Chuck jaw-slide wear?

[rsser]

Jaws on the VM100 seem to be rather more sloppy than I recall them being at the start, so am wondering about whether the slides or the chuck body or both can wear.

It's about 5 years old and has done the lion's share of chucking.

Have looked at the slop on the newer SN2 and it's much less.

[Skew ChiDAMN!!]

Do you mean wear in the teeth/splines where they engage the mechanism, or on the shoulders wear they rub against the body?

I'm assuming the former, but wouldn't be surprised if 'twas the latter. (That's what you get for buying inferior clones of the SN2. :p:D)

[rsser]

Cough!

I'll need to check Skew, and it's occupied atm.

Just that with shark jaws on, I grab a jaw and wiggle and there seems to be a fair amount of slop. In a sense, it may not matter that much, cos maybe the slack is taken up evenly when all four jaws are under pressure.

[Gil Jones]

Ern,
I too have a VM100 which has seen about 4 years of regular use. I cannot say that it feels (or looks) any more worn now than it did when new (and it scrolls VERY smoothly). We both know there has to be some slop or there would be little jaw movement without beads of sweat forming, but I had the same thought as you about all of the slop it taken up under load. Unless you are now turning unintentional ovals, there is not much to fret over. I just received the SN2 (Teknatool September Draw Prize), and it is a bit tighter than the 4-year old VM100, but not much. Also, the jaw sets are not machined with much care, as there are burrs at (and along) every cut-line, and while the jaws do not close perfectly together, they perform their intended function admirably. The burrs will file off easily, so they are just a nuisance. I am not sure why Teknatool designed them to scroll open and closed in the reverse of other chucks (clockwise turns of the 8mm key LOOSENS the jaws), but I am sure that I will have the rotational directions firmly burned into my memory in short order (after I drop a few pieces by turning the wrong way). Good luck with your VM100. If the slight wear really bothers you, I'll send you my address. :wink:

edit: Another thought is that the pinion gear teeth may be where your wear is located as they are castings, and may wear faster than the jaw slides or scrolls. Just a thought.

[tea lady]

I just received the SN2 (Teknatool September Draw Prize), they are just a nuisance. I am not sure why Teknatool designed them to scroll open and closed in the reverse of other chucks (clockwise turns of the 8mm key LOOSENS the jaws), but I am sure that I will have the rotational directions firmly burned into my memory in short order (after I drop a few pieces by turning the wrong way).


Nice to see that you "free" jaws are a bit annoying.:p I can sent you MY address too if they get too much of a nuisance.:U

[rsser]

Thanks for that advice Gil.

No, no ovals ... just in all likelihood worrying where I need not.

Teknatool tightening direction .. yeah, have the same problem. Don't like to stop and 'reverse' think :-{

And yes, I think the Nova jaw quality is pretty ordinary. I'm not the first to make this comment on this forum.

[Manuka Jock]

I am not sure why Teknatool designed them to scroll open and closed in the reverse of other chucks

Gil ,
it was Teknatool who pioneered the 4 jaw chuck about 20 years ago , so the fault lays with the other manufacturers I reckon :D

[rsser]

Poop. They could've followed Jacob's chuck key direction.

[Grumpy John]

Gil ,
it was Teknatool who pioneered the 4 jaw chuck about 20 years ago , so the fault lays with the other manufacturers I reckon :D

Metal lathe chucks have always closed turning the chuck key clockwise, having been a fitter & turner for over 40 years I find the Teknatool chucks a PITA. No surprise there, eh Calm?

[Calm]

Metal lathe chucks have always closed turning the chuck key clockwise, having been a fitter & turner for over 40 years I find the Teknatool chucks a PITA. No surprise there, eh Calm?

John just take your medication and go to bed - it's beeen a big day for you:D:D:p:roll:

[hughie]

Metal lathe chucks have always closed turning the chuck key clockwise, having been a fitter & turner for over 40 years I find the Teknatool chucks a PITA. No surprise there, eh



:U yep dunno what possessed them to go the way the did. :? :~

Ern if you look at the chuck on the lathe see if you can move the jaws left to right this is the most likely spot for wear and the most trouble some. See that the body is most likely not hard just tough and this is where the most dust and dirt will gather.It stands that you will get more wear there.
If on the other hand the excess mvoement is vertical then your scroll is worn. Not too bad as it will effect the run out of the chuck as you can make allownces for that as you go along.

When and if you strip it down only use dry lube, any wet lube will only retain dirt and dust and so advance the wear.

[Ed Reiss]

Metal lathe chucks have always closed turning the chuck key clockwise, having been a fitter & turner for over 40 years I find the Teknatool chucks a PITA. No surprise there, eh Calm?

hmmmmm....eht nepo/esolc noitcerid fo ym avoN kcuhc sah reven neeb a melborp rof em .....of course that might be because of the intermittent dyslexia!:doh::C

[RETIRED]

I was told that the reason (if you think about it) was that with the speed capabilities of the wood lathe as opposed to a metal lathe, the chuck could vibrate loose if it followed the normal pattern.

I have a 3 jaw metal lathe chuck that I occasionally use to hold small brass and copper fittings and it will rattle loose at speed.

[joe greiner]

Are you doing both of these?

One of the manufacturers (I forget which) advises thus for attaching the jaws:
Tighten to almost the closed position with the jaw screws almost tight; then tighten the jaw screws. This should facilitate accurate centering.

When closing (compression) or opening (expansion), use both (or more) key/handle positions sequentially. There was a debate a while back on this subject for Jacobs drill chucks; IIRC, multiple purchases of the key was preferred, to equalize irregularities in the scroll action. When operating on soft wood, I've found several tightenings beneficial.

Joe

[Grumpy John]

hmmmmm....eht nepo/esolc noitcerid fo ym avoN kcuhc sah reven neeb a melborp rof em .....of course that might be because of the intermittent dyslexia!:doh::C

That may be because the Nova chuck was the first chuck you ever used (correct me if I'm wrong) and this is what you're used to.

[rsser]

Thanks Hughie and Joe. (Calm, didn't think you liked hijacks!)

I'll be able to remove and check the chuck today - it's been tied up due to a chucking dilemma http://www.woodworkforums.com/blog.php?b=357 (http://www.woodworkforums.com/blog.php?b=357)

Joe, I've heard that advice about centering too but I don't bother. And yes, I always tighten both sides (twice each for green wood!).

[Ed Reiss]

Well GJ, you kinda" got me on this one ...actually the Super Nova is the second one, the Nova was the first. Chances are that the Nova scroll mechanism, if it was key operated instead of the levers, in all likelyhood moves in the same direction.

[rsser]

So between projects did some pulling and pushing:

Slop radially is much more than tangentially.

Guessing that this could mean wear on either or both of the scroll/teeth and on either or both chuck body and slide. I need to check again to distinguish rocking from sliding movement.

Thanks again.

[Robomanic]

Rant alert...

As far as key direction goes, I'll bite.

Nuts, chucks, water taps - they all follow a convention. My Canadian friend refers to it as lefty-loosey, righty-tighty. (imagine the accent). Even the case on my stack of blank CD's opens anti-clockwise - and its not even a thread. Stereo: more volume - clockwise, less volume - anti-clockwise

The point about high speed and vibrating loose could be valid, but how many people regularly use their chuck to open into a recess? Or those that mount their chuck on the outboard end of the lathe? They could have put the scroll gear on the left hand side of the key sprocket, then connected that through to the scroll ring on the right hand side - but that's extra cost and why bother anyway? IMOH they should have just cut the scroll ring the other way and been done with it, instead of trying to be too cute.

Please feel free to educate me if I have missed something.

(I don't own one btw, but things designed and built without the user in mind makes me want to slap someone)

...rant subsiding.

[rsser]

Rant quality 10/10 ;-}

Direction wouldn't matter to a user like me if I didn't mix my chuck brands.

And yes, with bowl bottom mounts I often expand the chuck into a recess.

[hughie]

Hmm, scroll direction etc. I have never heard of a three jaw chuck on a metal lathe vibrating loose. 4 jaw chucks on same type of lathe are independant jaws.
The reason being I suspect is that the jaws are locked solid on to the piece being turned and ther is no give in the material.

On the other hand wood has give and if the vibration was sufficient and work piece moved in the chuck or compressed slightly through act of turning... the x and y axis etc. It is possible. But how much vibration and how often would it occur?

Dunno, design of a scroll is such that it should not moved under almost any circumstance because of the angle of the scroll to the jaw teeth would lock it in position, much like a morse taper... well sort of.


What ever the reason its still a PITA

[joe greiner]

Although chuck jaws are machined fairly precisely, there must be some tolerances. I almost always mark the jaw numbers on my workpieces, to restore the initial clamping, or at least mark the position of the number one jaw, in case of accidental or deliberate dismount. Ditto with the spur drive with a scratch mark on one of the spurs. I can't count the number of times this has reduced the amount of re-cutting.

Joe

[Ed Reiss]

The original Nova would work its way loose on occasion, even when I made damn sure the levers had been tightened sufficently. Finally I found a grub screw thats suppose to be tightend after all others...that cured the problem.

If I had just read the manua......what am I saying, men never read manuals!:no::2tsup::2tsup:

[rsser]

Slop radially is much more than tangentially.

Guessing that this could mean wear on either or both of the scroll/teeth and on either or both chuck body and slide. I need to check again to distinguish rocking from sliding movement.

Back on topic :rolleyes: .. hate to quote myself but does this appear to make sense?

Edit: just fitted one of the bigger VM100 shark jaw sets via Vermec adaptors to an SN2.

There's very little radial movement; bit more tangential.

(With your comment in mind Joe, and given the prospect of adaptors adding slack, I centred the jaws before final tightening. Reason for this is that it's the first time I'm trying to chuck the foot without marks. Haven't cared that much before but I'm getting sick of cleaning jaw marks off the foot. Tried the VM step jaws but it seems Mr Raffan goes for higher feet on his bowls than I like :p ).

(Back off topic - yeah, what a hypocrite :- - a downside to the SN2 for me is that the jaw travel is about a cm less than on the VM90/100).

[INVENTOR]

Ern, you certainly got everyone going with that topic. And for what its worth I will add a few extra observations.
Woodies have long thought that 'they' did things first. Metal lathe chucks have been around for decades with removable top jaws in various 2,4,6 etc self centering styles.
And most ( if not all, I suspect) tighten the 'correct' way.
So forgive the metal workers if they laugh at us 'woodies' for thinking that we invented 4 jaw chucks with removable jaw tops.
As for the slack in the jaw slides/chuck body. Have a close look at a well made metal lathe chuck and see how well the jaw slides fit in the body. Very neat! Remember that they also have to contend with tiny fragments of various metals /coolant/oil etc etc. Maybe not dust, but is it that some wood chucks are not made well, because they know we don't expect them to be?? Metal lathe owners would not tolerate it.

And while we are looking, compare the price. Our wood chucks are very expensive, considering the general lack of quality in them, compared to our metal working cousins.

While I am still on the 'soapbox' lets also look at why wood lathes persist in using spindle threads instead of going over to cam locks for attaching the chuck. Some wood lathe manufacturers have 'tried' to go over to this style of fitting, as they obviously know the benefits.
As to the question about speed, the 'cheaper' metal lathe chucks are sometimes rated up to approx 2500 rpm, the better quality units go much higher. So once again, nothing is new with wood chucks, that hasn't been done before.

Sorry if I went on, but I laugh when ever us 'woodies' forget to look over the fence.
:U

[Manuka Jock]

Ern, you certainly got everyone going with that topic. And for what its worth I will add a few extra observations.
Woodies have long thought that 'they' did things first. Metal lathe chucks have been around for decades with removable top jaws in various 2,4,6 etc self centering styles.
And most ( if not all, I suspect) tighten the 'correct' way.
So forgive the metal workers if they laugh at us 'woodies' for thinking that we invented 4 jaw chucks with removable jaw tops.
As for the slack in the jaw slides/chuck body. Have a close look at a well made metal lathe chuck and see how well the jaw slides fit in the body. Very neat! Remember that they also have to contend with tiny fragments of various metals /coolant/oil etc etc. Maybe not dust, but is it that some wood chucks are not made well, because they know we don't expect them to be?? Metal lathe owners would not tolerate it.

And while we are looking, compare the price. Our wood chucks are very expensive, considering the general lack of quality in them, compared to our metal working cousins.

While I am still on the 'soapbox' lets also look at why wood lathes persist in using spindle threads instead of going over to cam locks for attaching the chuck. Some wood lathe manufacturers have 'tried' to go over to this style of fitting, as they obviously know the benefits.
As to the question about speed, the 'cheaper' metal lathe chucks are sometimes rated up to approx 2500 rpm, the better quality units go much higher. So once again, nothing is new with wood chucks, that hasn't been done before.

Sorry if I went on, but I laugh when ever us 'woodies' forget to look over the fence.
:U


You are speaking about yourself here aren't you ?
"So forgive the metal workers if they laugh at us 'woodies' for thinking that we invented 4 jaw chucks with removable jaw tops."
:p

[Sawdust Maker]

...

Sorry if I went on, but I laugh when ever us 'woodies' forget to look over the fence.
:U

Fence - what fence?
Mine fell over when I used all the posts to make bowls :D

... and out of the goodness of my heart. If any of you with novas are finding it too difficult to tighten/untighten send them to me. I promise to look after them :D Think of me as a safety deposit box (with a little wear and tear)

[INVENTOR]

My appologies if I ruffled a few feathers with my comments. I work in both metal and wood and just get tired of how 'new' woodies are told only half the story.

The same applies for Tungsten tip tools, next we will have woodies saying they invented them, when 'most' of them are just non ferrous (aluminium) inserts. Available in packs of 10 at engineering supplies, trick is to select the right one. ( not easy)

The sooner we ( woodies) adopt new technologies, we progress.
:)

[Manuka Jock]

My appologies if I ruffled a few feathers with my comments. I work in both metal and wood and just get tired of how 'new' woodies are told only half the story.

The same applies for Tungsten tip tools, next we will have woodies saying they invented them, when 'most' of them are just non ferrous (aluminium) inserts. Available in packs of 10 at engineering supplies, trick is to select the right one. ( not easy)

The sooner we ( woodies) adopt new technologies, we progress.
:)

Pal , nobody has said the 'we woodies' invented the 4 jaw scroll chuck :D
It has been said that ,
"it was Teknatool who pioneered the 4 jaw chuck about 20 years ago "
And that was in response to ,
"I am not sure why Teknatool designed them to scroll open and closed in the reverse of other chucks"
and considering that this is a woodturning forum , it is obvious that the subject is about wood turning chucks :cool:

[tea lady]

I can never remember which way they turn anyway, so no matter which way they go I will prolly try the wrong way first.:rolleyes:

In my minimal research on the matter ofjaw construction they appear to be made so spinning in one way will assist the tightening of the chuck. This would prolly mean that using in the expansion mode would "let go" more often because the spin would assist the jaws to contract rather than expand. ........ I think.:hmm:

[Manuka Jock]

I can never remember which way they turn anyway, so no matter which way they go I will prolly try the wrong way first.:rolleyes:

In my minimal research on the matter ofjaw construction they appear to be made so spinning in one way will assist the tightening of the chuck. This would prolly mean that using in the expansion mode would "let go" more often because the spin would assist the jaws to contract rather than expand. ........ I think.:hmm:

A member of the Nova owners forum thought this ....

"They assumed that the chuck would be used in an expansion mode, I imagine. I use mine that way almost always, which means that righty is tighty, because Leftie Lucy doesn't spread 'em for Chuck.

Coriolis may count in sextants and cyclones, but not in sewage"

:U

[Gil Jones]

I wonder, did metal workers invent the Internet?:D

[Manuka Jock]

I wonder, did metal workers invent the Internet?:D

:U :D:2tsup:

[Paul39]

Although chuck jaws are machined fairly precisely, there must be some tolerances. I almost always mark the jaw numbers on my workpieces, to restore the initial clamping, or at least mark the position of the number one jaw, in case of accidental or deliberate dismount. Ditto with the spur drive with a scratch mark on one of the spurs. I can't count the number of times this has reduced the amount of re-cutting.

Joe

Yes, yes, yes!! On both my metal and wood lathes this is true.

Paul

[NeilS]

....but how many people regularly use their chuck to open into a recess? Or those that mount their chuck on the outboard end of the lathe?

Almost always to both questions, but I still find the key direction a real pain.

Neil