Olympus BH2 Drop-In Fine Focus Gear Replacement - .4mm FDM

-IMPORTANT- This part must be printed in vase mode with a .4mm nozzle to achieve good results!

Background:
One of the most frequently damaged components on the Olympus BH2 is the small nylon gear that meshes between the righthand fine focus knob and the fine focus planetary gear system. This usually occurs due to insufficient packaging when shipping the microscopes and they take a hard bump to the knob or sharp drop which jolts the focus block. These parts are no longer commercially available so this is a pain in the butt for hobbyists haphazardly gobbling up eBay BH2s. Since the part is tiny, it seems like resin would be the only way to go, but they can be made quite finely with a .4mm nozzle and standard filament (I used PETG).

This part:
This is a drop-in replacement fine focus gear for the Olympus BH2 microscope. It functions much like the original part, slotting snugly into the gear shaped socket in the fine focus knob with a gratifying click. When properly fitted, these will give you smooth, backlash-free focusing. Because it's printed in vase mode, there are no seams or strings to jam up operation. But because this is such a small and precise part, material and printer properties are likely to have a measurable impact on the end result as well as the condition of the gear it meshes with. You may need to vary the X/Y scale, elephant footing, or hole compensation to get good results - make sure your slicer doesn't get weird with the layers near the bottom. Thankfully these only take a minute or so to print, so you can populate the bed with a few variants and pick the one that works best for you. Make sure to print it with the narrow side down so you get consistent geometry where it counts.

A note on the STL:
Please don't judge me. This was less a 3D modelling problem and more about coaxing the slicer to the correct solution. I included a dxf which I believe is the ideal gear profile if you want to make your own via a different method.

What do we say to resin printing? NOT TODAY

This part is licensed as public domain - feel free to sell it on your eBay shop or use it for business purposes with or without attribution to me. Keep those BH2s running!