a question on hollow forms

[Wally Wenzel]

I am ready to tackle my first HF ,i have a chuck to start it but how am i going hold it to finish off the bottom? I don't have a vacumn system and i don't see one in the my future. Thanks for any help.
Wally

[Jeff Bower]

Wally, I've never done a HF, but I've also never thought about how they do the bottom. I'm interested to see how as well. I would assume a donut chuck would be one choice.

[Ken Fitzgerald]

Wally.....I use a donut chuck. To do the bottom of a NE I use double-sided tape to adhere as many layers of foam insulation together to reach inside bottom of the NE. I attach the foam to the donut chuck base and turn it to a cylinder. I place the NE over the cylinder and insure the sides are not touching the donut chuck base and clamp it to the chuck with the donut. Then I turn the bottom tenon off and finish the bottom.

Depending on the HF I may use the foam or just grip the HF on the donut chuck.

There are many more ways of doing it without a vacumn chuck and I'm sure others will share their methonds.

[Gary Garmar]

A jamb chuck also works well.

[Dennis Peacock]

A jamb chuck will work well for ya, but vacuum chucking makes life a lot easier for HF's as well as bowls and platters. I simply couldn't imagine turning without a vacuum chuck any more. :)

[Sean Troy]

A vaccum chuck is always a good tool to add to your collection. You'll see some pretty expensive prices on the pumps but you can get a good one for a lot less here: http://www.surpluscenter.com/item.asp?UID=2005112610274439&item=4-1540&catname=air If your a member of a turning chapter, someone there would most likely be happy to help you put together a system.

[Bernie Weishapl]

Wally I use a donut chuck to do the bottoms of most things I turn. Like Ken said it works well and is secure with full access to the bottom.

[Mike A. Smith]

Wally, looking back at all of the HFs I've turned so far (one), I used a jamb chuck on all of them. (I also used a web of painters tape just to be sure.) I think no matter what you end up with as your preferred method, sometimes you will just have to improvise.

[Mark Pruitt]

I turn a scrap to just under the size of the opening and use some shelf lining material (or tool box drawer liner) between the HF and the scrap, to give a better grip to the jam fit and to prevent damage to the inside of the lip. I keep the tailstock in place right up to the end, and stop when I have a little nubbin only 1/8 or smaller which I can break off. Then I use a tiny sanding disc in my Dremel tool to clean at the very center.

I have used a donut a lot, but this seems to be my favorite method presently. It's just as fast and seems to give better access. The only danger is in cutting that final nubbin to too small a diameter and possibly launching the piece or banging it against the tool rest. But that's easy to control if you watch carefully enough and work slowly.

[Jim Sample]

Wally

As Sean suggested get some help putting a cheaper Vacumn setup together. I have the Vac. pump he refers to, the Oneway adapter and home made chucks. I showed this setup at a club meeting some time ago, if you want, call me and come on down to my shop to see it set up.

Jim Sample

[George Guadiane]

A jamb chuck also works well.
If you are going to use a jamb chuck (a piece of wood that you "jam" the HF onto/into), may I recommend:
Make the seat for the jamb at the widest point of the turning. It will be much more stable that way.
Hollow out the jamb, as if you were making a bowl and make an inside rim that will catch the HF at the wide point. Turn the outside edge thin, and on a contour that sort of flows with the HF.
Mount the piece in the jamb chuck, using the tailstock to hold it in place (I often use a piece of old wet suit to keep the finished piece from getting marred).
IF everything is squared up and run true, turn off MOST of the tenon and start working on your bottom design (which is a little difficult with the tailstock in the way...
NOW, I use pallet wrap to "bond" the HF with the jamb chuck.
Nibble off the remains of the tenon (with the tailstock still in place).
Pull back the tailstock.
IF the HF still seems secure, turn and sand the bottom to completion.
Otherwise, remove it from the jamb and sand by hand or with a Dremel type tool.Those are the steps that I take. The widest point creates a really stable base for this part of the process.

[Paul Engle]

When I do my bowls and hf's i use a screw chuck and ts to hold while i shape the outside and most of the bottom, i remove the ts and put in a recess / mortise so the chuck fits inside , finish off the bottom and sand up to 400 , unscrew the blank , turn it around and begin my hollowing process.

[Allen Neighbors]

This is a jam chuck I use on some small boxes. It's covered with a white stick on "foamie" from Walmart (48cents).You can turn one to more of a point, to use for openings as small as 1/2".
The rod is a 3/8 piece of steel with leather taped to the end.
There is a set screw knob that tightens the rod in place.
When I'm ready to turn the bottom of a form, I extend the rod out 'til it's too long, then use the inside bottom of the HF to push the rod back in. Soon as the opening makes contact with the foamie, I tighten the set screw. Then I bring up the tail stock and center the form with the tailstock.
Turn off the bottom.
Hope this gives you an idea.

[Bill Grumbine]

Wally, I have a vacuum chuck, but many of the hollow forms I turn have enough holes in them that the vacuum chuck will not work. I use a friction chuck, which is not much more than a padded cone for the top and the tailstock against the bottom. I turn away as much of the tenon as I can, and then finish it off the lathe by hand (with a hand held power sander that is!).

Bill

[Wally Wenzel]

WOW, i learned a bunch today on how to reverse a piece on the lathe if i can remember it all i will be set forever. Thanks alot there is more enough info there overcome any problem i might have, now i have get busy and get started. Thanks every one. Wally