Gaps at aluminium engraving

1

Need help please. I have an N40630 laser, and try to engrave a morse sign on alu cards (see link at the end). A normal line works, but when there are spaces between the lines there are missing parts. On wood it works perfect! I’ve tried with constant power, but no luck. My only think that the power of laser doesn’t goes quick enough high…
How it should look:

WoodIsGood
WoodIsGood512×683 116 KB

How it is on alu: BadMorse
Normal line on alu:
LineIsGood
LineIsGood198×952 178 KB

Gcode of the morse line:

 LightBurn 0.9.21
; GRBL device profile, current position
; Bounds: X-0 Y0 to X76 Y0
G00 G17 G40 G21 G54
G91
M4
; Cut @ 300 mm/min, 80% power
M8
G0X-0Y0
; Layer C00
G1X10S800F300
G0X1Y0
; Layer C00
G1X10
G0X1Y0
; Layer C00
G1X10
G0X1Y0
; Layer C00
G1X10
G0X1Y0
; Layer C00
G1X10
G0X1Y0
; Layer C00
G1X10
G0X1Y0
; Layer C00
G1X10
M9
G1S0
M5
; return to starting pos
G0 X-76Y0
M2

Cards

2

It should be related to the material

3

I’ve got 50 cards. None of it works with 300mm/m and 80%. A friend of me with the same card engraved successfully with A40640 with 1000mm/min and 80%. So I don’t think it’s material related.

4

Yours is N40630, the laser power is half that of A40640

5

That’s because, I’ve tried with 30% of speed.

6

You can continue to increase the laser power and test it

7

Tried, also with 100% with 6mm/m. No luck. My friend gonna try with 40% and 300 , and I come back to you. Thanks for the replies!

8

There are the results with A40640. (left side speed, right side power)

unnamed (3)
unnamed (3)1243×932 179 KB

unnamed
unnamed1600×1200 239 KB

9

Are aluminum sheets straight?

10

Yes, they are

11

There is a high probability that the material will behave inconsistently after being heated.