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Ruler to Caliper (0.1mm Resolution!) - 3D Printed (Left Handed Version Included!)

I recently ordered a digital caliper from China. Spent 20$ on it, and it’s completely worthless - totally unreliable. After I was done mourning over my 20$, I decided to make my own. For those of you who are unfamiliar with what a caliper is, it’s a tool that is most often used to measure out/inner diameters of objects, and there are more than a few instructables on how to use them.
I figured that if I base my caliper on a ruler, which is super cheap and 100% reliable, I could end up with a very reliable caliper. Also, by using adding a Vernier scale I could reach a resolution of 0.1mm. Plus, I figured that if I made a CAD model I could make a left-handed version too! You guys are always forgotten, but not anymore!
In this instructable I’ll show you how to turn a ruler into a caliper. I used my 3D printer to make it, but if people are interested I might make one out of stuff everyone can find. If you’re new to 3D printing, this is a great first project for you! The prints are fairly simple and you’ll end up having a caliper, which is often used when you want to design your own models.
Let me just add that making a reliable caliper was my #1 priority, so while making the tool I’ll also show you how to overcome the accuracy limitations posed by your 3D & regular printers too, which will allow you to achieve good results. It’s also possible to make a caliper without attaching an actual ruler, but I figure an actual ruler would be more robust & reliable (see the step about attaching a ruler to the caliper for details).
Hope you find this instructable useful!

Turn a ruler (1mm resolution) into a caliper (with 0.1mm resolution).
Right-hand / left-handed versions available.
STL’s, Tinkercad & more - all included here.
Super cheap print (~30grams of PLA) + super cheap ruler = high accuracy.
Simple design - very reproducible!

You’ll need a cheap metal ruler, instant glue, access to a 3D printer & and to an ordinary printer.”

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