Rockwell grinder parts?

[yardiron]

I was given a .5 hp Rockwell grinder over the weekend that's missing the right hand washers and nut to hold the wheel or buffer pad on.
The left side is complete. The model number is a 438023140518.
I'd guess it to be late 60's or early 70's vintage.
The threads appear to be square pitched, so a standard nut wont fit. I need at least the special threaded nut, I can fabricate the washers.
My plans for this are to use it for polishing more than grinding.

 

[yardiron]

Here's a few pics
The shaft is 5/8" in diameter. The thread is square pitch or 'Acme' thread. If I can find a nut to fit this, I can fabricate the washers by copying the those from the other side if I can't buy them.

 

[Ponchoguy]

Here's a few pics
The shaft is 5/8" in diameter. The thread is square pitch or 'Acme' thread. If I can find a nut to fit this, I can fabricate the washers by copying the those from the other side if I can't buy them.

Not sure if it's the same company, but have you tried to contact them?

https://www.rockwelltools.com/en-US/Contact-Us.aspx

 

[WhoWhatNow]

You may still be able to get parts for that grinder from Rockwell or a site like eReplacementParts. If not your best bet will be eBay. Before you start looking too hard though do you have 3 phase power? If not you will not be able to run that grinder without a phase converter or a VFD.

 

[jakemac]

Not sure if it's the same company, but have you tried to contact them?

https://www.rockwelltools.com/en-US/Contact-Us.aspx

This is not the same company as the old Rockwell name.
Essentially, this new company purchased the rights to the Rockwell name from Delta/Bosch (I might be wrong about the name holder at the time) about 15yrs or so ago. The reason was to resurrect a name brand that was no longer being used, and to associate the new products with the quality and name recognition from the past. I do not believe they have the rights to the old tooling or that they have the means to support the old tools.

This was told to me by a company rep sometime around 2005 when he was trying to get our hardware store to carry the new (at the time) Sonicrafter oscillating tool. (He succeeded)

I suspect that to get parts for the older machines, you would need to contact Delta. Be prepared to be told that they no longer support those tools. Your best bet for the nuts would be McMaster-Carr or Zoro once you determine the size and thread count. Other parts might be found on eBay if someone is parting out a grinder.

 

[notlob]

Lots of places carry Acme thread nuts:

https://www.fastenal.com/products/fasteners/nuts/acme-nuts/_/Navigation?r=~%7Ccategoryl1:%22600000%20Fasteners%22%7C~%20~%7Ccategoryl2:%22600072%20Nuts%22%7C~%20~%7Ccategoryl3:%22602447%20Acme%20Nuts%22%7C~

http://www.mscdirect.com/industrialtools/acme-threaded-nut.html

http://www.use-enco.com/1/1/16760-acme-steel-heavy-duty-hex-nuts.html

 

[yardiron]

I have a fastenal about a block away from me, the guy there looked at me like I was from Mars when I asked for 5/8" x 12 TPI acme threaded nuts. They have a listing for a 5/8" x 8, and I've seen 5/8" x 11 in both regular thread and Acme thread but I took a collar of a lathe I have with a 5/8" x 11 acme lead screw and it won't go. Neither with a standard 5/8x11 nut. I'm guessing that it may be some oddball proprietary thread pitch?

I used a thread gauge and a ruler and both agree with the 5/8" x 12 thread count.

The wheels that were on this were huge, they used all the threads on the spindle. It came out of a boat building plant that closed down a few years ago.

I have three phase in the garage, its one of the reasons I bought this place. My milling machine, lathe, and air compressors all run three phase. I had called Delta a while back and they had no info or listing for it, its too old. I was told its circa 1970-73 or so.
It spins quiet and smooth, and has gobs of power compared to my 8" single phase Craftsman grinder that's supposedly 1hp. I like the huge dust collectors it came with too.
I'll mainly be using it for light polishing of parts.
I suppose if I can't find anything else, I can turn down the armature on the end to the next smaller size and rethread it to a standard thread but I hate to go that route if I can buy the right part somewhere.

 

[WhoWhatNow]

Try this:

http://www.ebay.com/itm/Delta-Rockw...-3-4-Washer-/301708710534?hash=item463f3d9286

I believe the Craftsman table saw screws were also 5/8-12 TPI so if you need a LH nut one of those may work.

 

[Dennis Leigh Henry]

You'd be surprised what Rockwell (the new one) still has.. I purchased a dilapidated vertical band saw a few years back, contacted Rockwell and they had the parts list, parts, etc.

Also, Try Joe at Plaza Machinery, he was a Rockewll dealer and even though tough to get ahold of (his parts lists are on line but a bit scattered / disorgainized), I'll bet he has replacement parts or knows where to get them.. I've worked with him in the past and his help is worth the wait..

 

[exmaxima1]

I was given a .5 hp Rockwell grinder over the weekend that's missing the right hand washers and nut to hold the wheel or buffer pad on.
The threads appear to be square pitched, so a standard nut wont fit. I need at least the special threaded nut, I can fabricate the washers.

Not sure if you ever found the Acme nut you were looking for. The old Unisaws use a 5/8-12 Left Hand nut (same as your left side assy), but Powermatic Model 66 table saws used a right-hand version:

PN 3530006

 

[Whitworth]

I'm pretty sure those are square threads. You've got a snowball's chance in hell of ever finding anything off the shelf that will fit.
Try eBay or try owwm.org

 

[yardiron]

The threads are square pitch or "Acme" threads. The problem I'm having is finding an Acme threaded nut in the right pitch, they seem to come in everything but 5/8"x11tpi.
I've got a few Delta Rockwell saws, none of the saws use acme threads.
The only other place I've come across threads like this are on lead screws on some lathes.
None of which use the same thread pitch.
I'd settle for an old tap to cut my own threads in a piece of hex stock. The only other option may be to remove the armature, turn down the end of the shaft and rethread it to take a smaller, standard thread. I'm not sure its worth all of that work.

 

[sk farmer]

take your grinder to your local machine shop. any machinist worth his salt could make one short order.

if you find a real blacksmith, tell him everyone told you it can't be done. he may just drop what he is doing and prove you wrong.

 

[exmaxima1]

The threads are square pitch or "Acme" threads. The problem I'm having is finding an Acme threaded nut in the right pitch, they seem to come in everything but 5/8"x11tpi.
I've got a few Delta Rockwell saws, none of the saws use acme threads.
.

Did you count the threads correctly? That grinder should have 5/8-12tpi threads.
The same ACME that used on the Delta Unisaw and Powermatic Model 66 table saws. The Unisaw is LH, and the Powermatic is RH.

To confirm, tomorrow I will try the nut from my Unisaw on my Rockwell 7-inch grinder (same as yours).

 

[exmaxima1]

Did you count the threads correctly? That grinder should have 5/8-12tpi threads.
The same ACME that used on the Delta Unisaw and Powermatic Model 66 table saws. The Unisaw is LH, and the Powermatic is RH.

To confirm, tomorrow I will try the nut from my Unisaw on my Rockwell 7-inch grinder (same as yours).

Just tried it: The Unisaw nut fits perfectly on the LH arbor. If it were me, I'd order the Powermatic nut (PN 3530006) for the RH side.

There's a number of them on the auction site:

Item 171706563981

 

[Whitworth]

Unisaw arbor threads are not Acme, they are square.

 

[exmaxima1]

Unisaw arbor threads are not Acme, they are square.

Ok, but the nut is the same on my Rockwell Unisaw and Rockwell 7-inch Grinder. Looks identical, and fits perfectly.

 

[yardiron]

Just tried it: The Unisaw nut fits perfectly on the LH arbor. If it were me, I'd order the Powermatic nut (PN 3530006) for the RH side.

There's a number of them on the auction site:

Item 171706563981

I own a Unisaw, it does indeed have LH threads but that nut won't go in this grinder, it threads on very loosely but jams and gets stuck. The threads don't look the same at all, the threads on the Unisaw are tapered with a flat top, the threads on the grinder are square shouldered and flat. I've got a pile of old equipment outback and so far nothing comes close to this thread. Its definitely 5/8" x 11, checked both with a machinists thread pitch gauge and a ruler. If anything its a half thread short of 11tpi.

The thread shoulders are pretty square, but not completely. They are not tapered enough though to fit the specs for ACME threads though.

I've tried every last 5/8" threaded nut I can find and so far its a no-go.
I even tried a handful of 16mm nuts just to be sure its not metric since its a loose fit for all the 5/8" nuts and it measures slightly undersize compared to a 5/8" bolt.

This isn't a 7" grinder, it had one 2 5/8" wide by 9 1/8" fine stone wheel, and one 3" x 8" cutting wheel, (It looked like a steel drum with four slots with planing blades in each slot). I'm not sure what it was used for but the thing was full of plastic shavings when I got it. It came from a boat building shop, so my guess is they were trimming resin or plastic or something.

 

[Tarnished]

Yardiarn,
What you have is a Buffer, not a grinder. Both were made by Delta, and Rockwell, but the difference is the extension on the ends of the motor bell. Grinder didn't have the extension. The grinder had cast iron wheel covers, and used a 1"x7" stone.

The covers in your first picture are for the cloth buffing wheels.



The inner flange for holding the pad/stone will have a slot cut in it to fit over the roll pin on the motor shaft. These are prone to breakage, and often hard to find.
Try this link for parts list, and

ereplacementparts
for the parts. Looks like your nut is available, though $$
Good luck.

 

[exmaxima1]

The inner flange for holding the pad/stone will have a slot cut in it to fit over the roll pin on the motor shaft. These are prone to breakage, and often hard to find.
Try this link for parts list

That parts list is for the Baldor-made 1/3hp model. Completely different style nuts.

 

[yardiron]

I was pretty much planning on using it as a buffer/polisher. When I got it it had wide very fine white and red stone wheels with it.
So far I've had no luck finding the nut I need or the backing washers.
I ordered both a 5/8" acme and square pitch nuts but neither are a match due to thread count.

If I ever find the nut I need I'll then start hunting for the right size cloth wheels for it.