This is a customizable tool holder written in OpenSCAD to attach round tools to the Mostly Printed CNC machine (MPCNC) ver 525. It has not yet been tested because I ended up finding a Thingiverse mount for my exact tool (a crappy Harbor Freight cutout tool). It's designed to make multiple holders for a single tool that has varying diameter across its length (such as the aforementioned Harbor Freight piece of crap). If your tool is a uniform cylinder, you can simply print multiple copies of the same mount (and skip most of the instructions below).

I'm not turning on the Thingiverse Customizer because you honestly need to OpenSCAD open to iterate quickly repeatedly and to see the echo output from the script.

If you use this model, please let me know if it worked! If you improve on it, let me know so I can link to it here.

Instructions:

1. put the tool's biggest diameter into td
2. hit F5 and observe the "effective tool offset" -- all holders for the same tool must use the same tool offset, but this value will be auto-bumped up if size of the tool necessitates it. Also, look at the model and make sure you can physically screw it in to the Z carriage as-is. There's logic to move the holes up if the tool ring is too big, but it's likely imperfect. You can increase the tool offset to make the screws easier to access (but this reduces rigidity). When done, make sure the effective tool offset is what's actually stored in to_proposed so that smaller holders for the same tool have the same offset.
3. if you're happy with the holder, F6 and save
4. put the tool's next biggest diameter into td, F5 to check, F6+save to get STL; be sure to keep the tool offset the same
5. repeat step 4 for as many holder models as you think your tool needs

Refinements:

• if you need more rigidity between the tool ring and mount, adjust tool_coverage
• if you need more play in tightening, adjust gap
• if you want a thicker or taller ring, adjust th and ht

Known issues:

• There's no nut trap on the clamp, so you'll need some pliers or a wrench while you tighten
• The "ears" that you screw it to the Z carriage through could use some reinforcement.