Man alive am I cursed or what?

[Joshua Dinerstein]

So I finally the shop is fully up and running. (My wife and I were selling 2 homes, post our marriage to each other, and then we bought a 3rd as our new home.) I got the new garage all wired up and finally and at very much long LAST I got the Powermatic Mustard Monster lathe all setup and did some spindle turning. It seriously turns like a dream. Love love love it, it is just so smooth. Skew work on it is a pleasure. I made the spindles that were needed for the "new" house to do a few repairs, I made some toys for the baby, etc...

After getting that out of the way it was time for some fun. Which for me means time to turn some bowls.

I got my chucks dug out of the moving boxes and with the adapters that I purchased with it and from PSI, I have 3 now, I got the chuck mounted.

Oh my word! You should seriously see this blank. I have taken several photos for you all to see. I cut true and smooth with the bevel riding using my bowl gouge and I got the most amazing swirl pattern. The light was pretty much perfect you can see the repeating wave and see it clearly.

Holy cow! If I could do that on purpose I would be famous. Doing it without being able to stop is terribly frustrating.

So I started working on testing things to figure out what is going on. If you recall once before I asked you guys about this as it was happening with a Jet 1642 lathe I had purchased. Once that lathe was turned up these adapters and chucks all spun perfectly true and worked like a champ!

I unscrewed the blank off of the woodworm screw in the chuck and left the chuck on the lathe. So that there would be no issues with the removing and remounting of the chuck. Turned out it made no difference whatsoever. You can visibly see the chuck wobble even with no blank on it. Sort of like the last time only way way worse. Worse you ask? This time there is no damage to the spindle that I can detect. No diggins, dings, bangs, etc... None. The lathe was after all brand new when I bought it.

My next step was to try and repeat what I had done to fix it last time. I got the chuck off and just checked the adapter. So I did. It showed some wobble too. My measurements with my dial indicator measure in "mils" and indicating the maximum amount of the swing from true:
- On the flat part of the 1" x 8tpi threaded tip: 3/4 mil
- On the base where the chuck seats: 1 1/4 to 1 1/2 mils
- With the chuck on at the face of the jaws: 12 mils

So I thought to myself no more messing with adapters. I went out and bought a TeknaTool chuck. The one I purchased came with an insert that was 1 1/4" x 8 tpi so that it would thread thread onto the spindle with no large and bulky adapter. It wobbles like a drunken sailor. Oh my word. It was both worse than the PSI chuck I was trying to use and was a TOTAL write off with a mil swing at the seating face of the jaws of over 20. Now I wasn't terribly impressed with the chuck in the first place... so on to a new idea.

My next step: I got out the faceplate that came with the lathe. I threaded it onto the spindle, it screwed in with no trouble and seated perfectly. Again no damage, nothing that should be off that I can detect. I put the dial indicator on it and rotated it by hand. I found that is was out of alignment and swung as follows:
- Close to the center hold in the face plate: 2 mils
- Close to the middle and inside of the screw holes: 3 mils
- As close to the outter rim of the face plate as I can get: 4 mils.
- Going around to the outside and measuring from the side: 1/4 mil.

Wow! Of all the attachments that I had for that lathe at that point, the faceplate was the one I would have trusted the most. But then I figured you never know about faceplates. Could be they aren't made to the same standards as good chucks for some reason. (Has anyone had bad experiences with theirs?) Given that I almost never use one, I decided to basically screw that and go out and get something good.

So living in Northern Utah, I went out and bought a VicMarc VM120 chuck. This chuck was brand new from Craft Supplies USA which is about 45 minutes from my home. A long drive but worth it if it solves the problems.

This chuck from what I have read online, and in the forums that I frequent, is seriously considered to be the best chuck in the world. (Tho some do give that title to the Oneway chucks... :) Definitely NOT made in China etc... So I put it on the lathe with a fair amount of trepidation and hope in my heart that it would work perfectly. To my shock it does the same thing. Though not quite as badly. So with no external adapter, brand new and precision ground etc... it still wobble visibly!!! What more could I possibly need?!!? I had no idea what to do at that point... Nothing left to try with things that fits onto the spindle. So I went on to check if the 3 pieces of the spindle that are flat. Here are the results I got from the spindle:
- The internal rim of the spindle where the MT2 slips in is so true that it is scary. I could see no motion in the dial indicator at all. (Actually just down inside the rim. Looking for a bent spindle or ????)
- The face of the very outter end of the spindle is so true I can't actually see any wobble visually but on the indicator there is a small flicker of between a 1/10th and a 1/5 of a tick.
- At the base of the spindle there is a set of discs. The chucks and faceplates seat on inner raised ring. This show only a hair of a flicker and back forth as it is rotated. Maybe 1/20th of a mil if even that much. So small that I would be willing to assume/believe it was the dial indicator if I hadn't seen it do so well on the tip of the spindle. Still I can't believe that little an amount is going to be a problem.
- The outer ring which nothing seems to seat on, is off. But again since nothing seats there I don't know if it matters at all. The inner edge was off by about a 1/2 mil. The outter edge by a quarter. But in each case it was clearly swinging unlike the other portions.

My last guess is that it appears that the threads were cut wrong tho I have come up with no way to verify this. The dial indicator I have just can't be used on threads.

I contacted the WMH toolgroup help line but I have yet to hear back from them. So I thought of the forum and thought I would ask here. So please tell me you can help me with this!!!

I have tons of questions:

Any thoughts on what are the next steps that I should be taking here?

Should the face plate be wobbling like that or is it bad as well? It would seem it should be extremely true.

And of course the biggy, what on earth do I do next?

Thanks,
Joshua

p.s. the mils on the dial indicator are marked as being .001in, which from what I know is the standard.

p.p.s The same 1x8tpi chuck that was bad on the Powermatic spins visibly true with a seriously small fraction of a mil of wobble, < 1/5th of a mil, when I put it back onto the old HF 34706 lathe. So I know it isn't the chuck. The adapter I would still suspect if I hadn't fixed it with the Jet I used to have.

[Joshua Dinerstein]

Lathe Spindle 001.jpg:

This picture shows the Box Elder bowl blank I was working on. It is only 6" in diameter. I was riding the bevel as you can tell from the smoothness of the cut and got the swirl pattern. When I went down to Craft Supplies in Provo I turned the smooth ring at the very outside of the blank. Same wood, another 3520b lathe, and same tools and the cut is exactly as one would expect. Smooth and true.

Lathe Spindle 002.jpg:

This shot shows the top of the bowl. This one I did with a flute closed scrape. Just to try and rough down top to see if it was the wood that was making the lathe wobble. You can see the same ripple but the much more torn grain from the change in tool work.

Lathe Spindle 003.jpg:

This is a backed off shot from #2. This side the outer most clean right was cut with the same general scraping action. Again clean and smooth.


One thing worth noting is that the swirls in the wood felt very much to my fingers as if they were opposite. So the high on 1 side was opposite the low on the other. But it was hard to tell how perfect aligned it was.

Pretty freaky stuff!

Joshua

[mike holden]

Josh,
The first thing I would do is: Mount each chuck and measure where on the drive shaft is the greatest runout.
If all 3 (4? lost count, btw "you suck!") are at their worst at the same location on the shaft, then it is definitely the shaft (I will NOT go for the cheap retort: "you got shafted")(grinnnn)(not funny really)
Whether it is the shaft or the threading, the fix would be the same - replace the shaft.

HOWEVER, if each of the chucks shows max wobble at a different point, then there is something else wrong.

Good news is its something mechanical, so its just a matter of digging till we find the problem and fix it. Bad news is: well its maddening in the meantime.

Good Luck!
Mike

[Ken Fitzgerald]

Joshua,

Do you have one of those plastic washers to prevent a faceplate or chuck from being overtightened and frozen on the spindle?

I was seeing similar problems but when I put the plastic washer on, the problem went away. I believe the problem lies with the relationship of the threads and the shoulder that you can screw a chuck or faceplate up against on the spindle. I think there is just enough slop in the threads to allow this to happen and yet you need a certain amount for the threads to work easily and smoothly.

[Dennis Ford]

I think that there is something else going on here. If your chuck or faceplate mounts up slightly off, the wood is still going around in a circle and the first cut removes the eccentricity. I often use home-made face-plates and some of them have run-out but it does not matter after the first cut on a piece.

The picture looks like the wood was moving on the screw or the screw was moving in the chuck.

[Rich Aldrich]

Joshua,

Do you have one of those plastic washers to prevent a faceplate or chuck from being overtightened and frozen on the spindle?

I was seeing similar problems but when I put the plastic washer on, the problem went away. I believe the problem lies with the relationship of the threads and the shoulder that you can screw a chuck or faceplate up against on the spindle. I think there is just enough slop in the threads to allow this to happen and yet you need a certain amount for the threads to work easily and smoothly.

It seems like what you are saying is that the threads are not machined perpendicular to the shoulder. This is at least something to check - either in the spindle or on the chuck.

With our large diameter (20" ID +) paper machine roll bearings, we find that the face of the lock nut is not always machined perpendicular to the thread. This causes the bearing to be locked on with an axial misalignment (cocked on the journal or shaft) and causes runout in the roll. We end up machining the nut face square to the thread and all is ok.

Not to say you can have it machined and all will be ok. If the plastic washer doesnt work that Ken suggested, you might need a new shaft.

[Joshua Dinerstein]

Joshua,

Do you have one of those plastic washers to prevent a faceplate or chuck from being overtightened and frozen on the spindle?

Crap I read that wrong. I have one but I have not tried it yet. I will give it a whirl tonight and see if it helps.

Thanks,
Joshua

[Mark Hubl]

Josh,

I would suspect the adapters. You didn't say if they were made specifically for your chucks.

I had a similar problem when upgrading to my new nova. Woodcraft was out of Teknatool adapters. So I bought a couple of woodriver adapters. They seemed to fit the Nova's (G3 & SN2) ok in the store. Got home and spun them up and could visibly see the wobble. Over 10 thousandths. Put the old Nova adapter back in and put the chuck back on my mini and less than 2 thousandths. I purchased teknatool adapters for the chucks and low and behold the new chuck and the two older ones all were back to around 2 thousandths. Seems the other adapter was not seating square in the chucks. Could be because it had shorter threads, anyway that was my wobble experience.

[Joshua Dinerstein]

Hi Mark,

Thanks for the reply,


I would suspect the adapters. You didn't say if they were made specifically for your chucks.
The one I put in the nova was a nova insert. The one in the VicMarc VM120 was the vicmarc insert. Both were supposed to have been made for the chuck. The larger external adapters, versus the inserts, were made by Jet and PSI.


Got home and spun them up and could visibly see the wobble. Over 10 thousandths. Put the old Nova adapter back in and put the chuck back on my mini and less than 2 thousandths. I purchased teknatool adapters for the chucks and low and behold the new chuck and the two older ones all were back to around 2 thousandths. Seems the other adapter was not seating square in the chucks. Could be because it had shorter threads, anyway that was my wobble experience.
I will have to check that out on the Nova. But I have the bag from the VicMarc right here. It is Vicmarc 5 1/2" chuck insert 1 1/4"-8 119-0222.

So as far as I can see from that, it was the true Vicmarc insert.

I am just wondering why the bigger better lathe is having so much trouble where my old HF lathe spins the chuck visibly true. It just doesn't seem to line up the way I expected too.

I borrowed another chuck and a faceplate from a friend in the local turners club and I am going to go out and try them to see how true the turn.

Joshua

[Jeff Nicol]

Joshua, There is no dobt that you have the luck of damned! With that many chucks and faceplates attached to the lathe it is the lathe and not the chucks, adapters etc. So like what has already been said the threads are either cut wrong or the flat surface where the chucks, faceplates etc touch when they are screwed on all the way is not flat. You may have to get a new shaft for the lathe, it is not out of the question that it was milled wrong, and as we know your luck sometimes runs to the bad side! I hope it is something easy, but with what you have been through I think Powermatic will have to come fix it for you.

Good luck,

Jeff

[Paul Atkins]

Something is vibrating. Here's what I would do besides checking the seating surface of the chucks/faceplates. Screw a piece of wood, even this one to your faceplate with 3 or more screws so you can't wiggle it a bit. True up the blank with another tool, even a scraper. Try turning again, but with less pressure on the bevel. See what happens.

[Joshua Dinerstein]

I would suspect the adapters.
Ok. I went home last night and checked the Nova chuck and adapter. It was a WoodRiver adapter as you had mentioned. I purchased a Teknatool adapter and found that still in the backseat of the car. Not remembering I had 2 I used the wrong one. I am going to try that chuck again with the other adapter but I have not had the time to do so yet. So there is still some hope it will settle down and work with the new adapter.

Thanks for pointing this out. At least it gives me something to try.

I couldn't find my nylon washer so I haven't tried that yet either.

Joshua

[Joshua Dinerstein]

Ok. Status update AKA the curse continues unabated...

I borrowed 2 chucks and a faceplate from a local friend. 1- The face plate is the 6" diameter one that came with his Jet lathe. 2- The first chuck is his SuperNova2 from the local Woodcraft with the silver grub screw enabled for bi-directional turning insert. 3- The second chuck was a PSI barracuda 2 on a large PSI external adapter.

His stuff on my PM3520b Lathe:
#1 The Face plate: I put it on my Powermatic and it spins true. I put my dial indicator onto it on the very outside edge where things should be exaggerated the most and found that it was right at 1 mil total swing on the indicator as I rotated the piece. This is what I had expected from mine so it appears my faceplate it just outright pooched.

#2 The SN2 chuck: I put it on and it spins pretty true. Staring at it closely I can see a bit of wobble at the very tip of the jaws but the body seems to be right on.

#3 the PSI B2 on the adapter: We have a winner! Once again while it was true on his lathe it wobble 10-14 mils on mine. So much so that it is clearly once again completely useless.

We had tried all of them on his before I brought them home. So on the owners Jet lathe:

1- The faceplate on the Jet was actually worse on his. With an almost 2mil swing.

2- The jaws were about 2 - 2.5 mils on his SN2 chuck on the Jet.

3- The PSI B2 chuck was visibly stable on his.


I had taken my Dial indicator, my Vm120 chuck and my PSI B2 with cole jaws and an adapter over when I went to pick this stuff up.

So my stuff on his jet:

A- The VM120 had what appeared to be a 1 to 2 mil wobble at the outside tip of the jaws. Is this normal? Is this within tolerance for this chuck? For chucks in general? It seems this is the best it is going to get. If it is good enough then I know it isn't the chuck.

The face of the jaws that came with the chuck had a 4-5 mil difference in height. But oddly enough that was within each jaw. So not going left to right across the face of the chuck but from 1 end to the other of each individual jaw. This was a surprise to me. Apparently tolerances are not what I had expected on this.

B- My PSI B2 with the big 10" cole jaws in place. On my lathe a 14+mil swing. On his Jet visibly true with no wobble detected. Within 2mils on the outside edge using the dial indicator.

My conclusions:
- His lathe runs truer than mine pretty much across the board.
- His Jet faceplate is nice and my PM one is junk.
- I need to get a new adapter installed on my SN2 and try it to see if it is as true as his was.

My questions:
- Has anyone done an measurements on the face of their Vicmarc jaws with the chuck mounted? What tolerances should I be expecting?

- What is a good replacement faceplate? Is a Don Pencil AC Aluminum faceplate a good idea? Or do I really need to get either a Jet like Ian's or a Oneway or ???

- If any of you have a VM120 chuck when you mount it up with the jaws set to the full circle, slightly open, do you see any detectable wobble? With the fully closed do you see any?

I don't even know how to ask the questions around the rest of my confusion. I will just have to keep working on things.

Joshua

[David Epperson]

I've seen that type of cycloidal pattern before. You have a spindle bearing that does not have enough preload on it. The heavier the attachment, the more pronounced the effect - which is why it doesn't show up at all with just the spindle. When you checked the runout on your heaviest chuck - did the max offset point always show up in the EXACT same place? The turning would suggest that it would not, which would be in line with a bearing "rolling around in the race" as opposed to spinning on a true axis. You may need to just snug the bearings up on the spindle.

[Rob Cunningham]

Joshua,
Have you checked your spindle for run-out/play on both the diameter and face? Put your indicator on the diameter and spin the spindle by hand. Is there any run-out? Do the same with the indicator on the face that the chuck seats on. Also, see if there is any play in the bearings, both radially and axially. It seems like something has play in it.
Do you have a micrometer or dial caliper? If so, check the outside diameter of the threads. Are they close to the size they should be?

[Kim Ford]

Josh;

Sounds to me like Dave is on the right track. Bearings can do different things under load than by just hand spinning.

The other point is that chatter like your pictures show mean the piece is moving on it's axis, and that means it is either in your chuck or your bearings. My bet with all the investigation you have done is that it is your main shaft bearings.

[Mark Hubl]

Joshua,

Sorry to hear that things are still not going well. Here is a pic of how I set up and measured tolerances on my lathe. It is around a month old. I am not a machinist, if there is a better way of doing these, I am sure someone will help out. I just measured by rotating the spindle with the hand wheel.

I agree with Rob and Kim and would focus on the spindle tolerances and the bearing.

[Joshua Dinerstein]

I've seen that type of cycloidal pattern before. You have a spindle bearing that does not have enough preload on it. The heavier the attachment, the more pronounced the effect - which is why it doesn't show up at all with just the spindle. When you checked the runout on your heaviest chuck - did the max offset point always show up in the EXACT same place? The turning would suggest that it would not, which would be in line with a bearing "rolling around in the race" as opposed to spinning on a true axis. You may need to just snug the bearings up on the spindle.

Very interesting. I am still hoping that tech support and WMH will come thru on the warranty and take care of the problem now that it is so clear there is on. I will make sure to pass this along to them.

As near as I could tell the answer was no. It didn't always show up in the same spot. I am not sure entirely how to test that myself. Get a bit bowl blank on there and moving and my dial indicator is probably not the best bet for testing... ;)

Joshua

[Joshua Dinerstein]

Joshua,
Have you checked your spindle for run-out/play on both the diameter and face? Put your indicator on the diameter and spin the spindle by hand. Is there any run-out? Do the same with the indicator on the face that the chuck seats on. Also, see if there is any play in the bearings, both radially and axially. It seems like something has play in it.
Most of these measurements were in the first message in this thread. I couldn't come up with a good way to test the outside thanks to the threads. So I tested the inside at the very end. The dial indicator needle was motionless on the inside right out near the end but again on the inside. I will see if there is anything on the outside to test but I can also test the spindle closer in behind the threads to see how it is doing.


Do you have a micrometer or dial caliper? If so, check the outside diameter of the threads. Are they close to the size they should be?
I have a dial caliper and a digital caliper. I will test the thread height this is one I hadn't thought of. Thanks!

Joshua

[Joshua Dinerstein]

Sorry to hear that things are still not going well. Here is a pic of how I set up and measured tolerances on my lathe. It is around a month old. I am not a machinist, if there is a better way of doing these, I am sure someone will help out. I just measured by rotating the spindle with the hand wheel.

That is pretty much how I set mine up as well. I also did a few from around the front on the jaw surfaces. inside, outside and the top edge facing the tailstock.

Thanks for the measurements! I really appreciate the answers. So on your dial indicator in the pics, the distance between 2 tick marks is 1000th right? So if it moved from 1 tick to the next you would have reported that as 1/1000th? I am correct in how I read your reply? I ask because I was getting similar measurements on my new chuck. Which would seem to indicate that it is withing tolerances...

BTW, what kind of lathe is it that you have. While the pics are small i didn't recognize the profile. A Nova DVR?

Joshua

[Mark Hubl]

Well,

I hope you find the problem. Yes the graduation on the dial indicator is .001" or 1/1000th of an inch (mille/mil equates to 1000 in Italian/maybe latin). Three ticks equal three thousandths. (.0039.. equals 1/256th of an inch) So your interpretation is correct. I am happy with what my lathe is giving me, the chucks could be a little tighter, but hey it's wood. It will move more than these tolerances. My lathe is a Nova 16/24. If you were not getting chatter on spindles I would still suspect the threads or the adapters. One thing I have learned with my moveable head lathe is that when moving back to between centers is to align the head and tailstock. The stop is there but not as accurate as you would want. I don't think this is an issue on your mustard since the head just slides parallel to the bed. Good luck.

[Joshua Dinerstein]

Wow, well Mark was 100% correct. I put a Nova adapter, a 1x8tpi, onto the chuck and put it on my old lathe. I did this and it seems to be spinning true and the chuck is perfectly true. Amazing what a difference there was between the 2 brands of inserts. I am going to have to go with "stay away from woodriver inserts". :)

I have checked for looseness in the spindle in every direction that I can think of to test. It seems to be locked into position very well.

I called in again and spoke with a guy named Danny a nice guy but he didn't much to add. I got transfered to talk to Dave and he was quite helpful. He was the one that helped me with the used Jet I had purchased this last spring.

I am down to waiting for a reply from Powermatic/WMH Tool Group on the issues with the lathe. It shouldn't be doing what it is so I am going to have it checked out. I will stop pestering you guys about it until I do hear back.

Thanks again for all the help!
Joshua

[Ken Vonk]

Have you measured the length from the end of the threads to the shoulder the chuck sits against. It might be that these threads are too long and the chucks are not fully bottoming out on the shoulder. Putting a washer in there would fix that problem. When you screw the chuck on do you see any gap between the shoulder and the chuck?

Just a thought.

Ken

[Joshua Dinerstein]

Hi Ken,

Thanks for the thought but I have measured that. I.e. used the insert without the chuck to see what was happening. It was fully seated and aligned. There is clearance inside of the chuck for the end of the spindle...

Joshua

[Skip Spaulding]

Joshua, Any follow up to your lathe problem yet? Hope you're making headway.

[Joshua Dinerstein]

Joshua, Any follow up to your lathe problem yet? Hope you're making headway.

I had thought I had responded to this but I don't see the reply here. I was searching for something else and ran across this thread again.

The lathe is working at long last and working well. The WMHToolGroup tech support got the proper parts out to a guy with the proper tools and smarts and he got out to my place. He replaced the spindle, a long piece of steel there, and the bearings that the previous guy had ruined and the variuos sundry locking parts etc... He got it all taken apart and then put back together and on the first few cuts is trued right up. No more ghosting. No more weird wobbles.

I haven't had the chance to turn as much as I would like even still but I am getting out there and having fun finally. I have turned a dozen new tool handles for some new tools I made and a bunch of pens and pen cups. Some bowls etc.. Not back into my own custom version of production mode but still having some fun and enjoying making dust and shavings.

I can't say enough good things about WMH's tech support. Dave there is top notch!

Joshua

[Bernie Weishapl]

Glad it is working for ya Joshua. Good that it worked out.