Headstock Too Long - Idea!

K

kevin_j

Guest
Hi Folks!

I'm an absolute newbie in this forum, but I've been doing some reading around here and the knowledge is great! This is my first post here, so please don't leave to many scars :)

So I think we're all familiar with the issue of having to wide of a headstock for chambering shorter barrels (that is if you're into that method). I like the idea of a dedicated cat on what normally would be the chuck side, very cool! I was thinking about chambering some short barrels today, and something struck me. What if after chambering, threading, and profiling the blank, you then cut to length and threaded on an extension using the threads cut for fitting into the receiver? You could place this through the headstock and use a range rod to indicate true before crowning. The extension would make up the distance to the outboard cat.

I realize using the steady is a much more direct route, I'm just sorta playing with the idea and wondered what issues you all might see?

--Kevin
 
Last edited by a moderator:
Kevin,

I do my chamber work on a Pratt & Whitney Tool Room lathe that is also too long to use a spider.

I have written several times on this Forum how I do this, even complete with pictures of me doing the entire proccess just a month ago. The thread was initiated by Gary Walthers...

Please do a search, and if you have any questions, I will be glad to answer.......jackie
 
You guys have been making this over-complicated for years.............

.............simply drive a 1.5" i.d. x 16" long tube containing 4 spider screws at spindle chuck end and 4 spider screws at steadyrest end. Install a dead center in spindle bore end for ease of initial alignment if you want.

This essentially gives you a 16" spindle over the bed using a steadyrest and you can axial align all your barrel work to your hearts content..........Don
 
Wow! Thanks Jackie and Walt for putting that together! I think I am in love with that chuck. Seems like the best of both worlds. Jackie that is a really ingenious way of centering in the headstock.

My main concern is maligning the crown. But my feeling is that if I get the range rod indicating to .0002 on the outboard side, I'm in good shape regardless of the extension alignment.

Don, thanks also for the steady rest suggestion. I'm really just playing around with this to see if there are ways of getting around using the steady.
 
Don said:
.............simply drive a 1.5" i.d. x 16" long tube containing 4 spider screws at spindle chuck end and 4 spider screws at steadyrest end. Install a dead center in spindle bore end for ease of initial alignment if you want.

This essentially gives you a 16" spindle over the bed using a steadyrest and you can axial align all your barrel work to your hearts content..........Don
Click to expand...

Don,
You wouldn't have any pics you could post of this set up would you?
 
jackie schmidt said:
I do my chamber work on a Pratt & Whitney Tool Room lathe that is also too long to use a spider.
Click to expand...
That alignment ring is so simple and effective! Here I was thinking how to do short barrels with an adjustable internal spider, but you have saved me a lot of time. I agree that putting tension on barrel for centering may cause it to spring introduces other variables when reaming. Thanks :)
 
Cowboy4 said:
Don,
You wouldn't have any pics you could post of this set up would you?
Click to expand...

Hi Cowboy4,

I do not have any pictures in my computer files, but the next time that I do a railgun barrel that does not fit in my 1 3/8" spindle, which is about the only time that I ever need to use this setup for barrel chambering/crowning, I will photograph the setup and post it here.

It is really nothing more than an oversized action truing tube setup, with the same 8 spider bolts, is 16" long, and spans between the spindle chuck and steadyrest.

Very easy to make and use.

If my health ever turns around, I plan to pick up a small 36" Atlas/comparable lathe, for at range machine work/experimentation stuff, using this same long 16" spyder tube and steadyrest................Don
 
thanks Don....

....a picture should provide a simplification of the set up. Not to wear you out with questions, but once the tube is set up in a 4 jaw, how do you indicate the spindle end of the barrel?

Hope your health improves.

Thanks.
 
Cowboy4 said:
Not to wear you out with questions, but once the tube is set up in a 4 jaw, how do you indicate the spindle end of the barrel?

Thanks.
Click to expand...

For axial alignment in chambering or crowning with this over-the-bed extension tube spider setup, it does not matter what the spindle end does and therefore needs no indicating, all the dial-indicating is done at the steadyrest end, although spider bolt adjustments are done at both ends in order to get the zero axial indicator readout.

If, for some reason, the barrel bore needs to be on center at the spindle end, a "dead center" can be placed into the spindle bore end, beneath the chuck jaws and spider tube, to accomplish this task.....................Don
 
A word from the plumber, or is it cobbler, anyway. When the barrel is installed, it is held by about .625" of one end. My lathe chuck will grasp about 2" of the barrel several inches in from the very end. ergo, the lathe chuck provides far better support than the action. Most barrels aren't straight anyhow. So, I don't get too excited about dialling-in the muzzle end. I do look down the back end of the lathe spindle to see how true the muzzle end is running, but this is to identify a bad hold by the chuck. Of course I work with crap barrels on crap guns, and they don't shoot too good when I'm done, but, there it is, an alternative viewpoint.
 
You must log in or register to reply here.
Back
Top