Thingiverse user lalbritton created this Ideal Harmonic Transformer:

Was “Analog Sine/Cosine Calculating Machine”, but then I found the actual name for this device, which I really like.

It is a thing to hold, enjoy turning the crank, and look at. If you can’t find your calculator, and need to know the sine or cosine of an angle real quick, you can dial in the angle and read off of the Scotch Yokes. It also works in reverse.

I plan to paint one up, hang it on my wall, and use it to help explain Trig to my kids. I have built and assembled one.

This was initially going to be a simple design to help me learn Alibre. Simple was lost at some point, I’m afraid. I am thinking about adding a paper feed and pencil holder, so I can plot with it.