Large Live Center Jam Chuck

[Marmotjr]

For those that didn't see my bowl journal, I figured I'd post this here, as this little trick is very useful in stabilizing large bowls with the tail stock.

If your bowl is a little sketchy in the head stock chuck, and you wish you could hold it in place with the tail stock, but it would only get in the way, use a tennis ball with a live center in the tailstock to hold your piece in place.  For smaller things like goblets, a normal tennis ball will do fine, but for bowls and such, a large 9" tennis ball (Amazon and walmart have them) works wonders.  I use a mandrel saver live center, as it has a blunt tip, to keep from deflating the ball, but a small piece of foam  or wood taped to a 60 degree live center would probably work too. 

In my case, when I was working the far edge of the bowl, I was getting a little shimmy that I didn't like, fearing it would lead to the piece getting launched.   With the jam chuck in place, I could actually get a little aggressive with the cuts with little to no vibration. 

Obviously, when you start working the inside, you're on your own, as this won't work.  Short of a steady rest, there's no way to steady a bowl like this.  But, as most of the wobble and vibration comes from the mass imbalance of the outside of the bowl, using this chuck will get rid of most of the wobble before you attack the inside unsupported. 

[wtnhighlander]

Did you feel there was any risk of snagging the 'fur' on the tennis ball, if your cutter got too close? I've never seen this trick before, it seems like a good one.

[Marmotjr]

Yep, I did snag some of the fur.  But the cutting heads are so sharp, or at least they should be, that most of the fur that actually touched the tool was just trimmed off.  Doing so did leave a bit of fuzz sticking out, but it allowed me to get very close to the ball, as I would hit the fur before I hit the ball it self.  Think rumble strips on the side of the road.