Angle grinder disc holder

There are a lot of angle grinder disc holder models, but I couldn't find one with the exact set of characteristics that I wanted:
* fits 4.5" discs with 7/8 arbor
* has the column attached to the base, not the top, so that you can take the top off and select the disc you want
* is the right height for my packout toolbox

So here's my model. I used soluble filament for the support for the bottom. If you don't have that available, I suggest filling in the base if you care about the print quality of the bottom.

This is a new version which has a custom 6-start thread, so it opens in one smooth motion and you never need to turn it more than 60 degrees before it starts threading.