Hello , I am working with a prc

[racastil]

Hello ,

I am working with a prc laser 3500 watts and we are cutting carbon steel .500" thikcness and have melted material at the bottom we are using 7.5" focus lens how I can meassure focal distance? from the end nozzle to the middle of the lens or begining i new working with laser and I dont have any manual for setup.

Thanks

 

[JayMaechtlen]

One classic method to find focus is to make a series of cuts in thin sheet, and adjust focus to get the narrowest kerf.
We always assumed that point would be focus on the material surface.
Another method I used was to set the cutting nozzle so the beam was just 'kissing' the edge of a block of plexiglass. I made a quick burn, and I could see the beam waist burned into the side of the plastic.
Easy on some machines, not on others.
ymmv.

Jay Maechtlen

http://www.laserpubs.com/techcomm

 

[LaserDave]

To Racastil:

I have 2 PRC's mounted on NTC systems. I also was a service tech with them for 7 years, so I do have some info on PRC's.

Hybrid: 7.5 lens, 2mm nozzle, .060 mPa oxygen, +1.5mm focus, +1.5mm nozzle deflection, 2800 watts CW, 45 inches/min.

Flying optic: 7.5 lens, 2mm nozzle, .070 mPa oxygen, 1mm focus, +1mm deflection, 3200 watts CW, 50-55 inches/min.

I could go faster but it cuts so well that I am happy. Your parameters probably should be around those since your mode size in your PRC should be close too mine in both my systems.

 

[LaserDave]

Here is a sample pic from some 1/2 A514 that we cut all the time. A514 is even harder to cut than A36 Dcoil and this is with no clean up.