# I'm doing something wrong



## jmurray (Sep 25, 2015)

It's probably a stupid question, but hear me out.

Lately when hollowing it seems my chuck is starting to turn itself off? I'm working on small stuff. I start hollowing with a big drill bit pushed down the center. Then I use the square carbide cutter to continue to remove material from the walls. I feel the chatter immediately when the chuck loosens. Shouldn't the force of my cut be tightening the darn thing.?
I never noticed this before, what am I doing differently/ wrong.
Thanks
Josh


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## Kevin (Sep 25, 2015)

The only time I' e ever noticed that happening is when I didn't titghten it well at first and stop it suddenly for some reason. I tend to stop my turning by hand on the outer wheel thingy as fast as possible (to the point I have hurt myself) to move to the next step and I've seen the chuck loosen because if it.

Other than that I can't imagine why it would do it.

Reactions: Agree 3


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## jmurray (Sep 25, 2015)

@Kevin I have the same bad habit of stopping the back wheel. I can't say I've ever really tightened the Chuck on real well, just kinda thread it on and let it bottom out. 
I think I'm gonna go to a turners club and get my fundamentals down, lol

Reactions: Like 1


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## duncsuss (Sep 25, 2015)

What lathe do you have?

And what chuck?

I posted on somebody's question about buying the Jet 1221vs that my club has one, and several of our experienced turners have had the chuck come loose while they were working on it. As you say, in theory putting a carbide tool against the side wall should create forces that tighten the chuck -- my best guess is that it's setting up vibrations that loosen it.

The reason I ask about which chuck, there was a spate of issues with the lathe-specific-insert that Woodcraft sold to go with the SuperNova2 chuck. The ones with this problem were for 1" x 8tpi spindles (i.e. not the Nova 1624-44, or Oneway, or Robust lathes which are 1.25"x8tpi). Genuine Nova inserts worked fine, the Woodcraft 3rd-party inserts didn't.


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## duncsuss (Sep 25, 2015)

p.s. it should not be necessary to spin the chuck on so tight that you can't get the sucker off ...


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## jmurray (Sep 25, 2015)

@duncsuss 
Its always hard to get off.
I just hand tighten. Sometimes I gotta use the bar to get it back off. I just now tried to torque it on there with the bar. Didn't move much if any?


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## duncsuss (Sep 25, 2015)

jmurray said:


> @duncsuss
> Its always hard to get off. I just hand tighten. Sometimes I gotta use the bar to get it back off. I just now tried to torque it on there with the bar. Didn't move much if any?


Yeah, they can unscrew themselves while you're turning something but the instant you actually want to remove them they suddenly lock tight

Reactions: Agree 1


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## jmurray (Sep 25, 2015)

@duncsuss only when I'm hollowing.


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## pinky (Sep 25, 2015)

Josh
What lathe
Does it have reverse
Do you turn outboard


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## Mike Mills (Sep 25, 2015)

That is _very_ strange. My stupid question; are you sure you are not turning in reverse?
You should be able to just thread it on hand tight. It may move a smidge but I would not use a bar to install it.
Do you have one of those plastic washers that some folks use that may be deformed?
I have had a chuck loosen but only when I was sanding in reverse and I did not use the locking set screw.
Yes it should be tightening as you turn. Only a possibility but some make a L/R hand insert but I have never used one and all of mine are only R hand. With a L/R I _assume _it would be possible to thread it onto the spindle by rotating the chuck towards you rather than away.

Edit..
I did look and Nova has an insert "T" that is 1 X 8 and dual threaded. 
The normal insert for 1 X 8 is insert "D" this R hand threaded only.

Reactions: Agree 1


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## jmurray (Sep 25, 2015)

@Mike Mills locking set screw you say? I'm not at the shop but if my Chuck has one I have never used it! 

Not going in reverse, but I have tried to cut in reverse by accident. Lol. 

@pinky its a rikon midi, and a nova midi 4 jaw


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## ripjack13 (Sep 25, 2015)

Would some teflon tape hold it in place?


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## Kevin (Sep 25, 2015)

Probably, if you were never going to take it off but I remove and replace my chuck numerous times during most of my projects and threading the threads with teflon tape would be a hassle and a time eater.

Reactions: Like 1


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## Mike Mills (Sep 25, 2015)

jmurray said:


> @Mike Mills locking set screw you say? I'm not at the shop but if my Chuck has one I have never used it!
> 
> Not going in reverse, but I have tried to cut in reverse by accident. Lol.
> 
> @pinky its a rikon midi, and a nova midi 4 jaw



If your chuck is the midi I am not sure it has a set screw for reverse.
Yep, did it also (reverse), teaching my daughter no less . That is why I asked.


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## Schroedc (Sep 25, 2015)

Wondering if there is some slop in the chuck insert. I'd first check if it has an insert or was made with that thread (I've got nova chucks with inserts and nova chucks that only fit 1x8 threads)

Possibly borrow another chuck from someone and see if the problem happens with that chuck too? If the problem goes away I'd suspect a bad chuck insert.


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## jmurray (Sep 26, 2015)

Well I was putzing around last nite and I think my problem was with the size of the hole and position of my tool rest. My big square cutter was rubbing its underside against the piece, causing a lot of vibration. 

I usually start hollowing a bowl with a big 1 1/2 forstner bit. Since I wanted a smaller opening I started with a 1/2" bit.
I got a lot to learn


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## Kevin (Sep 26, 2015)

jmurray said:


> My big square cutter was rubbing its underside against the piece, causing a lot of vibration.



I still don't see how that could cause it (not saying it didn't). I only ever hand tighten my chuck, but when I'm going to be turning at or close to its capacity, I'll use the T-handle and the rod thingy to cinch the chuck down more than just hand tight. Sorry I don't know the accessory terms very well. Maybe it's best to avoid advice from someone who doesn't even know the name of his own tools.

Reactions: Funny 1


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## jmurray (Sep 26, 2015)

@Kevin I'm not sure that was my problem, but I had things running smoother. 

What do you use to hollow when u make peppermills?


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## Kevin (Sep 26, 2015)

Josh I use forstner bits for pepper mills. Every now and then I will need to do a little modyfying for a special detail or maybe salvage a mistake and use a chisle but 99% of my pepper mills only see forstner bits.


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## NYWoodturner (Sep 29, 2015)

The set screw was my first thought. I don't use them because I've seen them work loose themselves then trash the threads on the headstock. I have had chucks work loose with a heavy and/or out of balance piece because I don't use them. If you lost yours and done have one I can send you one. 
I also turn in reverse fairly often, usually cleaning up the neck and shoulder of a hollow form. Its much easier that overreaching into stupid human positions to get the right bevel angle. In those instances I just turn in reverse and reach directly across the tool rest.


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## duncsuss (Oct 7, 2015)

@jmurray -- just to let you know, over the weekend I was at the Topsfield Fair with my turning club and it happened again.

It was the Jet 1221vs lathe, Oneway Talon chuck, end grain hollowing.

I don't remember exactly which tool I was using at the time -- could have been a regular round-nose scraper or a round carbide bit tool. I switched to using a Rockler carbide bit tool (the ones that have a cup-shaped carbide bit, meaning it's a cutter not a scraper -- like the Hunter tools) and had no further problems.

Reactions: Like 1


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## Kevin (Oct 7, 2015)

I thought it was a shear scraper not a cutter. ???


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## Mike Jones (Oct 7, 2015)

There is only one instance I can think of where loosening might occur while hollowing: *Braking,* whether electronic/automatic, or by hand on the hand-wheel, will cause the spindle to want to slow while centrifugal force on chuck and work-piece want to keep going, and if the chuck is allowed to spin a turn faster than the spindle, it will loosen.


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## Mike Mills (Oct 7, 2015)

duncsuss said:


> It was the Jet 1221vs lathe, Oneway Talon chuck, end grain hollowing.



That is just freaky to me. Now with a different brand chuck and lathe.
I don't have any new suggestions but would sure like to know the cause.


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## duncsuss (Oct 7, 2015)

Kevin said:


> I thought it was a shear scraper not a cutter. ???



@Kevin if you look at the pix of these Hunter tools, you'll see the rim of the carbide bit is up-turned. That's a very sharp edge, and should be presented to the workpiece just like the edge of a gouge. It even has a "bevel: (granted it's not much more than 1/16" wide) that you can -- and should -- rub as you're cutting in "push" mode.

It's most definitely not a scraper -- until you start pulling back along the side-wall of a hollowform (but a bowl gouge would also be functioning as a scraper during that operation).

Here's a video by John Lucas (an excellent turner and teacher) showing how it works ...

Reactions: Informative 1


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## duncsuss (Oct 7, 2015)

Mike Jones said:


> There is only one instance I can think of where loosening might occur while hollowing: *Braking,* whether electronic/automatic, or by hand on the hand-wheel, will cause the spindle to want to slow while centrifugal force on chuck and work-piece want to keep going, and if the chuck is allowed to spin a turn faster than the spindle, it will loosen.



Mike, that's how I feel about it as well. It certainly was not being slowed down by hand (both mine were on the tool at the tail-stock end of the lathe). 

Which leaves electronic/automatic ... I can imagine a scenario where the vibrations set up while hollowing could cause intermittent drag on the workpiece ... an electronic speed control might attempt to compensate by increasing torque, then suddenly discover the spindle is turning too fast and decelerate quicker than the inertia of the chuck and workpiece allows.

Improbable, but it's the only explanation I can come up with for what ought to be impossible.


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