End mill diameter for 1/16" slots

.0625 and .0625 deep.

Political Correctness is a doctrine fostered by a delusional, illogical liberal minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.

That slot looks like it might have round bottom as if to accomodate a coin rather than a screwdriver. Even if it's a flat slot I'd use a woodruff key seat cutter and traverse it in one pass. Like this:

Or -- a 1/16" conventional mill (for horizontal mills and adaptors in vertical mills) with probably around a dozen flutes. (I've never actually counted them, so I'm just going by appearance.)

The cutter looks sort of like a small sawblade -- and some of them actually are, with no side cutting available. With this shallow a cut, it should not matter at all.

You could line up a bunch of your brush caps in threaded sockets in a split block so tightening the vise will keep all of them from shifting/rotating during cuts.

Enjoy, DoN.

The problem with nylon..is that if you push it too hard..it melts. So you need a 1 or 2 flute cutter, razor sharp, moderate spindle speeds and go in and out quickly. Coolant..water based... will allow you to cut it faster..ie in CNC mode.

The split block is a good idea if he has CNC capability..but if he doesnt..shrug..it can be an utter pain in the ass trying to mill more than one at a time.

Im not terribly sure Nylon is a good material for a motor bush cap quite frankly. Melting point is far far too low.

Delrin would be a far far better choice and is as cheap in most cases. And its available in black.

Gunner

Political Correctness is a doctrine fostered by a delusional, illogical liberal minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.

Thanks all. Nylon 6/6 was the only 3/8"-16 black threaded rods I could find. Don't think operating temperature or electrical insulation properties will be a factor in this case.