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Hi, I have a Jet 1642 lathe that I love. It's the right size for what I like to do. I've been using a Nova Cole chuck to finish my bowls. Final sanding and turning the dovetails off. It will handle up to a 12" bowl but I'd like to be able to do up to a 16". What are my alternatives for chucking up larger bowls? A tapered plug out of Basswood attached to a faceplate or something else? Thanks, Jim
I think what you described with the tapered plug is probably in the jam chuck category. There are some variations on a jam chuck, one is you jam the bowl interior against something held on the spindle end and bring up the tailstock. Do the turning and then take off the little remaining stub with it removed from the lathe. Another variation is to carefully make a recess in some wood held by a faceplate or chuck. This recess allows the bowl rim to be tightly jammed into it. Carefully done, this will hold the bowl and allow complete access to the bottom but the tailstock should be used until the very last little bit of turning is done.
My favorite mechanical method, it to make what is called a donut chuck - lots shown online. This is basically a plate with 3 or more bolts around it (carriage bolts are handy) and a matching plate with a suitable size hole in the center. The bowl is sandwiched between the 2 plates and the bottom protrudes through the hole. By making just the "hole" plate you can accommodate various sizes of bowls and the hole does not have to be carefully matched. It is also a very secure method of holding the bowl - make sure the protruding ends of the bolts face the headstock!
My real favorite is vacuum chucking but that requires some $$ and setup.
You can make accessory wooden jaws to increase the size.
You can add a vacuum chuck, or just friction drive the bowl with the tailstock up. You can turn it down to just a nubbin and then carve and sand that off. I actually use my vacuum chuck as the friction drive when I don't want the pump running.
This is what I typically do as well - before I had the vacuum chuck, I saved the inner core from a cored piece of wood (about 7-8" in diameter) and made a recess to fit my jaws as a jam chuck that I can use over and over again. I then put 2 layers of grippy shelf liner over the jam chuck and mount the bowl using the tailstock to turn away all but a narrow cone-shaped nub. I sand the majority of the bottom on the lathe and then remove the bowl and take off the remaining nub by sanding or with a saw, and then sand the very center with a power sander to completion. It typically only takes minutes to do this entire process.Quote:
Originally Posted by Richard Coers
The one thing that I used to always forget was to leave a center tailstock mark in the bottom of my tenon which makes it much easier to get the bowl perfectly centered on the jam chuck, but even then you can get it close enough to centered that it only takes a little sanding to blend in the new cuts with the old cuts on the perimeter of the bottom.
Overall, this process is pretty quick and simple, though having a vacuum chuck is a little bit quicker/easier, though not by much.
Good luck,
Tom
You could get one of these.... https://www.leevalley.com/en-ca/shop...s?item=66B1306
The only problem with that is I don't have a Oneway Strong hold chuck. It looks like I would have to spend around $500 or borrow my friends. Jim
A faceplate with a 2X mounted to it is what I use. Bring the tailstock up for a friction drive.
I have several different sizes of 2X southern yellow pine, cheap wood here, for different size bowls. I usually turn a groove to fit the bowl. Sometimes I use the no slide shelf liner material with no groove. When the piece of wood gets chewed up I face it off and glue a new face on the base wood.
When doing the second turning of a now-dry bowl which is a bit warped, I just throw a piece for craft foam or equivalent over my chuck, bring up the tailstock and true the tenon for remounting. Could use this for the final cleanup of the bottom but I prefer the vacuum. Since the bowl is in the chuck and I have the chuck thread adapter for my Oneway live center it is easy to get the bowl mounted true on the vacuum chuck. Probably could use it with other non-vacuum mountings.
Attachment 517799Attachment 517800
Wooden sub jaws have always worked for me, I have made many sets with varying designs. These are JUMBO, at 24", holding a 19" platter.