Z axes height changing over night?

helocat · Dec 8, 2011

Been running the same part for the last three days. All the offsets are the same. Started up this AM to run the parts and saw the first tool was going to cut the jaw on the vise. Hit feed hold and shut it down. I checked the height off set in the program it was correct, checked the physical height offset for the tool and it was off about -.400" . I reset it, and checked the next tool and it was still dead on. Ran the program (Yes should have checked ALL tools) and the third tool in, stuffed my 2.5" shell mill into the soft jaw. I shut it down as it alarmed out. Check the physical height of that tool (off the one remaining non shattered $14 insert) and it was post crash off by -0.420!

WHAT? :willy_nilly:

I have never had this happen before. How does a tools height off set change over night? Its like the machine origin changed in only Z. X and Y are still dead on.

Should I be rechecking my tool offsets each time after the mill goes though its start up origin setting?

2005 TM-1 with tool changer

Mark

behindpropellers · Dec 8, 2011

helocat said:
Been running the same part for the last three days. All the offsets are the same. Started up this AM to run the parts and saw the first tool was going to cut the jaw on the vise. Hit feed hold and shut it down. I checked the height off set in the program it was correct, checked the physical height offset for the tool and it was off about -.400" . I reset it, and checked the next tool and it was still dead on. Ran the program (Yes should have checked ALL tools) and the third tool in, stuffed my 2.5" shell mill into the soft jaw. I shut it down as it alarmed out. Check the physical height of that tool (off the one remaining non shattered $14 insert) and it was post crash off by -0.420!

WHAT? I have never had this happen before. How does a tools height off set change over night? Its like the machine origin changed in only Z. X and Y are still dead on.

Should I be rechecking my tool offsets each time after the mill goes though its start up origin setting?

2005 TM-1 with tool changer

Mark

Anything in G52? Z column?

helocat · Dec 8, 2011

behindpropellers said:
Anything in G52? Z column?

Good one to check. But All set to 0.0

Loner Industries · Dec 8, 2011

Off by .420 huh? Sounds like your TM is smoking something. Is there any way that you were on your offsets page just before you shut it down an accidentally changed it?

Personally when I fire up for the first time in the morning I slow down the rapid and opp stop the first time I run a program even if it was the same setup as the night before, just to be safe. Then go back to loading and pushing the green button.

Tom3197 · Dec 8, 2011

When you did the zero return/home for the Z axis... did it actually go all the way home? We have a lathe that will do that every once in a while for some reason...It thinks its home, but it will be 1-2 inches away from its actual home position. If we jog it forward and HOME the axis again it goes to where it should.

Mud · Dec 8, 2011

It's possible it homed the Z axis off by one turn of the ballscrew, but that doesn't explain why the second tool was correct.

Tom3197 · Dec 8, 2011

Mud said:
It's possible it homed the Z axis off by one turn of the ballscrew, but that doesn't explain why the second tool was correct.

Ah, I skimmed though it and missed that detail... strange...

helocat · Dec 8, 2011

Tom3197 said:
When you did the zero return/home for the Z axis... did it actually go all the way home? We have a lathe that will do that every once in a while for some reason...It thinks its home, but it will be 1-2 inches away from its actual home position. If we jog it forward and HOME the axis again it goes to where it should.

I will shut it down and check. I turn it on and hit the start up/home button and walk away. Being a TM-1 its slow to "go home".

No did not access the offsets page before shutting it down. I am the only one here who knows how to turn it on, let alone get into the settings. My EE's know they don't touch the mill.

Yes I drop the rapids to 25% and walk through the program like I am running it the first time, if I am turning it on and running the same program. This was the only reason I caught the first tool off.

This whole thing makes me think of adding the prob system! I don't what to check tool heights every day by hand. :skep:

Keep the suggestions coming, this must have happened to someone else. BTW, the mill is kept clean, lubed and well taken care of. (I love my Haas too much to let be dirty. My EE's tease me for always cleaning it inside and out)

Mark

tc1999 · Dec 8, 2011

so - 2 tools (or more) off by .4" and at least one not off at all?! :eek:

SCARY SCARY STUFF....!!!!!!!

I really hope this is some simple operator error - otherwise the devil is inhabiting that machine.

behindpropellers · Dec 8, 2011

Did you call HAAS in Oxnard?

KenFoulks · Dec 8, 2011

Most Haas machines keep a keystroke history. Stop pressing keys, call Haas, and hope you haven't pressed too many keys since the crash.

Ox · Dec 8, 2011

Sure sounds like a bad HOME on the Z axis this morning.

I fully agree that it doesn't 'splane tool 2, but I am questioning that _ that tool was actually correct. ??? Especially if T3 was off as well... ???

On another side of the coin - I have a Seimens control that DOES pull up a slightly diff offset on one particular tool now and aggin. Fortunately it is not enough to crash. Just enough to make parts out of spec is all.

Edit the offset and the next batch is all off the other way - and you hafta edit it right back to where it started, and then it is fine for a cpl weeks, or ????

It's not just a HAAS thing!
They all have quirks occassionaly.

-------------

Think Snow Eh!
Ox

DMF_TomB · Dec 8, 2011

z axis change

helocat said:
Been running the same part for the last three days. All the offsets are the same. Started up this AM to run the parts and saw the first tool was going to cut the jaw on the vise. Hit feed hold and shut it down. I checked the height off set in the program it was correct, checked the physical height offset for the tool and it was off about -.400" . I reset it, and checked the next tool and it was still dead on. Ran the program (Yes should have checked ALL tools) and the third tool in, stuffed my 2.5" shell mill into the soft jaw. I shut it down as it alarmed out. Check the physical height of that tool (off the one remaining non shattered $14 insert) and it was post crash off by -0.420!

WHAT? I have never had this happen before. How does a tools height off set change over night? Its like the machine origin changed in only Z. X and Y are still dead on.

Should I be rechecking my tool offsets each time after the mill goes though its start up origin setting?

2005 TM-1 with tool changer

Mark

i would home the machine each day on startup

it would not hurt to check each tool holder as a chip stuck to it can throw thing off especially if only one tool offset appears to have changed. tool holder could be dirty or spindle taper got a chip stuck in it

any hot tool 10" long and 100 degree F difference in temperature will change length about 0.006"

Chuck_Jaws · Dec 8, 2011

Did you check the z offset again after doing a tool change then changing back? Could be worn out bellvilles?

helocat · Dec 8, 2011

I shut down, let it sit and restarted with it finding home on its own like normal. I checked that is was going full Z and it is. Pulled the tooling (installed $70 worth of new inserts :angry:

), Removed inspected, re installed and re cut the soft jaws. Re-installed the program tools, new height off sets then stepped the program through. Perfect part, and is repeating dead on. :nutter:

I will check everything in the morning of course. I realized that the offset spook did not effect the tool change as if the machine origin was off, I would think it would have a problem changing that tool.

I want to think operator error as I am used to that. Just can see what I did wrong.

KenFoulks said:
Most Haas machines keep a keystroke history. Stop pressing keys, call Haas, and hope you haven't pressed too many keys since the crash.

I have pushed to many buttons at this point. I will keep that in mind next time I have an issue.

behindpropellers said:
Did you call HAAS in Oxnard?

No. I will if this happens again. They have been outstanding in the past when I have called them.

tc1999 said:
so - 2 tools (or more) off by .4" and at least one not off at all?!

SCARY SCARY STUFF....!!!!!!!

I really hope this is some simple operator error - otherwise the devil is inhabiting that machine.

I know spooky.

DMF_TomB said:
i would home the machine each day on startup

it would not hurt to check each tool holder as a chip stuck to it can throw thing off especially if only one tool offset appears to have changed. tool holder could be dirty or spindle taper got a chip stuck in it

any hot tool 10" long and 100 degree F difference in temperature will change length about 0.006"

It homes on its own every time I start the mill. Spindle and tool holders are all clean.

Chuck_Jaws said:
Did you check the z offset again after doing a tool change then changing back? Could be worn out bellvilles?

I did after I ran the first new part, all dead on. The mill has really low hrs on it, I doubt the bellvilles are warn.

I will post up if this comes back.

machineit2 · Dec 8, 2011

What was the tool change height like, was it .400 off too?

Mud · Dec 8, 2011

Measure the Z home height with a tape measure, then shut off and restart the machine a dozen or more times and check the Z home height each time, see if it's off one or more times. That should find a problem if it's too close to the midpoint on the servo null.

That's assuming it uses the null position for home - does anyone know if that's relevant on a TM1?

viper · Dec 9, 2011

As Ox pointed out, the Z home switch is VERY highly suspect. If it were my machine, I would turn it on and off multiple times and let Z home and see if it lands in the same place. I did have this happen before and was a switch related issue.

I have some doubt that some tools were on and some were off. maybe your "on" tool was a drill with lots of room to be off.

Machineit - Good point on the ATC but being a TM1, not sure if there is one.

I still think a sticky switch could be the culprit.

machineit2 · Dec 9, 2011

viper said:
Machineit - Good point on the ATC but being a TM1, not sure if there is one.

My old brain seems to always be stuck in VF mode!

helocat · Dec 9, 2011

Yes it does have the tool changer. (Could not imagine not having one!) It changed tools no problem at all.

Powered up and no issues at all, all tool height off sets are dead on. I know my #'s were right in the program and the offsets but I must have done something I did not see. I will keep checking it each day and if its off again I will look for the home switch to see if its clean and operating correctly.

Once again great parts coming off the mill today.

Thank you for all your help and suggestions.

Mark

Z axes height changing over night?

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