Contact wheel help

[TexasJ]

Hey guys, brand new here. I hope this is the right place for this post. I've looked high and low and I can't seem to find this posted anywhere else yet.

I have a 2x72 grinder that I just got a 6" contact wheel for. The contact wheel has 6206 bearings which have an ID of 30 mm. The wheel itself is 50mm wide.

I am trying to mount the wheel to my tooling arm, but I need a bushing to put through id hole of the bearings that I can run a bolt through. I would love it if I could find a shaft bushing with an od of 30mm, id of 1/2", and oal of 50mm, but so far no luck. Does anyone know where I can get a bushing like that?

If no such thing exists, I can drill whatever size hole I need for the bolt through my tooling arm. So I could even use a bushing with a metric id hole if needbe. But I can't even find a bushing that has an od of 30mm and oal of 50mm with a reasonably sized id to fit a bolt. Everything is either too big or too small.

Any help is greatly appreciated. Thanks!

 

[Ken H>]

That is a HUGE bearing for a 6" wheel, almost 2.5" od for the bearing? 1.181" ID? I suspect about the best you're going to find is have a "spacer" custom made, even aluminum would work. If you have a lathe it's easy, just take a 1.25" (1.5") rod, turn down 50mm of it to required OD of 1.181", drill a 1/2" hole for the bolt and use that. The "spacer" can then be cut to 50mm, or cut longer so the 1.5" becomes the spacer between the contact wheel and tooling arm.

 

[TexasJ]

That is a HUGE bearing for a 6" wheel, almost 2.5" od for the bearing? 1.181" ID? I suspect about the best you're going to find is have a "spacer" custom made, even aluminum would work. If you have a lathe it's easy, just take a 1.25" (1.5") rod, turn down 50mm of it to required OD of 1.181", drill a 1/2" hole for the bolt and use that. The "spacer" can then be cut to 50mm, or cut longer so the 1.5" becomes the spacer between the contact wheel and tooling arm.

Yeah I didn't realize when I bought it about the size of the bearing. I don't have a lathe, and there is no way I can drill a precise enough hole to center the inside perfectly even if I did.

 

[P.Brewster]

You can buy bronze sleeve bearings on McMaster Carr to step it down from 30 mm to 12mm but it would take 3 nested bearings (30x25, 25x18, 18x12) per side. Or you can get a 30x16 hollow shaft on https://us.misumi-ec.com/ and use a 16mm bolt.

Probably the easiest approach is to get a 30mm shaft from Misumi with the option of tapped female threads on both ends. Use threads on one end to mount the shaft onto your tool arm. Use threads on the other end to retain the wheel on the shaft.

Your spacer doesn't actually need to be concentric - all you need to do is immobilize the inner race of the bearing. The wheel rotates around the inner race.

 

[TexasJ]

You can buy bronze sleeve bearings on McMaster Carr to step it down from 30 mm to 12mm but it would take 3 nested bearings (30x25, 25x18, 18x12) per side. Or you can get a 30x16 hollow shaft on https://us.misumi-ec.com/ and use a 16mm bolt.

Probably the easiest approach is to get a 30mm shaft from Misumi with the option of tapped female threads on both ends. Use threads on one end to mount the shaft onto your tool arm. Use threads on the other end to retain the wheel on the shaft.

Your spacer doesn't actually need to be concentric - all you need to do is immobilize the inner race of the bearing. The wheel rotates around the inner race.

Ok I looked at that link and I'm having trouble finding the right part. I found one that I think is right, but I can't figure out the dimensions. There's so much info and so many options I don't know what I need to select. I'm not an engineer so the shorthand and abbreviations are all greek to me. I think I'll have to call them, or get something custom made at my local machine shop.