The middle attempt you see was 65% max power, 400 speed. The left and right attempts were 65% power with the min power set to 0%, with 100 speed.
Details about the laser:
Chinese laser with a Ruida controller. (The kind you see everywhere with the blue/tan enclosure.)
50W max tube using a 40W power supply. I don’t think this is a problem? It doesn’t need full power to engrave. The old power supply stopped working, so we just replaced the power supply and tube with basically identical ones. This problem did just start after replacing them, though.
Just realigned the laser beam as well.
The laser is not connected directly to lightburn, so I’m unable to do any sort of modifications via the Lightburn console (like $32). I make .RD files and put them on the machine using a USB drive.
I’ve searched this forum and haven’t found any solutions that work. Any ideas of how to fix this burning during the scanning/travel moves? I can see it firing and burning during those moves and have no idea why!
A bit of history would help… did it just start doing this or is this a new machine/rotary?
The $ variables only apply to grbl machines, not a Ruida. They also have internal settings, but you have to access them via Edit → Machine settings in Lightburn. Before changing anything, save a copy in a couple of places as a factory fresh setting…
You are doing this as a scan operation, there is no use for a minimum power settings using this mode.
Never a good idea to under power devices…
How long is your tube, my 50W machine had an 880mm tube in it, not long enough to produce 50W.
Do you have a voltmeter? … you can check a few things to isolate the issue if you have one.
An 850mm tube can only produce about 40W, Power is a function of physical size. So you’re probably ok. Just realize it’s not a 50W machine, more likely <40w.
Mine was 880mm and produced 43W. Out of curiosity, where did you get the replacement?
The high voltage side of these is generally out of reach to most users.
Working with the control voltages out of the Ruida, so the highest voltage is 24, mostly in the ttl range 0 to 5V.
The output of the Ruida tells the lps (via the PWM or Analog control outpu) what the maximum current limit is and runs continuously while that layer is executing… When the head is where it needs to lase, it pulls the L input active or low.
I’d check the IN pin on the lps or it maybe more simple to read these right off the controller… most controllers are well labeled. Read the L-PWM1 voltage when the power is set to 20%, it should read 1V. 20% of 5V is 1V… at 70%, 3.5V
Off hand the only other thing I can think of is the lasers minimum power… however, you didn’t change this out, so I’d exclude it…
Thank you for the advice. I won’t be at the laser again until tomorrow, so I will check those settings tomorrow, and try to find those pins as well, then return to this thread. Thank you
Thanks for your patience. I was able to test again today. I’m unable to access the Machine Settings because the laser is not connected to a computer. However, I did test the voltages.
At 20% power, the voltmeter on the L-PWM1 read 0.9 volts the entire time it was cutting, including on travel moves. Though I don’t know if it had time to dip down because the travel moves were so fast. Is there a way to slow down the travel moves?
It is still burning slightly during travel moves.
I also tried cutting a square at 80% power. The voltage during the cut was 3.8V. During the travel move the voltage rose to 0.7V. And the voltage at the end of the cut took a second to die down, just like the laser beam. I saw it reading 0.8V for a split second while it was burning during its travel move back to the origin after cutting.
I think the voltage is dropping smoothly rather than dropping instantaneously.(Worth noting: I don’t know the response time of my voltmeter.)
