The wtf-ridden chinese laser engraver/cutter adventure

Out of curiosity i bought one of those very cheaply built K40 china laser engravers/cutters from ebay. I knew that the machine will probably have terrible shortcomings, and i never expected the software coming with it to work. But it would be a nice project to tinker with.

Warning: I have CO2 laser protection gear. Your eyesight is at risk with this machines, so the first thing you should buy are good CO2 laser googles. be careful: those goggles with red glass that are sold on ebay are not laser safety goggles!

My machine arrived with multiple defects: laser tube broken, pulley of the y-axis broken, software not working.

there should be no water in the outer tube

20.000 volts arcing, yeah

The merchant told me they have no technician in germany, so they cant repair or diagnose anything, and i cannot return the machine as the shipping would be too expensive. So i did my best to get a very good deal for the broken machine:

bought for-600€
got back+400€
sold controller+100€
new lasertube-100€
 200€ spent, yay!

Safety problems

more than you can count. these machines are inherently unsafe and the ce sign on them is (obviously) fake.

Product problems

if you ignore the highly problematic safety problems it's still a shitty product. at least mine has a newer laser power supply, with digital power settings and not the older analog gauge (which is in-line with the 20kv anode, wtf)

Fixing it


Thats about it. Now it's working and i only invested 200€ plus a few evenings worth of awesome tinkering time. It's now a valuable tool for me, but i'm still cautious around it: invisible lasers beams at 40 watts are extremely dangerous.

electronics (mostly only an arduino and 2 stepper drivers)

warning label with hilarious spelling (and power panel with added emergency cut off)


If you are not comfortable with hardware reverse engineering or writing software don't buy these machines. they are cheap, unsafe, unreliable and will cause you grief and dispair.
Tags [ ]