Question about Reverse Chucking

[Hilel Salomon]

How do you folks finish the bottoms of your bowls? I usually use a faceplate and create a spigot (dovetailed if I'm going to use a Nova or Vicmarc and straight if I'm using a Oneway) turn it to more or less the shape I'm want, put it on the chuck and hopefully finish hollowing it, sanding and finishing it. Then, ugh I have to face doing the bottom! I've sanded it off, tried to use cole jaws, a grooved plywood and a few other ways, but I never get a very good result. Right now, I have about a dozen bowls that need their bottoms finished.
I've hesitated getting a vaccuum system-but I'm not sure why?
I see such beautiful work being done by most of you and wonder what techniques you use?
Thanks, Hilel.

[Ken Fitzgerald]

Hilel....I made a donut chuck out of 2 pieces of plywood. A solid piece turned round attached to the face plate. A 2nd piece with a hole turned in the middle is bolted to the first piece with the bowl to be finished captured between the two pieces. I use my tailstock and the mark on the bottom of the bowl to get the bowl centered between the 2 pieces of plywood. It takes a few minutes to get the bowl centered and then tighten the bolts and turn the bottom, sand and friction finish if doing so.

To use it for NEs I use double sided tape to tape several layers of 2" styrofoam insulation to the base piece of plywood...enough to hold the NE proud of the base piece of plywood......turn them round or cone shaped...put the NE over the styrofoam......capture it and then finish turn the bottom of the NE.


I hope this makes sense.

[Dario Octaviano]

Ken, If you get one of these... http://bestwoodtools.stores.yahoo.net/tailchucad.html

Your alignment will be perfect each time and fast too

[Bernie Weishapl]

I use the donut chuck and Cole Jaws. I have the Vicmarc Cole jaws which I really like and will hold bowls to 14". When using the donut chucks (I have 2 sizes for 2 different size lathes) I always make sure I leave the livecenter mark on the bottom when I had the blank on a faceplate. That makes it sooooo much easier to center in the chuck. I also use styrofoam on my donut chucks when doing NE's to keep them proud of the base piece just like Ken does. Both work pretty well for me. I used the donut chuck for a long time before I got the Cole Jaws for my Vicmarc.

[Ken Fitzgerald]

Thanks Dario! I'll bet that will speed things up!

[Gordon Seto]

Vacuum chucking is the most convenient of them all. But you still need other reverse chucking methods, because you can't use it when there are voids, bark inclusion porous bowls.

Gordon

[Andy Hoyt]

Jamb chuck. Free!

[Dario Octaviano]

I use both jamb chuck and before...donut chuck. Haven't make a donut chuck for my new lathe though.

Vacuum chuck is on the horizon...if I can get my lazy butt start working on it!

[Jim Becker]

If I'm not using vacuum, I use the Ellsworth method...turn a "blob" that will fit into the vessel, put some soft material on it, like foam padding, put the piece back between centers with the tenon toward the tailstock, get it as close to centered as possible and then trim off all but the smallest nub with gouges, parting tools and a specially ground 1/4" spindle gouge (another Ellsworth idea). You can actually part it off if you have a true variable speed machine that you can slow down to almost nothing at the end as I do, but a small nub can be removed with a simple carving gouge or a chisel. You can do a nice undercut rim on the base this way if it's appropriate for the piece, too.

[Travis Stinson]

Vacuum chucking is the most convenient of them all. But you still need other reverse chucking methods, because you can't use it when there are voids, bark inclusion porous bowls.

Gordon

Vacuum chuck hands down! Blue painter's tape is your friend.
This one was reverse chucked in a vacuum chuck.

[Bernie Weishapl]

Travis are you spoofing me???????? Don't be messing with me. How did you do that with a vaccum chuck.

[Hilel Salomon]

Thanks to all of you. I'm going to try the donut method and use the cole for smaller pieces. I will, though, break down and get a vacuum chuck. Have a PM and a Nova DVR, both (one in Cola, one in VA) and both have wheels on the headstock. Will I need special adaptors? What's the best vacuum system around? I'll get a Gast from my local dealer, but would like a system for the mechanically impaired-ME!
Thanks again, Hilel.

[Mark Pruitt]

Ken, If you get one of these... http://bestwoodtools.stores.yahoo.net/tailchucad.html

Your alignment will be perfect each time and fast too

I would assume that using that accessory requires a vacuum chuck, right?
(With bowl still mounted in scroll chuck, remove scroll chuck and screw onto tailstock adapter, install vacuum chuck, bring bowl up to vacuum chuck, turn vacuum on, release scroll chuck, remove tailstock and finish turn bottom of bowl)

[Ken Fitzgerald]

Mark.....You'd leave the bowl on the chuck...Unscrew the chuck....screw this adapter into the chuck....Place outer ring of your donut chuck over the bowl......put the entire assembly in the tailstock...mount the base of the donut chuck (on you faceplate) on the headstock.....bolt the outer ring of the donut chuck to the base and you have your bowl centered and captured..

In short it would center your bowl on the donut chuck by leaving the bowl attached to your chuck until captured by the donut chuck....I hope this makes sense.

[Paul Engle]

Hilel, I use a wood worm screw in the bowl face backed up by tail stock , I turn the outside shape, then recess , sand and finish , remove from wood worm screw ,then chuck bowl by bottom ( as is done) finish outside, then shape the rim then hollow the bowl , sand , finish. nothing fancy and I only have to flip it once.If you put a foot on it then you turn the foot before you flip it, jam chuck and remove the tennon ,sand, finish. Most of my bowls etc use recess so I do not have to go back.If I turn the foot after I make the recess then flip it but I dont like to do that so most of thetime I use recess with the bottom flat for a foot.