What did happen? Did it make no mark at all or did it burn through?

@3Ddave: it burnt through. I tested on .104” thick mild steel. If success then I will etch on 1/4” thick mild steel.

• https://files.engineering.com/getfile.aspx?folder=8a80cd73-21b8-4cae-9c26-3

Maybe the scan/feed rate is too low. Most times I've seen marking the laser is passing over the surface too rapidly to see.

That looks like a machine not intended to do engraving.

Not sure how applicable this could be - but if one were to interpose a slotted disk that rotated at a high speed in the laser path it could redirect the energy elsewhere and turn what looks like a continuous wave laser into a pulsed one. It could be put most anywhere. If the surface of the disk was not flat then the energy would be dispersed and more easily dissipated. Or if it is very flat, a highly cooled target could be used.

To clarify the options - the disk axis could be at 45 degrees to the beam, so the energy would be reflected at 90 degrees to the beam; also, any other angle is possible. The disk might be dropped into position only when required or mounted such that a detector would force the slot to align with the beam when the continuous output was required.

Engraving with a 4kW laser? You have a long road ahead of you. Systems like that are intended for cutting, not engraving.

Dan - Owner
http://www.Hi-TecDesigns.com

@MacGyverS2000: that’s what I told my supervisor but he insisted I should try. He contacted Mitsubishi and the guy over there told him to send the dxf file so he will code for us.

engrave with N2

Chris Krug http://krugtech.com/
Maximum Up-time, Minimum BS

i etch all the time with a 4kw laser but i do not use all the power

Make sure your marking condition has the right bits on for marking under ADD FUNC they should be 00101100

In your program make sure you select the condition you set up for etching. For example Condition 4

G0G40XxxYxx
M98P9008 (this is the etching program)
#501=104 (marking condition)
G1XxxYxx

As far as settings you can start with
Power: 300
Freq: 300
Duty: 30
Feed: 120
Gap: .125
Gas P: .8

@laserkatana: thanks

parameter with old co2 amada 3kw
speed mm/min 6000 (+/- 1000)
power 1000w ( i try under 500w but with bad result)
hz 1000-1200 (1000 more strong)
duty :
18 with oxigen
22-25 nitrogen
30-40 nitrogen strong
20-30 air
pres. 0.1-0.15 mpas (1-1.5 bar)
h.nozzle 2-2.4 mm
no edge power control.
ciao

@burex2: thanks

@laserkatana: I tried to etch on stainless steel (0.040” thickness). If I set the parameters as you suggested, the etching is too light. If I increased the power to 450W and speed 200ipm then the etching is ok as my boss wants. The problem is that the plate/part is warped due to the heat. I etched lot of small double-line letters. I think that I have to reduce the power to 350W later to see if it helps. Do you have any suggestion?

Increased the cutting speed then got what desired