Chuck Z reference shifted on QS30-the WRONG way.

I tried searching this. No luck.
I. New to CNC. Learned it from a guy before he retired.
QuickSlant 30,Mazatrol Cam T-4.
So after a week or so he is watching me run a simple thread on a shaft.
"I'll tell you before you make a mistake." He says
Load the PROVEN program from the computer. Programs he has been using for years.
I push the "Cycle Start"
CRASH!!!!!!!
First time I push the button!!!!

It seems that the reference to the chuck the program has shifted. About a quarter inch..
Machine folks couldn,t figure it out.
There is no regiment to the programs never has been since thw machine was new.
But all the ones in the computer he has used before.
The Program file screen has a coloum headed "Chuck Z" and ha sort of had them all at one number.

Sorry if I have rambled and didn,t ask the right question.

Any ideas what to check.

Yeah I now check the "Z" on all the programs now. He never had to.

Thanks
Rob

Check the Z axis motor / ballscrew coupling and check the Z axis ballscrew thrust locknut.

Not familiar with your machine. How does Z=0 get set in the first place? Home switch? Index mark on linear scales? That is where I would look, first. Plus any coordinate transforms/modifiers on the CNC control.

?????????????

Did you crash into the face of the bar stock or into the chuck?

either way:
*It should be a simple check:
BRING YOUR REFERENCE TOOL TO THE FACE OF THE BAR STOCK, TO THE POINT YOU'D BE SETTING AS "ZERO"
from there:
>select "POSITION"
>select "SET UP"
>cursor to "Z OFFSET"
>select "TEACH"
>tell it "0 / ZERO"
>hit input

>>without moving the turret, go back to "POSITION" make sure your "Z" desplays "0/ZERO"

Don't let this get to you, it won't be the last time, after 36 years of doing this crap, six months ago I had a situation similar to yours happen to me, and why? because I got used to trusting all the programs in memory, in my case, it was fine, just that someone cut the bar a bit too long and I didn't double check it, my bad I guess!

BRUSH IT OFF! AND MOVE ON!

Steelcutter;
I do just what you said.
With severe ADD most of what I do is intuative.
So some things take a while to learn. The guy that taught me did things one way.
We use a collet system. 2 1/2 inch max. And the roughing tool ran into the collet. The first step in all programs (except between centers) is a "pointer" that is positioned .100 above the part(top turret) to gage the amount to face off of the end of the shaft. All tools set to the same "0".
Hit cycle start.
If sticking a scale to check length was a waste of time or what I don,t know.
The guy ran a lot of shafts thru that machine before he retired.
The ADD part of me says to check things.
What I do is scale from the face of the collet to the pointer, then move the "0" far enough to avoid a crash(it seldom is), and run the program.

What my problem is wanting to correct the programs before putting them into a database to link prints to the programs. Now we look them up in a looseleaf binder by a rough couple of specs.
You always have to read over the program to check it is like the print.

It SEEMS like the turret "0" reference in relation to the collet has shifted and I want to understand the machine.
Except for one machining center, all the CNCs are using Edgecam,so can,t get much info.
Thanks for the time and ideas.

Any good info on the net on programing these machines? Ours are MIA.
Rob