Love the original design. 

Remixed to octagonal shape, so it's no longer rolling away on the table.

Can use heat insert nuts (M3x3x4.2mm or M3x4x4.2mm) , no panic if you happened lost the nuts on site.

Still can use regular Hex nuts as well.

Optimised for 3D printing.

Added easy reading marks.

Tips

The diameter of the model is actually 0.2mm bigger than the nominal size, In theory, it is possible to use ±0.2mm of the nominal size drill bits.

Use M3x8mm bolts for 3 ~ 4mm’s models if heat insert nuts are applied. M3x12mm for using regular Hex nuts.

Use M3x10mm bolts for 5 ~ 7mm’s models if heat insert nuts are applied. M3x14mm for using regular Hex nuts.

Use M3x12mm bolts for 8 ~ 13mm’s models if heat insert nuts are applied. M3x16mm for using regular Hex nuts.

STEP Files are uploaded. Feel free to modify your own size, or let me know if you want to have a particular sized one.

Printing Tips

I personally print with 4 walls, 0.2 layer hight. Adjust the "Max fan speed threshold" when having shorter layer times to get better cooling to ensure a good quality on thoese marks‘ printing, especially when you just wanted to print one of them.

Enjoy!