Newbie and the Jet Lathe

That looks really nice. Hopefully one day I’ll get to put some fresh paint on my 1236py


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Hey all,

It's been a while since I provided an update on my progress so I figured I would post. No pictures this time, I'll snap a few tomorrow and toss them up. The top half of the machine is done and fully assembled. Carriage, apron, chuck, tailstock all done. Head completely drained, cleaned, re-lubricated and ready to go. All the dials and levers have been pulled apart, cleaned and polished, and made to operate nice a smooth. Gear box was already in good shape so just did some minor cleaning and put it back together. There remaining checklist includes: stripping and painting the lower aspect of the machine (base/coolant reservoir), removing the existing electrical components, replacing existing motor with 3-phase motor, and wiring in the VFD. To that end, I had a feel questions for you guys.

1. I cant seem to locate a head gasket for the machine. I'm thinking I'll need to just buy gasket material and cut my own. Is that what you guys do for these machines? What about some of that gasket-in-a-can stuff?

2. The original motor is a single phase 3-HP metric motor (112M). It has a 28MM shaft. I would just use it for now until forced to upgrade to the 3-phase/VFD, but half of the keyway sidewall has been broken off. It's basically just a large flat area on the shaft until you hit the opposite side of the keyway where it transitions back to round shaft. I could weld it up, turn it down, and re-cut the keyway, but I don't have a lathe without that motor. Here's the question: A new 112M 3-phase inverter motor is like $700. Finding a different motor with say a 1"-1.250" shaft would be nice because they're more widely available, but then the pulley wouldn't fit. The pulley is a double-B groove pulley with a journal for the brake. I can't seem to find a part that would replace this pulley (the journal for the brake is the problem). Any ideas?

Any recommendations on the gasket and motor would be helpful. I'm not so much worried about the base configuration and mounting, that can be changed quite easily. My concern is finding a VFD-friendly motor (inverter duty) and a matching pulley that will allow me to still use the original brake.
 
Gasket eliminator by Loctite. Even Bristol board will work. Silicone sealer will work but hard to remove the top if the bond is really good.

A bit of back and forth to get to the new drive system.

Reinstall the motor
Buy a new pulley or repurpose an old one.
Machine to fit it to the current motor shaft.
Swap the pulleys
Now machine the OEM pulley to fit your new motor shaft.
Now replace the old motor and electrical controls with the VFD.
Stand back and sigh a happy sigh.
Pierre
 
Gasket eliminator by Loctite. Even Bristol board will work. Silicone sealer will work but hard to remove the top if the bond is really good.

A bit of back and forth to get to the new drive system.

Reinstall the motor
Buy a new pulley or repurpose an old one.
Machine to fit it to the current motor shaft.
Swap the pulleys
Now machine the OEM pulley to fit your new motor shaft.
Now replace the old motor and electrical controls with the VFD.
Stand back and sigh a happy sigh.
Pierre

Genius! Thanks for the G2 on the gasket. I'll pickup some gasket eliminator and roll forward. For the motor, good ideas. I think the big issue as it stands is that it cant be keyed to the shaft with the shaft broken. So plan of attack will be to find a 28mm pulley, which shouldn't be hard and weld that to the shaft of the existing motor since it can't be keyed. With that setup, I'll chuck up the existing pulley and machine it out from 1.100" to 1.127-1.128 to have nice slide fit on a 1.125 motor shaft.
 
Do you have or know someone with a milling machine (or know someone with a lathe)? You could bore the pulley on the mill to fit the new motor.
 
Do you have or know someone with a milling machine (or know someone with a lathe)? You could bore the pulley on the mill to fit the new motor.

I have a Bridgeport I just rebuilt. Good call, I could just use a boring head as long as I got the work indicated in well.
 
I have a Bridgeport I just rebuilt. Good call, I could just use a boring head as long as I got the work indicated in well.
Hi Ceej0103, I have the exact same machine and if you need any pictures or info I might be able to help.

I see one of you images looks to be from the service manual? If so could you find the part number for the slide nut for me? Also if you have any pictures or know the thread pitches of your slide nut that would be useful. Mine is worn out and I would rather not take the machine apart until I have a replacementIMG_20210106_013909.jpg
 
Btw the model is 1340p and during that period multiple lathes of different sizes had many shared parts 1289.jpg
 
Hi Ceej0103, I have the exact same machine and if you need any pictures or info I might be able to help.

I see one of you images looks to be from the service manual? If so could you find the part number for the slide nut for me? Also if you have any pictures or know the thread pitches of your slide nut that would be useful. Mine is worn out and I would rather not take the machine apart until I have a replacement

@Braschlosan here's the manual I have. I hunted for a while to find this and I'm still not sure it's exactly the machine I have, but maybe it will help. The part you showed in your picture, not sure where you're referring to on the machine. Is that the crossfeed nut? Wouldn't be any problem to pull my crossfeed apart if it is since I don't have a tool post mounted or anything. Let me know and I can pull it apart and put a thread gauge on it.

EDIT: Looks like the PDF is too large to attach here. Shoot me your email and I'll send it over.
 
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