If you don't mind me asking.. could you explain a little more on the light
source. What kind of light are you using and how do you suspend it in the
bowl. Are you attaching it to the quill on the tailstock and running it in
that way..?

"." wrote in message
...
I generally hollow the inside and finish sanding and oiling or waxing
first,
then have the light inside the object and turn the outside when turning
thin
items. Using this method I have turned goblets with a wall of 0.4 mm which
is 1/32 inch note the light is ON when the lathe is spinning and to give
even more contrast I reduce the other lighting near the lathe, ie. no
overhead lights and minimal workshop lights.
This really shows the unevenness allowing me to accurately use the SKEW so
that the surface does not need much sanding (sanding starts with 300 grit
followed by 400 and finished with 1200 grit then lightly finished with oil
and wax this is the tricky part)

"charlie b" wrote in message
...
Having just recently blown through the top of a turned lidded vessel,
and having noted that a light shining into the inside while looking
from the outside makes it semi-obvious how thick or thin the walls
are. But you can't put a light inside while your working on the inside
- duh. And it's kind of a PITA to turn the lathe off, get the tool
rest out of the way, stick the light up against the opening of the
hollow form then look at the piece from the chuck side.

BUT - You Can get donut shaped fluorescent light bulbs. And if
you can fix it to the drive end of the lathe - behind the chuck
or around the chuck - and made some kind of shade - then
you might be able to use light to tell you how thick the wall
of the piece your working on is getting. Could probably turn
a "shade" even.

Brilliant idea or a dumb idea?

charlie b