Soft Jaws

[TomG]

Steve,

That's why you need to get one of those stainless envelopes. It will prevent oxidation by keeping air away from the parts. You can even go one step further and put a piece of paper in with the parts to consume any oxygen in the envelope. Warpage is always a risk when you heat treat parts so you may have some fitting to do when they are done.

Tom

[DaveH]

Steve,
Some use their BBQ and charcoal fuel, and a hair drier for the forced draught

DaveH

[Hopefuldave]

(03-17-2013, 04:29 PM)EdK Wrote: Have DaveH (the other one) make a set for you.

Ed

OI! I haven't even made the jig yet!

AND it'll be scroll-specific

Dave H. (the other one)

[stevec]

(03-18-2013, 09:46 AM)Mayhem Wrote: Steve - I've annealed hardened drill couplers by heating them to orange where you just get little sparks leap off the surface and them bury them in a bucket of ash and let them cool slowly.

I'm sure there is a more technical procedure but that is what worked for me. Then again, they were used for nothing more than scrap metal to practice with. With what you want to do, the oxidation will need to be limited and I'm unsure of the steps required.

So - come to think about it - this probably isn't any help at all

Darren, ole bud, don't sell yerself short? I introduced my jaws (no, CHUCK jaws) to the red inferno of our large air tight stove and left them there for almost 24 hrs. and several re-stokings of the stove.
I then buried them in the ash bucket for 18 hrs. This morning I dusted them off and took a file to one.
TA DA! score, file 1-jaw 0. The jaw still felt pretty hard but then my chubby digits are not a Brinell hardness tester (Damn! I have a hardness tester, oh well to late for the "before" test).
Step 2 in the test appears in this pic.
   
I figured the blade is old so let's try. That's the third jaw partway through!
I know from experience that good bi-metal blades can cut pretty hard stuff (like files can).
Next test in the drill press.

   

So it looks like I'll be reporting further on this project!
Thanks Darren, it's a good think I don't live next door or you'd be in for a HUG!

[stevec]

Here's the tops of the master jaws faced.

   

I previously removed the scale that formed on the jaws during the annealing/cooling process and made sure that they still fit and worked in the chuck. I also wanted to make sure they were smooth enough to clamp well in the mill vice.

Here's the soft jaw index "keyway" cut in the jaws.

   

Next comes the choice of fastener size and the drilling and tapping for them.

More to come.

[Mayhem]

No hug required Steve - just glad I was of some help. Looks like you are making good progress.

[TomG]

Good to hear that you got them soft Steve. To reverse the process, try quenching them in oil rather than letting them cool slowly, although you won't have to let them soak like before. It sounds like your stove has enough of a reducing atmosphere so oxidation is not and issue.

Tom

[stevec]

Tom, as mentioned I'm not going to bother re-hardening them.
1) because I don't wanna remove the scale/oxidation again.
2) I don't wanna induce distortion caused by heat treating a machined and stress altered part.
And
3) I don't need hard soft jaws .

This is not going to be a commercially available product sporting guarantees of service for the next century. It's just a crummy old Cushman chuck that may allow me to experiment with the use of soft jaws on. If it works for me it'll outlive me.

[f350ca]

Well done Steve, Red Neck engineering at its best. Or as my mentor Red Green would have said, "If the women don't find you handsome, they should at least find you handy"

[stevec]

Greg, the women don't find me, they aren't looking for me!

Here's the last pic from phase 1

   

Phase 2 will be to machine a back plate.

Phase 3 will be to make the soft jaws.