Bottom turning a deep, natural edge bowl

[alex grams]

I have a few forms I am turning as deeper, natural edge bowls. I typically use a vacuum chuck to turn the bottom, but these are too deep and will hit the drivehead.

The only other thing I can think of is a jam chuck. Any other options/suggestions?

Thanks in advance.

[Robert McGowen]

I make my own vacuum chucks out of 4" pvc pipe. Screw a face plate onto a 2" thick piece of wood, turn it round so that the pvc snuggly fits over it, and drill a hole in the middle. Next, put the pvc on with a silicon bead to seal it and a few screws to securely hold it in place. Could you do this and just use a long enough piece of PVC that the bowl cleared everything?

[Adrian Anguiano]

an extended donut chuck, a hollowform rod chuck, or a jamchuck pad (http://www.woodturnerscatalog.com/p/...wl-Chucker-Pad)

[James Combs]

I make my own vacuum chucks out of 4" pvc pipe. Screw a face plate onto a 2" thick piece of wood, turn it round so that the pvc snuggly fits over it, and drill a hole in the middle. Next, put the pvc on with a silicon bead to seal it and a few screws to securely hold it in place. Could you do this and just use a long enough piece of PVC that the bowl cleared everything?

I am more like Robert in that I will just make me a longer vacuum chuck. I have some 4" ones made from 2" PVC, they are also great for small items like birdhouse roofs and such.

To make mine:
I have a 1"8tpi tap that I use to thread a piece of hardwood or MDF. I will soak the threads with thin CA to reinforce them and run the tap through them again. I then screw the wood(MDF) onto my spindle, then round, flatten, true and size it a little larger in diameter then the anticipated PVC. I then drill a center hole for the vacuum. I will grove it about a quarter inch or so from the edge for what ever size PVC I will be using and epoxy the PVC into the groove. After the glue sets I will true up the end of the PVC and add a little craft adhesive back rubber sheeting(cut to fit) to act as seal and blemish prevent-er. Very reusable I have not had any problems with it staying true.

[Prashun Patel]

Jam chuck.

[Dennis Ford]

+1 on jam chuck, it has been a LONG time since I used anything else.

[Russell Neyman]

1. Jamb chuck, engaging the tailstock as a safety precaution; you can always sand off the small remaining nub.
2. Part off the base and clean up the base via sandpaper.

[Mike Cruz]

Alex, there are a million ways to skin a cat. Many have already been given. Unless I missed it, here's another: They make spindle extensions. These are simple, basically a male threaded section on one end and a female threaded section at the other...both with the same size threading. So, you can screw it onto your spindle and it basically gives you another 3-4" of "depth". In theory, if you want to, you could buy two and put them both on for very deep vessels. But as you are well aware, I'm sure, the further you go out from your headstock with "adapters" of any kind, the more likely you will get some sort of wobble or runout. IF the extensions are perfectly milled, you'll get none...but again, IF they are PERFECT... I'm going to be getting one for my lathe. I've run into just the situation you are describing one too many times...

[robert baccus]

Try a simple inside jam chuck. Buy a foot long piece of plumbing pipe that your inside chuck jaws will grab. My nova takes a 1/2" ID pipe. It clamps up rigid and true. Turn a piece of scrap to a knob square ended and glue it on the pipe. Turn to true and use it inside a bowl or vase. Bring up the tailstock, center and tighten. A tailstock cone with a 1/4" end on it works great. Sets up quick and costs about a buck. I have several that will take up to 22" vases.

[Adrian Anguiano]

I saw a video with Mike Mahoney where chucked a bowl then mounted his rough bowl onto the chucked bowl as a jam chuck. Seemed pretty smart, and held it closer to the edges of a bowl instead of just the center.

mahoney.JPG

[Adrian Anguiano]

Another thing Mahoney did in the video was he uses a vacuum chuck with various size PVC tubes with rubber on the ends for protection. He uses a faceplate with a block of wood installed, it has rings cut in them to fit the pvc tubes nice and tight.

The video is called From Tree to Table.
Its not a very good instructional video, doesn't explain how to do the cuts but shows what cuts he uses. It does show a beginning to end view of how he goes about doing his bowls from start to finish.

save2.JPG

[Jeff Nicol]

For me it has always been the Jamb chuck because I don't like to take the time to put on the vacuum chuck and deal with all of that when it is quick to put on a jamb chuck for the type of turning I am doing. I have a number of different sizes and shapes of jamb chucks and most all of mine are made with a tenon on them so that I can grip them in the chuck and reverse the vase, bowl, vessel etc and finish off the bottom. I have flat ones for platters and larger bowls, round ball type, and several that are tapered like and egg to fit many different diameters and depths. With these I get a good amount of surface contact and make sure the one I use is the best for the piece being turned. If I have a piece that has a very fine finish on it I will put a piece of cotton cloth or a sheet of thin silicone rubber that I have to keep it from slipping with the rubber or with the cloth if it slips a bit there will be no marring. So far with many hundreds of satisfied customers I will stick with it.

Time is money,

Jeff

[Paul Engle]

My vote is jam chuck / s , extra saftey margin and still versitile, cheap , fast to set up .