Procedure For Boring Soft Jaws

Thanks Tony, these look great and so simple to make. Are there any downsides to this configuration?

What diameter and thickness are the jaws, I guess it would not matter, but just to get an idea.

Also what is a spider?

Thanks

Joe
 
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I often use soft jaws. I make mine out of aluminum thats been keyed to fit the profile of the masters but your steel ones will give the same results. As someone above said close the chuck on a suitable sized piece of stock grabbing it with the master jaws and machine the profile you want in the soft part with a boring bar. If you want steps to grab on the ID of a part you will need to expand the chuck on a piece of pipe over the outside of the jaws to remove the slack.
If milling the waste material away is going to be quicker than making the intermittent cut go for it.
My aluminum ones wear fairly quick if Im making a run of parts, your steel ones will be better but will of course wear faster than hardened ones. The beauty of the soft ones is it only will take a few minutes to reface them.
I use the soft jaws sacrificially to hold parts that I don't want to damage, say a gear. Machine a pocket in the face the size of the part you want to hold, remove the blocking piece from the hard jaws and the gear will then be held with virtually no runout.
IMG_1094.jpg

Greg
 
Joe, I just read the post that Tony Wells linked to, and came up with an idea. For pre loading the master jaws toward the OD, you could use a large SS screw clamp, like a hose clamp only big enough to fit around the chuck circumference. put the clamp on chuck covering the T-slots, then expand the jaws out until they push against the clamp. Now they are "loaded" and you can turn the outside steps. Tony, the pictures you linked to are the best tutorial on boring soft jaws I've seen, so thanks for that. Hope this helps, Joe. JR49
 
Thanks JR, sounds like a good idea. Great solution when you want to turn the OD on the jaws.

Joe
 
this is what I call a spider
Joe Pitz said:
Thanks Tony, these look great and so simple to make. Are there any downsides to this configuration?

What diameter and thickness are the jaws, I guess it would not matter, but just to get an idea.

Also what is a spider?

Thanks

Joe
Click to expand...

spider 001.JPG
 
Thanks Tozguy,

Now what is it used for, sorry newbie question.

Joe
 
Joe, keep the questions coming , I love it!

A spider is used to hold stuff with better concentricity than is possible with conventional lathe chucks. I use it for holding reloading dies or short gun barrels. I have a different spider for chambering long barrels thru the headstock.

The adjustment screws along with a dial test indicator allows me to get a level of concentricity that is only limited by my patience.

BTW this spider was made from the hub of a faceplate that I found at the scrap yard. Note the interrupted cut required to salvage the hub. This pic shows what is left of the face plate.

spider 002.JPG
 
Tozguy, So if I am understanding, you mount the barrel in the center and used the set screws and a dial test indicator to get the concentricity?

That is way cool.

Thanks

Joe
 
You got it Joe.
Thanks for the compliment.
Been looking out for a suitable piece of scrap to make one for a while. When I finally found something suitable it was a blast to make.
Making my own D1-4 studs is especially fun. Not counting the purchase of some high quality taps for the female threads, it cost around $15.
 
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