I am not new to CNC, but am new to laser. I've gutted my new machine and rebuilt it square (which it was anything but from the factory!) I've added an air assist, cable chain, replaced the mirrors and lens and head with better quality parts, built a motorized Z bed and changed to a Cohesion3d Laserboard controller. I've added cooling flow sensors and temp sensors.
My laser power supply is the type with (3) European style green plugs. (2) 4 position and (1) 6 position connector. When I got the laser new, I hit the power switch and watched smoke billow out. They plugged the 120v feed and the 24v and 5V plugs in to the wrong PSU outlets.
I received a "new" 40 watt power supply from the manufacturer and bought set of high voltage connectors (since the original PSU had the HV line directly wired to the tube).
The new setup works, but at full power, I can only get it to draw 8ma. The beam is consistent and it burns wood, vaporizes paint, etc, but it won't cut even the thinnest acrylic.
I've read that 15ma is the normal "upper" limit for these tubes and that most of these lasers will do 20+ma out of the box (albeit at a much reduced tube life).
My question is... do you think the new PSU is the problem? It almost looked like a used PSU when it arrived. The cooling fan in the supply makes all kinds of racket and it had scratches all over looking like it was pulled from something else.
Second question is... if I purchase a better quality power supply, is it OK to buy a larger supply (maybe for a 60 watt laser) and use it with the 40 watt tubs **as long as I limit the current to 15ma or so** ? Do the larger tubes run at a similar voltage while excited?
Assuming the consensus is my PSU is weak/bad, are there any suggestions on replacement brands?
K40 low current draw
Reply with Quote
