and how much friction you want. More friction means it will stay together easier and hold your lens beter, less friction means a smoother operation.