# How to Set Up a 4 Jaw Chuck by Robert Bastow (Tubal Cain)



## HMF (Nov 29, 2010)

Subject: 
        Re: 4jaw chucks -- how to?
     Date: 
        Fri, 12 Sep 2003 12:43:17 +0000 (UTC)
     From: 
        DejaVU &lt;PublicDaF@iwr.ru.ac.za&gt;
 Organization: 
        I'm alone out here
 Newsgroups: 
        rec.crafts.metalworking
  References: 
        1




tony &lt;antoniogatta@hotmail.com&gt; scribed in
&lt;CL28b.68614$R32.2102331@news2.tin.it&gt;: 

&gt; how do i center workpieces in a 4jaw
&gt; chuck? they are 4 independent jaws.
&gt; do i need a dial indicator everytime i load
&gt; a workpiece? am hoping someone could
&gt; walk me through the steps.

instructions from the master at the end....

&gt; when (if) i get used to working with a 4jaw,
&gt; will i ever need my 3jaw again? does it take
&gt; *alot* longer to work with a 4jaw?

yes, you'll need them both. some things just don't need a 4 jaw 
setup. other things cannot be done without it. sometime syou have 
something in the 3 jaw, and need to turn another something so you can 
complete the previous something. just swap chucks, I do it often.

&gt; the lathe is in a fabrication shop.. we dont do
&gt; alot of highprecision work (though it comes around).
&gt; mostly making pins/bushings/collars for weldments.
&gt; being able to bore square stock would be a godsend.


setting a 4 jaw..... by Robert Bastow (teenut) [damn, I miss him]
(found on Google)
" -- quoted --

The master speekith from here:

From: Robert Bastow (Tubal_cain@hotmail.com)
Subject: Re: Centering square stock
View: Complete Thread (7 articles)
Original Format
Newsgroups: rec.crafts.metalworking
Date: 1999/01/28

The quick way to get PDC (pretty damn close) is to first set a ROUND 
bar of the same dimension to run true in your four jaw. Then back 
off ONLY two ADJACENT jaws to remove it. Put in your square piece 
and retighten ONLY the aforesaid two jaws. Most times it will be 
close enough for "Govmint" work.

Quick tip for setting work true in a 4 jaw in two revolutions!

(I learned this, setting up roll turning lathes with 108" swing and a 
jogging speed of two to four MINUTES per revolution.)

1. Revolve the work through one revolution..noting the TOTAL swing of 
the indicator needle. Bring the spindle to a halt at the MIDPOINT of 
the swing and ZERO the dial to the needle.

2. Revolve spindle to bring jaw one to be "on the plunger". Adjust 
jaw one and jaw three to ZERO the needle again.

3 Rotate 1/4 turn and adjust jaws two and four to re-zero needle.

Job is done!

Robert Bastow
"

swarf, steam and wind


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