Off-Center Bowl

[Bob Hovde]

That looks fantastic, how did you do it?

Thanks for the kind words.

The bottom and a "cone" around the top are turned on the main axis, just like any HF.

For a 6-7 in. vessel, you then move the drive center about 1/2 in. one direction and the live center the other direction to about the middle of the "cone" surface. (If you look at a flat drawing of the vessel, this is a 20 deg off-center axis. You can draw this out and make exact measurements for the centers.) I also cut the tendon off at a 20 deg. angle to make the drive center work better. (You now cut a new tendon to match the new angle.) While on the centers, shape the top (which is skewed at 20 deg.) to blend in with the original bottom.

The hollowing is done on the secondary axis, using the second tendon you cut. Since I planned to do significant carving, I left it about 1/2 in. thick on the short side. The side that sticks out is mostly wood, since it is only hollowed out to match the short side. I thought about going in through the bottom to hollow out the entire vessel to the same thickness, but decided it wouldn't add to the finished piece.

If you can find the original article, it's explained the process in detail so that even an old pilot can understand it.

Bob

[Gary Conklin]