Built-in stresses

[kmanuele]

I made a stop collar for my lathe tailstock. The final step was to slit the piece. When I did that, the part collapsed and clamped down on the slitting saw. The gap ended up about half the saw thickness.

Apparently there was some built-in stress in the material (12L14). I see this in wood sometimes, but in steel?

 

[pontiac428]

Oh, most certainly! There are things you can do to normalize tensions, like heat cycling. Some materials have more than others (1018 CRS is known for this). Hopefully it is minor, and you have the dims you need. Otherwise, you might have to remove a little more metal. It's tough to plan for unless you are making repeat parts.

 

[kmanuele]

ok, thanks.

Fit is tight, but it will work.

K

 

[benmychree]

Drive in a wedge into the slot a tad oversize on the diameter and heat to a very low red, let cool, remove the wedge, and the fit should be improved.

 

[kmanuele]

Drive in a wedge into the slot a tad oversize on the diameter and heat to a very low red, let cool, remove the wedge, and the fit should be improved.

Thanks, but not really necessary here since it won't be moving often -- if at all.

This is where it's going (after bluing). Keeps me from pushing the drill chuck out of the tailstock --- which I've done many times

K

 

[ChazzC]

Yes, but you’re losing close to 30mm of travel. Take the arbor out, cut that 30mm off of the end and replace: you won’t pop out the drill chuck arbor and you’ll be able to drill deeper holes without sliding the tail stock.

 

[kmanuele]

Yes, but you’re losing close to 30mm of travel. Take the arbor out, cut that 30mm off of the end and replace: you won’t pop out the drill chuck arbor and you’ll be able to drill deeper holes without sliding the tail stock.

Yikes ! Why didn't I think of that ?!

Oh well. At least it was fun making the collar

Thanks !!!

Kevin

 

[ChazzC]

Yikes ! Why didn't I think of that ?!

Oh well. At least it was fun making the collar

Thanks !!!

Kevin

No problem; the finish on the collar looks good - cold or hot blue?

 

[mickri]

I often do the same thing. I would keep the collar but open it a little so when you loosen the clamping screw the collar will slide on the quill allowing you to easily remove the drill chuck. Otherwise you will probably have to smack the chuck with a hammer to free it from the quill.

 

[kmanuele]

No problem; the finish on the collar looks good - cold or hot blue?

Finish is Brownells oxpho blue. Room temperature. I use a piece of gray scotch brite instead of cloth. Doubt it makes a difference, but a suggestion from the 'net.

2 coats per the directions, then maybe a third, or partial, for touch up if there are lighter areas.

When dry, wipe with a cloth dampened with WD40. This seems to really bring out the black and even out the color.

I often do the same thing. I would keep the collar but open it a little so when you loosen the clamping screw the collar will slide on the quill allowing you to easily remove the drill chuck. Otherwise you will probably have to smack the chuck with a hammer to free it from the quill.

Yup. That works. I had to open the collar a bit to get it on and move it easily. Loosen it and it slides to remove the chuck.

I'll probably still cut the arbor and get an extra inch+ of travel.