Grinding chuck jaws.

[Ksracer]

My Gator chuck has very little tension on the nose of the jaws. The scroll applies the closing pressure inline with the heel so if my material (barrel shank, or anything else) doesn't extend all the way through, even moderate tightening will spring them open them at the nose. It's been like that since it was new. It finally irritated me bad enough that I'm going to fix it.

 

[GenePoole]

Looks pretty small. Maybe you just need a bigger 3-jaw? Personally, my 3-jaw has seen almost no use. Mostly my 4-jaw or spiders. My Cushman 4-jaw is older than me, and is still tight as ever.

 

[Dusty Stevens]

Looks pretty small. Maybe you just need a bigger 3-jaw? Personally, my 3-jaw has seen almost no use. Mostly my 4-jaw or spiders. My Cushman 4-jaw is older than me, and is still tight as ever.

He cant go any bigger on that tru bore alignment system

 

[boltfluter]

Looks like your pup is ready to help! Let us know how it works out for you.

 

[55fairlane]

Please let us know how this works for you. I have tried this before, and never had very good luck, if I may offer some advice, either run soft jaws or replace your chuck with a better quality chuck.

 

[shortgrass]

I have seen this done before, and it didn't help or work. If the chuck wasn't right when new, I'd have sent it back, or sold it on ebay and bought a better one. Sending it back would have been my first choice.

 

[LVLAaron]

Why are the jaws like that? Are they not ground well to begin with, or are they a sloppy fit into the body of the chuck?

 

[xr650rRider]

 

[akajun]

I did it on a worn out 3 jaw import chuck because I had nothing to loose. Made a ton of difference
To do it right you need to find a scrap piece of pipe that will barely slip in the hole of your chuck and about 1.5-2” longer than your jaws. Turn the od and id true with each other
Next put it in a dividing head on your mill and cut three slots in it the length of your jaws and wide enough that the jaws can go through the slots and be ground but still clamp on the pipe on the sides.

The idea is to load the jaws as you would when gripping your stock to the jaws grip flat. Some people use rings and do it in a two step process but I never got good results like that.
You can check your work by clamping up a piece of turned stock and using feeler gauges.

 

[DaveTooley]

I'm thinking soft jaws.

 

[Ksracer]

Looks like your pup is ready to help! Let us know how it works out for you.

More like supervise....

I have seen this done before, and it didn't help or work. If the chuck wasn't right when new, I'd have sent it back, or sold it on ebay and bought a better one.

This is probably the 4th or 5th one I've done and it works well. The others were older and I used my Dumore tool post grinder, but I don't have a small enough spindle to get inside this chuck.


The trick is to load the jaws in the right direction. Seems like most people want to close them on a ring way in the back or open them with a ring around the nose. Both methods load them in the wrong direction.

Why are the jaws like that? Are they not ground well to begin with, or are they a sloppy fit into the body of the chuck?

No, its actually a pretty nice little chuck. Everything is tight and smooth. I'm guessing the jaws were ground straight with the intention of having a work piece that extended all the way through them. A Rem Varmint only leaves about 1" or less of shank to grip.

The idea is to load the jaws as you would when gripping your stock to the jaws grip flat. Some people use rings and do it in a two step process but I never got good results like that.
You can check your work by clamping up a piece of turned stock and using feeler gauges.

I prefer to have mine ground to a smaller ID at the nose. As they make contact the scroll will force the heels closed so you have contact the entire length.

 

[Ksracer]

Pretty much exactly what I'm doing. I hadn't seen that one before. I just need to find time to watch them all.

He has a very good way with words and illustration so explain what he's talking about.

 

[butchlambert]

I did it on a worn out 3 jaw import chuck because I had nothing to loose. Made a ton of difference
To do it right you need to find a scrap piece of pipe that will barely slip in the hole of your chuck and about 1.5-2” longer than your jaws. Turn the od and id true with each other
Next put it in a dividing head on your mill and cut three slots in it the length of your jaws and wide enough that the jaws can go through the slots and be ground but still clamp on the pipe on the sides.

The idea is to load the jaws as you would when gripping your stock to the jaws grip flat. Some people use rings and do it in a two step process but I never got good results like that.
You can check your work by clamping up a piece of turned stock and using feeler gauges.

I have a production tool like that.

 

[JMA]

I'm thinking soft jaws.

I used them all the time when I worked in a job shop.
They work great for for holding thin parts and special parts that are difficult to hold with conventional jaws.

Grinding the the jaws in an attemp to fix a cheap or worn chuck may help but it will not fix the wear and slop in the chuck parts

 

[WSnyder]

The trick is to load the jaws in the right direction. Seems like most people want to close them on a ring way in the back or open them with a ring around the nose. Both methods load them in the wrong direction.

^^^Right on!

 

[JasonT]

^^^Right on!

Love that guy. He really knows his stuff.

 

[Ksracer]

They turned out nice. They were ground nearly flat in the relaxed state and it took a total of .0035 depth of cut to clean them up all the way to the nose after tensioning them. That isn't nearly as much flex as some of the other chucks I've ground had. These are really nice little chucks and I wouldn't hesitate to buy one again.

 

[tobnpr]

^^^Right on!

Interesting video. I had never considered that the body/face of the chuck itself could actually distort due to the forces exerted when the jaws are tightened to the max.