optical endstop mount and adjustable target

thingiverse

First of all, this is my first posted project. When I made it, I wasn't thinking of posting it online, so sorry there aren't any photos of the parts unassembled or of the assembly process. I used a brass 3mm threaded insert in the target piece and pushed it in with a soldering iron. However, you could probably just as well thread the screw directly into the plastic. The screw itself passes through the top with a washer under its head, another washer, then a fiber lock nut. Tighten the nut until there's no play in the screw but still easy to turn. The holes in the lower part are designed for press fitting with brass rods, and the holes in the upper part are for a slide fit. I had to clean up the holes slightly with a rat-tail file to get the correct fit. I used 3mm brass rod, but you could use whatever size fits. The top unit is then bonded to the X carriage part using plastic solvent. This type of solvent is commonly used for making plastic models and can be found at hobby shops - not the stuff in a tube, which is water-thin and comes in a jar. The base that holds the optical end stop is longer than needed and was cut short to the desired length. There are no holes for screws, so I stuck the end stop on it with double-sided sticky pads. For now, this works fine, but I may change it later. I hope someone finds this helpful.