Bipolar Balls

[eblob]

This is an older design recently updated. It consists of 2 stainless steel balls, one with an inner thread and the other with a through hole. A partial insulates screw is connecting the balls. To separate the balls I used a printed spacer.

[Joanne]

That is a very clever use of 3D printed parts, well done. Thank you for sharing a pic with us all, I have no doubt it feels great in use.

[eblob]

After testing it I think, that the contact area is to big in relation to other electrodes. Coating part of the balls might be a solution.

[Joanne]

You could maybe try putting some heat-shrink tubing between the balls and shrinking it so it stays tight and covers part of the surfaces between the balls.

[eblob]

Interesting idea. I thought about printing a spacer that covers more of the balls and coat it with epoxi or tape part of the balls and coat the rest with epoxi, before removing the tape. Heart shrink can create a sharp edge.

[Joanne]

Yes you would probably need some silicone against the edges of any heatshrink if you went down that route.