I saw this video where an interesting robot wrist mechanism was shown. I designed the base mechanism in Fusion 360, then 3d printed the parts in PLA plastic, I used 1.75 mm filament rivets for the joint shafts, I made them flat with a soldering iron(on ~150 C°) covered in kapton tape, so this way the filament won't stick.
This model needs:
- 2 base
- 6 joint and
- 3 rod (needs support)
This mechanism works like if two sphere would rolling on each other, except the axial rotation, basically a universal joint. I'm planning to make a robot arm with this wrist mechanism in the future.
In the CAD model i can't rotate the joints more than a few degrees, I don't know if this a limitation of fusion's kinematic solver or I have done something wrong.