My ongoing feud with my new Jet 1642 continues with an interesting turn...

[Joshua Dinerstein]

I took the various advice from those here on the forum, thank you very much BTW, and I got started with great seriousness on trying to diagnose the problem with my lathe.

I got lucky and HF put a Dial Indicator and a magnetic base for it on sale this last Monday. A little more than half off on each. Seemed like a sign so I bought 1 of each. After a bit of experimentation and a discussion with a metalworker at work I got it figured out and started testing out my Lathe to see what could be causing my problems.

I started by measuring the outside of the chuck with it fully seated and ready to use. I am not entirely certain what each "tick mark" on the dial indicates in terms of a measurement but I figure almost no movement would be the key to things are good. I set the base and the indicator up to be rubbing against a smooth portion of the outer edge of the chuck. I rotated the chuck slowly by hand while watching the dial. It was from a -2 full ticks to a +3 full ticks back and forth as I rolled the chuck around. This was pretty bad in my opinion. I could still see the chuck wobble as I rotated and this "proved it" in my mind.

So I removed the chuck and started looking for my drive center. My plan being to full seat it and then use the dial to check it out. My thought was that if the spindle was bent then this would be off as well. I couldn't it in the normal spot, things have been getting stirred as I have been doing this, and instead I located my pen mandrel. This mandrel is a high end hardened shiny steel-rod version and spins so true it is scary. "AH HA!" I thought to myself. Into the headstock it went and I turned the lathe on expecting to see a massive swing of the tip of the mandrel back and forth. No suck luck. The mandrel spins so true it was freaky! This was both good news and bad news. It meant the spindle in the last isn't bent. The bad news... I was back to square one and had no idea what was wrong.

Next I took the dial indicator to the "face" of the spindle right out on the end. It spun pretty true. The indicator did flutter a bit but only a touch and never got 1 full tick away from the starting point. I then moved to the face of the spindle in the headstock. I don't know exactly how to state it but the small "flat" at the base of the threaded area that the chuck seats up against. In measuring this I get about 1 tick swing as I again rotate the spindle by hand. This seemed a bit bad to me but I am not sure how bad.

At this point I noticed that things were a bit damaged, well more damaged than I had seen at first when I bought the lathe. On this flat plane on the spindle there is what looks like a catch would in wood from a bowl gouge. A nice dig in with a raised portion just on the up hill side of it. I then started looking at the rest of that area. The previous owner used a chuck with a grub screw to be able to go in reverse without unscrewing the chuck and must have had some serious catches. The screw has dug into and chewed up a bit of the side of the spindle. (Pics will follow I am just at work at the moment...) And also the bottom threads closest to the face of the headstock are pretty chewed up from what would appear to be the same darn screw. Well I figure those threads are pretty darn important. and between the dings and threads I am wondering if the chuck is really seating right even though it tightens down or if it is canting off to the side somehow as a result.

So I went digging thru the box of goodies that came with it and found the standard Jet faceplate. I screwed it on and got it seated, set the test up and started rotating by hand. Nothing. Spins extremely true. ARGGH! So is it the threads or not?!!? Back to the chuck and the same wobble exists.

So off to Woodcraft I went and bought one of those white easy-off no-lock nylon washers in the 1 1/4" size. My thought was to try and change where it was sitting on the threads and also to try and use the nylon to cover of any of the sharp bumps from dings etc... on the spindle.

I slipped it on and then seated the chuck and wouldn't you know it but almost all of the wobble is gone. I don't get it? Visually I don't see any wobble in the chuck anymore. The dial indicates about a +/- a half a tick on the outside of the chuck now. Again I am not sure how much that really means.

So I am left still frustrated and seeking some advice.
- Is this "close enough"? Is this kind of run-out enough to worry about or have I effectively solved my problem?

- What do those tick marks on the dial indicator (there a 100 of them) really mean? :)

- Is there a good way to clean up the threads on the spindle? I look for a die and a rethreading die but apparently 1 1/4" x 8 tpi is not a common thread size. Any ideas or is it dangerous to mess with the threads and potentially introduce slop into them?

- Is cleaning up the threads really even needed? What do you think?

- Is there a good way to clean up the dings in the front face of the spindle? Do they really have any effect? Anyone ever had one before? I have never seen anything like this on my old lathe.

Any other thoughts or answers or suggestions I missed? I would love any information anyone might be able to provide!

Thanks,
Joshua

[Joshua Dinerstein]

I spoke with Jet a week or so ago and they sell replacement spindles and bearings. I had thought the bearings bad but apparently that isn't the case for me. Just the end of the spindle itself.

Anyone here ever replaced the spindle in the headstock? Or have the directions to do so? For $75 or so it would be pretty nice to get a clean true spindle from the lathe. But getting the old one out and the new one is could be... a challenge. :confused:

The manual for the lathe shows the assembly drawing but isn't all that clear on extrapolating a process from etc...

So if anyone has done it, seen it done, can help or whatever then please by all means do! :D

Thanks,
Joshua

[David Walser]

Joshua,

Won't Jet provide you with full instructions for replacing the spindle?

[Sean Ackerman NY]

Joshua,

Won't Jet provide you with full instructions for replacing the spindle?
Josh, I'll email / gmail chat you tomorrow.... lemme see if I can get you instructions on this.

[Brian McInturff]

Josh,
You should be able to clean up the threads with a few machinist files. You tried other chucks right? Are you using an adapter? Mark Norman had a slight wobble in his. He said his wasn't seating properly, took a little off the insert(or adapter, can't remember) and presto, all fixed. Check that before you drop some more cash on a new spindle. I think Mark mentions what he did to his in his thread about Walnut Bowl 3.

[Ted Evans]

Hello Joshua, sorry to hear about your difficulties with the spindle. Something you may wish to try before proceeding to more drastic measures is try cleaning up the threads with a triangle file. These have 60 degree angles and will fit into the threads fairly well. Use them to smooth out any rough places or high points. It should not damage anything being that it is the back threads. File the high spots off and test, if still not good file a little more and try to determine if you have all the high spots removed. I have done this procedure numerous times when I did not have a die the right size. Good luck.

Bear

[Jeff Nicol]

Joshua, Does the chuck have an insert that makes it 1", 1 1/8", 1 1/4" or what ever size? If it does, like my stronghold chuck does, the threads on it or the face of that could be the problem. It sounds like the taper is good and the threads are fine if the faceplate is true. So check the chuck before you go to changing the spindle. If you have a very flat level counter or glass top table use the dial indicator and the base to see if the insert is off. I think if you took the jaws off and set the face on the flat surface and touched the dial indicator to the flat on the insert you can slowly turn the chuck and see what is what.

Jeff

[Mike Lipke]

Here is a way to end fretting and start turning:
Use 2 washers.
But don't buy them. Make them out of a milk bottle, or a sour cream container.

[Scott Conners]

That machined face at the base of the threads is what chucks and faceplates index off of to run true. The threads themselves are just to pull the chuck tight to that face. It sounds to me like the ding in that face is causing the chuck to not seat fully and since it protrudes further from the headstock, it shows more runout than the faceplate. It's also possible the faceplate is touching in a different place than the chuck and so isn't affected as much. Personally, I'd try and clean up that face myself with sandpaper/dremel/files before I replaced the spindle...it's already bad, so if you make it worse it won't hurt anything. I'd probably take a small taper grindstone to it in a dremel and try and relieve the high spots only, to make them into low spots and let the chuck seat fully on the remaining true surfaces.

Each graduation on your dial indicator should be one one-thousandth of an inch, or 0.001" if it's built in the standard way. When I finally bought a dial indicator I realised how useful a tool it is for someone with a lathe, it make removing and replacing work with difficult mounts on the lathe much easier, as well as many other useful diagnostic purposes.

[Ken Fitzgerald]

Joshua,

Most of the dial indicators I use have the measurement graduations written in small print on the white face of the dial indicator..



It'll say 0.001"

[Dave Halter]

Joshua,
From everything you describe it sure sounds like it is a chuck problem and not a spindle problem. I would definitely try a different chuck before I bought any replacement parts for the lathe.

Dave

[Scott Hurley]

I had the same kind of issue with my 1642 and a Talon chuck. I took the insert out of the chuck, rotated it to the next set of holes and reseated it. It ran true after that. If you have a Nova chuck with a screw-in adapter, I don't know what to add...

Scott

[Richard Madison]

Joshua,
Sound like you have already pinpointed the problem, which is the chuck insert. Incidently the fact that you get a few thou radial run out in the chuck O.D. is probably not a big deal. It is the jaws that hold the wood, not the O.D.

[Sean Ackerman NY]

Josh, give me a call or check your email.

[Joshua Dinerstein]

Sorry I am late with this. My wife and Daughter had other plans for my time last night. :)

Yuck. I had hoped these would be better. Some were too washed out with the flash and others to dark with the same flash. Hopefully you can see well enough the damage to the threads and the round base of the splindle behind the threads and of course base plate behind it all on the front of the lathe.

Joshua

[Joshua Dinerstein]

Something you may wish to try before proceeding to more drastic measures is try cleaning up the threads with a triangle file. These have 60 degree angles and will fit into the threads fairly well. Use them to smooth out any rough places or high points.

Thanks for the suggestion. I have a small pack of diamond files that various shapes and sizes. I looked this morning after taking the photos and found a triangle one. I used it for just a bit and it looks like I will be able to clean up some of the threads with it. I will do some more work carefully this evening and see what I can come up with.

Thanks!
Joshua

[Joshua Dinerstein]

Joshua,

Won't Jet provide you with full instructions for replacing the spindle?
When I called them I got a very nice lady who had no idea what I was talking about. When I asked about the part she told me they had them in stock and could ship one out if I wanted to buy it. When I asked about a repair manual or instructions there was silence and then she started reading the part description from the website to me. Very nice just not quite what I was hoping for... :)

Joshua

[Joshua Dinerstein]

You tried other chucks right? Are you using an adapter?
I have tried 5 chucks now. They are all in the same general brand. 2 Tecknatool SuperNova2's and 2 G3 and one they just sitting there at the local store. Each has wobbled to different degrees. I have yet to be able to try a Oneway Talon but I am tempted to go back into the store and buy one just to see what it will do.

All of this searching and trying has had 1 silver lining. I found a great sale on a SN2 chuck. I got a brand new chuck for $80. I was and am VERY happy about that find! :)

I am no long using the adapter I tried them and they were wobbling first. Worse actually than the chucks with their inserts. I will still like to get them working as that is where my Cole Jaws are and it would be nice to be able to finish the bottoms of a few bowls I have piled up.

Joshua

[Joshua Dinerstein]

I think if you took the jaws off and set the face on the flat surface and touched the dial indicator to the flat on the insert you can slowly turn the chuck and see what is what.
An excellent idea. I will try that this weekend. I really would like to get this all figured out and fixed!

Thanks for the help,
Joshua

[Joshua Dinerstein]

Joshua,
Sound like you have already pinpointed the problem, which is the chuck insert.
I agree. The outside didn't concern me except that it was SO FAR out. Seemed to be an indication of the problem. As for the insert that is what I thought near the end. Which was why I went out and got more chucks and pieces. I have 2 brand new clean inserts for the various chucks and they show the same wobble. So it is related the threads and the chucks/inserts in some way. The oddity is the faceplate which seemed to run so true in comparison.


Thanks,
Joshua

[Richard Madison]

On this flat plane on the spindle there is what looks like a catch would in wood from a bowl gouge. A nice dig in with a raised portion just on the up hill side of it.

Joshua, Is this flat plane the "shoulder" of the spindle which faces the tailstock, the surface against which chucks and faceplates are screwed? If so, very gently and carefully file the defect flat with a flat diamond hone. Remove only the burr that sticks up, which is probably not more than .002".

[Jim Underwood]

The photo marked below shows the areas to be concerned about.

The inserts, chucks, and faceplates all register against the face marked "this should be true". There should be next to ZERO runout on that face.

And yes each "tick mark" on the dial indicator measures one thousandth of an inch. Acceptable runout in my opinion should be less than that, and hopefully not even register.

I'd clean up those threads too, since they might affect how the inserts or the faceplates register on the spindle. I'd probably use some thread files (any auto parts store should have a set) since that's what I have. Barring that, one could always buy a die to run up on those threads...

I wouldn't worry about the gouges from the grub screws too much. Clean 'em up with a file if you want- just remember to loosen the screws before attempting to remove a faceplate with them cinched down.;) These gouges in the groove shouldn't affect how a faceplate or insert registers to the spindle.

[Gary Chester]

It seems to me that the shoulder of the spindle is where the problem is, the area Jim described in his picture as "this surface should be true".

I'd take a sharpie and darken that area, then take a small flat file and very gently touch the file to that area. If there's a high spot it should show its self pretty quickly.

Just a thought...

[Jim Underwood]

I would think that area would be the easiest thing to fix for a turner...

After all, you make spindles true by spinning them on a lathe. ;)


I should also note that the taper should show no runout with the dial indicator. But since the pen mandrel spun true, it's likely that the taper is ok also. Just to make sure, I'd put the dial indicator on it... (One could also do this by inserting the mandrel in several different spots to check that a bent mandrel isn't simply canceling out the runout in the taper.)

[Joshua Dinerstein]

I should also note that the taper should show no runout with the dial indicator. But since the pen mandrel spun true, it's likely that the taper is ok also. Just to make sure, I'd put the dial indicator on it... (One could also do this by inserting the mandrel in several different spots to check that a bent mandrel isn't simply canceling out the runout in the taper.)
Thanks Jim.

I spent about 30 minutes on the phone with WMHToolGroups head Tech support guy. He was both very nice and extremely knowledgeable. He was able to give me the steps for replacing the spindle. If anyone should want them let me know and I will pass on my notes.

I haven't yet ordered the replacement spindle as I would like to see if I can fix the one I have and make it work properly.

He agreed with your comments exactly. That the runout on the "this should be true" is the key. Dave's comment was that anything less that 1 in the dial indicator would be enough. The truer the better. He suggested I not turn on the lathe and do it that way but rather that I mark any high spots with the dial indicator and file/dremel them off. No deeper than flat if at all possible to do so.

Oh yeah and he was also able to hook me up on the re-threading die for my spindle. So I think that rather than file them any further at this point I will way for the die to come in to finish cleaning those up.

He also agreed completely with the comment about the grub screw area. As long as it doesn't impede the ability to get a chuck on and off then it just doesn't matter. Good to know. I will just leave it alone.

Thanks all the help. I am going to start trying to true up the face of the base of the spindle and see if I can't get this thing running right.

Thanks to 1 and all for the help. As always you guys and gals are the greatest.

Joshua

[Jeff Nicol]

Joshua, If you mount a pen to the rod of the magnetic base for the dial indicator and bring it up to the spindle face and get it close but not touching and turn the spindle by hand you should be able to find the high spot but moving the pen in until it just makes a mark on the high spot, or make the whole thing black and bring a scribe or something up to the spindle and turn it to see where the black rubbed off. This will give you and Idea where the trouble is.

Jeff

[Dick Sowa]

It may be a bit off topic, but several posts mentioned the plastic spindle washers from Woodcraft and others. It turns out that most bathroom sink drains are also 1-1/4" dia...so you can grab some plastic washers for them at your local hardware store. I did it, and they work just fine.

[Joshua Dinerstein]

I got home last night and armed with the information I had received here and with the comments from Jet tech support I got to work on my 1642 lathe.

I got out the dial indicator and found the high spot on the spindle. As expected it was right where the visible damage was. It was interesting to me that it was on the left-hand edge of the visible damage. It would appear that the "smack" happened while the lathe was running in reverse. Interesting perhaps only to me but there you go. I got out my flat diamond file and went to work on the high spot. It scored the metal nicely but it took it down to flat. Perhaps a hair below it but pretty darn close.

I then kept measuring and found that outside edge was pretty damaged. (Also visible in the pics.) The greatest swing in the dial was here. I mounted the adapter and before it was even fully seated I could see that it was hitting these dings full-on solidly and that they were going to have to go. So I got out the file and knocked the high points down. Once again it scored the metal nicely but made fairly quick work of the high point.

I didn't like the scoring. I could see ridges in the metal but they really were pretty fine. I tried to use the dial indicator and it got terribly hung up in the grooves from the file. So I got out a cotton rag to use with the lathe running as a buff of sorts and it just kind of got caught and did a whole lot of nothing. So I got out a piece of sand paper that I had used before. It was either 320 or 400 grit but well used and worn down to at least 600. I started the lathe and set the speed to about 390rpms. I lightly touched the sand paper to the outer rim figuring that if something went wrong here was the least problematic. Withing a 30 seconds or so that portion of the sand paper was black with the removed steel and the end of the "this should be true" portion was bright and shiny and smooth. The scoring fully removed. (I possibly could have done this sanding faster but I was going slow on purpose! :)

I retested with the dial indicator and it was so close to true that it barely flickered. When it did it was into the depth of the gouge mark which is still there as I was trying to removed the high spot not the low spot. The face on the outside, ignoring the pits, was now 1/20th or so of a tick mark from perfectly true! Amazing!

So I took a different spot on the same sand paper and went to work on the face where the scoring the file was there. I started the lathe back up and tried to keep the face of the paper flat and even and moving constantly. Again within a few seconds the scoring was smoothed off and the face was polished. Another run with the indicator showed it was very very close to true. Most of what I noticed with the indicator is that I got what I paid for at HF. It would drift after a bit of use. Meaning I could set it one spot, roll things by hand a few mm's on the face of the spindle and then go back and it would be ever so slightly different. But after enough moving it would seem to stabilize and then I could really check things over. I expected a bit better but given that it was $7.45 at HF I suppose I got both what I paid for and and a deal on what I needed. :D Kind of nice when the two coincide so inexpensively. So I am not all that disappointed.

So for the final tests. After all of that I mounted my older SN2 chuck on the spindle. Spins true visually. Very true actually. I am so pleased! There is still a touch of play visible in the jaws but they aren't perfectly round so there is really no getting rid of that.

Next I went to my borrowed Teknatool G3 chuck. What a piece of crap. It wobbles terribly. Seems to actually just be the chuck or the insert that was in it. Glad I borrowed that one instead of buying it because it is going right back on Monday! :mad:

The last couple of tests involved my spindle adapters and my older PSI and Craft Supplies Apprentice chucks. These are the 1" x 8tpi chucks that I have had for about 2 years now. I got the adapters seated and tested with the indicator and they are all extremely true now. The cole jaw chuck that had been so terrible before now spins so true it is scary how accurate it is! The Apprentice has a bit of wobble and play in the jaws. This seemed different to me so I got the old HF green machine set back up enough to put the chuck on and see how true it is there. I was shocked to see more play on the old lathe that had seemed so true than I now have on the Jet. The PSI chuck even with the extended cole jaws seems to be quite a bit more accurately made. A nice thing to discover.

Thanks again for all the help and ideas. It is nice to get it fixed and to get ready to turn the next round of projects.

Joshua

[Steve Schlumpf]

Congrats on finally getting things figured out! Now do some turning!!! Have fun!

[Jeff Nicol]

Joshua, Never let it be said that you are not thorough with your diagnosis and remedy of a problem! At least it was something that did not require the complete dismantling of the headstock! Have fun now and enjoy your Jet. But when is the 3520b going to get its chance? Still in the box or in pieces on the floor? Your to busy so you better send it to me so I can put it to work!

Jeff

[Jim Underwood]

Well good on you... I'm glad things seemed to have worked out.:)

I am noticing more things wrong with my little Jet mini now that I've started using the larger 1642 also. It's not nearly as rock steady as the 1642. It's a whole lot easier to get a good cut when the blank isn't rocking like mad.....:rolleyes:

Interesting that you mention that about the G3 chuck. I have one, and I haven't been able to get a piece of cold rolled 5/8 round stock to run true when I put it in the small jaws I have for it... Time to check that thing out too...

[Bernie Weishapl]

Great job Joshua. Glad to see things are coming around.

[Sean Ackerman NY]

Rock on Josh, glad it all got sorted out :)