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Laser isn't engraving properly

Posted: Tue Jun 24, 2014 6:58 pm
by Lightworks
I fitted a 60W laser to an old Universal Laser ULS-25PSR using the ULS controller. The ULS originally had a Synrad RF excited laser. I connected the PWM output of the controller to the laser power supply. The system cuts okay, but when I engrave I don't get a sharp edge in the X direction (scanning direction). Instead I get a ramp on both the start and the end of the engraving. See the attached image. I'm wondering if this is due to the laser turning on/off too slowly, or if it is due to the controller. Anyone have any idea?

Re: Laser isn't engraving properly

Posted: Fri Jul 04, 2014 1:09 pm
by wmgeorge
Lightworks wrote:I fitted a 60W laser to an old Universal Laser ULS-25PSR using the ULS controller. The ULS originally had a Synrad RF excited laser. I connected the PWM output of the controller to the laser power supply. The system cuts okay, but when I engrave I don't get a sharp edge in the X direction (scanning direction). Instead I get a ramp on both the start and the end of the engraving. See the attached image. I'm wondering if this is due to the laser turning on/off too slowly, or if it is due to the controller. Anyone have any idea?
So your using a controller meant for a RF tube on a CO2 tube? I am surprised it works at all especially using the OEM ULS controller. I am assuming its a new power supply for a CO2 tube. Did any documentation come with the setup software for the machine?
You might need to change out the controller for one of LightObjects 608 models.

Re: Laser isn't engraving properly

Posted: Mon Jul 14, 2014 11:48 am
by Lightworks
I bought a new power supply for the new laser. The power supply accepts PWM control, which the old ULS controller provides.

I looked at things this weekend with a 'scope. I had a small galvanometer based meter on the return ground of the laser to monitor current. Looking at the return line it showed that the laser is taking about 2mS to rise to full power. Also, on examining the actual engraving achieved it looks like while turning on the laser spot is far from focused well.

Will a controller made for this type of laser compensate for the incredibly long turn on time?