How to Prevent "burn" marks when cutting paper

[Mitzi Pages]

Hi Carol, may I know if you have successfully found the correct setting in cutting your paper? Like you, I also have a 60w China laser. I am trying to cut a 230gsm paper and was able to cut through using 100 speed and 70% power. I searched in this thread and found out 70% power is just too much but if I make it lower, it just wouldn't cut through, instead it will just leave a burnt marking on the paper. I also contacted my supplier and asked about the frequency setting. Same with Vicky, I was told not to change the setting of 20000. I am using a 23mm focus lens. Any info will be greatly appreciated. For reference, here's a photo of the paper. image.jpg

[Mike Null]

Mitzi

Welcome to SMC.

I do not have the same type of laser but I lower the power and also lower the frequency. The power and speed settings depend on the thickness of the paper stock. Your best bet is to test several settings. Vary the frequency first to see the effect of that then vary the power, then the speed. You should be able to find an optimum setting for each type of paper.

[Robert Walters]

Carol,

Since you don't want to mess with PPI/PWM and may not even be able to on your machine,
Give this a try and see what happens:

Create a grid of 10x10 1/2" squares (no fill, hairline outline, red if need be to CUT), spaced about 1/4" apart.

Across the top (left to right) create ten text field numbered 10, 20...90, 100.
These will be your POWER percentages.

On the side (up and down), create any ten text fields numbered 10, 20...90, 100.
These will be your SPEED in percentages.

If you "speed" goes from 0-1000, just divide by ten, and anything below 100 make 10.
You can always change the scale later on.

For example, If speed is:
1000 = 100%
500 = 50%
<101 = 10%

Start in the middle of the grid (50 power/50 Speed) and see what you get.
Go half (let's say 30% power or speed, your choice) and see what you get again.
If that's worse, try the other direction (70%), etc.

By the time you get done cutting all 100 squares, you'll know which combination of speed/power will work best
as you have gone thru every possible combination from 10/10 to 100/100 speed/power combinations and everywhere in between.

[Mitzi Pages]

Thank you Mike! This forum has helped me a lot. Regarding the frequency, my Chinese laser seems to lack this feature. There is a frequency box but I was advised by my supplier not to change the setting of 20000.

[Mitzi Pages]

Hi Robert, I will give this a try as this might help me solve my problems as well. Thank you!

[Kev Williams]

we have our PAD power set at 80%/80% so that the tube isn't running at full power all the time

re: the 80%/80% setting on the pad-- and I'm basing this on my Triumph laser and the PHcad software that runs it (which I believe is very similar to Laserworks and Laser Cut)

My software has a "laser mode" setting, either "auto" or "manual". I'm sure Laserworks and Laser Cut has a similar setting.
--- when in AUTO mode, the power and speed settings the laser will use are those set in the software, and the pad settings are ignored. The pad will show the software settings while the laser is in use, then revert back to the pad settings when the laser is done...

--- when in MANUAL mode, the power and speed settings the laser will use are those on the laser's touchpad, and the software settings will be ignored.

Also, my pad has 2 power settings, "Power 1" and "Power 2" which can of course be set individually. The power setting I want can be chosen from the software. But again, the main software power settings will be ignored.

Finally, when firing and/or slewing the laser from the pad, the laser will use the pad settings, not the last settings sent by the software.

When in auto mode, the pad settings will not act as a 'laser limiter'. I have the 'power 1' on my pad set at 8%, so I can test fire without much burn. I don't even know what 'power 2' is set at!
----

Question about the paper cutting problem-- is the table being cut on solid or open (like honeycomb)?