prototype base, cut to size, began millwork of underside

One of four ABEC-5 precision bearings for the paddle arms. McMaster-Carr PN 57155K355. They have a great feel and should be outstanding for this purpose. It will be a fun challenge to machine with the precision required to use these bearings!

September 15 - majority of base millwork is complete. Top view.

Bottom view of the base

Rare earth magnets I bought for the arm return - I plan to use them in a repel configuration

5OCT - finished posts and insulators

Future paddle arms milled from 1" square aluminum alloy stock (down to .625 square, one side to be milled to further to .250)

Updated pictures showing progress - 10 November. This basically shows where I'm at right now. Several pieces still need to be made, the finger pieces CNCed, arms polished, and base beveled and finished.

The first of four adjustment screws, formed on a lathe out of 1/2" brass rod. The center is tapped 4-40 to retain the contacts. I made the nuts as well from the same brass rod stock.

Bottom view of the bearing retainers for the paddle arms. The is no noticeable friction whatseover - very smooth motion.

These are the pieces that make up one of the bearing "systems" - from left: paddle arm and post, upper bearing, inner race spacer, outer race spacer, lower bearing, inner race retainer and screw (affixes the post), outer race retainer (screws into the base).

Another look at the bearing system I designed, fully assembled except the outer race retainer and the outer race spacer. All pieces (except the bearings) were made on a lathe with 5/16 or 1/2 inch brass rod.

November 14 - here's the base after I added a 45 degree chamfer to all edges, and did some rough finishing to the surfaces. The steel base will look nice once finished with a clear laquer coating (renewable if chipped)

Started machining the magnet cups - 1/4" mill into 5/16 brass rod. Still lots of work to go on these (my project for tonight's class)

I was concerned that I wouldn't have continuity through the bearings, and ordered these springs to create a path to ground through the paddle arms. It appears the bearings are conductive, and hopefully I won't need them. These have too high of a spring constant so I'll have to make some if necessary (they're tiny - only look large in the photo)

This is the lathe used to make many of the pieces

close-up of the lathe with a collet setup for more precision work with smaller pieces

One of the milling machines also used

Here are the two rough pieces of brass that will be the finger pieces - with blue dye that can be scribed for laying out measurements

One of the pieces is here in the vice, to mill three straight edges to use as touch-off points

This tool is used to touch off the piece - it is spun at high speed, and moved in against the work. It will jump slightly to one side at the exact point of being centered, allowing you to zero-out the table

Three sides of the finger pieces are squared, and I just finished milling a small section of the piece.

Showing how I know where I'm at on the table