Euler angles (Yaw/Pitch/Roll) demonstration gimbal / jet fighter desk toy

A desktop model to demonstrate the Euler angles typically used in aviation (roll/pitch/yaw). 

For the pins: You need to print 4 of them. The 18mm length is correct for two pins, but you'll need to stretch it vertically for mounting the aircraft (the roll axis). Unfortunately, I didn't note the length required. 

There are two configurations, with the rings centered or offset (see the pictures to get an idea). 

If you use the centered pitch ring, you can print the rings with the provided diameter and it'll have little friction and rotate freely. 

However, I found this to be less pretty than I wanted, so I also designed an offset version. However, the center of mass is below the axis of rotation, so you need friction to keep things in place. To get this to work I had to scale the pin STL in the horizontal direction by a few percent, to get the right press-fit. The number that works for you will depend on your machine, etc., so some trial and error is required. Just print a bunch with varying diameters (I did +1,2,3,4,5%, then just tried a few). 

I didn't design the jet. You should be able to replace it with some other model if you want, just add the holes for the pins.