Jet 1642 2hp lathe - inconsistant wobble.

[Rhythm House Drums]

Wondering if anyone has had this sort of issue before or any ideas where to start trouble shooting...

The issue I'm having is that I'll smooth out a my piece on the lathe (I'm doing stave built drums, with slight taper. Sort of like a barrel but one end at 12" diameter and the other around 6. Typical length is 12" to 28"... and I turn these between cones on head and tail stock. Ben using this method for quite a few years with no issues so far) As soon as I smooth it out there is more wobble (haven't adjusted the piece or changed RPMs). It's small, and can usually get it close enough that I can sand it out with some extra work. The head stock and tailstock are tightened down good and I cannot move them at all. The spindle seams to be turning smooth. This has recently started happening.

It seems like something must be moving. Any ideas on how to trouble shoot? It does feel like it goes off closer to the tail stock side. I have some bowls to turn soon which don't use the tail stock... so if I turn them and don't have the issue, the problem would be with the tail stock... Is there an easy way to tell if the tail stock is moving (maybe not seated sturdy enough) or if the tail stock spindle could have a slight movement.. It feels tight and smooth to spin by hand, but I know it's a different game at 600RPM with 10lbs of wood spinning on it.

 

[Wyatt Co.]

Run it with something between the head and tail. Run it as long as you would if working on a piece. Shut it down and feel for heat at the tail stock live center. The bearing could be the culprit.

 

[sawman101]

The bearings in the tail stock don't seem to last forever. This is particularly true if over tightened, or used under a heavy load. Fortunately they are not too costly to replace. Good luck with your fix!

 

[riggsp]

Make sure the tailstock is locking down tight...if the tailstock is loose at all between the ways it will pivot sideways if not tightened enough...and if you're swinging a 10 lb chunk of wood, it can make the tailstock move even when you think it's tight enough.

 

[Rhythm House Drums]

Thanks for your feed back. This gives me somewhere to start. I've had the lathe about 6 years and yes I typically run some heavy stuff - typically 15-20lb drums. I also run it in revers and put more pressure on it than I should for sanding... so maybe the bearings are telling me it's not a good idea. I'll check the bearings and also double check the tightening lever. There is some play with the tailstock between the ways, but I feel like I've always been able to tighten it enough so it doesn't move on me. I'll see if there is some way to shim the play...

 

[Roy G]

After you lock down the tailstock and advance the quill, do you also lock the quill in place?

Roy G

 

[Pop Golden]

Don't fell like the Lone Ranger. I bought a delta lathe a few years ago. The headstock has always wobbled. 1st machine wobbled out of the box. Swapped it. 2nd machine wobbled out of the box. The head was rebuilt by Delta service. Wobbled when I got it home. Returned it. Service guy told me he had gone through 5 or 6 shafts before he found a straight one. It ran fine for about 6 months then the wobble returned. I have a $1000 piece of junk. I would give anything for a decent lathe.

Pop :no:

 

[Jim Wallace]

Just something to check. I think that tail stock is one that has the locking bolt for the quill register in the slot milled in the quill to keep it from rotating while you are tightening or loosening it. Sometimes this bolt gets turned too many times when it is loosened and then the whole quill turns as you turn the handwheel to tighten or loosen it. When this happens you have trouble either tightening or loosening it. The fix is to back the tailstock away, then turn the quill until the slot until it faces the bolt (on the back side of the tailstock) and then screw the bolt in until it registers in the slot, but is not tight enough to lock the quill in one place. Move the tail stock back up, tighten the center as much as you normally do, then turn the locking bolt to lock the quill in place: no more than a half turn or so. If you have to turn it more than a half turn you have loosened it up too much. Jet has changed this model a couple of times so you'll have to look closely to see if your tailstock is made this way.

 

[DaveD]

Buy yourself a dial indicator that measures in thousandths. 2" diameter face. They can be found on Amazon, eBay, shares for $15-20. At the same time get a magnetic back for it for about another 8$. Use it to see if surfaces you have tightly clamped down are moving under power. Do not use the indicator on a surface moving under power. All you will get is a bouncing needle and possibly a ruined indicator.

You can also get a magnetic base with movable arms to mount the dial. That will give you a lot more flexibility. About another $20.

That way you wont have to guess if something is moving or off center. With power off put the indicator against your cones, headstock, tailstock, etc.and then rotate and pull/push on the item you have the dial indicator against and see if it moves and how much.

 

[Mike Davis]

When i buy parts for my lathe I look for metal lathe parts that are rated for 250-500 pounds and speeds much higher than my lathe will go.

Overkill, but have fewer problems that way.

 

[chris_goris]

Wondering if anyone has had this sort of issue before or any ideas where to start trouble shooting...

The issue I'm having is that I'll smooth out a my piece on the lathe (I'm doing stave built drums, with slight taper. Sort of like a barrel but one end at 12" diameter and the other around 6. Typical length is 12" to 28"... and I turn these between cones on head and tail stock. Ben using this method for quite a few years with no issues so far) As soon as I smooth it out there is more wobble (haven't adjusted the piece or changed RPMs). It's small, and can usually get it close enough that I can sand it out with some extra work. The head stock and tailstock are tightened down good and I cannot move them at all. The spindle seams to be turning smooth. This has recently started happening.

It seems like something must be moving. Any ideas on how to trouble shoot? It does feel like it goes off closer to the tail stock side. I have some bowls to turn soon which don't use the tail stock... so if I turn them and don't have the issue, the problem would be with the tail stock... Is there an easy way to tell if the tail stock is moving (maybe not seated sturdy enough) or if the tail stock spindle could have a slight movement.. It feels tight and smooth to spin by hand, but I know it's a different game at 600RPM with 10lbs of wood spinning on it.

Im guessing these are fairly thin walled drums? Are you removing alot of material?. You say youve been using this method for a number of years without issue, did you change materials? When you say its wobbling, do you mean its suddenly off center or did your surface move?, meaning, the wood moved from removing material. It doesnt make sense that you have a mechanical issue with your lathe if it works fine until the part gets lighter.... do you have alot or too much pressure on the conical drives of the part causing it to distort (unevenly) when you rough them?

 

[nn4jw]

Chris may well be onto something here. The turning itself may have warped a little due to internal stresses. You can check that with a pair of calipers. Just manually turm the work between the calipers and see if it has the same diameter all the way around.

 

[Rhythm House Drums]

Thank you all for the feedback. I've done some more research and investigating. I do lock down the tailstock and quill, so that's not the issue... Also the drums aren't turned that thin, and it's not the material moving on me. I had turned a large conga drum a big ago and I think this is the cause of the problem. I reversed the lathe for sanding and didn't lock down the faceplate--- so the threads got jammed up when the face plate tried making its way towards the tailstock, but the tailstock didn't move... I had to file the threads on the spindle to get the faceplate back on after it jammed up... I totally didn't think about this because I was onto other projects and been a few weeks since I got back on the lathe. The wobble is for sure in the headstock... and I'm guessing because it's not consistent that a thread is slipping or not engaged enough so that at higher speeds it shifts just out of alignment. I have a 20" disc plate with sandpaper on it that I use to true up the edges, and when I mounted that thing on the lathe it jumped all over the place and the wobble is very clearly at the spindle.... (that's when the previous issue of me jamming up the threads came back to me...)

So - I ordered a new spindle, and went ahead and ordered the bearings as well. Figure if I'm going in there to replace the spindle I might as well replace the bearings.. I'll report back once it's all set up and will know for sure if that's the problem... but it seams pretty clear to me now that it would be.

Also this doesn't happen to me on other forums, but when submitting my post, I guess I take too long typing and get kicked off - then have to log back on.

 

[Wyatt Co.]

I'm sorry to see the trouble but I'm happy you found the culprit.

I'm in dire need of just turning on my lathe. It's definitely a money maker.

 

[Raymond]

Also this doesn't happen to me on other forums, but when submitting my post, I guess I take too long typing and get kicked off - then have to log back on.

Kevin, when you login, remember to click the "Remember me" check box prior to entering your login information. That will keep you logged in.