Wobble in Headstock

steve ramsey

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160
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Lafayette, IN
I have an older Jet 16-42 VS. What I am experiencing is a wobble in my threaded attachments (face plate, strong jaw, talon). When I insert something with a mores taper there is no wobble which indicates to me the shaft is not bent or a bearing issue. I believe it is in the threads of the shaft. Has anyone else experienced this and is there a solution short of replacing the shaft. The more I am learning the more this is becoming an issue.
 

Dave Hoskins

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Using a morse taper piece and there not being a wobble is not necessarily an indicator of no bearing issues. Keep in mind that when using a face plate or a chuck there is most more weight involved. So, don't rule out the bearings, yet. But, I would try Jon's idea of a synthetic washer first. Try the simpler solution first. But, depending on how old the lathe is, it might be time for a bearing replacement.
 

Darren Wright

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And to add to what Dave says. If it is bearings, check the type used. If they are tapered bearings, you may just need to adjust the run out on the shaft to tighten them up.
 

steve ramsey

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Lafayette, IN
The lathe is around 6 years old. I purchased it used from a guy in northern Minnesota who only used his shop 4 months per year. He let it go because he did not like turning. All that being said I don't believe it was used to heavily. I put a Jet face plate on and do not see any visible wobble. When I put the One Way attachments on there is visible wobble. This surprised me, I wouldn't expect a problem in the One Way attachments. I'll dig into Jet info on the web and dig out the dial indicator tomorrow.
 

Ryan Mooney

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Steve, here you go with a quick video on how to make them (the answer is more or less "yes any washer" but not very compressible or even not really compressible at all). You might have to add a couple of them. The problem that the washers fix is that sometimes the threads on the chuck are carried all the way to the back OR the threads on the headstock don't go back far enough and so the shoulder of the chuck doesn't seat well against the shoulder of the spindle. If you look at the Jet faceplate I'm betting you'll notice that there's more of a relief cut on the backside of it so there's more "open/unthreaded" space allowing the shoulder of the faceplate to register against the shoulder on the spindle. What you're doing with the washers is extending the shoulder on the chuck out a bit so it has a chance to register against the spindle. Threads don't make good alignment systems (in this case at least) square shoulders on the mating surfaces do.

 

Ryan Mooney

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If your chuck has an insert to match the spindle threads you might also check if there's a similar issue there... and maybe add a similar washer between the chuck & the insert.
 

steve ramsey

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160
Location
Lafayette, IN
Made & installed plastic washers with no difference. Tried to take the bushing out of the chucks but the bushing won't budge after removing the retainer bolts. So I am assuming it is on to the bearings. I am seeing a number of options for Jet replacement parts.
 

steve ramsey

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Location
Lafayette, IN
Thanks Johnathan. I've been to 5 sites and the cost varies between $92-$155 with MM Tool being the cheapest for the bearings and a belt. I'm curious if there is a difference in quality.
I've downloaded the manuals for the One Way chucks and found the way to remove the adaptors. Plan for tomorrow is to take the chucks apart, clean everything and check runout on the spindle, then check the runout on the chucks. Should probably check the runout on the chucks prior to disassembly to see if I made matters better or worse.
 
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Steve, I have also had my local NAPA store do a cross reference once given the ID and OD of the bearings and they can sometimes come in cheaper. I don't remember, someone on here might, but a "bearing" store and had very competitive prices. Having 16 lathes in the wood shop at school, I have torn my share of the lathes apart. Little patience, good penetrating oil, tap here and there, they'll come apart.
 

Vaughn McMillan

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...Plan for tomorrow is to take the chucks apart, clean everything and check runout on the spindle, then check the runout on the chucks. Should probably check the runout on the chucks prior to disassembly to see if I made matters better or worse.
Since you have a dial indicator, I think that's the best plan of action at this point.
 

steve ramsey

Member
Messages
160
Location
Lafayette, IN
Here is a mornings worth of measurements & observations.
Started with running the lathe with no load for +/-45 min. No discernable heat in shaft or bearings. Minor heat (barly warm) in belt pully.
Run with oak bowl blank in strong hold jaw for +/- 45 min. Again no heat at bearings & minor heat in belt pully.

Then started with dial indicator:
Shaft shoulder at housing .0005
Shaft End .0005
Side of shaft shoulder at housing .0005

Strong Hold chuck
Side at back edge .007
Side at middle .0005
Side at front edge .0025
Face at outer edge no plasric washer .010
Face at outer edge w/plastic washer .018
Face of jaw .010

One Way chuck
Side at back edge .010
Side at front edge .010
Face of jaw .016

Next I took out taperlock adaptor, cleaned it and reinstalled it in each chuck being careful to alternate between bolts and tighten equally.
Strong Hold chuck
Face .012
Side at front edge .002

One Way chuck
Face .012
Side at front edge .001
Jaw mount insert .018

From all of this I do not believe I have a bearing problem. The problem is either in the shaft threads or the chucks. Any suggestions or observations. I believe I'll call One Way on Monday and see what they have to say.

I can add pictures for each of these measurements if necessary.
 

Ryan Mooney

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Maybe take the jaws off of the chuck and clean everything really well and re-assemble?

I've also noticed on some of my chucks that they have more "wobble" when not tight, so try screwing the chuck completely closed and see if the measurement stays the same.

Based on the Strong Hold chuck measurements I'm leaning towards it not being the threads on the lathe either...
 

steve ramsey

Member
Messages
160
Location
Lafayette, IN
When I removed the taperlock I took it apart and cleaned both chucks. I couldn't remove the snap ring so I flushed it with mineral spirits and blew them out until they were dry. Then I rechecked the face measurements.
 
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