Thread: Goodell Pratt bench grinder

Looks like a left hand thread?
H.

It is

I assume that you've measured the diameter at 1/2 inch? Short of using a thread gauge you can use a ruler and count how many pitches per inch. From that you have something to ask for if you can find somewhere that sells left hand nuts. Or find a machinist, or twist someone's arm here to make one.

Graham.

I'm definitely more of a wood worker than metal worker :/

I'd hazard a guess that the tpi and the even the pitch angle/thread profile might not be a standard imperial thread on that grinder. It's a nothing job for a machinist to make one (or a couple), but convincing one to do it may be your undoing.

Goodell-Pratt were bought by Millers Falls, which was in turn bought by Ingersoll-Rand and then looks to have been spun off and then taken over by a Chinese company. Given the dive that has occurred in the quality of the tools they make, I'd say that the intellectual property died around the time of the spin-off from Ingersoll. Which kinda kills the opportunity to email them and ask if they still have plans in a dusty cabinet.

I can't access it from my current internet connection (annoying blocks all over the place), but this may help: Restoring a Goodell-Pratt Hand Grinder - Lone Pine Toolworks

Yes, this is a pretty simple job. If Stew draws a blank on a source, I'll volunteer to make one. I'd need to check that I have some hex stock of the right size, and without a complete thread definition (dia. pitch, thread from, required fit) I'd need the shaft to fit the nut to. I'm located in northern Sydney.

Graham.

I've probably got some hex if you haven't.
H.

Impressive looking grinder but I bet it would enjoy eating the odd finger or two!

Originally Posted by clear out

I've probably got some hex if you haven't.
H.

clear out, I found some 1 inch hex stock, so we're OK thanks. Stew is mailing the shaft down.

I think it needs a machined flat spacer to go between the nut and the grinding wheel. Can anyone suggest how this would have looked?

Graham.

Originally Posted by Oldbikerider

clear out, I found some 1 inch hex stock, so we're OK thanks. Stew is mailing the shaft down.

I think it needs a machined flat spacer to go between the nut and the grinding wheel. Can anyone suggest how this would have looked?

Graham.

Graham,

Unfortunately the image for the No.115 (which I think this one is) does not show the spacer, but I am guessing it would be similar to this one:



cheers,

Camo

Just a plain spacer then, same diameter as the wheel flange. Stew, can you measure the diameter of the flange. I'll make the spacer match.

Graham.

almost looks to me like beaten up Acme thread, possible? it is American.

Yes, from the photo it could well be a square thread of some sort. I'll wait for the shaft, measure it up, then grind a tool if I need to.

Graham.

Stew has sent the shaft to me, it arrived today. The thread is a 1/2" 13 tpi V groove thread, so it's 1/2" UNC. I have a thread cutting tool somewhere, just need to dig it out and get the nut turned.

Graham.