How to Mount Metal CBN Wheels on Bench Grinder Made for Ceramics?

[Chips O'Toole]

I put CBN wheels on my 8" bench grinder because they are fricking incredible. Far superior to white aluminum oxide in every conceivable way. Problem: the wheels don't mate up with the spacers included with the grinder. The spacers are made for wheels that are about an inch thick all the way across. My CBN wheels have prominent hubs, but they're recessed between the hubs and the outer grinding areas. The wheels work fine if I don't apply a lot of pressure, but if I push too much, they slip because they're not supported correctly.

I'm wondering if anyone else here has solved this problem.

Each side of my grinder has an interior spacer which is basically a long tube with a flat disk on the end. The tube must rest on a bearing inside the grinder. I could make new spacers with deep rims that press against the wheels, or I could make metal rings to fit between the old spacers and the wheels.

The exterior spacers are like giant washers that are convex in the middle. I could try similar tricks with them.

I'm a little concerned that whatever I make will introduce runout, but maybe I'm just overly cautious.

 

[middle.road]

I'd suggest making up some custom spacers.
Those in the picture are for standard solid oxide wheels.
Here's a vid:

Woodturning Videos | Basics for CBN wheel setup and use

CBN wheel setup and use instructional videos, bright magnetic lamp videos and ultimate sanding system video

woodturnerswonders.com

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[Chips O'Toole]

It's weird that they don't care about applying torque farther out. If I used their washers, I would still have the problem I have now.

My existing spacers are made so they contact ceramic wheels almost 3" out, where they can apply decent torque and not slip.

I guess I should make some rings. I'll have to find 3.5" bar, though. Or maybe I can do it with tubing.

 

[Chips O'Toole]

I've been fooling with this, and I'm thinking I should just leave it alone. The wheels run true as it is, and I have to apply a lot of pressure to make them slip. I made some rings for spacers, but it looks like I can get by without them.