Problem cutting 3mm stainless
Problem cutting 3mm stainless
(OP)
Hi all,
I am cutting 3mm stainless with a 2.2kw bystronic bysprint but having problems. When cutting holes approx 10mm dia, the head comes down pierces fine, and then cuts around - but, when it is approx half way round the head keeps moving but jumps up slightly and then down again to 1mm clearence. Its like there is a lump on the sheet it is jumping over.. but there isn't and the pierce isnt leaving any lumps on the surface!! Any ideas would be much appreciated!
Because it jumps up, the focal point goes out and you get a horrible bubble on the bottom edge of the hole.
There is a video of it at https://www.facebook.com/photo.php?v=1015227164817... which shows it best on the first hole. It does it on most holes but not all.
Many thanks for any help given!!
Best regards,
SJClaser
I am cutting 3mm stainless with a 2.2kw bystronic bysprint but having problems. When cutting holes approx 10mm dia, the head comes down pierces fine, and then cuts around - but, when it is approx half way round the head keeps moving but jumps up slightly and then down again to 1mm clearence. Its like there is a lump on the sheet it is jumping over.. but there isn't and the pierce isnt leaving any lumps on the surface!! Any ideas would be much appreciated!
Because it jumps up, the focal point goes out and you get a horrible bubble on the bottom edge of the hole.
There is a video of it at https://www.facebook.com/photo.php?v=1015227164817... which shows it best on the first hole. It does it on most holes but not all.
Many thanks for any help given!!
Best regards,
SJClaser





RE: Problem cutting 3mm stainless
Dan - Owner
http://www.Hi-TecDesigns.com
RE: Problem cutting 3mm stainless
B.E.
You are judged not by what you know, but by what you can do.
RE: Problem cutting 3mm stainless
check to see if an M code got slipped into the middle of a cut.
B.E.
You are judged not by what you know, but by what you can do.
RE: Problem cutting 3mm stainless
Thanks for your replies. Right I have finally done some more tests and I am sure it is not the code. I nested 1 of the parts (disc 3.5mm I/d 12mm o/d) on a small blank. I then cut this program many times on the same sheet and same parameters etc. One will cut fine, then on another the head will rise up slightly on the outer circle in one place, and some times it would rise up twice while cutting the outer circle. When rises up it affects the focal position and the cut is bad or doesn't cut through at all! Where the head is at the right height the cut is perfect!
Can it be to do with the sensitivity of height sensing? cut control or something? I also slowed the cutting speed right down from about 3000mm per min to about 1000mm/min, and the same problem exists. I did this to prove it is not because it is going to quick to cut through and then looses the cut.
Any help would be really be appreciated - its driving me mad!! Thanks Sjclaser.
RE: Problem cutting 3mm stainless
Chris Krug http://krugtech.com/
Maximum Up-time, Minimum BS
RE: Problem cutting 3mm stainless
Thanks Krugtech for the reply. The ceramics are from bystronic. When you say internal leaks, you mean leaks in the head? cutting larger circles (e.g. 25mm dia) are absolutly fine... so if it was an internal leak would it not affect all circle sizes?
When ever i have cutting problems, i ring bystronic and the first thing they say is nearly always 'clean the ceramics in the head'!! I don't understand how the head works and why they need such clean ceramics - surly all ceramics do is stop heat getting up to the lens? Ceramics do not conduct electricity so they surly can't have much to do with height sensing do they??
Any help is always very much appreciated. Thank you very much.
RE: Problem cutting 3mm stainless
Chris Krug http://krugtech.com/
Maximum Up-time, Minimum BS
RE: Problem cutting 3mm stainless
If the pierce height is set to 1mm (same as cutting height) then it doesnt seem to do this. Cant work out why it goes down to the sheet first then up to the pierce height!
thank you for all help given.
Best regards.
RE: Problem cutting 3mm stainless
Chris Krug http://krugtech.com/
Maximum Up-time, Minimum BS
RE: Problem cutting 3mm stainless
RE: Problem cutting 3mm stainless
but, when it is approx half way round the head keeps moving but jumps up slightly and then down again to 1mm clearence. Its like there is a lump on the sheet it is jumping over.. but there isn't and the pierce isnt leaving any lumps on the surface!!
Are you sure? I know that the pierce is done quickly but in nitrogen cutting (and piercing) you are just melting the material and not vaporizing it. Until the pierce is complete and there is a hole in the sheet the melted material has no place to go but back up and can sometimes create the situation you have described. I am used to working with LVD lasers and when you look at the pierce point you usually see little fingers of stainless spreading out from the pierce hole. These can cause the cutting head to jump with the Precitec capacitive sensing system that LVD used.
On the LVD lasers that I am familiar with the post processor would change the code for small holes in stainless to help with this. For small (less than 24 mm dia) holes we would issue a G code to lock the height of the cutting head (z-axis) after piercing and after the nozzle height was set for cutting to prevent the head from jumping. It was assumed that the plate would be level enough in that small of an area that not following the plate would not cause the nozzle to hit the plate. Again, this was only done for small holes. Krugtech could tell you if anything similar is used for the Bystronic or if he has seen this in the past.
Good Luck!
RE: Problem cutting 3mm stainless
-HR
RE: Problem cutting 3mm stainless
Make sure the element (outer or inner circle in this case) only contains one contour.
If using Bysoft, use the 'Display Options' to show 'End of Contours' in the 'Geometry' section.
Machines hate 'unclean' code, and this is quite common when importing from a DXF or similar.
Bystronics, when faced with this, jump around, skip parts, quit cutting halfway through etc.
Pain in the @$$ trying to convince the customer, 'machine is fine', its 'your programming!!' (spoken from experience