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Question for Lathe Guys
Posted by:
Andrew White
(---.ks.ks.cox.net)
Date: January 21, 2008 02:03PM
I've recently run into an unexpected problem with my new JET mini-lathe (1014I). I've had it about six months, and I've put about 10-12 hours on it. On this last project, I noticed some wobble, and I just attributed it to mandrels that were slightly un-true, really hard wood, etc. As I checked closer, though, I noticed that my actual headstock is turning out of round. It's especially noticeable with a threaded screw-on chuck. But, it's also fairly noticeable when using a morse-taper chuck. (FWIW, I checked the threaded screw-on chuck on another lathe; the screw-on chuck is true.) I've cleaned out the morse taper. I've pushed and pulled on the headstock; nothing seems to be loose at all.
It's possible that the problem has been there all along, but if it has been, it's not been this bad. I would've noticed something this significant a long time ago. Or, maybe I didn't notice it because I was always using a tailstock before, and the tailstock was straightening things out a little...? Any ideas of what is happening, and what to do? If there's an easy fix, I'd like to try it before hauling the thing 90 miles to the Woodcraft store I bought it from, OR worse, shipping it back to JET. Re: Question for Lathe Guys
Posted by:
Anonymous User
(---.ptld.qwest.net)
Date: January 21, 2008 03:51PM
Might be a little drive, but call woodcraft first, then take it back. I had a problem with a chuck and took it back they check it and replaced it on the spot. Not being able to look at the lathe first hand everybody would be guessing. CALL WOODCRAFT they will work with you to cure the problem. Another possibility is to see if you and someone else in your area can make the trip together and share gas. Re: Question for Lathe Guys
Posted by:
Scott Bazinet
(---.range81-129.btcentralplus.com)
Date: January 21, 2008 04:04PM
Andrew
It sounds like the headstock bearing to me. When you say pushing and pulling on it do you mean in and out or side to side? Any noises coming from it when its running? If you have a dial indicator set it to 0 and give it a wiggle. There really should only be a couple .000 clearance How much tension are you putting on the belt when after changing speeds? You should still be able to compress the belt with your fingers. Scott [www.solwaycustomcomponents.com] Re: Question for Lathe Guys
Posted by:
Dave Orr
(---.nt.interNORTH.net)
Date: January 21, 2008 04:46PM
It sounds like a bearing issue to me also, do as Scott suggets and check the runout. Regards Dave Fishing is Life the rest is just Details Re: Question for Lathe Guys
Posted by:
Andrew White
(---.ks.ks.cox.net)
Date: January 21, 2008 05:28PM
I pushed and pulled in every direction imaginable on the threaded portion of the headstock. There's no movement at all. Granted, I don't have any instruments to measure such a thing, but it's tight. There's no noise coming from anywhere; in fact, the machine is amazingly quiet.
I don't generally pay that much attention to my belt tension. I just drop the motor till there's some tension on the belt, and lock it in. It does seem that the wobble gets just a tad better if I put more tension on the belt, but again, I'm just eye-balling it, so I can't say that for certain. Something else I checked is the inside of my MT. I took the chuck off, then looked straight down the MT hole, and turned the hand wheel. Something is out of round in there also. I can't tell if it's in the MT section or the section for the knockout bar. All this being said, I've turned some pens on it, and lots of cork and wood on mandrels. Up until a couple of days ago, I'd never noticed anything amiss with it. While the machine has never seemed "precise," it always seemed well within acceptable tolerances. Could I have knocked the headstock out of whack? I have been kinda' rough with it, trying to get some really hard wood on and off of mandrels. Re: Question for Lathe Guys
Posted by:
fred schoenduby
(---.dsl.chic01.pacbell.net)
Date: January 21, 2008 05:51PM
ANDREW....YOU MAY HAVE ANSWERED YOUR OWN QUESTION WHEN YOU SPOKE OF "WHACK"....YOU ARE REMOVING THE MANDRELS
BEFORE TAKING THE TURNED ITEMS OFF OF THEM ARE YOU NOT ?? ....IF YOU ARE HITTING THE ITEMS WHILE THE MANDREL IS CHUCKED INTO THE LATHE THAT IS A NO-NO Tight Lines Tight Wraps Fishin'Stix by Fred Re: Question for Lathe Guys
Posted by:
Dave Orr
(---.nt.interNORTH.net)
Date: January 21, 2008 05:54PM
It's possible that the shaft is either bent or out of alignment, the best way to tell would be to use a dial indicator.
Alternatively if you were to slide the tool rest up to the shaft , butt it up against the shaft with the rest left loose and rotate the the shaft through 360 degrees manually. The rest should have moved toward you if the shaft is out of alignment. Now if you rotate the shaft once more slowly while watching if the gap between the shaft and rest changes, the amount the gap changes is your runout. This is far from being the best way to do this, but it's better than just scratching your head. If you know any machineists maybe you could borrow a dial indicator of them. Regards Dave Fishing is Life the rest is just Details Duplicate Post
Posted by:
Dave Orr
(---.nt.interNORTH.net)
Date: January 21, 2008 05:54PM
Duplicate Post Edited 1 time(s). Last edit at 01/21/2008 05:55PM by Dave Orr. Re: Question for Lathe Guys
Posted by:
Andrew White
(---.ks.ks.cox.net)
Date: January 21, 2008 06:47PM
Per Dave's suggestion, I moved the tool rest up against the shaft of the headstock. There is the ever-so-slightest difference from one side of the shaft to the other. One side touches, but the other doesn't. The difference is almost too small to see (i.e. gap between rest and headstock shaft), but it's there. I can feel it and hear it in the rest as the shaft turns.
So, what now? Re: Question for Lathe Guys
Posted by:
Dave Orr
(---.theedge.ca)
Date: January 21, 2008 07:57PM
Talk to the vendor that sold it to you. If you can see the gap it's too big. Regards Dave Fishing is Life the rest is just Details Re: Question for Lathe Guys
Posted by:
Edward D. Smith
(---.ard.bellsouth.net)
Date: January 21, 2008 10:24PM
Make sure your lathe is well anchored to the table. Mine has become loose at times. Use lock washer and/or nuts to anchor lathe to table.
Ed Smith Flat Rock, NC Sorry, only registered users may post in this forum.
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