CBN Bench Grinders

[custard]

I was doing some subbing work recently and when I delivered the components I saw they had a bench grinder with CBN wheels, an 80 grit and (I think) a 240 grit? The grinder itself and the tool rest didn't strike me as all that great, but when I saw it in operation the Axminster CBN wheels were very impressive.

I use the Pro Edge system and generally I'm pretty content with it, couple of little niggles but it gets the job done. However, CBN seemed a step up.

Has anyone any experience of using CBN wheels? What are the best brand of grinding machines and best tool rests? Are there better wheels than Axi's? It looked like the CBN wheels ran so cool that a slow speed grinder wouldn't be relevant, what do experienced users think?

 

[Noggsy]

I’ve been using an 8” CBN wheel on a slow speed grinder for about 7 years and I love it. I mainly use it for Woodturning chisels, but have used it for everything except carving tools. I’ve got a medium white stone as well on the same grinder which is more aggressive. What I love about the CBN wheel;

- Not having to true it up (I detest the dust that’s created). I’ve probably trued the white wheel about once a year in that time.
- It cuts very cool. It’s almost impossible to blue a tool I find.
- Using a jig, it’s as fast and accurate as anything I’ve ever used (and I had a Tormek for years).

It still cuts as well, if slightly less aggressively (by a very small amount) than when I bought it. From memory, it was around £300 from Peter Child and the grinder is called Optigrind. Some of the best workshop money I’ve ever spent.

 

[Robbo3]

I have 80 & 180 grit CBN wheels on my 8" Axminster slow speed grinder.
+1 for every thing Noggsy said above.
As a flat worker rather than a turner I'm not sure what benefit you would get.

 

[Sideways]

I have an 80 grit, 40mm wide 8" axminster wheel - a customer return sold off cheap which I understood when it took an age to find a grinder to fit it.
I run it on a full speed record grinder.
It cuts very fast, cool and clean. And takes 3-4 minutes to stop after you turn it off.
It's very heavy so machining needs to be good to achieve that perfect balance which is what you want from these. Axminster's wheel plus bushing weren't quite good enough and I nearly sent it back again myself but figured how to offset the error in one part to counteract the error in the other. Now setup, I'm pleased to have it. I don't plan to sell the Pro-Edge though.
If I were paying full price, I'd look at other makes in the hope that the machining precision of the bore and bushings is better.
I have an old thread on here somewhere that talks about the tolerances I measured