# Newbie and the Jet Lathe



## Ceej0103 (Apr 18, 2020)

Howdy everyone. So I'm 90% of the way homefree on the Bridgeport machine that I've been posting about in the Newbie and the Bridgeport thread.  Should have the machine wrapped next week and move on to getting a VFD installed and will be ready to make some glorious chips.

With some down time today I thought to myself, "self...you should take apart that lathe and not waste time".  So I embarked. This JET 1340 lathe came from the same food processing plant as the bridgeport and was neglected.  That said, all of the ways look to be in REALLY good condition after hitting them with some kerosine and a soft brush to see what's under there.

In the matter of 2 hours I had the chuck and backing plate off, all the doors/covers, front plate of the threading gear box, pulled the lead screw, feed rod, clutch shaft, tool post, compound slide, apron, carriage, and tailstock.  Despite the condition of the machine, nothing was too challenging to get moving.  And with a nice dose of way oil, she slid really well.  Took the 3-piece rack off the bottom of the bed as well.  Got everything in a box and will start digging in to each part individually clean and ensure it's fully operational.

Based on another thread I started about the electric aspect of this machine, I think I'm going to replace the single phase motor with a 3-phase to operate it with a VFD. I cleaned out the chip pan well and got down in to the collection basin for coolant.  That was where I found what nightmares are made of.  Looked like a cave of hellish stalagmites. Luckily they just chipped off and came out with the shop vac.  I did notice some holes in the collection basin where it's rusted through, so that will definitely be a project I need to fix.  It looks like it was built and then just tack welded to the frame underneath.  So as long as I can break those tacks and pull it out in 1 piece, I should have an excellent template to build a new collection basin and will probably do that from stainless steel to avoid corrosion in the future.  The whole thing is going to need to be freshened up with a coat of paint after stripping the old one.  And similar to the BP, i'll go glossy black on this machine as well.

I've had the machine running and it sounds bad, but I'm fairly certain I've isolated that to a really loose/banging around brake assembly.  I think it's making contact wit the belt as it rotates and is getting banged around. When I pull the motor, I'll get that dialed in. 

I think my main concern at this point is sourcing parts....or I'll have to make them.  One is the cross feed screw, it was worked hard and shows some significant wear. I can probably just use this machine to turn a new one once I get it back up and running.  I've never turned acme threads, but theres a first time for everything. The wipers came off as just a piece of plastic.  I was expecting to see some type of aluminum wiper bracket with some felt behind it, but not the case.

Anyhow, that's it for now. I'll keep updating this thread as I creep along with the project.  Next step is two-fold.  Start dunking parts in evaporust and getting them cleaned up and begin the process of stripping all the paint off the machine and giving it a new coating.

Also, I'm calling this thing a JET 1340A, but I dont even know if that's correct. I bought a manual from one of those companies that sells them and what I received was almost a match for my machine, but not the exact one.  The one in the manual is referred to as a JET 1340T - J170.  The difference is, mine only has 3 levers on the gearbox and the one pictured as 4.  Otherwise it's an exact match.  Anyhow, if anyone can identify the exact model of this machine, that would be helpful.


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## Z2V (Apr 18, 2020)

Looks like a fun project, I’ll be following along.


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## JimDawson (Apr 18, 2020)

Looks like a project.  Based on a search of pictures, it looks like Jet never made two lathes the same.  I found a couple that looked kind of like yours, and one that looks kinda like mine. But none exactly the same.


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## Liljoebrshooter (Apr 19, 2020)

I have a 1340A that is similar.  You can get some parts from grizzly that will work, you just have to do a little research and hope they fit.
Joe Hynes


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## Ceej0103 (Apr 19, 2020)

Liljoebrshooter said:


> I have a 1340A that is similar.  You can get some parts from grizzly that will work, you just have to do a little research and hope they fit.
> Joe Hynes



Hah...you say similar and I look at this machine and think it's nothing alike!  Then again, I'm learning that the guts of these machines dont very drastically, it's how those guts are manipulated that JET likes to change (ie.  same drive train, diferent lever appearance to adjust it). I actually stumbled on a post last night that mentioned Grizzly and them having a good online parts directory with exploded images/etc.  

Honestly, now that I looks back on the dissasembly, I'm not too concerned about the parts that need proper fitment.  It's in really good shape and doesn't look to have been abused mechanically. It's more items like the coolant pump.  I want a direct replacement, but that's not going to exist, so I'll just have to retrofit some modern pump in there. My biggest part concern was the electrical component, but now that I decided to just get a 3-phase motor, all that becomes a non issue when I switch to a VFD. 

I think it may be a good idea, when I pull all these sub assembles apart, to document the specs on each gear.  That way, if I lose a gear one day, I can go back to my documentation and see the size, number of teeth, bore size, etc.  Then I can look for a commercially available option, or commission someone to make one.  Hell, maybe I just start making all of them as fun projects to learn the art of gear cutting.


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## Flyinfool (Apr 19, 2020)

I have a Jet GHB 1340 not the A. It looks nothing like yours. When I called Jet for parts (Wanted to buy the OEM 5C collet closer that was made for the machine) they only had parts for the newer "A" version, nothing whatsoever for the older ones. I was going to mention that the wiring diagram is on the inside of back panel but it looks like there is not much left of any of the original finish anywhere let alone a piece of paper glued to it.


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## Ceej0103 (Apr 22, 2020)

Flyinfool said:


> I have a Jet GHB 1340 not the A. It looks nothing like yours. When I called Jet for parts (Wanted to buy the OEM 5C collet closer that was made for the machine) they only had parts for the newer "A" version, nothing whatsoever for the older ones. I was going to mention that the wiring diagram is on the inside of back panel but it looks like there is not much left of any of the original finish anywhere let alone a piece of paper glued to it.



Suprisingly, after you mentioend that, I went and looked.  And the paper glued to it is still in pristine condition!


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## Flyinfool (Apr 22, 2020)

Cool, so now you know where all the wires go. My Jet is now sneaking up on 20 years old, It should still be fairly easy to replace a bad contactor. You do not need the exact same part, just one with the same function and ratings.


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## Ceej0103 (Apr 22, 2020)

Flyinfool said:


> Cool, so now you know where all the wires go. My Jet is now sneaking up on 20 years old, It should still be fairly easy to replace a bad contactor. You do not need the exact same part, just one with the same function and ratings.



im fairly certain I’m going to pull the single phase motor and drop in a 3 phase and just use a VFD. Then the wiring will be modernized, I will have built it and understand it, and will add some features.


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## Ceej0103 (May 3, 2020)

Wrapped up the Bridgeport so now I'm officially focusing all my time on this machine.  Had a productive weekend.  I decided I want to start with the bed/ways and work myself left and down. That will enable me to reassemble the majority of the parts that a currently cluttering my garage.  I haven't had a clean garage in a month and it's killing me.

First step was the bed/ways.  I feel like this area of the machine is really the hardest part.  Along with the carriage.  It has a ton of nooks and crannies and I have to be careful when cleaning many of the surfaces.  Lots of white scotch bright and kerosene. The machine has a ton of body filler on it. Because the body filler seems to be holding tight to the machine, I only took what I had to.  The top blue coat is crap...that had to go.  Under was a green then the body filler, then a red primer over bare metal.  In many cases I just went down to the body filler.  This created some irregularity in the finish, but I'm not trying to win a beauty contest with this machine....just make it work and last.

Once I had that stripped down to where I felt it was good, I went back with an oil based primer and then an oil based top coat.  Same thing I did for the Bridgeport.  Jury is till out as to whether this paint will create a nice hard enamel coating.  Takes a long time to fully cure.  Bridgeport seems good though.  After the Bed/Ways, I tackled the carriage.  Another challenging part of the machine that I wanted to get out of the way.  I needed to get it done so things can start bolting back on to it.  The V-way was in great shape.  The flat way was a little rough.  I used some precision ground stones to dial it in.

Also got the rack for the carriage cleaned well and put back on the machine.  I'm going to go the same route with the machine as the Bridgeport.  Mostly black, but parts that are machined (not rough casting) will be polished and put back on without paint.  For areas like the rack gear, those will stay lubed and greasy so not worried about rust.  Areas that aren't going to see constant lube will get clear coated.

Anyhow, here's some pics of the progress. The ways on the carriage aren't as bad as they look. The pictures were taken after I oiled the ways heavily to protect them from flash rusting while I worked other areas.  The oil is dirty and has crap in it.  They actually look decent when wiped down and freshly oiled.


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## walz10 (May 6, 2020)

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


Sent from my iPhone using Tapatalk


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## Ceej0103 (May 27, 2020)

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.


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## pdentrem (May 27, 2020)

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


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## Ceej0103 (May 28, 2020)

pdentrem said:


> 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.
> 
> ...



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.


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## Flyinfool (May 28, 2020)

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.


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## Ceej0103 (May 28, 2020)

Flyinfool said:


> 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.


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## Braschlosan (Jan 6, 2021)

Ceej0103 said:


> 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 replacement


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## Braschlosan (Jan 6, 2021)

Btw the model is 1340p and during that period multiple lathes of different sizes had many shared parts


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## Braschlosan (Jan 6, 2021)

You'll enjoy this


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## Ceej0103 (Jan 8, 2021)

Braschlosan said:


> 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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