Trying to cut 1/2" and up to 3/4" HELP?!...

So i am running a STX510 2500watt. using co2. once i get the pierce in it seems like there is way to much heat in the sheet so when it starts the lead in to the part it explodes and send material all over then makes a big unwanted hole... i have added a dwell after the pierce but it sill is "shooting the laser" how do i make the beam shut off and wait for a few seconds to let the pierce cool then turn beam back on and start the cut? i will insert my conditions let me know where and what i need to put in the code to make the beam stop, then start again after a few seconds..
Thanks for your time.

%
O5502
(.500 MS MED F028)

( PIERCE )
G88P08M56
M32
G87P03
G82P1500Q025R017M69
M20
M22
/G04X1.0
/G82P1500Q030R020M69
/G04X2.0
/G82P1500Q040R025M69
/G04X2.0
/G82P1500Q050R030M69
/G04X3.0
/G82P1500Q060R035M69
/G04X3.0
/G82P1500Q070R030M69
/G04X4.0
/G82P1500Q080R040M69
/G04X4.0
/G82P1500Q085R040M69
/G04X6.0
/G82P1500Q100R048M69
/G04X7.0

( CUT )
G88P06M56
G87P13
G82P1500Q100R100M69F028
G04X0.5(dwell)
G64
M99
%

Your pierce isn't through the sheet. Do a pierce on some scrap with no leadin or cut and flip it over. There probably won't be a hole. Piercing 3/4 is going to be tough. I recommend trying to peck pierce, where you hit it with a sequence of short pulses between 10 and 60 hz at around 10-35% duty cycle. This will help with clearing the material less violently, but I expect it will take ten seconds or more to pierce just 1/2" this way.

On our laser 4kw laser we just embrace the flare up. It isn't enough to hurt anything in our case, as long as the head does not move before the pierce is complete. If it moves early, you get violent rooster tailing. We also use higher pressure during piercing to protect the lens, at the expense of a rougher pierce hole. To deal with the roughness of the hole edge that the cut will start at we use a leading a bit longer than the material is thick, and use a somewhat low leadin acceleration so it picks up the cut at low speed. This means that the leadin cut has considerable dross on the first bit due to low speed towards the start, which doesn't really matter.

If you have the option to change focus through programming on your head you can try starting a bit above the material, peck, go lower, peck, go lower, peck, and so on. We did not have much success with this approach but we did not focus on it much as we did not have extra material to play around with at the time, and continuous wave piercing was delivering more immediate results.

We did shoot compressed air at the sheet periodically to clear the piercing debris, as cutting with oxygen does not use enough pressure to keep the sheet clean like high pressure nitrogen will.

Also, even piercing thin material like 10 gauge we will always be at our full laser power, but with reduced duty cycle to get the average power we want.

In your case I would pierce at the full 2500 watts at 100% duty cycle with a larger nozzle gap (0.1"-0.2", as high as you can get away with), 4 times the gas pressure you would use for cutting, a nozzle a little bit on the small side but not by much (1.5-1.8mm for us, at 0.6 bar) and critically, as long of a delay as it takes to get the beam all of the way through the metal.

A key way to tell if your piercing is working:

material "exploding" out in a circle, typically not rising up very high- normal piercing

material shooting in one direction, opposite the leading direction, often going very high in the air- rooster tailing; you did not pierce all of the way through the sheet.

Strostkovy said:

Your pierce isn't through the sheet. Do a pierce on some scrap with no leadin or cut and flip it over. There probably won't be a hole. Piercing 3/4 is going to be tough. I recommend trying to peck pierce, where you hit it with a sequence of short pulses between 10 and 60 hz at around 10-35% duty cycle. This will help with clearing the material less violently, but I expect it will take ten seconds or more to pierce just 1/2" this way.

Click to expand...

Thanks for the feedback. thats alot to take in but im trying. one thing i forgot to mention was when my workplace got this laser used it didnt have proper conditions. previous owners did a lot of stainless work with nitrogen. where as we do a lot of normal A36 & A1011. so what we did to start off is took the conditions from our 1500 and copied them to our 2500. anyways, i am fairly certain that i am piercing all the way through, but it seems like it is making it so hot right there that when it does begin to move it throws material all over. i mean i could just make the pierce longer to make sure im through, Right? but it seems like way to much heat. what i was looking for was a way to cool it after the pierce. for example.. say there are 5 lines in the program to pierce and then i have a .5 second G04 Dwell. but when it dwells the beam of light is still being shot through the plate. how do i say i want it to dwell for like 1 or 2 seconds with no laser beam active, like close the shutter but have the oxy. still flow to cool then open shutter to start the lead in?

i am sorry if you cant understand what i am trying to say sometimes. like i said i am a newbie when it comes to machine work. never went to school for it or anything we were running short on workers so they said hey go shadow that guy and learn what hes doing because hes retiring in a month. i have learned ALOT in that month. but now he is gone and there is no one here that really knows how to do more than me... and i dont know much.... but id say i only know how to make it cut the material. i dont understand how everything works or how to fix little issues like im having. all the help is super appreciated! thanks again! is there a place i can find proper conditions specifically for this machine? and just FYI WE/I use striker for our layout thing. not sure the proper term..

trick30 said:

Thanks for the feedback. thats alot to take in but im trying. one thing i forgot to mention was when my workplace got this laser used it didnt have proper conditions. previous owners did a lot of stainless work with nitrogen. where as we do a lot of normal A36 & A1011. so what we did to start off is took the conditions from our 1500 and copied them to our 2500. anyways, i am fairly certain that i am piercing all the way through, but it seems like it is making it so hot right there that when it does begin to move it throws material all over. i mean i could just make the pierce longer to make sure im through, Right? but it seems like way to much heat. what i was looking for was a way to cool it after the pierce. for example.. say there are 5 lines in the program to pierce and then i have a .5 second G04 Dwell. but when it dwells the beam of light is still being shot through the plate. how do i say i want it to dwell for like 1 or 2 seconds with no laser beam active, like close the shutter but have the oxy. still flow to cool then open shutter to start the lead in?

i am sorry if you cant understand what i am trying to say sometimes. like i said i am a newbie when it comes to machine work. never went to school for it or anything we were running short on workers so they said hey go shadow that guy and learn what hes doing because hes retiring in a month. i have learned ALOT in that month. but now he is gone and there is no one here that really knows how to do more than me... and i dont know much.... but id say i only know how to make it cut the material. i dont understand how everything works or how to fix little issues like im having. all the help is super appreciated! thanks again! is there a place i can find proper conditions specifically for this machine? and just FYI WE/I use striker for our layout thing. not sure the proper term..

Click to expand...

On our laser piercing and leaving the beam on doesn't really add extra heat to the metal. I highly suggest you do a pierce without any cutting and flip over the piece and look at the back side.

If you can't flip the sheet hold a piece of paper under it for just a pierce. I still suspect you are actually piercing during the leadin. I'm not familiar with the machine but it's typically M3 for beam on and M5 for beam off. A picture of your cut and pierce conditions on the machine would be helpful.