Jet 1236P

All discussion about lathes including but not limited to: South Bend, Hardinge, Logan, Monarch, Clausing and other HSM lathes, including imports

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ctwo
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Re: Jet 1236P

Post by ctwo » Tue May 10, 2016 11:20 pm

Thought I had another post here. I found the main headstock bolts missing, yet home depot had them.

I like the easy access to the qc gears and oiling systems so far. It needs a motor, so I will contemplate the 1hp Dayton I have sitting here (in green no less), or maybe play with a DC motor. Either way I'll still try to fabricobble some sort of switch to the apron lever...

The 3-jaw that's on there needs a jaw grind.

One thing at a time.
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ctwo
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Re: Jet 1236P

Post by ctwo » Wed May 11, 2016 12:42 am

[where'd spro's post go?]

Indeed. I've had no time to get far into it. I noticed air on at least the last serration when clamping a hardened, long shank end mill while just checking run out (4 thou).

There is a set screw on the side of the head stock, I assume for helping with the alignment. I think I'll give rollie's dad's method a whirl?

The lathe was free of chips and dry (yet no rust), so I assume (hope) the head stock may have been removed for a move and the bolts forgotten, or there's treasure to be found... Gasp if it was run that way, but I'm sure it would've let you know... the counter bores were not clean though.

Anyone know what kind of spindle bearings it has? There are oil cups and sight glass in the casting. I have it all dripping with ATF while things loosen up.
Standards are so important that everyone must have their own...
To measure is to know - Lord Kelvin
Disclaimer: I'm just a guy with a few machines...

Harold_V
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Re: Jet 1236P

Post by Harold_V » Wed May 11, 2016 3:03 am

ctwo wrote:[where'd spro's post go?]
I'm afraid our friend spro has a nasty habit of posting, then deleting after the fact, which has the potential to ruin a thread. How I wish we could break him of that bad habit, as he often provides some excellent guidance.

Harold
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spro
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Re: Jet 1236P

Post by spro » Wed May 11, 2016 8:17 am

While the Jet 1236P is very similar to the Enco 1236B, I went into suppositions and my reply became too cluttered. There were issues with this lathe but can't say they are the same. The mention of re trueing chuck jaws, compelled me to mention the obvious setting of the head in lateral relation to the bed. Headstock bolt removal and separation from the bed (for transport) is a distinct possibility with the J1236 P and less so, with E1236 B.
From the beginning, the head must be checked against the bed, not the tailstock. The bedways are hardened but the saddle isn't. The wipers are terrible plastic things(or were). It is well to clean, flush grit from under the saddle before proceeding to lateral and axial checks. The bed is also checked for warp. Heavy as it is, warp. The tailstock could be of use if the ram is fixed and an accurate test bar between centers is measured but that doesn't address which one is "off". When the head is clamped, a larger plate fixed to the spindle can be turned. Register against that plate outer face will magnify inaccuracy for measurements.
Then, as was said, a trued chuck with an accurate shaft-not one made in the chuck- can indicate the head/spindle relation to the bed. Cluttered, again ripe for deletion.

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Re: Jet 1236P

Post by spro » Wed May 11, 2016 2:26 pm

Both these lathes were popular some decades ago. Back then, machine shops were everywhere and decent machine tools were expensive. If we focus upon a few years between aprox 1978- 1983 ctwo's lathe and mine are very similar. I'm sure the head spindles and gears were the same, same satin handles, tail stock and same yellow change gear levers. Mine is directly before the gear head model with gap bed. His has the classic feed reverse handle to left of head, whereas mine is on the face. That one extra shaft and gearing required the head casting to be deeper/wider so the face extends to the QC. Other than that and the contactors, they are the same. Same helical gears sharing the head with belts. :) It does work, however and everything is adjustable. We both share the "tray top" which is loaded with stuff when you need to open it :)
There used to be a site "Asian lathes" on yahoo groups where there are particulars like the nefarious feed gear by the non interlock...But that was all over and guys made those gears and it doesn't happen when familiar with the machine.
Nuff.

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ctwo
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Re: Jet 1236P

Post by ctwo » Wed May 11, 2016 3:10 pm

Are you talking about the feed/lead drive lever? I have the covers off the QC gears, which look fine - still some flats on the teeth, but sharp.

I do not like the back gear / direct drive mechanism - that threaded pin comes loose fairly quick.
Standards are so important that everyone must have their own...
To measure is to know - Lord Kelvin
Disclaimer: I'm just a guy with a few machines...

spro
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Re: Jet 1236P

Post by spro » Wed May 11, 2016 4:28 pm

No! the nefarious gear is in the apron. The shaft below the lead screw drives this this gear for power fine lateral or cross slide. It is at the right , looking into the open apron. It does wear and it does shear for reasons. The interlock between , fine feeds and main screw feed wasn't the best. In some cases the lead screw could be clamped while that feed was engaged. Fortunately-depending how you look at it- the brass gear got its teeth stripped before further damage up the train.
Then many people had that problem and there were replacement gears. Then some fit and some didn't and then persons made them and then they didn't but they remain. It is mostly about not knowing how to operate these particular lathes. I screwed up and dang near ruined mine when it was new.
Let me take you back some decades ago. Lathes which had metric capability and were new, were expensive. I was a newbie(still am) and had bought really beaten stuff and spent time trying to fix the machine instead of why I bought it. This did evolve but at that time I spent over $2000.00 for the lathe we are discussing. It was New! It has hardened ways etc.
Old news but shortly after, the down turn caused many shops to close, auctions etc. Cincy Traytops, LeBlonds rushing past and what I bought is what I have. Then almost immediately the whole 12X36 engine lathe turned to a gear head with gap bed. Whole different thing and different factory.

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ctwo
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Re: Jet 1236P

Post by ctwo » Wed May 11, 2016 5:36 pm

Alright, the works there seem a little sloppy, but they work.

I found quite the rat's nest in my Logan's apron and am really glad I took it apart, so I may as well do the same here. There is nothing better than knowing what you've got.
Standards are so important that everyone must have their own...
To measure is to know - Lord Kelvin
Disclaimer: I'm just a guy with a few machines...

spro
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Re: Jet 1236P

Post by spro » Wed May 11, 2016 6:14 pm

That is good and I had the time. It is bit sloppy and certain things can be improved. I think we meet by practical means and how this is a tool. It is almost like the junk cars which some of us owned. One person's experience is a wandering uncontrollable, 2 ton piece of junk and another drives that battleship smoothly because all the bugs have been worked out. The "devil is in the details" and we may see that as investment of time. Well this isn't a battleship nor classic automobile and allows us to exploit this tool to full extent by working some relatively small details.
Yes the weak link , thumbscrew between the bull gear and pulley but in ...nuff

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ctwo
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Re: Jet 1236P

Post by ctwo » Thu May 12, 2016 10:07 pm

Hi Folks,

Slight crack that needs fixed. Are these hand wheels cast? Will I be able to mig weld this? JB weld the handle in? Or just drill/tap a new hole?
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Standards are so important that everyone must have their own...
To measure is to know - Lord Kelvin
Disclaimer: I'm just a guy with a few machines...

John Evans
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Re: Jet 1236P

Post by John Evans » Thu May 12, 2016 10:12 pm

Were it me drill and tap. That bypasses any material issues ,welding problems.
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ctwo
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Re: Jet 1236P

Post by ctwo » Thu May 12, 2016 10:46 pm

Yeah, I was leaning that way to the other side, and I could JB weld in a little button head bolt for thumb leverage to polish off the hole. Those have to be cast.
Standards are so important that everyone must have their own...
To measure is to know - Lord Kelvin
Disclaimer: I'm just a guy with a few machines...

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