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green wood--chucks or face plates?

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Much to my surprise, several nice trees have come down in my neighborhood this summer and I'm now overrun with green wood. It's about 2 years ahead of my intended slow slide into turning addiction and I'm not really prepared for turn-dry-turn but I tried a couple of maple blanks. After the last one flew out of the chuck the 4th time, I decided I'm in over my head. Looking at videos and talking with senior turners, suggests face plates, first one side then the other. I was under the impression that self-centering chucks are the 'modern' way to do this. Could you all share your thoughts? Thanks.
 

john lucas

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Dean First of all we need to know what chuck you have. metal working 3 jaw self centering chucks don't work very well. The jaws crush the wood in a very small area and the vibrations of cutting wood that varies in density will work the wood loose.
Using woodturning 4 jaw self centering chucks it's important to have a shoulder on the tenon. The tenon should not bottom out on the bottom of the chuck. The shoulders of the tenon should bottom out on the face of the jaws. Think of a T with the jaws touching the horizontal part of the T. This not only grips the wood but keeps the wood from rocking. There is less chance of the wood coming out.
that being said a faceplate with multiple screws of the proper size is probably the safest way to hold wood. I drill extra holes in my faceplate so I have 6 or more screws. I use sheet metal screws. I counter sink the wood side of the holes in the faceplate so the wood pulled from the screws won't hold the wood off the faceplate.
 
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Thanks, John. I have been using a tommy bar Nova chuck, standard sized but probably older. I have the blank flat and flush with the outer surface of the jaws and the tenon isn't touching the base of the jaws. Obviously, I'll need some hands on help to move on, but I wanted to get some perspective from capable turners on whether a properly used chuck can handle green wood or whether everyone uses face plates.
Dean
 
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Dean, are you cutting the tenon with a slight dovetail profile? Most of the Nova jaws use a dovetail tenon. Once I finally got that through my head, things got a lot easier. ;)
 
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Scroll chucks are the way to go for more fun and less fiddle. You can even start your piece on them with the woodscrew or the pin jaws on the Novas. I use a dedicated pin chuck to start mine. Easiest way to get out of the jaw-changing business that I know, and unlike a faceplate, I can use it to re-mount the dry piece.

If you have the Nova chuck with the 50mm jaws, you have the worst tenon holders out there. Best solution I've come up with is to make just a little cut into the tenon at the shoulder with my narrow parting tool or with the skew. I make it less than 1/8" and it serves as a poor cousin of a real dovetail. Since I use the tailstock when hollowing, it will suffice, but it holds nowhere near as well as the 75mm or the power grip profile. One of the reasons I use a mortise rather than a tenon is that I started with only the 25 and 50mm jaws, and the mortise hold is superior.

While you learn, keep the piece between centers. This uses the pin chuck, but by flattening for the faceplate or the worm screw you may do the same. http://i35.photobucket.com/albums/d160/GoodOnesGone/Bark-up.jpg

Leave the pillar in as you hollow, use it later to mount the dry piece back between centers. http://i35.photobucket.com/albums/d160/GoodOnesGone/Method-One.jpg

http://i35.photobucket.com/albums/d160/GoodOnesGone/Method-Two.jpg

Works the same with the worm screw, or if you have them, the pin jaws.
http://i35.photobucket.com/albums/d160/GoodOnesGone/Four-Quarter-Pin-Jaws.jpg

When you're all round and mostly thin, take away your prop and finish the bottom. http://s108.photobucket.com/albums/n28/MichaelMouse/?action=view&current=PillarSmall.mp4

Staying between centers will keep the piece out of your lap or off the ceiling.
 
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Didn't notice anyone yet recommending to re-check the jaws' grip on the tenon OFTEN when holding green wood, especially near the beginning, when the wood is the wettest and you're taking those heavier cuts.

Along with matching dovetail angles, proper tenon length, etc., also be certain to match the tenon diameter to the diameter of the jaws where they form a (near) perfect circle. For both stability and grip, maximize the contact area where jaws meet wood, and tighten snugly while avoiding crushing the tenon's fibers.
 
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My two cents is, that if you have a variable speed and heavy lathe, you can mount the green wood between centers, rough turn the exterior, shape a tenon to accommodate your chuck (I still use the old nova on occasion) reverse and continue. Faceplates are fine, Used that method for years, but have evolved to a more direct method of between centers.
By the way, it helps very much to have an oversize drive center much like that marketed by Bill Rubenstein of Stubby Lathes. It's big enough that the spurs do not spin on the blank, and become the equivalent of a forstner bit. There are various methods of making/modifying a larger diameter drive center.
Best wishes.
 
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Thanks, everyone. What I'm hearing is chucks are the contemporary way to go, rather than face plates. I've gleaned the tips on tenons and jaw size from other posts and my execution has undoubtedly been lousy. I'll get together with my mentor as soon as I can and not invest in a bunch of faceplates.
Now about chain saws.....
Dean
 
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A couple of cautionaries. Spur centers were designed to drive in end grain. They are prone to cam-out in face grain, so consider your face's gain and drive them into a recess made by an appropriately sized Forstner. That way if they spin and shred wood the piece will still stay mounted.

Advice on checking chucking "grip" often is somewhat misleading. It might encourage you to squash your work or even splinter it if you're using a wedge hold. My recommendation is to loosen the tailstock if in use (yes!) and check for droop, which indicates the front of the jaws are not registered against the shoulder of the tenon or the bottom of the mortise. If you're not using the support, grasp the front edge and check for movement. If it moves a bit, reengage the tail in the old spot if used, loosen the chuck slightly and check it is properly bottomed, adding a bit of push from the quill if you can. Then snug the chuck back up to maintain position. It's a bit like screwing the the oil filter on your car - seat, and no more than a touch more. Loosen the tail or shake again if you have doubts. If the piece droops or moves, you have a split at the base of the tenon or the end grain of the mortise.

If you left a mortise, screw hole or center mark and a pillar, no sweat to reverse, mount and repair. If you turned any of the above away you'll want a couple of those faceplates set up as pressure chucks to remedy the situation.
 
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Face plates, worm screw,glue blocks, compression or expansion, etc - all are different ways to mount and hold your work for turning.
I have the a couple Super Nova II chucks and have powergrip jaws on one and spigot jaws on the other.

Like Vaughn said once you get the hang of making the dove tail on the tenon you will no longer have any problems.

As mentioned -Do not bottom out the tenon - make it slightly bigger than when the jaws are closed - create the dove tail - On wet wood tighten up the jaws every now and then to keep it tight - keep the jaws tight up against the tenon like some mentioned.

I have turned many bowls using the expansion technique in a recess and it is not the best way and you can split your work easier than you think.
I have yet to split a tenon when compressing it. With the powergrip jaws and a good tenon I can turn large vessels and bowls with a far better hold then the other methods. Like mentiond though I have used face plates with steel screws on alot of projects because it is the safest method of holding........
Just a opinon and there are many ways to hold your work .....I just perfer my method over the rest them...................
 
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Another two cents worth:

Instead of using pin jaws or wood screw, use the dovetail jaws in expansion mode in a hole pre-drilled with a Forstner bit. Shape the tenon at the tailstock end to suit the same jaws in compression mode. A slightly easier way out of the jaw-changing business, with only one chuck.

Like Mouse says, keep the pillar until it gets in the way of hollowing.

Mark one of the jaw numbers on the workpiece, to assure accurate re-mounting if necessary. The jaws are substantially identical, but the amount of crushing of the tenon can vary, just enough to make a difference. Same with a drive spur; scratch an identifying mark on the drive, and transfer it to the workpiece. If the drive has a removable point, the setscrew provides an identifier. All of the marks on the workpiece can be applied to a small piece of masking tape.
 
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After faithfully following the posts and reviewing old threads on the board here, I was apparently pretty prepared to avoid the mistakes mentioned. I hadn't made any of them prior to posting.

Today I took a very green piece of elm and tried again. This time, I made the tenon a little longer and it worked fine. Not sure if the maple blanks didn't hold because the tenon was too short, or maybe I was trying to preserve too much of the wood and made my tenon out of fragile sapwood just under the bark. In any case, I've got a nice little elm bowl roughed out and drying.

Thanks for all the help.

Dean Center
 
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