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

[Charles Henderson]

So, after the U-haul leaking and getting my headstock wet, I was lucky enough to have an easy solution. Steel wool and WD40 took care of the surface rust on the headstock (thanks again to John Lucas), and the electronics seem to be okay.

Now, I bought a chuck adapter at the show so my Nova chucks would fit the PM. I was very, VERY lucky that I read this thread -

http://www.aawforum.org/vbforum/showthread.php?t=6237 - "Keep your chuck and faceplate threads clean"

Had I not read that I might have been stupid enough to trust the machining of the adapter. There were burrs all over it, inside and out. Inside there was a burr in the center of the threads that protruded well over .01". Had I screwed that onto my spindle the threads would have been damaged forever. However, I WAS stupid enough to trust the alignment of the set screw. It was aligned with the EDGE of the mating surface of the spindle. Now, my spindle IS damaged. :mad:

Questions:
1. Should I dare to go at these burrs with a flat file, or would I risk damage the mating surface?

2. Will this small of a divot cause vibration if I have a very large or unbalanced turning on the lathe?

Again, thanks for your help and sorry for the length!

Oh, Nova is going to hear about this as soon as I'm done with U-haul. :mad:

Somebody wish me some luck, I must have broken a mirror

 

[Aaron G+11]

Yes you lathe is permanently damaged. So much so that I feel that you should ship it to me and I will pay you the 15 cents per pound for the "scrap" metal.

Seriously, you have just experienced the first dent syndrome. You know, when you buy a new car and hold your breath any time something bad might happen. The you get your first dent , paint chip, etc, and you relax.

If there is a raised area at the edge of the divit, file it flush to the surface , so that the next thing that is screwed on is not damaged, but just the a raised portion. Don't do more harm to the rest of the spindle. And, in the future, be more mindful of set screws and the like. If you are still very uncomfortable with the situation, you can buy a new spindle and replace it. More trouble than it's probably worth.

happy turning.

 

[Bill Boehme]

So, after the U-haul leaking and getting my headstock wet, I was lucky enough to have an easy solution. Steel wool and WD40 took care of the surface rust on the headstock (thanks again to John Lucas), and the electronics seem to be okay.

Now, I bought a chuck adapter at the show so my Nova chucks would fit the PM. I was very, VERY lucky that I read this thread -

http://www.aawforum.org/vbforum/showthread.php?t=6237 - "Keep your chuck and faceplate threads clean"

Had I not read that I might have been stupid enough to trust the machining of the adapter. There were burrs all over it, inside and out. Inside there was a burr in the center of the threads that protruded well over .005. Had I screwed that onto my spindle the threads would have been damaged forever. However, I WAS stupid enough to trust the alignment of the set screw. It was aligned with the EDGE of the mating surface of the spindle. Now, my spindle IS damaged forever. :mad:

Questions:
1. Should I dare to go at these burrs with a flat file, or would I risk damage the mating surface?

2. Will this small of a divot cause vibration if I have a very large or unbalanced turning on the lathe?

Again, thanks for your help and sorry for the length!

Oh, Nova is going to hear about this as soon as I'm done with U-haul. :mad:

Somebody wish me some luck, I must have broken a mirror

Instructions: Insert tongue in cheek and then read the following important operating information for new machine owners.

I think that you may be obsessing over some nits. Threads do not fit together tightly -- the thread clearance is far greater than than the 0.005" inch bur. In fact, the spindle threads and chuck normally are Class 1A and Class 1B which are the loosest fitting tolerances for threaded fasteners. It is not the threads that provide alignment of the chuck on the spindle -- it is the mating of the register surfaces on both parts that are responsible for correct alignment. Be careful about filing on the threaded portion of the spindle or on the adapter because you can wind up with a really really loose fit in short order if you try to get things too smooth. If the tiny bur is really annoying you, take a very fine diamond hone and carefully remove it without touching any other part of the threads.

Your new machine is hardly permanently "damaged" unless you only plan to use it as a pristine museum piece.

I can guarantee that it won't be too long before you touch the tip of a bowl gouge against the spinning chuck and permanently "damage both of them.

By the way, there are numerous flaws that you have not discovered yet -- being cast iron, your lathe has a multitude of small holes, cracks, and other casting flaws that you can't see because they have been covered up by paint along with body filler in some instances (just like a wrecked car).

Inside the motor, the steel laminations of the armature and field have flaws like stamping burs and the wire used to wind the field has a few nicks and scrapes in the Formvar insulation. The bottom surface of the headstock is not polished and neither are the bed ways so if you were to slide the headstock, it would create numerous microscopic scrapes in both surfaces. Therefore, never slide the headstock. The same goes for the toolrest and tailstock.

The spindle socket is the one precision machined and polished part of your lathe. Sooner or later, you are going to spin a tapered insert in the spindle socket because it was not inserted properly or wasn't clean or (heaven forbid) was a damaged one that you just did not want to throw away. It is going to raise one heck of a bur (if you are lucky) or a bunch of burs (if you are not so lucky). Go buy a Morse taper hand reamer and associated dressing tools for repairing your spindle socket. Then throw away the damaged tapered insert because it can't be properly repaired without the right machine tools. Or you can keep it in order to increase your proficiency at repairing spindle socket damage.

Happy turning and don't worry about spilling anything such as lacquer or shellac on your lathe because that is something that almost never happens and the odds of it happening to your lathe are nil as long as you don't plug the lathe in.

 

[MichaelMouse]

http://www.101kidz.com/classics/aesop/62.html

Try to please everyone, you please no one. You've got a "universal" item in that chuck. It will fit some machines perfectly, some only with care, but that has to come from you. It is not made specifically for your machine, nor is your machine made specifically for it. Clean up the damage you've done trying to lock the chuck and press on. In the future, don't be as trusting, and definitely don't crank against the kind of resistance you must have felt to damage that spindle with the grub screw. I like to do a "snug and shake" on things like that. Stop at the first sign of resistance, make sure nothing's out of line before proceeding. Too many cross-threaders out there that don't. It's also a good procedure to use with smooth jaws on wood.

Not sure what you mean by "adapter," whether it is the Teknatool insert or some 1 1/4 to 1" 8 type thread adapter, but it's probably a good bet that it was made out of softer stuff than your spindle, so it wouldn't hurt the spindle it as it cleaned itself with the first threading. Good engineering would have done it that way. Quick trip around the threads with a flux brush would likely have done all the cleaning required.

 

[Charles Henderson]

Make light all you want, but I think the problems I've had (in the first week) are pretty serious and I was trying to seek help from fellow turners who have likely gone through this. If I came off as a worry wort then I don't believe I've communicated to you thouroughly.

The furniture pad underneath my headstock was quite damp, which means my entire headstock received enough water to be reasonaby concerned. The headstock was sitting upside down, and there was enough standing water inside to soak two blue shop towels. That the electronics weren't damaged amazes me. U-haul assured me a sealed trailer, and I feel I have a right to be a bit peeved about that.

I was very tired (still am) and using calipers I'm not familiar with when measuring the burr on the inside of the adapter. I measured with my dial caliper the earlier measurement, and it was protruding just over 1/100th", and stuck out to the side even further, but I couldn't measure that. That burr was huge (and not the only one by far), and yes it would have badly damaged the spindle threads, and probably locked the chuck up as well if I had carelessly threaded it on. This insert was atrocious, and I was trying to give warning to others about the 1 1/4"x8tpi Nova insert. Actually dealing with the burrs was done before I ever posted. I'm familiar with the proper way to fix that. My concern was...

The set screw for the adapter lining up with the edge of the mating register is a serious design flaw, and yes it DID damage my spindle enough that my chuck was very difficult to back off from the mating register. Again, I was trying to give warning to others about that Nova insert. Maybe this post will keep somebody from getting the same divot in their shiny spindle. I wanted to seek advice before filing the most precision part of the spindle. It seems that at least the two of you believe it's cosmetic. Honestly, I've received and/or seen good advice from the both of you, so I trust your advice. I've filed it down, and everything seems fine, but I'm turning finials. I think it's conceivable that under heavy load, a damaged surface could cause vibration. I don't know, and that's why I asked.

Respectfully,
Charles :cool2:

 

[Vaughn]

Charles, I understand your concern, but I've got divots much bigger and nastier than that on the spindle of my 3520B. (I've gotta remember to loosen the setscrew before trying to remove the chuck.) I touched them up with a diamond file so that nothing is sticking up, and just carried on as if nothing happened. I've turned everything from small finials to 100 pound 24" wet elm blanks, and haven't seen any ill effects from the divots. Be forewarned that you will get vibrations, but it'll be the wood or tools vibrating, not the chuck to spindle joint. That's the case with any lathe. I think.

I agree that the setscrew should have been coming down a little farther away from the shoulder of the spindle. I don't recall seeing the details, but is your insert made by Nova, or is it the "compatible" one sold by (I believe) Woodcraft? Either way, I agree you should not use the setscrew until you get another insert (or simply drill and tap a new hole a little farther east). Keep in mind the setscrew isn't mandatory unless you're turning in reverse or turning something really heavy.

And as an aside, and you probably already know this, but the water is not likely to harm the electronics unless you apply power to the circuits before they are completely dry. I can see why you were alarmed by the rust.

 

[MichaelMouse]

This insert was atrocious, and I was trying to give warning to others about the 1 1/4"x8tpi Nova insert. Actually dealing with the burrs was done before I ever posted. I'm familiar with the proper way to fix that. My concern was...

The set screw for the adapter lining up with the edge of the mating register is a serious design flaw, and yes it DID damage my spindle enough that my chuck was very difficult to back off from the mating register. Again, I was trying to give warning to others about that Nova insert. Maybe this post will keep somebody from getting the same divot in their shiny spindle. I wanted to seek advice before filing the most precision part of the spindle.

One of the difficulties I have with your post is that I own four Teknatool chucks, and have put in seven inserts (one was threaded 1" 8) to use them on my old and "new" lathe. Not one problem, unless you count the chuck that came with the used lathe. The insert was cattywhompus. Must have swung an 1/8" circle at center on the chuck. How, or why the former owner tolerated such a thing is beyond me. I removed the insert, cleaned and insured the mating faces were clean (wire waste from tapping in the way) and reinserted it to the position it has been in for the last three years. I also have one of the "L" adapters with the locking grubscrew, and it's a perfect match for things like the DVR, as advertised, a bit less than perfect on the PM, if your post is accurate.

The answer is to exercise good sense and proper care in the setup to avoid damage. May not give you the outcome you desire in all cases, but there will be no divots. As they taught us, "first, do no harm" is a great motto.

As an aside from a guy who has experienced water and liquids of other sorts - mouse urine and circuit boards do not get along - in electronics areas, I'll tell you that wet sawdust, with its dissolved extractives will give you no end of short problems. Keep those boards clean and dry.

 

[Mark Warden]

I feel bad for ya Charles and I hope things start going better for ya.As for the other replies it's upsetting I also have received some great advise from you guys and I thank you.But keep in mind Charles just spent alot of money on a NEW machine not a used one.Uhaul should have to at least pay him for the time and aggravation they have caused by not mataining there equipment that he PAID for.Nova should have better quality control than to send crappy products out the door it aint universal if it DON"T FIT.If I buy a new car yes I'm gonna eventially get dents and scraches does that make it ok for the dealer to damage it before I leave the lot? I amazed how people are just willing to accept sloppy work and I think you guys are out of line with the smarta** replies. Just had to get that off my mind.Have a nice day

 

[Jake Debski]

Charles, not to be overly simplistic, carefully file the divot. Using a small fine file, use it in a rocking motion to help prevent creating a "flat." Don't beat yourself up over the poor insert. The damage is very doubtfully going to affect the performance. Better luck in the future.

 

[Charles Henderson]

Thanks, gentlemen.

All problems solved. My 4 leaf clover is in the hiding spot in the tail stock, but it's difficult to turn with all my fingers and toes crossed.

Aside from dealing with U-haul and notifying Nova's QC, my job is done.

 

[David Wilkins]

Hi Charles,
I think your going to find that lathe is able to take these things just fine. It will not vibrate from that nick. Not if you are turning at speeds under 4000 rpm. As far as the lathe getting wet, plenty of us turn wet wood, and everything in the shop gets splattered when you do that.
With the insert match, is it the spindle thats off, or the insert? Maybe the good people at powermatic could machine that spindle a little closer to the specs that all chuck manufacturers use.

 

[Charles Henderson]

http://www.101kidz.com/classics/aesop/62.html

Try to please everyone, you please no one. You've got a "universal" item in that chuck. It will fit some machines perfectly, some only with care, but that has to come from you. It is not made specifically for your machine, nor is your machine made specifically for it. Clean up the damage you've done trying to lock the chuck and press on. In the future, don't be as trusting, and definitely don't crank against the kind of resistance you must have felt to damage that spindle with the grub screw. I like to do a "snug and shake" on things like that. Stop at the first sign of resistance, make sure nothing's out of line before proceeding. Too many cross-threaders out there that don't. It's also a good procedure to use with smooth jaws on wood.

Not sure what you mean by "adapter," whether it is the Teknatool insert or some 1 1/4 to 1" 8 type thread adapter, but it's probably a good bet that it was made out of softer stuff than your spindle, so it wouldn't hurt the spindle it as it cleaned itself with the first threading. Good engineering would have done it that way. Quick trip around the threads with a flux brush would likely have done all the cleaning required.

I stand by what I said, the machining was of inexcusable quality. I also have several other Nova tools and chucks of adequate quality that I've used for years and been pleased with. This is my first quality complaint.

I agree completely that it is a universal insert (the 1 1/4"x8tpi chuck insert for Supernova2, sorry I wasn't clear). I also believe it is worth considering that the set screw is for turning in reverse and the 3520b is (I would think) the most popular lathe with those threads that turns in reverse. That's quite a bit of people they don't care much about pleasing, and many possibe spindle divots in a bad place. Again, I stand by what I said that it's a serious design flaw.

Thanks for your advice. I will remember not to crank down on the set screw. I've never turned in reverse, and I was a bit nervous about the chuck trying to unthread itself.

 

[MichaelMouse]

.Nova should have better quality control than to send crappy products out the door it aint universal if it DON"T FIT.

Apparently you do not understand. The chuck insert is fine, it's the LATHE that doesn't fit. Perhaps they should review their quality control.

As to U-haul, I have availed myself of the service many times in self-help moves, and the paperwork always included a disclaimer that the trailer was not waterproof. Even my own Haulmark has the disclaimer.

 

[Mark Warden]

I think I understand fine Micheal I'll consed I have not seen the adapter or the lathe so I can't comment on the location of the set screw.Being as I'm also looking into lathes I would like to hear from other PM owners as to if this is a problem with any other chucks or just Nova.If there was burrs in the threads that's POOR QC.This is not a harbor freight special.As for the Uhaul the disclaimer is there for the floor many trucks and trailers leak up between the floor boards but overhead leaks are not acceptable by any stretch.And finally just so I know where you are coming from may I ask if you are in anyway affiliated with Teknatool?

 

[Bill Boehme]

The set screw for the adapter lining up with the edge of the mating register is a serious design flaw, and yes it DID damage my spindle enough that my chuck was very difficult to back off from the mating register.

I am in agreement with you, if as you say, the set screw is located so that it mates against a register surface on the spindle. Many turners and apparently some suppliers of lathe accessories do not know about register surfaces for precision alignment. I think that you should send it back to them along with a thorough reprimand for their apparent ignorance.

As a retired EE, I can address the electronics issue. For the type of electronics used in the VFD, getting wet for a few hours is not a big deal as long as you dried everything thoroughly before using it. Sometimes water (clean distilled) is even used to clean electronics assemblies because in some situations, solvent cleaners can leave an assembly more contaminated that before cleaning. I once cleaned a computer motherboard with tap water and a final rinse in distilled water followed quickly by compressed air and heat to dry it out.It worked fine after the cleaning.

I think that U-Haul and you were not on the same page. To the person you talked to, apparently "enclosed" equaled "sealed from the elements" -- the world is full of clueless people so good luck dealing with them. I can't imagine that they have any weay to verify that an enclosed trailer is "sealed". In addition, how do we define sealed? It is going to leak at some point, but where is that point?

It seem to be increasingly difficult to find threads that are done well. Part of the problem might be traced to the elimination of the heavy CFC coolants that have been banned -- the new generation of thread cooling and flushing materials do not seem to be nearly as effective and I see a lot more galling, spalling, brinelling, and chipping on threads these days.

 

[rsser]

There is a QC problem with some later Nova inserts so caveat emptor.

Recent inserts I've seen are not threaded right down and are flat next to the hex nut, so provided you back off the set screw while mounting the insert you should be fine.

I wasn't happy with a recent insert replacement for the Titan chuck: there was a 3 thou runout on the tailstock end of the chuck side and 2 on the headstock. No, these aren't huge but why not obsess harmlessly?

An aftermarket insert from an eng. firm with a good rep did no better.

 

[Bill Boehme]

Since we are sort of on the subject, I did a search a couple years ago to find out the difference between a "grub" screw and a set screw since I had not encountered the term grub screw before getting into woodturning. The answer: about three thousand miles of ocean. It is one of those "separated by a common language" things.

 

[rsser]

Yeah, we call em grub screws down under.

 

[Bill Blasic]

I currently own 10 Nova chucks with inserts, several of which were purchased recently and are used both on my 3520b and my DVR 3000 and my new Delta 46-460. I have not encountered any problem with the insert nor with the location of the grub screw in relation to the spindle. I know that people are having problems with the $5 adapter that Woodcraft sells but no problems from those who use the Nova equipment here in my area.
After looking at my 3520b spindle the hole in the Nova adapter would have to be drilled so that the grub screw would actually run out of metal at the back of the insert to touch that ridge on the spindle. Maybe I'm just lucky
Bill

 

[rsser]

Or others have been unlucky with their inserts; maybe just a bad batch.

If I were going for another 4" chuck I'd go for a Vermec. Can take both 4" Vicmarc chuck jaws and almost all Nova jaws.

And in my book the Vicmarc jaws outperform the Novas by a country mile (if you have that expression in the land of the free).

I use Vermec adaptors to fit VM jaws to an SN2; no problems.

 

[MichaelMouse]

And finally just so I know where you are coming from may I ask if you are in anyway affiliated with Teknatool?

I come from good sense. If PM made an insert, I would expect it to be a great fit for their spindle, maybe not so good for anyone else. From anyone else I expect to have to check suitability on my own, and would use my good sense to check for fit and revise any finish issues. I certainly would not apply so much torque to a grub screw as to force it to thread an opposing piece of steel.

Pretty simple. Like the saying, I'm trusting, but I check things out. Doveryaj a proveryaj

I do own four Nova chucks and various jaw sets, not to mention the 3000. I also kick my own butt when I make mistakes, even when, as yesterday, the pilot on a flush-trimming name brand router bit departs and I ruin three hours work and teach my wife some words she claims to have never heard. I should have been checking tightness periodically, especially when edging one inch oak.

 

[Charles Henderson]

I come from good sense. If PM made an insert, I would expect it to be a great fit for their spindle, maybe not so good for anyone else. From anyone else I expect to have to check suitability on my own, and would use my good sense to check for fit and revise any finish issues. I certainly would not apply so much torque to a grub screw as to force it to thread an opposing piece of steel.

Pretty simple. Like the saying, I'm trusting, but I check things out. Doveryaj a proveryaj

I do own four Nova chucks and various jaw sets, not to mention the 3000. I also kick my own butt when I make mistakes, even when, as yesterday, the pilot on a flush-trimming name brand router bit departs and I ruin three hours work and teach my wife some words she claims to have never heard. I should have been checking tightness periodically, especially when edging one inch oak.

In a post where you were responding to whether you were affiliated with teknatool, you appear to be hinting pretty strongly to my lack of good sense for expecting a 1 1/4"x8TPI insert to properly fit the most popular lathe with those threads, much less be machined of even acceptable quality. I would first mention that chuck makers make the inserts for the chucks, and the chucks are sold to be used on many different lathes. I don't even think PM makes inserts or chucks, and especially not inserts for any commercially available chucks. That being said, it seems you're being needlessly defensive of a company that has obviously, at best, overlooked the PM crowd on this insert. No, this is not the Woodcraft cheapy. I bought it from Woodworkers' Supply at the symposium and it came in a Nova box. You also didn't directly answer the question by the way, though I imagine you're just having the same reaction I get to people trash talking Fords. I understand, but I'm sorry because it appears as though both Ford and Nova make some lemons. It happens to the best of them, and more when they rely on China for production as I've heard Nova is shifting to. What matters is what they do about it, and I'll find out when I talk to them next week. Is the PM crowd just SOL when it comes to using reverse with this chuck? I don't know. Maybe they have a specific adapter for PM - not a universal - that the salesman at the show didn't know about. I'll give them a chance to explain. I have a hard time believing I'm the first person this has happened to with where that set screw aligns on my PM. I even have a new problem with Nova. The old insert on the old lathe put the chuck body out of round, but the jaws were pretty close, and now with the new insert the chuck body is right on, but the jaws are out of round. However, I'll add into this thread one more time that up until this insert I've had no issues with my Nova products.

You go on to say you have the good sense to not apply so much torque to a grub screw, again I guess you're implying my lack of sense. Maybe I did, but how much torque do you expect I'd get out of my thumb on the small end of a hex key? I'm not trying to be facetious, I'm curious because I don't believe I used too much, and that it was an alignment issue. Additionally this lathe was used by Rolly Munro and Michael Werner for demonstrations at the symposium, and their set screws from their chucks left significant marks, in the right place (one of them was a Vicmarc), so I didn't figure that I could use too much pressure with my thumb. Maybe I'm making the wrong assumption about the pressure they used for reverse turning.

After all this hinting at my lack of good sense, you admit you pulled a doozy in the shop yesterday yourself. Did your good sense escape you for a moment (like it does to everybody)? However, I doubt if you go on another forum to ask some question about it, that you will have your good sense questioned (Heaven forbid if you were to question that name brand router bit and run into a die hard fan). After all, internet forums are generally where people go for answers they need from more experienced people, especially when they get in a jamb. I'm trying to be as cordial and respectful as possible because I don't come across right in text at times. I'm just saying maybe it's not so necessary to make me feel bad for making a mistake, if in fact I made a mistake at all other than trusting the modern machining, design, and quality assurance of your favorite lathe accessory company.

 

[Steve Worcester]

What I can tell you is that no one who answered your questions (right, wrong or indifferent) work for Nova or Technatool.
Everything up to this point is conjecture until you talk with them.

 

[Charles Henderson]

An apology and an update.

First, Michael Mouse, I noticed you weren't around for a couple days after my last post in this thread. If that post was the reason, then I apologize. I got a little defensive, maybe too much so, but I really was trying to be nice about it.

Second, I have an update. On July 15 I spoke to Tim Geist with Teknatool USA, and told him of the problem I was having. He hadn't heard of the problem before, so I guess I'm the lucky 1st. He was pleasant, but less concerned than I had hoped. He offered to send me a new adapter, but I would have to send him mine first and be without a chuck for the 3520b for about a week. He explained that he couldn't trust me to send him the bad one because of prior experiences. I understand, so I just bought a new one and will be returning the bad one for a refund.

Having them both at the same time gave me a chance to compare them. As you will see in the pictures below, there is a difference in the placement of the set screw.

In picture 1 you can see that the new insert on the right has the set screw placed closer to the threads and further from the mating surface. In picture 2 the two inserts are screwed together by the setscrew, and at the left of the picture is a .014" feeler gauge underneath the old insert. This shows the (fairly) exact difference in placement.

Results: The setscrew on the new insert also contacts the mating surface of the spindle. It is barely enough to contact it, but still enough that it could raise a burr. I didn't tighten hard enough to find out. I hoped that adding a no-lock spindle washer would be enough to back it up, and fortunately I was right.

So, 3520b owners be advised. Hopefully you'll get a good insert, or atleast one like my new one that you can get to work with a no-lock spindle washer. Good luck, but to be honest I think after this I might try out the Vermec or the new Sorby Patriot chuck from Packard. Both will fit Nova jaws, and neither are shifting production to China.

 

[MichaelMouse]

Well, as the Teknatool site says, the L insert is for the DVR. Doesn't look like a huge difference from here, that's for sure. I'd go with the one that hits the threads and a brass screw.

Actually, I wouldn't do either, because I don't reverse. No reason that I can see for doing so. I do have an L insert, but that was because it was the only 1 1/8 they had.

 

[Jeremy Williams]

Charles, I understand your concern, but I've got divots much bigger and nastier than that on the spindle of my 3520B. (I've gotta remember to loosen the setscrew before trying to remove the chuck.)

Man, was that nice to read. When I got my 3520b the first day, I didn't realize they set screw even existed. I'm a big guy, and I put my back into trying to remove that thing ... before seeing the set screw. It really dug into the spindle and made a nasty burr. I've left it along, and its not caused me any trouble ... but it was a HUGE bummer when it happened. Seems that would be a nice thing to know BEFORE you try to take it off!

 

[Charles Henderson]

Well, as the Teknatool site says, the L insert is for the DVR. Doesn't look like a huge difference from here, that's for sure. I'd go with the one that hits the threads and a brass screw.

Actually, I wouldn't do either, because I don't reverse. No reason that I can see for doing so. I do have an L insert, but that was because it was the only 1 1/8 they had.

The Teknatool site does not say that where I'm looking. It says "For lathes have reverse turning ability." See this page http://www.teknatool.com/products/Lathe_Accessories/adaptor_page.htm about 3/4 of the way down. This same table lists ~30 lathes with inserts specifically for them. A specific insert is not listed for the 3520b or the DVR. The L-type is the only one that fits the PM with reverse turning. If that doesn't (consistently) work for the PM, then they should make one that does like they have for those other lathes.

It's not a huge difference, but with "precision" machined parts .014" is obviously significant enough. My grandfather was a machinist, and I guarantee you differences like that in his production work did not exist. I guess Nova doesn't take the same pride in their work that my grandfather did.

There are many purposes for reverse turning. If there was no demand or use for it, then the lathe manufacturers wouldn't bother. I'll formulate my own opinion once I finally have a chance to try some things out. Maybe you're right and it's just useless.

 

[Mark Warden]

Hi Charles what about the most important thing hows the lathe working out for ya

 

[Bill Boehme]

Well, as the Teknatool site says, the L insert is for the DVR. Doesn't look like a huge difference from here, that's for sure. I'd go with the one that hits the threads and a brass screw.

Actually, I wouldn't do either, because I don't reverse. No reason that I can see for doing so. I do have an L insert, but that was because it was the only 1 1/8 they had.

I agree that the need for reversing is minimal. I am sure that there are some special cases, but not for the more common stuff. A few years ago, I modified the motor on my lathe so that I could use a switch to run either direction. It is a fairly simple mod that requires identifying both leads of the start winding and bringing them out to a DPDT switch along with both capacitor leads. After congratulating myself on the accomplishment, I went back to running the motor the same way as always. I wrote a tutorial along with pictures and schematics describing how it is done and posted it on this forum, but apparently it disappeared somewhere along the way. Doesn't really matter since it is over rated.

 

[Steve Worcester]

I do use reverse on occasion, but rarely with the setscrew in.

I do find it odd that the mating surfaces are wavy and not flat.

 

[Charles Henderson]

Hi Charles what about the most important thing hows the lathe working out for ya

I would have to get really picky to find anything to pick on so far. I could use a little touch up paint, though. What little time I've had to turn on it has been like a dream come true. Going from a Jet Mini (an excellent machine that will stay in my shop) to this glorious monstrosity is quite a change. I can't wait to explore the options that this and a few more planned purchases will open up to me.

I'm excited to say the least, and now that the 4-leaf clover is in the tailstock, everything seems to be going fine.

 

[Charles Henderson]

I do use reverse on occasion, but rarely with the setscrew in.

I do find it odd that the mating surfaces are wavy and not flat.

Wouldn't the chuck unscrew without the setscrew?

I am guessing that they turn away the hexagonal edges to keep them from raising a burr on the spindle mating surface. Just an assumption.

The biggest reason I've been looking forward to using reverse is because there are two guys in my turning club that swear by sanding that way. They tell me - and I've heard this elsewhere - that it takes care of any fibers that have been laid down instead of sanded away. I've noticed that some turnings, once sanded and ready to remove, are smooth if I rub my hand in one direction, and not quite as smooth going the other way. Honestly, beyond that I can't think of many uses. At the symposium in Albuquerque, Rolly Munro did most of his hollowing in reverse -on my lathe (which he autographed ). He says it puts you in a better position instead of leaning over the lathe, and this demonstrated very well the versatility of his articulating hollower. I'll be trying that out shortly.

 

[Steve Worcester]

Wouldn't the chuck unscrew without the setscrew?

After you have done the turning, the chuck is pretty well tight on there. Not saying I shouldn't snug down the screw, but I usually forget. Don't reverse that often though.

 

[Gretch Flo]

sanding in reverse

I have noticed when you have a bark crack, a knot or some warpage, that when sanding and I can't get the former scratches out, I reverse and they may disappear. Maybe it's 'cause i was sanding too fast ( ie more than 50 rpm) and it would skip over a hi point. The when you go in reverse, you sand "before" the hi point and don't skip over it. Make sense? Gretch

 

[Rick Taylor]

Gretch,
I had never thought of it in that way but it makes good sense to me. It would sure help ride out the bumps at low rpms and give you more of an opportunity to remove sanding scratches.
Rick

 

[Bill Boehme]

I have noticed when you have a bark crack, a knot or some warpage, that when sanding and I can't get the former scratches out, I reverse and they may disappear. Maybe it's 'cause i was sanding too fast ( ie more than 50 rpm) and it would skip over a hi point. The when you go in reverse, you sand "before" the hi point and don't skip over it. Make sense? Gretch

My take on the matter is that when turning has some surface "character" (euphemism for holes, cracks, larval trails, etc.) sanding with the lathe running regardless of direction is going to ruin the crispness of these features by rounding them over. On such pieces, it is better to use your turning tools to get the surface to an almost finished final state that can be touched up in a more selective manner with the lathe turned off using 320 or finer grit paper.

Anyway, that's the theory. I won't say that I sometimes cheat, but it's OK to revert to the 80-grit gouge when the wood or human won't behave.

 

[MichaelMouse]

The old insert page has been revised, and that DVR wording is gone. You'll still find it in the manual, which is also there. In any case, I still feel it is the responsibility of the owner to insure compatibility.

As to reversing, I sand with a rotary sander, so all directions are possible without reversing. Whoever took the old flat-sanding technique of setting with water and sanding back into rising grain apparently forgot that s/he sanded some places R to L some L to R as long a it was into the rising grain. Works great for sanding along the grain, not much at all for going round and round, where what was down is up and what was once up is down.

Setting with water works great for divots and defect too, but the final sand should still be by hand, along the grain, and into any rising areas. Don't even want the lathe on for that.

 

[Joe Greiner]

Setscrews

IIRC (highly unlikely), one of the many bellyaches here related to the setscrew beating up threads. IMHO, this is not good design or workmanship. Setscrews work best when engaging a flat surface, which can be ground after marking the position of final assembly by gently tightening the setscrew. That was once the usual practice on round shafts too.

Note: I'm not a real machinist, nor do I play one on television, but I have stayed at Holiday Inn Express. My grandfather WAS a real machinist though, so maybe it's just inherited in my genes.

 

[Bill Blasic]

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.

 

[MichaelMouse]

I do use reverse on occasion, but rarely with the setscrew in.

I do find it odd that the mating surfaces are wavy and not flat.

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.