We have a three jaw chuck ( Bison brand) on our old lathe at work. The
chuck is about 18 inches in diameter. It is a brute to open and close with
the chuck key. I took the jaws out and cleaned everything then put light
oil the jaws. It is still stiff.
The scroll spins smothly when the jaws are out. There are no burrs that
I can feel in the slots or on the sides of the jaws. To put the jaws into
the pockets I have to tap them in with a soft face hammer to get them deep
enough for the scroll to engage. All three jaws are equally stiff in their
slots.
I don't want to stone anything at this stage. Do we simply have a stiff
chuck??? The unit has been around a long while but has not seen much use
and is in good condition. Any suggestions appreciated.
Randy

"Randy Zimmerman" wrote in message
news:%5NDe.7382$s54.3783@pd7tw2no...
We have a three jaw chuck ( Bison brand) on our old lathe at work. The
chuck is about 18 inches in diameter. It is a brute to open and close
with the chuck key. I took the jaws out and cleaned everything then put
light oil the jaws. It is still stiff.
The scroll spins smothly when the jaws are out. There are no burrs
that I can feel in the slots or on the sides of the jaws. To put the jaws
into the pockets I have to tap them in with a soft face hammer to get them
deep enough for the scroll to engage. All three jaws are equally stiff in
their slots.
I don't want to stone anything at this stage. Do we simply have a
stiff chuck??? The unit has been around a long while but has not seen
much use and is in good condition. Any suggestions appreciated.
Randy


I had the same problem with a chuck. We found some little dings that had
displaced some metal. We stoned them out and it's like silk now.

Look for scrape marks on the jaws and chuck itself. After you have
ascertained where the problem is, do a gentle stoning with an extra fine
stone and the jaws will probably start moving nice and silkily.

--
Why isn't there an Ozone Hole at the NORTH Pole?

Next time I have a slow day I guess I will take it apart again. I ran my
fingers in the slots trying to feel a burr and on the sides of the jaws.
This is after flushing the grooves with a solvent soaked toothbrush. It is
odd that all three jaws are stiff right from their entrance in the slots. I
will try the stoning next.
Randy

"Bob May" wrote in message
...
Look for scrape marks on the jaws and chuck itself. After you have
ascertained where the problem is, do a gentle stoning with an extra fine
stone and the jaws will probably start moving nice and silkily.

--
Why isn't there an Ozone Hole at the NORTH Pole?

Hey Randy,

I've got a chuck I don't use a lot with the same symptoms, but have
not tried anything yet. Mine's the same, in that the scroll works
fine with-out the jaws in place. I did intend to experiment to find
out if just a single jaw was the culprit by trying them one at a time.
Maybe after I see the conclusion of this thread I'll give some of
these ideas a shot. Please let us know how you make out.

Take care.

Brian Lawson,
Bothwell, Ontario.
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On Fri, 22 Jul 2005 04:07:05 GMT, "Randy Zimmerman"
wrote:

Next time I have a slow day I guess I will take it apart again. I ran my
fingers in the slots trying to feel a burr and on the sides of the jaws.
This is after flushing the grooves with a solvent soaked toothbrush. It is
odd that all three jaws are stiff right from their entrance in the slots. I
will try the stoning next.
Randy

"Bob May" wrote in message
...
Look for scrape marks on the jaws and chuck itself. After you have
ascertained where the problem is, do a gentle stoning with an extra fine
stone and the jaws will probably start moving nice and silkily.

--
Why isn't there an Ozone Hole at the NORTH Pole?

You should probably stone the corners of the jaws to achieve a small radius
or chamfer. It's possible the cutters used on the chuck itself were worn to
some extent and some interference is occurring in that area. Use a
'sharpening stone' which
will give real nice results without scratches, etc. Also, a sharpening
stone when passed lightly over a flat suface
will highlight any dings, etc. (You can also 'feel' them if you are using a
light touch)

The same technique can also be used in the chuck slots with the correct
sized stone.

Ace

"Randy Zimmerman" wrote in message
news:Jh_De.10762$%K2.9000@pd7tw1no...
Next time I have a slow day I guess I will take it apart again. I ran my
fingers in the slots trying to feel a burr and on the sides of the jaws.
This is after flushing the grooves with a solvent soaked toothbrush. It
is odd that all three jaws are stiff right from their entrance in the
slots. I will try the stoning next.
Randy

"Bob May" wrote in message
...
Look for scrape marks on the jaws and chuck itself. After you have
ascertained where the problem is, do a gentle stoning with an extra fine
stone and the jaws will probably start moving nice and silkily.

--
Why isn't there an Ozone Hole at the NORTH Pole?