It's not really necessary. If you use a spider to locate the jaws for machining, you can set jaws that are similar in profile to your needs and remove only a few thou for the new setup. You need not even clean up the old surface completely---just cut enough so you achieve a decent mounting surface that won't indent the parts when chucked. By reversing soft jaws, you can have two profiles per set and get by with only three sets or so. I did that when in business and had no problems at all.BadDog wrote:Soft jaw capability is the only thing that makes me consider mounting a 3 jaw on the rotab. I've wished for it a couple of times. But then I'm so cheap it actually HURTS to have to cut a soft jaw for a single job, though I do it.
Again, key to success is an adjustable spider, so you don't have to remove unnecessary material from the jaws.
Hard aluminum (6061-T6, or even better, 7075-T6) serves quite well for soft jaws, but if you'd like to use them for the rest of your life, make them from mild steel. When you've used them to the point of being useless, simply weld on a new piece of material and start all over again.
For the record, I have made soft jaw setups for one-offs as long as I remember. It is one of the finest methods of holding parts.
Harold