I have a question about engraving raster images with the J-Tech 2 watt laser and a Ramps 1.4 3D printer controller and the Repetier firmware (using this firmware is because I also still 3D print with the device).
I had purchased the 2 watt laser back on 2015 and I have hooked the laser to the fan control hardware connection - D9 on the Ramps 1.4 per the J-tech instructions for PWM of the laser.
The Arduino is using the Repetier firmware v0.91.
My question concerns the fact that I cannot seem to get decent raster images. I have no issues with vector images.
So I assume my problem is related somehow to the firmware control over the D9 circuit. I did a simple raster image consisting of 3 lines representing the 3 axis and I am seeing that the laser (while it seems to turn off in the Repeiter host), when crossing the empty space in-between the aprox. 45 degree line and the vertical line - still has some burning - as if the laser is not cycling off fast enough.
I also saw this in the Repetier firmware…
#define FAN_KICKSTART_TIME 200
Please note that I have tried lower feed rates (down to 1000) and lower power all with the same results.
Are there some instruction somewhere that you guys are aware of that addresses this issue?
Ok, I got it figured out with help from the JTech people/person (Thanks Jay). Repetier Firmware does not like to modulate the Fan output D9 at high enough Hz for PWM to work well for a laser.
Whereas Marlin Firmware does. Which means I have switched over to Marlin Firmware 1.1.6 on my Prusa i3 Clone.
My other choice was to hook up a Fan multiplexer circuit to another output on the Arduino and run it that way. Since I already have everything wired that seemed like a longer running choice.
Picture shows output from Repetier on left and Marlin on right.
No I did not- I decided to get a Eleksmaker A3 without laser and then move my JTech Laser diode that that platform. I am currently using GRBL 1.1f on that hardware platform.
I also have been using LaserGRBL on the EleksMaker with decent success. LaserWeb seems to be picky about browsers and sometimes I can’t get it to generate g-code even if I do the same steps that worked in a previous session.
For the Marlin software and the Prusa and JTech Laser, to generate g-code that worked using M106 and M107 Fan speed commands - I used either the Inkscape plugin from JTech with some of my code mods or I used the application 3dpBurnerGcode2, also with some of my code mods.
That worked well - but I decided I wanted a larger work area.
Let me know if you have any specific questions I can answer.
Thanks for the response, Scott. I’ve successfully used the JTech extension for Inkscape but I wanted a good raster software. I found LaserWeb through googling but I can’t seem to get it to work with my printer. I like how you can adjust the power levels very easily with LW. I was hoping to not have to switch my firmware because I’m afraid of messing it up somehow.
LaserWeb officialy supports Grbl (>1.1), Smoothieware, TinyG and MarlinKimbra.
Repetier and normal Marlin are not supported because they don’t allow to send the laser power in the G1-3 commands (S value), which we need for raster engraving.
