The UK's Finest Independent Forum for Shooters and Gun Owners. Est 2010.

As per the title what is your preference if you could only have one lathe chuck would it be a 3 jaw scroll a 4 jaw scroll or a 4 jaw independent.

Why do I ask this question:
Obviously in these difficult times we/I have lots of free time on our hands I have never spent so much time at home in all my life. If it goes on much longer my Wife of 45 years is going to divorce me.
I am going stir crazy.
Any way I spent some time working on my dialing in skills with a four jaw independent chuck. Then I replaced the chuck with a 3 jaw scroll to turn what I thought was an easy peesy job.
Turned it down to the right diameter then reversed it in the chuck it all ready had a hole drilled through it so I ran a boring bar up to it and turned the chuck by hand.
The hole through the center is out not a million miles but definitely out. I am not happy.

Any way moving on what would be your preference if you could only have the one chuck and why.

Simple really a 4 jaw independant if your doing one offs

although sacrificial jaws on either of the others bored as neccesary

If I could only have 1 it would be a 4 jaw ( independent).
You soon get used to clocking every job in.

A 3 jaw is probably convenient however mine get used seldom if ever. I use Pratt Burnerd (PB) chucks for all applications and they are certainly good, if I chuck up a piece of 30,0mm ground steel bar in my 3 jaw on the Colchester it will be within 0.0015" in old money of concentric so OK, but not good enough for my needs. So I use PB 4 jaws. I do also use a Crawford collet chuck on the Colchester which takes a variant of the 5C collet and it is accurate, hopefully around the 0.0005" mark. The big machine wears a micro adjust D6-1 5C collet chuck so as near as perfect as I would be able to clock a 4 jaw in.

I try to avoid using ER collet chucks on any of my machines however a couple of my rotary tables often have an ER32 or ER40 collect chuck fitted and I have been using a very nice ER16 system for my ongoing experiments with CNC chamber reaming. (It works as well!)

As an aside, I know of one gunsmith who uses a good quality 6 jaw scroll chuck for all of his chambering, it again runs to around a thou or so on the OD and he uses the same floating reamer holder as I do with no further clocking in. The only difference is he is barrelling a lot more barrels as I am and before you ask, yes they invariably shoot very well.

With a 3 jaw self centering chuck the trick is plan the job so you do as much as possible without taking the work piece out. If you need to turn the work piece around then put a mark on one of the jaws and another on the work piece, now when you relocate the work piece you can line it up with the same jaw and succeeding cuts will be pretty close in concentricity.

andrew375 wrote:With a 3 jaw self centering chuck the trick is plan the job so you do as much as possible without taking the work piece out. If you need to turn the work piece around then put a mark on one of the jaws and another on the work piece, now when you relocate the work piece you can line it up with the same jaw and succeeding cuts will be pretty close in concentricity.

Thanks for the reply.
I decided to start again from scratch using the four jaw and dialing it in. I have got nothing else to do at the moment.

Dellboy wrote:Simple really a 4 jaw independant if your doing one offs

although sacrificial jaws on either of the others bored as neccesary

Sacrificial jaws I am not sure I understand what you mean.

Ovenpaa wrote:A 3 jaw is probably convenient however mine get used seldom if ever. I use Pratt Burnerd (PB) chucks for all applications and they are certainly good, if I chuck up a piece of 30,0mm ground steel bar in my 3 jaw on the Colchester it will be within 0.0015" in old money of concentric so OK, but not good enough for my needs. So I use PB 4 jaws. I do also use a Crawford collet chuck on the Colchester which takes a variant of the 5C collet and it is accurate, hopefully around the 0.0005" mark. The big machine wears a micro adjust D6-1 5C collet chuck so as near as perfect as I would be able to clock a 4 jaw in.

I try to avoid using ER collet chucks on any of my machines however a couple of my rotary tables often have an ER32 or ER40 collect chuck fitted and I have been using a very nice ER16 system for my ongoing experiments with CNC chamber reaming. (It works as well!)

As an aside, I know of one gunsmith who uses a good quality 6 jaw scroll chuck for all of his chambering, it again runs to around a thou or so on the OD and he uses the same floating reamer holder as I do with no further clocking in. The only difference is he is barrelling a lot more barrels as I am and before you ask, yes they invariably shoot very well.

I think I know off the gunsmith you refer to.
I also have a ER40 collet chuck and a full set of metric and imperial collets. I also have the ability to use it on the Mill. More often than not its used on the Mill.