Thank you all for your input. I checked all the suggestions and I think
I've probably found the answer. One of the jaws is slightly loose, this is
caused by the fact that one of the the machine jaws( the one that the other
jaws screw on to) is slightly thinner than the slot it fits into. I don't
think that anything can be done about this so I will just have to suffer it
and re cut the rim each time I reverse the bowl for hollowing out. I
always use dry wood and everything else that was suggested works out fine.
Once again this group has come up trumps for me.

Tom

Tom,

Try a thin metal shim alongside the loose machine jaw. If you go to
Harbor Freight and buy a cheap set of flat feeler gauges you will have
a complete set of shims that will last the rest of your life. You
might also try to make a shim from an aluminum beer can, empty of
course.

burtwitlin wrote:

Tom,

Try a thin metal shim alongside the loose machine jaw. If you go to
Harbor Freight and buy a cheap set of flat feeler gauges you will have
a complete set of shims that will last the rest of your life. You
might also try to make a shim from an aluminum beer can, empty of
course.


Just don't empty too many before you start working on the chuck.
Interesting things happen when you do that. ;-)

Deb

If you were stranded on an island and had to make the chuck work, a shim
would be an option to try. My suggestion is: take it back where you bought
it and see what help they can offer. If this is due to faulty manufacture,
they should help you in getting the problem fixed. I would ask them to take
a chuck off the shelf and try a different jaw in your chuck. If this fixes
the problem, , then it becomes a question of who pays for the replacement.
Even if you have to pay (which wouldn't be fair,) it's better than living
with the problem. I think it would probably be difficult to keep a shim in
place.

Good luck.

Hi Tom,


I'm sure that you mark the bowl blank so that you relocate the same
"loose jaw" in its original location, but I wonder if a loose slot is
really the cause of your troubles and woes. Do your chuck jaws close
evenly when tightened fully closed? Check if they tighten evenly on a
piece of round bar about same diameter as your tenon or dovetail. I'm
betting they do.


For sure fix your chuck if a jaw is quite loose, but don't count too
much on being able to accurately remount an unfinished bowl blank on it.
For the most of us turners who can't do this either it's almost always
the wood, not the chuck so we tend to "turn & blend".


I've experimented with making a centered dimple with a center drill on
the tenon or in the dovetail and cobbled up a spring loaded centering
pin thru the chuck jaws. I've also tried an expandable thin circular
sheet metal sleeve over the jaws even tried short pipe segments so as
not to crush the wood. Didn't work for me. Okay, I blame the wood, but
maybe it's me. Anyway I hope I'm wrong. Let us know the outcome.


Turn to Safety, Arch
Fortiter


http://community.webtv.net/almcc/MacsMusings

Has the chuck ever been taken apart ? if so, the jaws might be numbered
and out of order. Just a thought.

Martin

Tom Dougall wrote:
Thank you all for your input. I checked all the suggestions and I think
I've probably found the answer. One of the jaws is slightly loose, this is
caused by the fact that one of the the machine jaws( the one that the other
jaws screw on to) is slightly thinner than the slot it fits into. I don't
think that anything can be done about this so I will just have to suffer it
and re cut the rim each time I reverse the bowl for hollowing out. I
always use dry wood and everything else that was suggested works out fine.
Once again this group has come up trumps for me.

Tom

"Martin H. Eastburn" wrote: wrote in message
...
Has the chuck ever been taken apart ? if so, the jaws might be numbered
and out of order. Just a thought.
^^^^^^^^^^^^^^^^^^^^^^^
If the jaws are put back out of order, you will know you have a problem
before you even finish putting it back together. The scroll slots are
offset from each other by 1/4 pitch per 90 degrees, to allow for the
rotation of the scroll, and bring the jaws together properly. If the jaws
are out of order, they simply will not form a circle, and will not meet at
the centerline.

I don't believe this is true for all chucks. I once managed to get the
jaws buggered up. As I remember it was something like 1 & 3 or 2 & 4
being reversed. Maybe it was both sets. It might also have been that I
had the wrong jaw number on the wrong jaw slide or the jaw slides in
the wrong place. I remember it happened and can't remember the
details. What ever it was the jaws closed properly. The problem
occured when I changed jaws. Then I wen nuts trying to figure out what
was going on. I finally took everything apart and very carefully
matched numbers. One thing is certain. I'm not going out to the shop
and deliberately bugger up a chuck to see if I can figure out what I
did wrong before. Point is you need to make sure that the jaw slide
goes in the right chuck slot and the right jaw attaches to the right
jaw slide.

OK thanks for that I'm sure the jaws are in correctly. When the jaws are
tightened into the recess naturally there is no loosness, it also looks like
the jaws are round as far as I can see. I think that because the No. 1 jaw
is slightly loose until it is tight in the recess is the cause. I think
that as I am tightening the jaws the No. 1 is displaced slightly.

In this particulr chuck (The Versa chuck) the machine jaws are always placed
in the slide with the same number, ie 1 to 1 2 to 2 etc
The O'donnel jaws are then mounted in the same way on top of the machine
jaws. For the super nova chuck the the No.2 and 4 jaws are reversed.
This is because the nova jaws are for a colockwise scroll and the nova for
an anticlockwise scroll.

Tom



"burtwitlin" wrote in message
...
I don't believe this is true for all chucks. I once managed to get the
jaws buggered up. As I remember it was something like 1 & 3 or 2 & 4
being reversed. Maybe it was both sets. It might also have been that I
had the wrong jaw number on the wrong jaw slide or the jaw slides in
the wrong place. I remember it happened and can't remember the
details. What ever it was the jaws closed properly. The problem
occured when I changed jaws. Then I wen nuts trying to figure out what
was going on. I finally took everything apart and very carefully
matched numbers. One thing is certain. I'm not going out to the shop
and deliberately bugger up a chuck to see if I can figure out what I
did wrong before. Point is you need to make sure that the jaw slide
goes in the right chuck slot and the right jaw attaches to the right
jaw slide.

"burtwitlin" wrote: (clip) It might also have been that I
had the wrong jaw number on the wrong jaw slide or the jaw slides in
the wrong place.(clip)
^^^^^^^^^^^^^^^^^^^^^^^^^
Okay, I may have added some confusion here. I was thinking about getting
the *jaw slides* in wrong. On my One-way chucks, it matters not what order
the jaws go on, except that the limiting pin MUST be in one of the slots.

Who would think that something as simple as a scrolling chuck would be
so confounding and confusing. I hate to think what it would be like
using one of those machinist chucks where each jaw moves
independantly. I would probably never turn again.