Print this gauge on what ever machine you plan to do your building with. Then you can use it to feel exactly what size opening you want to leave in your model. This eliminates guess work when trying to determine friction fits, threading into the plastic, exact fits, or loose fits.
one is designed to have 4, 5, and 6 mm rows broken into columns from 0.0 to 0.9
The other is the same principal with 7, 8, and 9mm rows.
I have used this to determine exact fittings for nuts, bolts, tools, pens, magnets, etc.
Model supports being printed single or multi color (recommended).
I will be making more of these in the near future.
UPDATE: added a second guage
The author hasn't provided the model origin yet.