About this tool grinder...

[ErichKeane]

How can you tell that the Grizzly part is Acme thread?

I assumed I guess! I have never seen a table saw arbor nut be anything but acme/square thread, but you could see if you can find the listing for the arbor (or saw) that nut fits and check?

 

[ErichKeane]

How can you tell that the Grizzly part is Acme thread?

So I confirmed it IS ACME thread, but it is a LH thread! Got me to thinking, most tablesaws ARE LH I think!

 

[bill70j]

The green wheel is worn but usable, though that side is missing its retaining nut. The diamond wheel was in pretty poor shape, and surprisingly, also wobbles a bit and should probably be replaced. Where should I be looking for replacement wheels?

I preface this with: It'll be used primarily to grind HSS lathe tools, and not carbide (unless the wheels can do both).
Based upon what was mounted on the grinder, it looks like it uses a recessed diamond wheel, like this one, https://www.mcmaster.com/4571A143-4571A62/. On the other side is a green recessed wheel, like this one, https://www.mcmaster.com/4468A21/

Great find on the grinder!

If you are going to use the grinder solely for HSS, then as @ErichKeane said, you could switch out the old green wheel and the diamond wheel with aluminum oxide wheels. I am not sure you would want to use a diamond wheel on HSS. I have found Ebay to be a good source - though many times the sellers turn out to be the big name suppliers.

FWIW, I designed my toolroom grinder to work on HSS, solid carbide bars, brazed on carbide bits, and carbide inserts. And importantly, to use cheap grinding wheels (<$60).

• For HSS, I use this type 50 aluminum oxide wheel on the toolroom grinder to flatten the hollow grind from the bench grinder, then follow that with a polish on a sharpening stone then a diamond hone. The aluminum oxide wheel works great, but unfortunately it took A LOT of balancing out of the box, as the photo shows.

• For carbide, first I use several grits of this type 50 green wheel for shaping, then follow that using these type of cupped diamond wheels. I have found these green wheels to be well balanced. I have bought four of the diamond wheels, and had to balance only one of them. Of course they require their own adapters to fit the toolroom grinder, but they are very cheap and work well.

HTH, Bill

Here is the Type 50 CGW aluminum oxide wheel. Took a lot of balancing effort.

Here are the cheap diamond wheels and the required adapters.
The one on top was the only one that required balancing.

And here is one of the diamond wheels on the toolroom grinder.

 

[C-Bag]

I came across a HF Baldor knockoff on the local CL for $135. It was in perfect shape and I didn’t question why it was so cheap. Once I got it mounted(he ran it sitting unbolted on the bench) it became apparent it it had balancing probs. It had the two green stones it came with new and a very nice diamond wheel. I had just gone through a mess balancing the wheels on another grinder so I knew what to do. Janderso had also gone through the wobble issue on his Grizzly which exactly the same grinder and had posted YouTube of a guy fixing his Baldor. It was the arbor, not the wheel and the best way to fix it was unmount the wheel and true the arbor in situ using the mitre and a cutter. Worked perfect. The diamond wheel had the most unbalance but once I got that squared away it’s wonderful, wouldn’t want to be without it.

I find the little goofy mitre is essential. Another essential is the rubber caps on the ends of the shafts. They protect your fingers when getting in there doing the kind of fiddly stuff you’ll be doing to cut custom grinds. I use to tool grinder for finish honing of my HSS bits and few of my carbide on the lathe and shaper and my 8” bench grinder for roughing in.

 

[kb58]

Waking this thread back up.

I failed miserably trying to make a 5/8"-12 ACME right-hand nut and don't care to try again. The tiny cutter necessary to get in there is pretty crazy, and the thread groove is very small. I've been trying to find a nut like this but it's proving difficult due to -12 ACME being very odd. They're out there, but they seem to all be left-hand thread (for table saws). A tap is out of the question for single use due to cost. If the nut proves impossible to find, maybe I can make a one-time use tap.

 

[Jim F]

Waking this thread back up.

I failed miserably trying to make a 5/8"-12 ACME right-hand nut and don't care to try again. The tiny cutter necessary to get in there is pretty crazy, and the thread groove is very small. I've been trying to find a nut like this but it's proving difficult due to -12 ACME being very odd. They're out there, but they seem to all be left-hand thread (for table saws). A tap is out of the question for single use due to cost. If the nut proves impossible to find, maybe I can make a one-time use tap.

I just saw something about cutting acme threads.
Start with a 60 deg tool and finish with the acme tool.

 

[kb58]

I found an online manual saying that this tool grinder uses both a left and right-hand 5/8-12 Acme* nut, which is confusing. Since the grinder runs in both directions, one wheel will always be trying to loosen its nut, so I wonder if they decided, "better to have one always wrong rather than both wrong in one direction." I'd have made both correct in the normal forward direction, but what do I know!

I can either try to find a nut, or buy a tiny boring bar, and make my own HSS cutter. The trouble is that I'm very new to both threading and using the tool grinder for its intended purpose, but I guess that's how we learn!

* I was wrong, see posts below

 

[kb58]

This tool grinder will be the end of me, mentally.

I found an owners manual online, and it says that the motor shaft is threaded right-hand on the right side (facing the grinder), and left-hand on the left side. I finally had a good look at the left side, the one that's supposed to be left-hand thread, and, well, what do you see? I see a right-hand thread. For "fun", I confirmed that the one right-hand nut I have screws right onto both sides. Another odd thing is that I bought a claimed right-hand 5/8-12 Acme nut and it doesn't fit, and it's hard to tell why not.

Anyway, so either I don't have a Rockwell 23-501, which seems unlikely because even though the ID plate is heavily worn, it clearly shows "501 at the end of the number. So I must have looked at an online manual that's similar but not exactly this model. The reason for this diatribe is for those who come later, and the various little surprises that can happen.

 

[Jim F]

That looks like square threads, not acme.

 

[kb58]

Well I learn something new everyday. I didn't even know that there was such a thing... scurrying off to see what I can find.