When designing new objects which will be printed on my 3D printer I am frequently needing to know what size hole I need to put into the design. For example I can't just assume that an M3 bolt needs a 3mm hole - doing so will produce a printed object where the M3 bolt simply won't go through that hole!
I am also regularly faced with requiring 2 different sizes of hole. First, I want a clearance fit where the bolt will slide through the hole unimpeded. Other times I'm looking for a hole which will grip the item being located by that hole. For example, for a bolt I want a hole with a clearance fit. However if I want to use a nutsert (sometimes called a rivnut) then I want the hole containing the nutsert to tightly hold the nutsert.
finding the correct sized holes can be a challenge involving repeated printing until I discover the right size hole. This challenge can be further complicated by using a different material - switching PLA for ABS or nylon can produce different results.
The answer to this challenge is to print the hole jigs contained in this project. Just once using the material you will be using. Then you've got a handy jig containing holes which you can pass your bolts etc through to find the right size. No more fiddling around trying to guess the sizes required - you get the required size instantly.
The attached STL files cover the range between 3mm and 25mm. For 3-9.9mm the holes increment by 0.1mm. For 10mm and above the holes increase by 0.2mm - you probably won't need anything with a closer tolerance than this.
Incidentally, the plates on which the holes are located are all 2mm thick, and the lettering sits on top. If you've got a smart printing application (such as Simplify3D), with a multi-extruder printer you can change the extruder colour at 2mm so that the legends shown on the jigs are printed in a different colour.
You can use resolution 0.2 if you want. It won't matter that much to have a coarser resolution, it's just a matter of personal preference.
All designs were implemented using TinkerCAD.