2018 K40 still going strong

I’ve had my K40 buried in the garage for over a year but dug it out and fired it up and I was still able to cut through 3mm ply in a single pass at 12mm/s and 70% power. Used to use 65% but didn’t even bother to test and went for 70%. Still had half the discs across the full 12" x 9" surface not break all the way free so ran a 2nd pass at 20mm/s and disks dropped. The plywood wasn’t that flat but it’s to be a template for engraving 50mm diameter wooden tags for a STEM Day next weekend.

I should have looked at more than the water level before starting though. After engraving 200 discs the water temp hit 23C so I stopped and was going to get ice but when I looked into the plastic tub behind the laser there were mold spots on the inside of the lid and something floating on the water surface. Time to clean and replace the water.

Connected another hose to the circ pump and emptied into a 5gal HomeDepot bucket, poured in a half gal of clean distilled to flush/wash stuff down to the pump. Wiped down the sides and then filled with 3 gal of clear distilled. Connected the pump to the tube input and the tube exit hose went to the HomeDepot bucket and I pumped about a half gal or so through the tube and then added a 4th gal of water to the tank, 1 drop of Dawn dish soap and sealed it back up.

I think the copper tubing I have in the tank helps keep the algae and stuff down because the mold was only on the lid.

Still running stock tube and stock power supply. But I did offload the 24V to a separate PS and I’ve been running Smoothieware. I did have to rebuild one of the stepper motors when a bearing went. Otherwise it’s been plugging along for 6 years now.

[40W High Precision DC-KIII CO2 Laser Cutting En…]
Item ID: 162356328528
Quantity: 1
Estimated delivery: Wed. Mar. 14, 2018
Paid: $371.74 with PayPal



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I was also very happy with my old K40, so… it’s not just crap that comes from China, (after we modified it) :wink:


Mods on This Olde Laser which was the olde school “analog” ones with power level POT and mA meter:
Removed the small bed and clamp.
Cut down the exhaust intake by removing, angle grinder, reinstalled
Air assist( custom combo cone and nozzle ) and large aquarium pump.
Drag chain for air assist hose.
Smoothieware based controller to enable LightBurn use.
24V 5A external power supply for stepper motor drivers
Red dot laser and beam combiner for in-path red marking dot
Greenhouse blower mounted on roof near vent pipe and 3D printed adapter on back of the laser
Water flow indicator and water temp display