question on Mazak NTX-48 laser 1999

[niall3]

Good Afternoon all
Can anyone out there give me a solution to our problem, here is a general senario...

The Laser head comes down and cuts the first pierce no problem and it makes no differance on what part of the sheet. The problem starts when the head travels back up to Z position and then comes down for the second pierce. The head seems to ignor all parameters / program codes and literally comes down and hits the sheet (regardless of thickness). No "gap alarm" appears on the screen". However in manual mode if we bring the head down, we get a "gap alarm"...We decided to only use the M32 code once in the program (which means the torch is now always only 1mm above the sheet, and this can be dangerous as sometimes parts "flip up" and there is a possiblity of the head crashing into a piece part)...We loaded up a "safe" sheet, and the program ran fine, cutting the full sheet with the head above the sheet by 1mm. So my guess is that the problem lies in the Z-axis codes or encoder or sensor.

Can anybody give me a solution from the info above?, for the minute i can cut but not un-supervised.
many thanks
Niall

 

[fab3]

Do you have a non-contact cutting head or are you using a stylus? If the first pierce is fine it sounds like a possible programming issue, maybe something got changed in your sub-programs or your actual "part" programs has different codes than usual.

 

[niall3]

hi fab3
thanks for the come-back, we have a non contact head. I have sent the program to mazask for checkeing. they are saying that this is an unusual problem. It seems to be happening when we are using the M32 and M31 codes. At the moment we only used the M31 program to bring the head down to cut the first pierce, then for all other pierceing we keep the head 1mm above the sheet and the machine cuts fine, but as you might guess, its a bit dangerous cos if one part flips up the head could crash into it.
The problem is recurring on an old program which is stored in the laser (this program we use each week and never had any isues), we wrote a very simple new program ( square plate with a hole), the machine cut the hole the moved to cut the outside profile, but as soon as the head goes to cut, it just crashes into the sheet and we get no "gap alarm"..so no matter what program we wrrite this seems to happen (only started in the last 2 days)..thanks again Fab3

 

[xbiggy]

I think you should check the G54 offset and make sure you have not put an offset into z by mistake........... Have a nice weekend Niall and glad we could help

 

[niall3]

hi xbiggy and fab3... so the worst thing about asking the whole world for help is when you have to tell the whole world when you make a stupid mistake!...you were right xbiggy..G54 ofset, in the shift screen... value for z was 250mm, so no wonder the head couldnt stop. So even tho i am not the operator, just the owner, i get to run my favourite machine for the whole night and boy could i do with a beer now!...enjoy the weekend also..and thanks again. i am in galway ireland if you are in town anytime i owe ye a pint!..cheers

 

[xbiggy]

Glad you got to the bottom of it. Was it the Mazak tech guys that pointed you at the problem, did you find it yourself or was it our help?

Take it you are happy with the machine being the boss and enjoying "getting to run your favourite machine"?