Why do i get a filled background?


When i try to do my letters with fill mode set, i get the background engraved as well, it is fine when doing lines.
Any suggestions why this happening?

When doing filled shapes, the system uses all G1 moves and just varies the power value, using G1 S0 moves to do the white areas, so if your minimum PWM value in the config is not actually “off” for the laser, you’ll get this.

ok, so how do i get it “off”?

In the config.txt file on your Smoothieboard’s SD card there should be a line that starts with:


You’ll have to experiment with lower values for that, assuming that it’s not zero as is. The number will likely be around 0.02, just as a guess - it could be higher or lower than that where the beam actually turns off, and you want to be just barely on the side where it actually stops firing.

These are the settings i can see via notepad.

As this is a second hand machine and i am absolutely ignorant on these things my next stupid question is how do i change this on the sd card?

Laser module configuration

laser_module_enable true # Whether to activate the laser module at all. All configuration is
# ignored if false.
laser_module_pin 2.4 # this pin will be PWMed to control the laser. Only P2.0 - P2.5, P1.18, P1.20, P1.21, P1.23, P1.24, P1.26, P3.25, P3.26
# can be used since laser requires hardware PWM
laser_module_maximum_power 1.0 # this is the maximum duty cycle that will be applied to the laser
laser_module_minimum_power 0.1 # This is a value just below the minimum duty cycle that keeps the laser
# active without actually burning.
laser_module_default_power 0.8 # This is the default laser power that will be used for cuts if a power has not been specified. The value is a scale between
# the maximum and minimum power levels specified above
laser_module_pwm_period 200 # this sets the pwm frequency as the period in microseconds

Just change the laser_module_minumim_powwr value from 0.1 to 0.02 as a starting guess using any text editor, like notepad, and save it back to the SD card. Don’t change anything else (and it doesn’t hurt to save a copy somewhere in case you need to put it back later).

If the 0.02 number works, I’d try going a little higher, like 0.03 or 0.025 until you find the spot where it starts to burn again, then back off.

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.