Laser not cutting at direction changes


I recently complete a 60w DIY laser built. I am running a Ruida RDC6445G. The laser is performing great over all but I am having an issue with the laser completely cutting thru my material just in the corners (any direction changes) .

This is my second laser and I have been thru lense alignment multiple times and everything checks out. I am cutting fabric similar to what you’d find in backpacks, nothing very thick.
If you were to cut out a square, each corner would be hanging on by a thread. Same on a star shape on each point. If you cut out a circle there will be one thread hanging on at the start/stop of your cut.
Measuring the cut items shows that they are exact to size. It seems almost like the laser stops firing for a split second at every point of direction change . I thought maybe I was running my speed to high so I slowed it down by half and have the same result.
I image it’s a setting in my Controller and not something in Lightburn? This happens if I draw my pattern in Inkscape or Lightburn. Any suggestions?

It is actually both. If I am understanding you, this is an issue with a setting in the controller known as ‘Start Speed’ or corner speed, which defaults to 10mm/sec. At that speed, power starts ramping up from the Min Power to Max Power. Cutting at or below that speed means you’re using Min Power only, so if you’re cutting slow, set both Min and Max power the same and you’ll have no issues.


What are you “max” and “min” power settings?
Max power is used when the laser can keep up with whatever speed you set.
When the laser slows down to navigate a corner, the laser power is ramped down to min power to compensate for the reduced speed. It sounds like you min power is too low if it’s not cutting fully in corners.

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Thank you. Looks like that was my issue. I don’t have to worry about burning corners with what I am cutting. I also set the Start Speed on my controller to 5mm/s. If I am understanding correctly that means that my laser should ramp up sooner if I fail to set the low power in Lightburn?

Appreciate the help.

Thank you! Something that was all set to zero since this was a fresh additional to Lightburn next to my smaller laser’s Gcode controller that has all that worked out. I never could run my lil laser this fast and it never was an issue. Much appreciated.

If your tube can fire at that setting, yes. Setting below the fire-point can cause issues when your job is set correctly in software as well.

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