Notice the splitting at the upper right.
Motor doesn't fit! The 3D printer's scaling might be slightly off - the inside diameter is 0.5mm too small.
The quality wasn't so great, either.
Laser-cut instead of 3D printed. Much faster, for a start...
The second print fits perfectly. This version sits inside the beams, rather than wrapping around them.
The upper side plate alone used 16 screws. Time to buy some more.
Ensuring the ends are all even
18 pieces cut for the robot's base. Need the plates before it can be assembled though.
Here with most of the upper arm assembled - the missing piece at the end needs to be tapped.
Universal joint test-fit - looking good!
A chainsaw pull-start spring. This torsion spring may help with preloading the arm against backlash.
Thrust bearings! These sit in the elbow to allow rotation without any wobble
Testing component layout