This months challenge is to turn a natural edge bowl which brings its own set of safety issues.
Natural edge blanks are often uneven shaped and can present significant vibration problems due to being out of balance. In addition the natural edge is like a saw blade rotating close to your hand and the gouge you are using.
So how do we minimize the risk?
1. Round the log using either a band saw or chain saw making sure the piece is sitting flat and not rocking. Wear proper safety equipment when using the saws.
2. Create a flat area on the bark side for the face plate or screw chuck by using a Forster bit in a drill press. Make sure the blank is held securely and hands are well clear of the cutting bit as the uneven surface can cause the blank to suddenly move.
3. Load the blank onto the lathe and capture it with a center in the tailstock for as long as practical.
4. Rotate the blank by hand to insure tool rest clears and get an idea of how out of balance it is.
5. Make sure speed is turned down then turn on lathe. Gradually turn speed up until vibration begins then back off until vibration disappears. The speed at which vibration appears will increase as you remove material and reduce out of balance, so you can adjust the speed up as needed. Speed can also be your friend when doing interrupted cuts as faster speed reduces the time cutting air and enables smoother cutting. Here is a link to a good article on speed.