Seeing as I'm new to this

[Jay Jolliffe]

and I really don't know what to expect. I bought a reconditioned SuperNova2 chuck from Teknatool. I installed it on my lathe which is a Grizzly G1495. I did it as to the directions twice....The body seems to run true but the jaws don't. When completely closed they're out about 1/16 to 1/8"
I chucked a practice piece I did between centers & that runs out too. I would think that there shouldn't be any run out. But being new to all this I need some feed back....

[Allan Ferguson]

Something sounds very wrong. The jaws should close tight and be smoothly aligned on the inside and outside. Do you have the numbered jaws on the corresponding numbered slides? Picture would help.

[Jay Jolliffe]

The jaws are in the right place. I checked twice buy taking it apart & putting it back together....When the jaws are closed they're ok.....It's when I chuck something that I turned between centers it doesn't run true.....Hard to take a pic of it running..

[Greg Just]

238875

A suggestion - Take the jaws off the chuck then then tighten as if to close the jaws. The 4 sliding mechanisms of the chuck should line up when in the closed position. This might tell you if the jaws are bad or the chuck is bad. I have 2 SN2's, one being a reconditioned unit and never had a problem

[Don Alexander]

does your tailstock align perfectly with your headstock? and does the chuck run true with nothing chucked in it?

if your lathe is not in alignment , anything you turn between centers is not going to run true when you put it in a chuck as the piece will be somewhat eliptical

[Jay Jolliffe]

The centers line up....With nothing in the chuck & the jaws closed it still runs out. It doesn't run out at the base of the chuck where it screws on to the head stock. About half way down towards the jaws you can feel & see it run out..

[Allan Ferguson]

Is the insert in tightly? You may need someone to look the situation over. Could even be a spindle problem. Good luck with the situation.

[Jay Jolliffe]

I put a dial indicator on the chuck & the run out is .006 in one revolution on the chuck & .015 on the jaws. One jaw is out more than the other & that is where most of the .015 is. They are tight against themselves when closed with one jaw a little proud and a very small space at the jaw base.....So buy this I gather that one jaw is off.

[Greg Just]

make sure there is no dirt on the backside of the jaws or the face of the chuck. That could cause a misalignment of the jaws. I would double check the numbers on the jaws and the numbers on the chuck to be sure they are the same. The insert might be off too.

[Russ Denz]

Jay, When you are doing this testing are they all done this way, as you wrote:
"It's when I chuck something that I turned between centers it doesn't run true"

It could be important, in that it is VERY hard to "re-chuck" anything and have it run true, especially true if you're re-chucking in a chuck as opposed to an "inside the shaft", Morse Taper-mounted drive like a StebCenter or the like that centers the wood leaving a center hole/indent.

If that's the case, you might not have a chuck problem at all, merely experiencing an idiosyncracy of woodturning.

[Jay Jolliffe]

Hello Russ....Got the tools today thanks....It's not that I'm turning between centers & the chucking it. It's the chuck itself that has the run out....To me it looks like it has to do with the jaws....The body of the chuck has a .006 run out & the jaws have a .015 run out....Should the body have no run out ?

[Michael Mills]

I don't think you can expect no runout at the chuck body but that is just mho. You have the spindle, insert, and then the chuck body.

I assume you installed the jaws per instruction; leaving jaw screws about 1/8 turn loose and then tighten the chuck. The jaws are machined from a single billet so they should be true.
Maybe an edge of a jaw is a little jagged from the billet being cut apart. Check for any small burr left from the cut. Before you tighten the jaw screws down fully run a thumb nail around to detect any “proud” area (across the top and around the diameter). I used a rubber mallet to give some a little tap to get them in line. On a set of powergrip jaws there was a small burr on the side which I filed off.
All of my chuck bodies are .002-.007. I never bothered to check the jaws themselves, just installed them as close as possible with the thumb nail test.

As per the instructions (for the 50mm jaws) from Teknatool did you form the spigot straight? Or with a dovetail as some folks may tell you to do?
Are the top of the jaws sitting flat and tight against the workpiece? If unsure bring up the tailstock for light pressure prior to using the chuck key.

I have quite a few Nova chucks and had never had that problem.

[Jay Jolliffe]

One of the jaws does sit a bit higher that the one next to it. Just on one edge. All the others are even to each other. One thing I did find is the spindle on the lathe does run out about .008"....When I put the center in it's right in....no run out....this is only a lathe for me to learn on...If I take to turning then I can get a better one. When I bought this there were 19 Robert Sorby tools with it so I didn't pay too much for the lathe.

[paul vechart]

I have a Nova G3 chuck and the run out on the body is .002". If I install a piece of steel round stock in the jaws the run out is .005" which I feel is OK for wood turning. My Delta 46-460 lathe spindle has only .001" run out. There were some issues awhile back with some of the inserts sold through Wood Craft that caused chucks to not seat properly.

[Rick Markham]

Jay, I don't have a way to test for runout on my chuck body. From your description it sounds like something is off on the jaws, is there anyway you have another chuck that you can try them on? I'd probably try to call/write teknatool's US distributor. (Especially if you can't try the jaws out on another chuck.) Do you have a different set of jaws you can try on the chuck body? Do you have another threaded insert you can try in the chuck? Is the insert seated tightly in the chuck?

Now my next question :D can you test the runout on the inside of the jaws while they are closed together? Is it largely the same as the outside of the jaws. I'd go as far as checking all the flat surfaces of the jaws. If you check all the reference surfaces on the jaws, you should be able to determine if one jaw is different from the others. This won't eliminate the jaw slide as the source of the problem, but it should be able to tell you what number jaw, or jaw slide is out of whack. It may just be one of the jaws.

All that said... it's probably easier to send it back, and have them send you another one. I would try calling them.

[Jay Jolliffe]

I'm going to call them on Monday...I don't have another set of jaw or another chuck....

[Bernie Weishapl]

One other thing is make sure the piece you are chucking up in not sitting up against the jaws on the inside or bottoming out per se. If so that can cause runout.

[Michael Mills]

Jay, sound like the runout on you spindle is the same as the run out on your chuck body.
The ring(?) under the jaws and the jaws slides grooves(?) are closely machined. Nova suggest for what you stated (One jaw higher) to use a block of wood to tap the jaw down then tighten the screw. After the first time the jaws should drop into place easier if you swap them out. If the top is sitting up a little I suppose it could throw the diameter off a little also.
Given you are starting .008 runout on the spindle and currently .015 on the jaws; I doubt if you can ever get below .010 - .012 on the jaws. I don’t think most turners could tell without a gauge. Like what Russ said…” merely experiencing an idiosyncracy of woodturning”

[Jeff Myroup]

I had run out on a SN2, and thought it was the chuck. It turned out to be the lathe bed was not completely level. I leveled my jet mini and never had a problem after. I did not notice anything wrong until I put the chuck on.

[Pat Scott]

Just for grins, if you have a plastic "no lock" washer between the chuck and headstock, take the washer off. I was at a Robert Sorby demo where the Sorby rep said a customer sent back several brand new chucks saying they didn't run true. He removed the washer and they were perfect.

[Jay Jolliffe]

I wish it was to be that easy Scott....No washer....