Designing simple spacers is an often recurring simple task that is not very exciting. It is much more fun to write a program does my work for me, so that is what I did. My program has generated .stl files for all spacers that anyone will ever need.

Making sense of the name:

• ID is Internal Diameter: 2.5mm (M2) to 8.5mm (M8) with increments of 1mm
• OD is Outer Diameter: ID + 1mm to ID + 3mm with increments of 0.5mm
• H is Height: 1mm to 50mm with increments of 1mm

The thickness is not specified in the names, it is simply (OD-ID)/2

Supports M3, M4, M5, M6, M7 (yup, that exists) & M8

Tip: If you need a spacer with very specific height that is not included, then take a 1mm spacer and scale it in height within your slicer.