Jet 1236 tail stock problem

[Cecil Dean]

I am new to wood turning and purchased a used Jet 1236. When checking the tail stock and head stock I found the tail stock off center about 1/16". I put a new live center and rechecked to be sure it was the tail stock. Is there a way to correct this?

 

[john lucas]

Need more info. Off left right or up and down. First thing to try is clean the mating surfaces well. When you lock it down bias it toward the front of the lathe. Also clean out the morse
Taper score Inserting the center If none of that works get back with us

 

[Odie]

if it's left/right, there is always a small amount of play between the tailstock and the bedways. Some amount of adjustment can be made by simply twisting the tailstock in the bedways prior to locking it down. It won't be 1/16", though.

The headstock is bolted to the bedways. Loosening the mount bolts and twisting the headstock can also provide some adjustment.

You do need something with a pointy center in both headstock and tailstock to check accurately, and it doesn't have to be a perfect match, but 1/16" is too much. The further the spread between HS and TS, the less difference it will make. I'd venture that half that, or 1/32" wouldn't make any difference, but it all depends on what you do with your lathe.

Maybe a combination of all of the above could make a difference........unless it's up/down.....then we are talking shims.

John has some good suggestions to try.......

ooc

 

[Bill Boehme]

In addition to what Odie said, there is more to misalignment than radial misalignment which you can easily observe and correct -- sometimes easily and sometimes with a bit of extra work. However, there is also angular misalignment which is not as easy to observe and much more work to correct. If you are turning between centers, the alignment is generally not a problem. If the piece is being held in a mandrel or chuck then it might be a problem.

 

[Charlie Knighton]

how level is your floor.......you should have on each leg an adjustable foot......or use shims as suggested above.....to lift up one end to adjust it, use a car jack perferable one that pumps up

 

[Cecil Dean]

if it's left/right, there is always a small amount of play between the tailstock and the bedways. Some amount of adjustment can be made by simply twisting the tailstock in the bedways prior to locking it down. It won't be 1/16", though.

The headstock is bolted to the bedways. Loosening the mount bolts and twisting the headstock can also provide some adjustment.

You do need something with a pointy center in both headstock and tailstock to check accurately, and it doesn't have to be a perfect match, but 1/16" is too much. The further the spread between HS and TS, the less difference it will make. I'd venture that half that, or 1/32" wouldn't make any difference, but it all depends on what you do with your lathe.

Maybe a combination of all of the above could make a difference........unless it's up/down.....then we are talking shims.

John has some good suggestions to try.......

ooc

I check and there is some movement in the head stock. Going to line it up then lock the head down to see if that works.
Thanks

 

[john lucas]

I forgot to mention that an out of level bed could twist the Bed and throw off the alignment left to right

 

[Mark Porter]

I have the same lathe. Anytime you move the headstock,(it's able to swivel to turn outboard) you need to move the tailstock up to almost touch the spur drive in the headstock lock it down and move the head a bit to align and lock it down. The factory lock point has some play in the slots. It may even move a bit on it's own with vibration while bowl turning especially if you get a catch. I learned to check it often however I never get catches anymore.🙄

 

[Shawn Pachlhofer]

another cause of misalignment for that lathe - saw dust or shavings under the tailstock, around the clamping block,etc.

 

[Mark Mandell]

Hi Cecil,

You've been given sound advise to check on various things. Notably, a twisted bed must be corrected before you go further. Use a good 3' level on and across the bed to make sure it's dead nuts level before going further. Yes, the 1236's bolt-together frame is a challenge to keep straight.

Having turned on a 1236 as my first lathe, it was a learning experience in a number of ways.

Your alignment issue is common, and while the 1236 is hardly a precision-crafted tool there are some things you can do to make it behave much better.

First, (after you plumb the bed) you must clean and true up your morse tapers in both head and tail stocks. Bumps, galls, dirt, etm. on those surfaces will trash all efforts to get them aligned on the same axis. So, start with a close visual inspection by putting a light source at each open end and looking into the taper opening, you'll be able to see nicks scratches and bumps (galls) that will keep your centers and spur drives off center, no matter what you do. If you have an AAW Chapter near you, go to a meeting, join, and see if they have a No. 2 morse taper reamer for loan. Carefully reaming your tapers (by hand ONLY) will make a world of difference. If they don't have one, see if you can make friends with a friendly machine shop so you can borrow theirs. If that fails, for $24 you can get one from ENCO.com.

Also ask the Chapter if they have one of these:
http://www.rockler.com/nova-acrulin..._campaign=PL&gclid=CP7Jyuven7wCFSUS7AodZzoAzQ

The double-end taper alignment tool is the one sure way to get your head and tail stocks dead nuts true with each other. If you will use your 1236 with the headstock rotated toward the outboard, buy your own alignment tool to be able to keep your machine properly set.

The 1236 tailstock may, as mentioned, have a bit of slop in the bedways. While it's a crap shoot as to which way to go, you can mostly eliminate that slop with the application of a strip of aluminum HVAC tape on one side or the other in the tailstock casting's tongue that fits down into the bed gap. (Works really well in table saw miter gauges as well)

Lastly, form a habit of cleaning your tapers before inserting and after removing a center or drive. Get a TaperMate from Packard [http://www.packardwoodworks.com/Mer...packard&Category_Code=lathes-acc-tapacc-tapmt ] to keep the dust and grit of turning from damaging these precision-made surfaces that are the key to your machine's accuracy.

 

[Sergio Villa]

Hi, if you turn between centers that 1/16 in my opinion does not make any difference: it will be always between centers.

If you use only a chuck to hold the wood that 1/16 does not matter of course.

A 1/16 off center will have an small adverse effect if you chuck the piece and support it with the tailstock. You can use a flat point on the tailstock live center like the one the new Robust center have or just use a "soft" center made by wood and held in a chuck screwed with an adaptor 3/4-10 in the tail stock live center of the oneway, jet, Robust type.

 

[Bill Boehme]

... Also ask the Chapter if they have one of these:
http://www.rockler.com/nova-acrulin..._campaign=PL&gclid=CP7Jyuven7wCFSUS7AodZzoAzQ

The double-end taper alignment tool is the one sure way to get your head and tail stocks dead nuts true with each other. If you will use your 1236 with the headstock rotated toward the outboard, buy your own alignment tool to be able to keep your machine properly set.

That thing gives me the willies. If there is any alignment error that isn't purely parallel to the lathe bed, that thing could bind and damage the MT socket on either or both ends. Morse tapers are precision surfaces that are accurate to about 0.0002 inches. Headstock and tailstock alignment errors, on the other hand, are frequently large enough to be observed by the naked eye. It would be a borderline miracle if all of the alignment error was strict in a plane parallel to the lathe bed. In any event, the only alignment error that instrument of the devil could help correct is lateral.

 

[Mark Mandell]

A misaligned lathe will accelerate wear on the bearings in both headstock and live centers and make turning things like pens and delicate finials very difficult. When its so easy to get the machine turning true, there's little excuse for not doing so.

 

[Mark Mandell]

That thing gives me the willies. If there is any alignment error that isn't purely parallel to the lathe bed, that thing could bind and damage the MT socket on either or both ends. Morse tapers are precision surfaces that are accurate to about 0.0002 inches. Headstock and tailstock alignment errors, on the other hand, are frequently large enough to be observed by the naked eye. It would be a borderline miracle if all of the alignment error was strict in a plane parallel to the lathe bed. In any event, the only alignment error that instrument of the devil could help correct is lateral.

The Big Blue Poolewoods came with that very tool because of the rotating headstock. You don't run the machine with it in place. You clean the headstock taper, insert the tool, bring the tailstock up to it until it seats in the quill's taper, You then lock down the headstock, retract the tailstock quill, and remove the tool from whichever side still holds it. I used one on a Poolwood and my 1236 and my drive and center points were within .0001 of dead true to each other with the spindle running. Mebbie not Mil-Spec, but close enough for gob'ment work.

 

[Bill Boehme]

.... You don't run the machine with it in place.

Well, of course not... I assume that any dang fool would know better than that. Getting points to align tells you zero about angular misalignment. The Poolewood was a top of the line lathe so I wouldn't have any problem believing that they went to the trouble to adjust out out all of the errors and in that case, the tool would be useful. But, I would not feel good about sticking it in any Asian built lathe because none of those machines are custom boresighted.

 

[Mark Mandell]

Well, of course not... I assume that any dang fool would know better than that. Getting points to align tells you zero about angular misalignment. The Poolewood was a top of the line lathe so I wouldn't have any problem believing that they went to the trouble to adjust out out all of the errors and in that case, the tool would be useful. But, I would not feel good about sticking it in any Asian built lathe because none of those machines are custom boresighted.

My Asian JET was not in Big Blue's class but with a bit of care, it would do quality work. The Poolewoods were actually made by Silverdrive, and were innovative for their time. The solid spindle was a drawback if you wanted to vacuum chuck, but the full torque V-S DC motor was a real plus before inversion drives took hold.

You are, however, correct, the double taper will not correct a vertical offset error. If a machine is off in that axis, it's time for a new lathe. Perhaps surprisingly, my JET was well within tolerace on vertical alignment. Maybe I was just lucky.

 

[Mark Mandell]

A Note on "Asian" Manufacturing

Having a couple of Asian clients, I've had the opportunity to learn a bit more about their business practices.

The single most important thing (to me) was their approach to quality control. I found the difference seemed to be cultural rather than ideological. In the "West" we put the responsibility for quality on the manufacturer, and companies compete on the basis of their quality and innovation. In the East (I'm told) "quality is the responsibility of the customer." Huh? Where an American or European craftsman will strive to put out the best quality he can as a matter of personal pride, the Asian craftsman will work to the specifications provided by the customer and take pride in exactly meeting the terms of his customer's order. A Taiwanese or Chinese shop may be fully able to turn out product with the precision to match anything made elsewhere, but they are also willing to meet lesser quality specifications at a reduced price. As the world continues to exhibit an appetite for "cheap" goods made to "sloppy" specifications with cheaper materials, the Asian manufacturers will be quite happy to continue to supply them.

Want true high quality Chinese-made woodworking machines? They'll make them for you if you give them the proper specifications, but the price will be the same or even higher than comparable domestic products.

 

[Bill Boehme]

... In the East (I'm told) "quality is the responsibility of the customer." Huh? Where an American or European craftsman will strive to put out the best quality he can as a matter of personal pride, the Asian craftsman will work to the specifications provided by the customer and take pride in exactly meeting the terms of his customer's order.

Taking pride in mediocrity is the new "pride in workmanship".

 

[Mark Mandell]

Taking pride in mediocrity is the new "pride in workmanship".

I rather suspect it is the middleman who is, after all, the Asian factory's customer, that is proud of the specs he wrote that allow him to get stuff made cheaper and compete with real quality based only on price and a good paint job.

"Lipstick on the pig" eh, what? 🙄

 

[hockenbery]

I rather suspect it is the middleman who is, after all, the Asian factory's customer, that is proud of the specs he wrote that allow him to get stuff made cheaper and compete with real quality based only on price and a good paint job. "Lipstick on the pig" eh, what? 🙄

Pride in profit has replaced pride in product in too many places

Fortunately most in the woodturning business have pride of product foremost.

Al

 

[Mark Mandell]

Pride in profit has replaced pride in product in too many places

Fortunately most in the woodturning business have pride of product foremost.

Al

Absolutely no argument with that.🙂