Public Apology to WSnyder,Tucker65and Dusty

[338 Mollett]

Gentlemen it is with Hat In Hand that I have to report the truing bars have failed ! The tool steel warped during the heat treatment to the point the centerless grinder could not take it out . We had a conference call between three guys to determine which steel to use and the wrong one was chosen . I apologize for not being able to keep my promise but that promise was given based on another . I feel worse about not able to come through on the project than being out 350.00 for rods. Sincerely Ralph Mollett

 

[Dusty Stevens]

Well damn what can they do?

 

[WSnyder]

Thank you very much for your efforts and thanks for letting us know. I'll proceed with another previously setup route for a set of mandrels. I'll report back as to how that goes so if anyone else wants to order.

 

[Tucker65]

That really sucks! Not so much about not getting the mandrels, mostly about you taking the time to put this together and loosing out on the time and money.

Did the bars just warp enough that they won't clean up to the size. Any chance of straightening them before grinding or would they just try to go back to their wrapped state.

 

[338 Mollett]

The steel that was recommended was M2 . As it turns out it warps the most . I bought an A2 rod for an experiment but I didn't want to leave you guys hanging any longer. S7 is also an option to be explored . D2 warps the least but is a bitch to grind . Had to get a spatula the size of a snow shovel for the EGG on my face ! LOL !

 

[338 Mollett]

I was told they couldn't be straightened and would pop with a BANG . I think the raw M2 rods might have worked. The people I ordered from only had 7 12 inch bars so I got 3 36 inch ones to cut to spec. I put them in my 3 jaw cut em squared the ends and put a bevel on them and the three jaw didn't leave a mark . Hmmm go figure .

 

[jackieschmidt]

What RC hardness were you shooting for?

S-7 is one of the most warp resistant Tool Steels, but achieving much higher than around 57RC is iffy. Your chuck jaws are probably case hardened higher tan that.

Just curious, wouldn’t you want to grind those between centers on a cylindrical grinder. A center less grinder can hold a size extremely close but I would’t think it would be the choice when wanting a piece truly straight.

 

[338 Mollett]

Air hardening would get about 60rc ,this is what the fellows wanted . The other questions I can't answer Because I don't work on them so I depended on my buddy's at P.A.T. to take care of my buddy's here. I do know that I poop freely now with a new A$% LOL

 

[338 Mollett]

That really sucks! Not so much about not getting the mandrels, mostly about you taking the time to put this together and loosing out on the time and money.

That means the world to me !!

 

[jkohler]

I believe Allen Warner did a run of mandrels out of A-10 about two years ago. That’s what he suggested they be made of. Wish I would of grab a set

 

[WSnyder]

Just curious, wouldn’t you want to grind those between centers on a cylindrical grinder. A center less grinder can hold a size extremely close but I would’t think it would be the choice when wanting a piece truly straight.

^^^Exactly. Centerless grinding is great for holding diameter but not so much for straightness at all.

BTW I should have a set in my hands very soon. Progress has been made.

 

[WSnyder]

Well so it goes... My next source for the bars can't finish the job either.