Roberval Balance with Bearings

This is a remix of Eckard College's Roverbal Balance. See the description in the linked source file.

This has been redesigned to use a 608 ball bearing rather than a joint using the printer plastic. Such bearings can be found in many places. Here is one listing:
https://www.thebigbearingstore.com/608-2rs-608-zz-radial-ball-bearing-8x22x7-skate-bearing/
Here is another:
https://www.amazon.com/gp/product/B06XTZJDCC

The unshielded bearing has much lower friction. But that's not really