1) Fix the camera to the arm on your hollowing rig.
2) With the power on to the TV, the receiver, and the camera, turn the tuning knob on the receiver to get a clear image.
3) With the cutter outside of the hollow form or bowl, place your ruler or measuring device on the tip of the cutter.
4) On the TV screen, use a dry erase marker to trace the outline of the tool and cutter head. I use a black marker for this.
5) On the TV screen, use a different dry erase marker (I use red) to draw a semi-circle around the cutter tip that matches the wall thickness you wish to achieve.
IMPORTANT: The image on your TV screen will most likely not be the same as the actual size of your cutter and tool. That is why it is important to use a ruler or some other measuring device that you can see on the screen by your cutter when you draw the red semi-circle.
Periodically, I withdraw the cutting tool and double-check the position with the image on the screen. If you get significant vibration during hollowing, the camera can move a bit off target which could really make for an unpleasant end to your hollowing session!
Also, don’t forget to erase and re-draw the cutting tools image any time you change tools.
Have fun and be safe!
-- Gerry -- "I don't plan to ever really grow up ... I'm just going to learn how to act in public!"