I have a PLA 3D-printed object made of several rings with a diameter of 150 mm and a thickness of 6 mm. The height of each ring is about 30-35 mm but it does not matter so much.
I'm looking for a way to keep the rings together (one on top of another). I cannot place anything inside the ring (like a thicker area to host a nut). Most of the rings may have a closed top or bottom, so I cannot access the inner part.
I'm using three tabs (at different angles to force the correct alignment) that fit inside matching slots on the counterpart:
They are a bit stronger than pins and holes due to the greater surface of the base layer, but of course are useful only for alignment.
Due to the very small thickness of the ring I cannot place a screw inside them to keep in position, the inner wall cannot hold a screw!
I was thinking about L-shaped tabs and slots to fix the rings rotating them a bit, but:
- it would not easy to clean the horizontal leg of the slots
- nothing would prevent to rotate the rings in the opposite way (even accidentally) so the disconnect
For my use-case scenario, I don't need anything too strong. Just avoid to disconnect the rings when taking the object in hands. I tried with magnets but:
- to make an acceptable resistance I needed 7-8 per ring (due to their small size)
- the electronics inside uses Hall sensors so I cannot use magnets!