M42 to M48 barlow lens adapter

thingiverse

Did you order an M48 Barlow lens from Aliexpress? Did they ship you an M42 lens and then stop answering emails? Never fear, this is an M42 to M48 lens adapter. This works with my Amscope microscope. Print in PLA with 0.05mm layers aka Ultra Detail. The printer must be finely tuned because the threads have near zero tolerance. Screw the lens on two turns then back it off one turn, like a tapping die, and repeat. This grinds out any irregularities in the threads. Avoid cross-threading because the plastic threads won't survive. NB: Fusion 360 doesn't have the correct threads in the standard ISO library. For reference the two custom threads are M48x0.75 and M42x0.75. Normal metric goes down to 1mm pitch but cameras for some reason use 0.75mm pitch. I've uploaded an XML fragment with the custom threads needed. Follow this guide to install it. https://knowledge.autodesk.com/support/fusion-360/learn-explore/caas/sfdcarticles/sfdcarticles/Custom-Threads-in-Fusion-360.html