Feel free to correct me, but I thought the runout in 3 jaw chucks
mainly comes from the scroll threads. Won't this error vary by the
thickness of the workpiece because the jaws will stop at different
places in the scroll? If true, a Buck chuck or other adjustable
chuck can only be centered for a fixed diameter and other diameter
workpieces will still have runout. I understand that wear in the
jaws and scroll will increase runout over time, but I am
specifically addressing a new 3 jaw chuck. Grinding the jaws can
correct worn jaws, but it will never turn true new or ground through
the range of jaw movement.
On 7/7/2023 11:33 PM, mike allen wrote:
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There's several youtubes on mounting a backplate to a chuck
& making the backplate fit your lathe . When you buy a chuck
& new 1 1/2 x 8 backplate you don't just bolt the backplate
to the chuck & start using it . Theres steps you need to go
through to get the best results using your new chuck .
Pick any of the tubes , probably the first batch , I don't know
. This Old Tony probably has one of the better ones .
Little machine Shop used to have a write up on their site but I
couldn't find it though I didn't find a bunch of time there . If
after watching a tube or 3 & you still don't get it let us
know & one of us will tell the procedure they did to mount
theirs . Odd's are 5 people will have 5 different procedures but
the end result is the same . I did my first chuck the old way of
installing & removing & testing the backplate till I got
it right . I probably spent more time removing &
reinstalling then I actually did cutting chips .
I decided to work smarter not harder & when a loose
headstok with spindle came available for my SOuth Bend 9A I
bought it for 25 bucks . One of the best 25 buck's I ever spent
, well maybe not as the 25 I spent before a concert ways back ,
but thats for another forum .
remember , when your through learning your through .
animal
On 7/7/23 6:17 PM, Greg via groups.io
wrote:
I think I'm confused... ;-)
Sent from my T-Mobile 4G LTE Device
-------- Original message --------
Date: 7/7/23 5:34 PM (GMT-08:00)
Subject: Re: [atlas-craftsman IO] I Need a 3 Jaw Chuck
The stub spindle is something you make & thread on your
lathe that duplicates teh threaded end of your spindle . That
way when your making a backplate to fit your lathe you don't
have to keep taking your chuck off the spindle to see if your
stub spindle fits .
animal
On 7/7/23 4:59 PM, Ralph Hulslander
wrote:
Yeah Bill, What is a stub spindle and how does
one use it?
Ralph
On Fri, Jul 7, 2023 at
7:50?PM vt_biketim <
tchock59@...>
wrote:
>>With a decent 4-jaw and a stub
spindle you get better accuracy than you would with all
but the best 3-jaw chucks<<
What?do you mean by a "stub spindle"?
Tim
On Fri, Jul 7, 2023 at
12:22?PM Bill in OKC too via
<wmrmeyers=
[email protected]>
wrote:
Oh, if
you buy an older chuck, you're taking pot luck that it
will be useable. I put a Shars 4-jaw 6" chuck on my
Atlas when I bought it, because the Atlas chuck that
came with it was out by .014".? And the Shars was
cheaper than an original Atlas chuck. Which might be
good, but might not. I would love to put a Buck
Adjust-tru chuck on it, but they cost more than I paid
for any of my larger lathes. If I were working as a
machinist, that would probably be easily justifiable.
As a hobbyist, nope! YMMV!
With a decent 4-jaw and a stub spindle you get better
accuracy than you would with all but the best 3-jaw
chucks, and less time spent dialing parts in. You
don't always need the accuracy of a 4-jaw, but I don't
see it hurting anything unless you're working for high
production. Your needs are unlikely to match mine, so
my advise may not fit at all, but! A stub spindle will
speed you up with a 3 jaw chuck, too, so very worth
doing.
Bill in OKC?
