Dilema(new to turning)

[Dave Stoler]

Nova chuck...Second practice bowl. First one was slightly out of round . When I did the inside the lip (?) was not even all the way around. Now on my second try I,ve got the same thing. I use the screw thingy first and turn the outside and foot (the part that go,s in the chuck) and when I take the screw out and clamp the foot in the chuck the angle matchs great and the bottom of the bowl is flsh againest the chuck..I,m doing this on the fly and obviously i,m missing something somewhere..

[Ken Fitzgerald]

Dave,

I've not been too successful using the screw attachment for the chuck. Let me suggest...place the bowl blank between the drive center in your head stock and the live center in your tailstock. Orient the future inside of the bowl towards the drive center. Now turn a tenon on the bottom of the bowl which should be facing your live center in the tailstock. Also turn a good flat shoulder where the tenon meets the bowl. Keep in mind, you don't want a tenon so long that it bottoms out in the chuck. You want the chuck to grasp the tenon but it's the shoulder resting on the jaws of the chuck that take the forces applied while turning the bowl.

While you have the blank between centers you can also turn the outside of the bowl.

If you are turning a green blank, keep in mind it will probably distort while it's drying resulting in a distorted shape. That's why most people rough turn the thickness of the walls of the bowl to 10% of the diameter of the bowl. Then you friction chuck the dryed roughed out bowl between the chuck and the live center......return the tenon to perfectly round....then mount the tenon in the chuck and finish turn the bowl. I hope I'm making sense.



Good luck!

[Bernie Weishapl]

Dave I agree with Ken on this. I don't use the screw because I haven't had good luck with it. The only difference is instead of turning between centers I use a faceplate. I center the faceplate on the blank to turn the outside and making the tenon. Don't make your tenon over a 1/4" long or so as Ken said so it doesn't hit the bottom on the chuck. Make very sure the surface your jaws fit against are square and straight. If I remember rightly the Nova chuck is like my Vicmarc and you need to dovetail your tenon so it grips tight. When I have the bowl in the chuck I finish the outside making sure it is round. and then go to the inside. Green bowls under 10" I leave 3/4" thick for drying and over that I leave at least a 1". I would get a couple of good DVD's on bowl turning to watch and then practice

Good luck and keep trying.

[Ken Fitzgerald]

Dave........Bernie's right....using the faceplate to turn your tenon is an even better idea......Duh! on my part!

[Andy Hoyt]

Nuthin' wrong with a screw chuck.

Here's Dave L. just last month using one

[EDDIE GLAZE]

I Agree With Andy. I Have Turned 18" Bowlws This Way.

[Steve Schlumpf]

Dave - I use the woodworm screw on my Talon chuck for just about every bowl I turn and find it works very well. For very large out-of-round blanks I use a faceplate. Trick with seating tenons is to make sure the tenon doesn't bottom out in the chuck and also that the shoulder area fits tightly. I usually grab a parting tool and clean up the shoulder area just before removing the blank and fitting the tenon into the chuck. Hope that helps some.

[Allen Neighbors]

All the above is right on, as far as I'm concerned... ('cept them strange folk that use the screw chuck [kidding, Chaps]) I always use the spur drive that came with my SuperNova2 on smaller bowls, and turn the tenon on the tailstock end, between centers. On larger bowls, I use a faceplate.

[Raymond Overman]

When you reverse the piece you may need to re-center the turning and true it up. Take some light cuts on the outside from the largest diameter to the smallest. Remember the geometry. The furthest away from the headstock, the more pronounced the wobble will be. By truing it up after reversing you should eliminate the out of round problems.

If this doesn't work, you may need to look at your headstock bearings or possibly the alignment of your headstock and tailstock. Vibration can also cause some of this problem so additional weight on your lathe may be necessary.

[Paul Engle]

Dave , two,three things affect the bowl when it does like you stated, one is if the face where the screw chuck screwed into is not mostly flat, when chucked up by the foot or tennon will seem to be out of round. two, if the screw chuck moves / moved after you turn the tennon / recess/foot ... it will throw the rim off also. If the piece is out of balance , lots of voids,sap wood versus heart wood etc. , it will not balance and that will throw you off also. I suggest you check these three , true up the inside/outside of the rim after you turn the tennon/recess , then reverse it and see if that does not help some what.

[Steve Campbell]

Dave each of the jaws on your chuck should have number stamped on them. Make sure that they are installed in the right number slot.

Steve

[Dave Stoler]

I have the numbered jaws in there respective places...
It just perplexes me that a chuck of this quality wouldn,t have factored in this kind of situation in there manual or web site..I,ve checked both.I,ll stay with it til I fiquire it out...
I,m useing a 1/4 in tenon with the correct angle and the bottom of the bowl sitting flush againest the chuck..
I was also instructed by a friend to use the tail stock while turning the tenon to help keep thing true.
I will continue the quest for concentricity !!

[Dean Thomas]

Have you checked the alignment of your lathe? Put your spur center and your live or dead center in the tail stock, push the tailstock to the head, and make sure that the points align perfectly. If your headstock is slightly off center, it can cause that kind of stuff. It ain't always the tailstock that's the culprit!

Have you made sure that nothing ugly is under the jaws or under the chuck itself? If the chuck or the jaws are not clean, they can cause misalignment as well. More stuff to check...

[Dave Stoler]

I am perplexed that a chuck of this quality would have this issue and that it is not addressed in the manual or website. I will try all advise given here until I find the problem.
Another friend told me to use the tailstock on center to help steady the piece while turning the tenon .
I went back and double checked the jaw numbers to be sure and they are correct. My search for concentricity continues.
I shall " endeavor to perservier" from the movie..Jerimiah Johnson

[Dean Matthews]

I use the woodworm screw all the time and I have not hit this problem.

Couple of questions:

are you doing green wood or dry? If it's green... not surprising that you are going out of round.

When you make the foot so that it goes on the talon chuck are you chucking to the inside or the outside? When I do mine I cut a recess into the wood and then expand the chuck jaws inside of the recess. Everytime I have tried to do a solid piece on the wood and "grip" the wooden tenon I have had out of round issues.

How are you making the piece you are putting into the chuck? Are you using a gouge, scraper, parting tool? I do not have the dovetail jaws but I do angle the lip in slightly using my parting tool.