Aluminum Soft Jaws ?

Pete Wass

Pete Wass

Well-known member
I asked this the other day on one of these threads and got no response but happened to bump into a Youtube about Soft Jaws on a Mazak machine so wondered if any of you gunsmiths or others might use soft jaws instead of copper? I'm interested to know the pro's and cons if there are any.

Thans,

Pete
 
I made some from an aluminum backing plate in an electrical control panel. Its about the same as a road sign. All it does it doesnt mark it doesnt provide a pivot like a round piece would.
 
Soft Jaws

never made any out of aluminum...but made plenty out of mild steel.....Usually made to precisely chuck up a particular part..... i.e. compensates for chuck run-out.Also good for chucking irregularly shaped parts...... must be turned with a chucking spider in place to take up play in scroll gear.
bil
 
Pete,

The copper wire between the barrel and the chuck jaws allows the barrel to pivot whilst one dials in the muzzle end when chambering through the headstock. A set of bored soft jaws, aluminum or mild steel, clamping directly on the barrel would not allow this. If bores ran dead nuts straight, and the O.D and I.D. of the barrel were dead nuts concentric, jaws bored to fit the O.D. would be the cat's meow...if the jaws themselves stayed parallel with the Y axis of the lathe. But I don't think they do. Somebody posted awhile back about boring their chuck jaws out so a gound mandrel would run dead straight, with zero runnout. It wouldn't repeat. So...I don't see any advantage with soft jaws over the regular chuck jaws when chambering a barrel.

I kinda think of bored soft jaws as a collet for a part that is too big to fit in a conventional 5C collet.

My two cents,
Justin
 
Pete Wass said:
I asked this the other day on one of these threads and got no response but happened to bump into a Youtube about Soft Jaws on a Mazak machine so wondered if any of you gunsmiths or others might use soft jaws instead of copper? I'm interested to know the pro's and cons if there are any.

Thans,

Pete
Click to expand...

It is very common to use aluminum soft jaws in job shops and production shops. On CNC lathes like the Mazak aluminum jaws are what are used most. Off the shelf aluminum jaws are available for larger chucks which are made for replaceable jaws.

The main usage is to bore the soft jaws to match the workpiece since the universal chucks are not accurate but are repetable.
 
Am envisioning some kind of large ball+socket joint (automotive CV joint?.) The barrel centered within the ball, and the socket held by the chuck, or in the spindle. If the details can be worked out, there would be plenty of wiggle room to center the barrel muzzle end.
F1
 
Last edited by a moderator:
Zebra13 said:
Pete,

The copper wire between the barrel and the chuck jaws allows the barrel to pivot whilst one dials in the muzzle end when chambering through the headstock. A set of bored soft jaws, aluminum or mild steel, clamping directly on the barrel would not allow this. If bores ran dead nuts straight, and the O.D and I.D. of the barrel were dead nuts concentric, jaws bored to fit the O.D. would be the cat's meow...if the jaws themselves stayed parallel with the Y axis of the lathe. But I don't think they do. Somebody posted awhile back about boring their chuck jaws out so a gound mandrel would run dead straight, with zero runnout. It wouldn't repeat. So...I don't see any advantage with soft jaws over the regular chuck jaws when chambering a barrel.

I kinda think of bored soft jaws as a collet for a part that is too big to fit in a conventional 5C collet.

My two cents,
Justin
Click to expand...

I see the point about the flat surface of the soft jaws. The problem I have found with the wire is it flattens out quite a bit. I use a piece of copper tubing split on the spider end of the barrel , which works pretty well but the bolts aren't very wide.

Thanks everyone.

Pete
 
Even with a decent universal jaw, soft jaws don't always guarantee a dead nuts true run on the part. The issue has to do with front/back play in the slots for the jaw. You pack the jaws behind the jaw surface with pressure in line with the scroll, but when actually hollding the part out in front, there is a bit of play that can come into effect. There needs to be some play for the jaws to move and that play gets taken up farther away from the scroll than where you
bore or turn the jaws. They can get you within 1/2 thou with a good quality chuck though.
 
dmoran65 said:
F1 -

From what your describing, you should look at a TBAS (True Bore Alignment System) made and sold by SSG.
http://www.straightshotgunsmithing.com/page25
The ability the TBAS has to dial in a barrel (or action) and hold it stress free, has left a lasting impression on me.

Donovan
Click to expand...

That looks like a great chuck. I reckon if the bore at the breech end is spinning true, the rest of the barrel can fend for itself. What is the ball-park price of the SSG chuck?
F1
 
Sounds worth it for a busy shop... which leaves me out. ;-) Watching the video, and thinking, has changed my mind about the necessity for muzzle ends to be dialed in. If the barrel is crooked, the sights will have to compensate at sight-in time, LOL!
F1
 
Watch gordys grizzly video. Very good explanation on how to set up the muzzle. He lets it runout instead of stressing it into place just to make an indicator happy. He explains with pictures on how to set it up to make the chamber go straight down the bore. Watch it and develop your own methods and deviations. Very good video for the money.
 
I'll make one more post on bored soft jaws, aluminum or otherwise and then I'm out of this discussion.

In the gunsmithing environment bored soft jaws are good for one type of operation, one where you want the ID to be exactly concentric to the OD. A muzzle brake for example would be a good application of bored soft jaws.

As to this video Dusty mentions, that is probably the worst way to align a benchrest barrel for chambering that could be imagined. This, let the bore go wherever, from a professional machining standpoint makes no sense at all.

When that method was first demonstrated at the 2008 SHOT Show in Orlando, a good friend and one of the winningest gunsmiths in modern times, called me laughing about it. This gunsmith who called me chambers hundreds of barrels annually for the US military snipers suppliers. With this method you can easily end up with a barrel that is so misaligned that your scope may not have enough adjustment to bring it onto the target paper let alone to zero.

Sure, you can as they say "clock" it. That adds an additional 2-4 hours to the process. Even then you can end up with a barrel that doesn't point along the same axis as the remainder of the action, scope, stock assembly.

Some of you will disagree with what I just wrote so be it. I've had enough years as a Manufacturing Engineer designing machining processes of machine parts many times more complicated that a chambered rifle barrel to say what I just wrote with confidence.

.
 
Other Methods

Dusty Stevens said:
Watch gordys grizzly video. Very good explanation on how to set up the muzzle. He lets it runout instead of stressing it into place just to make an indicator happy. He explains with pictures on how to set it up to make the chamber go straight down the bore. Watch it and develop your own methods and deviations. Very good video for the money.
Click to expand...


Yes there are other ways to do most jobs......All up to the person doing it.......with bores never being straight.... this brings up another method.
Similar to our discussions on chambering methods... steady rest/4jaw/spider/collet......each way works and has benefits......
bill larson
 
Not to be argumentative

JerrySharrett said:
I'll make one more post on bored soft jaws, aluminum or otherwise and then I'm out of this discussion.

In the gunsmithing environment bored soft jaws are good for one type of operation, one where you want the ID to be exactly concentric to the OD. A muzzle brake for example would be a good application of bored soft jaws.

As to this video Dusty mentions, that is probably the worst way to align a benchrest barrel for chambering that could be imagined. This, let the bore go wherever, from a professional machining standpoint makes no sense at all.

When that method was first demonstrated at the 2008 SHOT Show in Orlando, a good friend and one of the winningest gunsmiths in modern times, called me laughing about it. This gunsmith who called me chambers hundreds of barrels annually for the US military snipers suppliers. With this method you can easily end up with a barrel that is so misaligned that your scope may not have enough adjustment to bring it onto the target paper let alone to zero.

Sure, you can as they say "clock" it. That adds an additional 2-4 hours to the process. Even then you can end up with a barrel that doesn't point along the same axis as the remainder of the action, scope, stock assembly.

Some of you will disagree with what I just wrote so be it. I've had enough years as a Manufacturing Engineer designing machining processes of machine parts many times more complicated that a chambered rifle barrel to say what I just wrote with confidence.

.
Click to expand...

serious question because I don't know: Are there any products made that would use the same process folks use to chamber barrels? I can't think of any, right of the top of my head but like I said, I don't know. I know of a well respected Smith who pays no attention at all to the muzzle when he chambers and he has made a heck of a lot of winning rifles.

Pete
 
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