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

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

Hi Charlie

I think that would be a not so smart idea.

However there are fiber optic cables, and you could tape a bundle to
your tool shaft, and have light shine on the one end and bring the
light inside that way, another is low voltage bare bulb also taped to
the tool shaft to light the inside, but my favorite way is,
stop lathe, clean out shavings, measure, etc.,
Hollow forms are not for the hurrying ones.

Have fun and take care
Leo Van Der Loo

charlie b wrote:
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

"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?


Thin glass and power tools in proximity? If you've got some fixation that
thin means skill, attach a flexible shaft light like the mechanics use to
the tool itself and watch through the sides. Used to do it with ornaments,
now I don't. If you blow through or sand through, so what? Grab another
piece of wood and start over.

Suppose I might feel differently if I were buying my wood or using something
truly rare.

Wondering how much fun you could have with a fluorescent and an interrupted
edge at certain speeds. Bet you could make it run backward optically like
the wheels in the movies....

On Wed, 13 Sep 2006 00:09:49 -0700, charlie b wrote:

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

I use one of those cheap flexible led lights, Charlie...
Still have to stop the lathe but no tool rest moving or anything... nice for
checking some thin bowls, too...

Mac

https://home.comcast.net/~mac.davis
https://home.comcast.net/~mac.davis/wood_stuff.htm

In article ,
charlie b wrote:
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?

You don't need to complicate it with a ring lamp - put a spotlight where
it shines on the bowl, and gauge the thickness of the bowl while the
piece is spinning by looking at the color of the spot. ie, you don't
need to have the whole piece lit, just as you don't need to have a
circular cutter to turn it round - a single point will do as you turn
the piece.

Look up Peter Bloch (blochofwood) who demonstates this technique from
time to time, and uses it to turn lampshades.

--
Cats, coffee, chocolate...vices to live by

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

The light is a 12volt halogen globe whis is mounted on a flexible (spring
type) mount which is inturn attached to a old magnet from a subwoofer driver
which I place on the lathe bed. I bend the light and insert it into the
hollow form and switch it on.For those interested I will post some photos on
alt.binaries.pistures.woodworking shortly.
:-)
"Jim Hall" wrote in message
news:l85Og.5138$TA5.125@fed1read09...
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

Photos now posted
PING Jim Hall From rec.crafts.woodturning Brilliant Idea or Dumb Idea
Photo 1



"." wrote in message
...
The light is a 12volt halogen globe whis is mounted on a flexible (spring
type) mount which is inturn attached to a old magnet from a subwoofer
driver which I place on the lathe bed. I bend the light and insert it into
the hollow form and switch it on.For those interested I will post some
photos on alt.binaries.pistures.woodworking shortly.
:-)
"Jim Hall" wrote in message
news:l85Og.5138$TA5.125@fed1read09...
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

On Wed, 13 Sep 2006 00:09:49 -0700, charlie b
wrote:

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?

What you're describing, I think I'd pass on... but I do use light for
thin stuff. What I do is take a floor standing goosneck lamp with a
cone shaped shade that we decided didn't look very good in the house
and shine it directly into the hole used for hollowing. They sell
decorative bulbs at the store that have very thick glass and come in
high wattages that are great for the purpose.

And yes, I've used this for making lampshades. Easiest way I've found
was to hollow first, then shine the light in while turning away the
outside. It's by far the easiest way to insure a consistant level of
translucentity (if that's even a word...)

Careful of the wood selection, of course- wet wood turned that thin
cracks sometimes, and when there's that little material holding the
wall together, you don't need to cut through. The air whipping past a
hairline crack is sometimes enough to make the thing explode.
Exciting, but not exactly safe!

charlie b wrote:
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.



Charlie - there is a small bright light that you can tape to your tool
just behind the cutting edge, that will give you sufficient light to
turn a consistently thin wall. The cord is taped at a couple spots
along the handle. I've seen these used a number of times - just have
not had the need myself.
Sorry I don't have a source for this - but suspect a bit of googling or
talking to major suppliers will turn it up.
- Hought