Interesting shop-made grinder

[leeko]

Hi all

I saw an interesting looking bench grinder at auction, and ended up winning it. Now that I have it in my shop, I think it's even more weird/interesting, and potentially quite useful.

There are diamond (or cbn) wheels on each end. The straight wheel on the left is mounted on a hub, which appears identical to the Sopko hubs for my B&S surface grinder. On the other end is a cup wheel, which appears to be held on with a bolt similar to a bench grinder spindle. There's a simple but very functional adjustable angle work rest mounted (albeit too low and too far away) in front of the cup wheel. The cup wheel end has a small pulley mounted just inboard of the wheel, and a belt comes through the bench from below.

I haven't had it apart yet, but I'm guessing it was cobbled together from either a surface grinder spindle, or a spindle cartridge? Either way, the ability to quickly change out the left side wheel could be quite useful.

I have a couple of questions for the group.

1) the wheels are pretty well used, and the markings are long gone. I'm guessing they're diamond, but I suppose they could also be CBN. Is there any way to tell the difference?

2) the left side wheel doesn't currently have a tool rest mounted. I'm thinking it would be more useful with a rest, so I'll likely make one. Or is there a good reason to leave it without? (Clearly the shop it came from didn't feel it needed one)

3) is there anything that can be done on the straight wheel, that can't be done on the cup wheel? I'm planning to mostly use it for lathe bit grinding, but wondering if the straight wheel would be better switched out for something else, such as a deburring wheel or a wire wheel. Space is pretty tight in my shop.

Thanks in advance for any advice!

Lee

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[John Hasler]

If the wheels are diamond don't use them to grind steel. Hot steel dissolves diamond. You can grind carbide with diamond.

[leeko]

Hi John,

Thanks for the advice. that was the reason I asked though!

Best regards,

Lee

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[NP317]

Use CBN wheels for grinding steel tooling. John H. is correct.
When I acquired a used tool grinder, I replaced the worn wheels with new CBN ones.
Nice results, and worth the expense!
RussN

[leeko]

Use CBN wheels for grinding steel tooling. John H. is correct.
When I acquired a used tool grinder, I replaced the worn wheels with new CBN ones.
Nice results, and worth the expense!
RussN

Again, thanks. But that wasn't the question I'm asking. I know not to use diamond for steel, or CBN for carbide. I was asking how to tell the difference between them on an unmarked wheel.

Thanks,

Lee

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[NP317]

Lee:
I do not have an answer for you on determining what material an unmarked wheel is.
Sorry. Hopefully someone else has an answer we can all learn from.
My unclear point was that the expense of new wheels was worthwhile.
RussN

[leeko]

Lee:
I do not have an answer for you on determining what material an unmarked wheel is.
Sorry. Hopefully someone else has an answer we can all learn from.
My unclear point was that the expense of new wheels was worthwhile.
RussN

Gotcha, thanks. I'll definitely be buying some new wheels for this grinder. But I'd also like to make use of the ones that are on there. The cup wheel has a lot of life left. The straight wheel is worn down to almost gone

Best regards

Lee


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[John Hasler]

Try the cup wheel on some carbide?

[leeko]

Yeah, I went ahead this morning. It works pretty well - I'm guessing it's diamond.

Thanks

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[BadDog]

Regarding "not much left" on the left wheel as an indication of worn out. While that may be true, before diamond wheels got so cheap, it wasn't unusual to find diamond wheels that had very little abrasive when new. And even now, you pay more for the same wheel with more grit, though I've not seen the very thin layers in some time (I have CBN and diamond for my purposes, so haven't been looking).