Jet 1236P cleanup?

The 120/127 large gear is for inch/metric feeds and threads. The manual will explain this. The lathe looks very good to my eye. As for the back gears, one of our members has just gone through a replacement of his using Grizzly parts. A search should pop that up for you. As for the motor and pulley, a future upgrade would be VFD and. 3 phase 2 hp motor.
Pierre
Thanks Pierre! I saw a youtube video of a guy that did a variable DC speed control on his Jet 1236 using a 3/4 hp DC motor. I was thinking that might be just as cost effective as finding the back gears and the missing pulleys. Any opinion on the comparative value of those options?
Steve
 
My lathe is a Taiwan clone of the Jet BDB-1340. Likely pre 1990 from what I was told by the second owner of it.

I did the VFD route a couple years ago. I have not touched the back gears since. I have the belts in the middle position. With a proper motor, you can get down to much lower rpms then from factory and higher within reason. 3/4 hp is a bit low for me as the factory supplied a 1 1/2 hp 220 volt motor.
Pierre

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Here is the page for parts that should fit. Like has been said many were just variations. So like mine used 32211 bearing in place of the 30211 on one end and then use the 30210 on the other.
The seals were all the same, and I found those in several places. I had an inside seal out on the rear bearing and was leaking the oil out over night. but while I was at it, I took the whole thing apart, and started doing a good cleaning of everything. One other thing, I see you have missing back gear on it, the shaft and other stuff is there but the gear is missing. that would be one way to hold the spindle while tightening the chuck. That chuck reminds me of the one on my sherline lathe, but it also has holes in the main cuck body so you can hold it while turning the scroll plate which is the back knurled piece. Another way to hold it while tightening it would be a web wrench.
 
I know nothing about these lathes but, in general, I have some suggestions.

First, a lathe is not a complicated machine. Well, it is but it isn't difficult to work on. There is a logic to how things go together and a parts breakdown goes a very long way to make sure you don't get lost. See if you can find one. For stuff outside of the headstock, I would just take pics as you go and disassemble anything that needs cleaning and adjusting.

For cleaning, I prefer the least toxic and most readily available stuff. Kerosene or mineral spirits cleans well and is cheap. Wear gloves, though. WD-40 also works well for cleaning a lot of stuff. I prefer synthetic Scotchbrite to remove grit and rust; I use the 000 synthetic steel wool 3M sells and the white non-scratching pad wherever possible. Coarser grits are available if needed. I used those blue shop paper towels over paint.

I suggest that anything that slides needs to be disassembled, cleaned, verified good and then lubed and adjusted. This includes the compound, cross feed and saddle. Nothing is complicated and you won't need to precisely adjust anything except the gibs.

Your compound has tapered gibs; the round screw has a projection that fits into a slot on the gib and as you turn the screw it will move the gib in or out. Adjust to a sliding fit and no play.

I would also break down the saddle and clean everything up so you can inspect stuff. You'll find chips, hardened grease and maybe dry gears and screws. Now is the time to get it all apart, cleaned and lubed. For any screw or gear that is protected, grease usually works fine. For screws that are exposed, used oil. The manual will tell you which lubricant is appropriate. Most good lathes will have lube nipples in the necessary places; some for grease, some for oil. Usually, nothing has specified torque values on the saddle. Most everything is cast, however, so avoid really cranking down on anything. By the way, the saddle lock is just a bolt that threads into a plate. One end of the plate bears on the saddle casting and the other end bears underneath the ways. Simple to make the plate from 1/4" thick mild or stainless steel and you can either use a bolt or a Kipp adjustable lever.

For grease, I use Super-Lube. My Emco manual calls for Mobilgrease Special, which I have, but Super-Lube doesn't harden and I prefer that. For oil, I use DTE 25 Hydraulic Oil and for way oil, I use Vactra-2.

Your headstock bearings should be tapered roller bearings. To deal with that, you need the manual, sorry.

I agree that you need to find the bull gear/s if you can. The first time you thread to a shoulder on a coarse-pitched screw, you will appreciate them.

Hope this helps. Can't help with the specific pulley stuff, sorry.
 
One quick one, Anyone know what oil goes for the Tapper Roller bearings in the head, Since I am rebuilding the head, with new Bearings and seals I figure I should use the correct oil.
 
I use Mobil DTE Med/Heavy for the spindle. Mobil Vactra #2 Way Oil for any sliding surfaces. Climbing Gear Oil or an appropriate lube oil for the gears.
Pierre
 
Hi Steve,

It looks like Both Pulleys are available at Grizzly. But from your pictures, it looks like your motor may have been changed. So you may want to verify shaft diameters before you order. I believe the motor shaft on my Jet is metric.

The Back gears also look to be available. http://www.grizzly.com/products/g9249/parts

Grizzly's customer service has always been good. My guess is they would be willing to measure the ID of both the Pulleys and Back Gears for you if you called, to save you the chance they don't fit.

Best,
Chris
 
Anywhere the oil is dark in color means dirt. Take it apart, inspect, clean and reassemble with clean lube.
The pictures look like everything is dirty.
Bearings use a 32wt spindle oil or a non detergent transmission fluid works well.
Edit: Should have said ISO 32 spindle oil.
Should be able to get any lube you need at a farm supply or tractor supply.

If you have a 1.5 inch through hole spindle it probably uses bearings that haven't been available for a couple of years.
The Chines bought em all up and the manufacture hasn't made another run yet.
If the spindle oil is dark then flush em out good and look for metal or brass in the flushed fluid.
A small amount of brass ( cage material ) might not be a problem but steel is.
I wouldn't pull the head apart unless there is a problem with the bearings, seals, locking pin, or pulley bushing .
May have some pictures and of the spindle assembly if you have to take it apart.

The pulley on the spindle won't be a problem until you get the back-gears but should be checked and lubed.
The pulley bushing should have a heavy weight oil like 80 or 90wt gear lube ( non detergent ) or I found a high quality low viscosity grease works great.
Just keep checking it for heat buildup. No heat, no problem!
If the pulley bushing ( brass ) is worn you can make it wobble on the spindle while the belt is loose.
It has to have about 0.0015" clearance to the spindle so a very slight amount of movement is normal.
The feed screw should be cleaned before each use but if it's been used dirty, looks like it has, then the split nut must also be cleaned.

After removing the carriage you will be able to see into the gearbox to look for problems.
 
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Many thanks to all. I feel a lot more confident that I can start tearing it down and getting it in good working order now with all the great advice.
I'd like to post updates on my progress as I go. Should I add to this thread or start a new one for that?
Not sure what the preference is on this site and I don't want to clutter with new threads if that isn't appropriate.
Kind regards, Steve
 
I should still have some pictures taken when I took the spindle apart and could offer some advise if you would like and you do have to take your spindle apart.
 
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