More bad luck with my new 3520b (bad Nova chuck adapter) - need more help

[Mark Warden]

Wouldn't reverse turning

help with some tearout situations like turning a board around in a planer.

 

[Steve Worcester]

Looks like the natural result of machining the corners off a hex to me. That way a slipping wrench won't peen metal and cause a misfit.

no, the surfaces that would mate against the back of the spindle and the back of the chuck.

 

[Walt]

Charles, I too had an issue with the set screw of the PM face plate. My bad! It screwed up the last 1/2" of thread on the spindle. I purchased a tap and die to clean up the spindle and the faceplate. That was a year and a half ago and have had no issues since. I do ensure that that everything is cleaned out and have removed all set screws from my chucks and faceplates. When needed I'll install them. Sorry to hear about your misfortune. Been there, done that unfortunately! I'ld say clean up the damage and keep turning. It's a great lathe, at least I think so.

Walt

 

[MichaelMouse]

no, the surfaces that would mate against the back of the spindle and the back of the chuck.

Not illustrated. They are, however, flat, as required. Mine, showing machining to produce the "wave", and the position of the grub screw. Note the "L" and the extra length.

 

[MichaelMouse]

help with some tearout situations like turning a board around in a planer.

Not that I could figure. We're not talking face grain planing, rather picking up in the two places on end grain. As you know, the answer for end grain on boards is usually a lower sharpness angle. One of the reasons I like my long-bevel, broad radius forged pattern gouges is they do that very well. Since I can skew them to the work like the "shear-scraping" set, only have my bevel too, they effectively lower the sharpness angle as skewing the plane to the direction of travel or skewing the board to direction of feed on the planer do.

 

[Bill Boehme]

I like the brass screw idea -- there is no reason that it needs to be a headless hex-key hardened steel setscrew.

Something that I have considered doing is to drill a small detent hole where the set screw parks, but then it occurred to me that there are problems with that idea such as the parking spot is different for each chuck and if you use a thin plastic washer, that also changes things.

 

[Charles Henderson]

In any case, I still feel it is the responsibility of the owner to insure compatibility.

We'll have to agree to respectfully disagree.

Charles,
Either of those two inserts you showed would fit on my 3520b without a problem. The ridge that you said was hit by the set screw on my lathe protrudes .110 from the surface that the insert seats on. This leaves about .070 to .080 clearance on every 1 1/4 X 8 L insert I have (I believe that that number is 6 of them). Perhaps yours is protruding further? The chucks have been batch tested for runout with an insert installed, Face runout maximum .1mm (.0039 inch) and Radial runout maximum .13mm (.005 inch), that is direct from the manual. I have 9 Nova chucks including those made in New Zealand and in China and they all run between .0015 and .002 Radial on all of my lathes and less than .001 Face on said lathes. I tested them all when I bought a couple of chucks that came from China. There were no differences that I found as I heard that the machine that made them in New Zealand was moved to China. Now that said the only problem that I have with any chuck or set of jaws is the 1" Pin Jaws made for the Patriot Chuck. I bought these because they have two screws per jaw and I felt they would hold better than the ones that only have 1 screw per jaw, WRONG! These are the worst jaws I have ever seen, if you are using a piece of wood that is not round these jaws actually bend. And if your lucky enough to get a small catch they can bend more than a half inch. There you go buyer beware, just because a copy of someone else's chuck is done does not mean that the stuff is any good.

We have the same lathe and they should have the same measurements. The 3520b has evolved, though. I obviously just bought mine. When did you buy yours?

I have given no measurement that would tell you whether the inserts would fit your lathe. Are you trying to judge by eye? I have a turning on the lathe I don't want to remove right now. When I get to a point where I can pull it, I will measure the protrusion of the mating register and post it here, but it'll be couple days. There is a picture of my spindle in post 1 of this thread, but I doubt you'll see a difference in a picture that isn't significant (unless you take a similar pic of your spindle for a side-by-side).

I won't deny the outside chance that PM made a bad batch of spindles, or made a change that would cause this. However, I think it unlikely. On the other hand, after seeing the insert Michael posted (#44) it is obvious that some change has been made in production between his and mine (note the rolled over edges and smoother steel on my inserts). Those may both be type L inserts, but they are not the same. Some change was made with machine and/or process. Nova has inconsistency with this insert, and I posted (#24) picture evidence of a .014" difference between the two inserts made by the same machine and/or process. I doubt PM would have that kind of inconsistency on their spindles, but maybe I'm wrong (we'll see when I measure). Leave alone the company, an insert is a $20 finished part, and a spindle is worth more just in steel alone. If I were running production, I know where I would put the less experienced worker.

About those Sorby Patriot Jaws, thanks for the warning. I think I'll just splurge when I buy a new chuck, and not settle this time around. I can tell you that the 1" pin jaws (with one screw) from Nova will also bend slightly in compression mode, but I think they are mostly meant to be used in expansion mode. I think they are strong enough that it would take a rather catastrophic catch to bend them 1/2". Maybe you should go with those instead. The Patriot jaws must have been made with a weaker cross section or weaker steel. Were they even salvagable after that?

Thanks

 

[Bill Blasic]

Charles,
My 3520b is two years old, my L inserts are from 6 or 7 years old to about 3 months and all are the same by eye. I was just saying that .014 difference on the insert would make no difference in my case. The biggest problem with having a grub screw on the L tightened to the spindle is remembering to loosen it before trying to take off the chuck. Yes to your question that I am looking by eye at your inserts and telling you that they look exactly like mine and unless they have been ground down .070 or .080 they would work without a problem on my lathe. I worked at machining for close to 40 years so there is no way that I would tell you that there was not a chance that the insert could be made wrong as folks constantly make machining mistakes and now in the day that actual inspectors are mainly a thing of the past and companies have made the operators responsible for their own QC it is easier to get a part not up to specs. One last thing, all my lathes that permit using a grub screw to secure the chuck have a little galling where I have forgot to loosen that screw.

 

[Charles Henderson]

Charles,
My 3520b is two years old, my L inserts are from 6 or 7 years old to about 3 months and all are the same by eye. I was just saying that .014 difference on the insert would make no difference in my case. The biggest problem with having a grub screw on the L tightened to the spindle is remembering to loosen it before trying to take off the chuck. Yes to your question that I am looking by eye at your inserts and telling you that they look exactly like mine and unless they have been ground down .070 or .080 they would work without a problem on my lathe. I worked at machining for close to 40 years so there is no way that I would tell you that there was not a chance that the insert could be made wrong as folks constantly make machining mistakes and now in the day that actual inspectors are mainly a thing of the past and companies have made the operators responsible for their own QC it is easier to get a part not up to specs. One last thing, all my lathes that permit using a grub screw to secure the chuck have a little galling where I have forgot to loosen that screw.

Thanks Bill. I'm still curious as to whether those Patriot jaws were salvageable after bending a jaw 1/2".

I got to thinking, and I don't think I have an accurate enough depth guage to measure the protrusion of the mating register. I'll see if I can find one locally for when I finally get this turning off of the lathe. Any suggestions for where to look?

I have an idea, though. It would be worth the shipping costs for me (both ways, of course) to send the bad insert to you, and see what experience you have. Although, I would need to get it back fairly soon, so I can send it back to Nova for a refund. Would you be willing to try that?

 

[Russ Fairfield]

Charles, why are you beating up on the folks on this forum. If you have a problem, it is with Technatool. You should be talking to them, or whoever you bought the adapter from, not arguing with the folks on this forum. They cannot do anything to resolve your problem other than relate their experiences and opinions.

 

[Charles Henderson]

Charles, why are you beating up on the folks on this forum. If you have a problem, it is with Technatool. You should be talking to them, or whoever you bought the adapter from, not arguing with the folks on this forum. They cannot do anything to resolve your problem other than relate their experiences and opinions.

Woah, ok. I didn't see that coming.

Aside from my post to Michael Mouse (which I apologized for) in defense of having my good sense insulted, I've been friendly and courteous to everybody. That's what I thought anyway. I've tried to be diplomatic at the very least. It's only a discussion, not an argument. If you read something else into it, then I believe you've misunderstood me.

The only reasons I started this thread were first, to seek help on how to fix what I screwed up, and second, to inform the woodturning community of my problem, so that what happened to me wouldn't happen to somebody else. Either Nova or PM made a change/mistake that caused this problem, and it's a recent change/mistake because I seem to be the first victim. I believe Nova supplied an insert that won't work with my lathe (in reverse atleast). Maybe PM changed their spindle. If Bill Blasic is kind enough to try my insert on his 3520b, then we can put this mystery to rest.

At this point, though, once there is an answer or resolution for me to post in this thread I'll be letting it drop like a rock. After that I'm thinking it might be a good idea to just go back to lurking and posting an occasional pic. I'm suddenly not feeling very welcome here. I think by being descriptive and longwinded I am being perceived as something entirely different than intended. Please don't misread that in this post as well. I'm just trying to explain myself because I really didn't mean to offend anyone or upset the atmostphere here. If you felt strongly enough to post that, then I assume others feel the same way. To anyone I offended/bothered, I sincerely apologize. I'm a nice, and very laid back person, but that doesn't seem to come across in text.

My apologies,
Charles

 

[odie]

Woah, ok. I didn't see that coming.

Aside from my post to Michael Mouse (which I apologized for) in defense of having my good sense insulted, I've been friendly and courteous to everybody. That's what I thought anyway. I've tried to be diplomatic at the very least. It's only a discussion, not an argument. If you read something else into it, then I believe you've misunderstood me.

The only reasons I started this thread were first, to seek help on how to fix what I screwed up, and second, to inform the woodturning community of my problem, so that what happened to me wouldn't happen to somebody else. Either Nova or PM made a change/mistake that caused this problem, and it's a recent change/mistake because I seem to be the first victim. I believe Nova supplied an insert that won't work with my lathe (in reverse atleast). Maybe PM changed their spindle. If Bill Blasic is kind enough to try my insert on his 3520b, then we can put this mystery to rest.

At this point, though, once there is an answer or resolution for me to post in this thread I'll be letting it drop like a rock. After that I'm thinking it might be a good idea to just go back to lurking and posting an occasional pic. I'm suddenly not feeling very welcome here. I think by being descriptive and longwinded I am being perceived as something entirely different than intended. Please don't misread that in this post as well. I'm just trying to explain myself because I really didn't mean to offend anyone or upset the atmostphere here. If you felt strongly enough to post that, then I assume others feel the same way. To anyone I offended/bothered, I sincerely apologize. I'm a nice, and very laid back person, but that doesn't seem to come across in text.

My apologies,
Charles

Charles......

Hang in there, and don't let comments like Russ's get to you. We need more people like you to post on here......the more opinion and comment, the better. You'll need some "thick skin" sometimes......but, that's just the nature of internet forums. You can hardly say anything at all without someone, somewhere taking offense, or disagreeing with you......just the way it is!

To me, you came off just as you intended......

ooc

 

[odie]

I like the brass screw idea -- there is no reason that it needs to be a headless hex-key hardened steel setscrew.

Something that I have considered doing is to drill a small detent hole where the set screw parks, but then it occurred to me that there are problems with that idea such as the parking spot is different for each chuck and if you use a thin plastic washer, that also changes things.

Bill.......

I believe the hardened steel threads of a standard set screw are better in the long run. What's needed is the soft brass to press against the threads on the spindle. I've seen an application just like this on some machinery where I work, and also on reloading dies for metalic cartridge reloading for firearms.

On these applications, the solution is simple........keep the steel set screw, and drop a small piece of brass rod into the hole between the threads on the spindle, and the set screw. That way, you can tighten as needed for controlled holding power, and won't damage the threads.........:cool2:

ooc

 

[KurtB]

Pm3520

Charles, I agree with what Odie said. You sometimes need a thick skin on these forums, and I read nothing into your responses other than what you intended. This forum was intended for the exploratory discussions of this type to help all of the members get the information they need.

 

[David Wilkins]

For what it is worth Charles, to me you did come off, a little off. I figured it was frustration over your new toy not playing right with the adapter. If you think you have something to gain by being here, then you should stay, simple as that.

 

[Joe Greiner]

On these applications, the solution is simple........keep the steel set screw, and drop a small piece of brass rod into the hole between the threads on the spindle, and the set screw. That way, you can tighten as needed for controlled holding power, and won't damage the threads.........:cool2:

ooc

For any manufacturers who might be prowling sites like this, brass and nylon tipped setscrews are available. For example, http://www.reidsupply.com/ Enter [brass nylon set screw] in the search box. This is an OEM supplier, and small quantities could eat your lunch, unless you order some other items, of which there are millions. They also have CAD files of many of their products.

No affiliation, except as a satisfied customer.

 

[Bill Blasic]

Charles,
Let me check and see if I have a new one down in the shop. Club picnic today so it will probably be tomorrow before I get down there. The Patriot jaws were bought with the intention of being able to turn my finials without a thought of the pieces jumping out of the jaws. Yes I was able to straighten them but now I'm in the same position I was with the Nova pin jaws(with one screw per jaw), that being that I had to be careful when going square to round to start being careful not to knock the piece out of the jaws.
Bill

 

[MichaelMouse]

Charles,
The Patriot jaws were bought with the intention of being able to turn my finials without a thought of the pieces jumping out of the jaws. Yes I was able to straighten them but now I'm in the same position I was with the Nova pin jaws(with one screw per jaw), that being that I had to be careful when going square to round to start being careful not to knock the piece out of the jaws.
Bill

I'm a regular user of the pin jaws on 1x1 squares to make ornament icicles, and cannot imagine how big a catch you'd have to have to bend metal on them, or even softer jaws. You were just gripping a quarter inch, or did you have a long spigot? Obvious the longer is better in these applications, and unless the wood is something really special, probably not difficult to do.

If you're going to do short square grips, consider filing some serrations across the "points" of the jaws. With a little care you can make them asymmetrical, so they pull the piece back into the hold as you tighten.

 

[Russ Fairfield]

I appologize for my posting. I fell prey to the problem of coming in late and reading a very long thread in one sitting and getting a perspective that is very different from those who were a part of its development over time.

 

[KurtB]

3520b

Russ,
Not to worry...just remember that somedays you're the windshield; and somedays you're the bug!:cool2:

 

[loberg]

To use a set screw and not have the possibility of messing up the main threads, find a friend that reloads and get a couple of lead pellets used in shotgunning. Put the pellets into the hole before you use the set screw, tighten down the screw and the lead will form into the threads and not hurt them. To get the set screw to release, just back it out and tap the area around it with a wooden mallet. RCBS used this method on their locking rings for reloading dies. Works great.

 

[Charles Henderson]

Final Update

I'm sorry to revive this thread once again, but this post will be my final update. The mystery is solved.

Bill Blassic was kind enough to help me figure out the problem by testing the bad insert on his lathe. He had the exact same problem with it that I did. He sent it to his friends at Nova with notes on what not to do. He was also very kind by sending me a good type-L insert that worked as it should (the set screw hits the spindle in the right spot), and it was even machined with acceptable quality. On top of that he sent me a generic 1 1/4x8 insert that I don't actually need and will be sending back with a box of wood in thanks. In fact, I even got an email a few days later from him requesting my address (he lost it) so he could send back the $5 that I sent for postage which he didn't use. I'm not giving it to him

I must say, Bill is a hell of a guy. Thanks Bill!

The inconsistency was, indeed, with the insert. Somewhere downthread I posted a pic showing the .014" difference between the bad insert, and the replacement that Teknatool sent me (the replacement insert that worked only with a no-lock spindle washer). I set up the replacement insert with the new one from Bill in the same manner. The difference this time was .043" which would make the total difference between the bad one and the good one .057".

I finally spoke with Tim Geist (Teknatool USA) last week, and he barely seemed to remember me or the problem. He hadn't heard anything yet about the insert that Bill sent back. I apparently was never charged for the replacement though, even though he took my credit card # and told me I would be charged. I'm not sure why he didn't. He was perfectly pleasant to deal with, but judging by his level of concern I'm not convinced the issue will be resolved.