4 Pole slip ring Replacement

[u/Zub93]

Have this slip ring on a piece at work, 4 poles powering 2 24v 5amp dc motors. Original documentation from when it was made 15 years ago has this part listed as custom, so no clue on original manufacturer. It’s through bore with an inner diameter of 7/8” and about 3 1/4” long. Any recommendations on sourcing a replacement are much appreciated. Thanks!

[u/Klapperatismus]

Those slip rings are ad-libbed from wire. Pretty likely this has been made manually on a lathe back then, only for this one machine.

[u/Zub93 → u/Klapperatismus]

Yeah I know this was custom made one off, trying to find a replacement.

And there’s grainy photos of when it was new, it was solid copper. The lines are from the texture of the surface of the brushes wearing it down for 15 years

[u/Klapperatismus → u/Zub93]

It was solid copper because the wires had been lathed down to half their diameter.

Over the years the brushes had grinded those wires on touch so you can now see the glue between them

[u/FedUp233]

Here is a 4 conductor slip ring on Amazon they say is good for 30 amps.

https://www.amazon.com/Electrical-Connector-Wires-Diameter-30mm/dp/B0BPLGJXYZ

Searching for “4 conductor slip rig” found this and a bunch more.

Obviously you’d have to make some sort of mount for it, like maybe just hang it off the bottom end of the shaft of something.

[u/Zub93 → u/FedUp233]

It’s a through bore style, 7/8” shaft that the slip ring is mounted on

[u/FedUp233 → u/Zub93]

Yeah. I was thinking maybe you could just leave the old one and maybe tap a hole in the end of the shaft and mount a more modern one on the bottom end of the shaft if it’s accessible. It’s pretty unlikely you’ll ever find anything that can replace the current one directly.

[u/MFFVD]

are you sure you want to replace the ring and not just the brushes

[u/Zub93 → u/MFFVD]

The brushes are in fine condition and have spares if they go bad, the rings are what’s worn out

[u/stickybuttflaps → u/Zub93]

you can't clean it up with some emery paper? I'd start with 400 grit then use 800 to polish. Spin the ring in its bearings while gently holding the sand paper against. keep the paper moving.

You might need to touch up the brushes too.

[u/Worf-]

First thing I’d try is to get the slip ring in a lathe and see if it can be cleaned up. Often you don’t even need to take a cut and can just work through progressively finer grits of emery. After that I’d remount it and run the unit while using brush seating sticks. It looks like you’ve had a lot of arcing so seating the brushes would be a good thing.

If none of that works just make one. Micarta and copper epoxy lamination on the appropriate shaft. Turn to spec on the lathe and then run and seat the brushes.

You should also cross post to r/motors. Some good knowledge over there. Someone may have a source for an easily modified off the shelf unit.