I was cutting acrylic the other day and, at first, all the cuts were fine. Gradually, the cuts started to fail. I looked at the temperature sensor for the laser tube and it read 44C! I took a look under the hood and saw water spraying on and around the laser tube and power supply. Before I could shut the machine down, the GFCI outlet the K40 is on tripped. Needless to say, I was pretty freaked-out about all this. I unplugged everything, opened the two top doors, put a fan on the whole mess and let it run for 24 hours. My first thought was the laser tube cracked. I gently removed the tube from its support brackets, removed the inlet and outlet hoses from this chiller:
and used a bicycle hand-push air pump to isolate the leak(s). Luckily, the glass tube wasn’t cracked. Instead, hose connections on the anode end were leaking. I replaced those with new tubing and used zip-ties to secure them. When I reconnected the water chiller, a new leak appeared on the cathode end of the tube. So…I replaced all the tubes on that end. That did the job and I replaced and re-aligned the laser to start cutting again. I’m sharing this experience with a recommendation that owners of K40 laser cutters, check their water hoses very carefully. For me, the original hoses were really easy to remove. When I trimmed the ends of the hoses, it was obvious they had stretched out quite a bit. Easy removal of the hoses could be a sign that they are about to fail.