Metric Hole Test Pattern

This is a metric hole test pattern that I developed years ago when I was doing more work with Shapeways. It is a flat, 3 millimeter thick piece with standard metric drill bit size holes, and can be used just as a decoration, or to measure detail, accuracy, and distortion (holes and flatness) in printed materials. It's also useful for judging the printed sizes of clearance or tap holes, or choosing a hole size to match a part you already have.

The holes range in size from 1mm to 3mm in 0.1mm steps, and from 3mm to 10mm in both 0.1mm steps and 0.25mm steps.

The holes are arranged in such a way as to require as little material as possible, and this was actually a bit of a challenge. After struggling with the math for quite a while, I ended up using a physics simulation library for the ideal placement. I think the result is quite pleasing to the eye.

There is a cleaner key available on my blog site here: http://www.thefrankes.com/wp/?p=2100