3 Jaw Chuck Jaw Alignment Issues

Since your chuck is new there won't be any wear in the scroll, so either method will work. Just be sure to indicate the outer gripping surfaces of the jaws before you do anything to the inner ones. They both must be concentric when you are done.

Tom
 
TomG said:
Ray,

The scroll is meant to work in both directions so it doesn't matter which way you pre-load the jaws. The important thing is to keep the inside and outside concentric. Otherwise the chuck may work well clamping on the inside of the jaws but will run out when using the outside. If you had trouble doing it this way, the scroll in your chuck was probably worn out.

Tom
Click to expand...

Tom my chuck was brand new it does not matter the force of the jaws cause them to tip or tweak slightly causing run out you are also running on the opposite side of the scroll you have to pre load in each direction and grind in each direction just as you would if you where holding an object I have done this many many times I worked in a machine shop for 25+ years and this is how I was taught by old German master who rebuilt lathes , Mills ,ect all of his life he would do this to new expensive chucks to cure run out as well...And these cheap chucks have a little play in them and in the scroll so it does matter.. Ray

Just Google ( The proper way to grind a lathe chuck ) and you will see more examples of what I have showed you other methods maybe easyier but they all hold down the same..
 
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:winner:key stock, I do believe I have some around already so I will give it try today. Thanks again, I'll post the results later.
 
It's done, and seems to have worked just fine. The first thing I chucked after grinding went in much nicer, I didn't feel like I had to crank down just to get it tight, and all the jaws grabbed at the same time. I guess I will see how it goes on the next project. Thanks again everyone!

grinding-chuck.jpg

grinding-chuck.jpg
 
I have never seen the keystock angle - I like that a lot.

I may have to do that on the new 6" Shars with .008" runout
 
A lot off good info in this thread .as i have a 4 jaw indipendent chuch that does obviously have this issue but has an issue off extreme tapper on the clamping faces so when round bar is clamped in it the front of the jaws clamp tight but the back end off the jaw is not tight slight gap .i was thinking off using a ring as suggested in this post on the outside clampping surface and zero it in center then grind the jaws internally .Any thoughts on this method and open to suggestions
 
Moper361 said:
A lot off good info in this thread .as i have a 4 jaw indipendent chuch that does obviously have this issue but has an issue off extreme tapper on the clamping faces so when round bar is clamped in it the front of the jaws clamp tight but the back end off the jaw is not tight slight gap .i was thinking off using a ring as suggested in this post on the outside clampping surface and zero it in center then grind the jaws internally .Any thoughts on this method and open to suggestions
Click to expand...

I personally haven't completed the process myself but have read enough to learn that if you intend to square up the "Inside" jaws you would need to apply an inside the jaws jig and apply closing pressure!
By placing a ring around the OUTSIDE portion of the jaws and then applying tension by OPENING the jaws (by turning chuck key in counterclockwise direction) you apply pressure in the wrong direction for the intended preferred outcome. If you then proceed to grind the Inside Jaws you will definitely st rhe very least end up being in the same boat but realistically speaking the chances are your boat now has a big hole in the hull!
So to Keep it simple, you need to clamp a jig of some sort that is correctly setup dimensionally so that you tension the jaws into the grinding
stone NOT Away from it! Basically speaking, placing the ring on the outside jaws is how you setup for grinding the outside jaws.

Hope this was helpful...... please update the thread with your results and the process you decide on using
 
O
Latinrascalrg1 said:
I personally haven't completed the process myself but have read enough to learn that if you intend to square up the "Inside" jaws you would need to apply an inside the jaws jig and apply closing pressure!
By placing a ring around the OUTSIDE portion of the jaws and then applying tension by OPENING the jaws (by turning chuck key in counterclockwise direction) you apply pressure in the wrong direction for the intended preferred outcome. If you then proceed to grind the Inside Jaws you will definitely st rhe very least end up being in the same boat but realistically speaking the chances are your boat now has a big hole in the hull!
So to Keep it simple, you need to clamp a jig of some sort that is correctly setup dimensionally so that you tension the jaws into the grinding
stone NOT Away from it! Basically speaking, placing the ring on the outside jaws is how you setup for grinding the outside jaws.

Hope this was helpful...... please update the thread with your results and the process you decide on using
Click to expand...
Yes can see what your saying and can understand this on a 3 jaw self centering chuck .i have the issue with independant chuck .the issue is not as described in initial thread but different type of issue off the clamping faces being tapered IE the tip off the jaws clamping the work while the rear of the jaws not touching .So my thoughts are if i was to put a ring on the outside off jaws and at the tip off the jaw this would hold the jaws at the front in tighter and when ground possibly may end up about right .
 
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