USB microscope stand extension

Lots of USB microscopes come with one of these rack and pinion type stands. I needed to increase the height of mine to accommodate some precision stages, so I printed out a couple of screw-in extenders. There are two sizes - 50mm and 80mm. Choose which one works for you.
The thread is a little unusual - it's M16 but with a 1mm pitch.
I printed using PLA in upright position without rafts. It worked well and fitted perfectly. I suggest doing a quick test print to make sure your printer prints to the right size before printing the entire model - just print the lower section and test fit to your stand.