A fool and his money

My laser cutter is a DC-K40III. It’s a budget Chinese machine available on eBay.

I chose the machine for its low cost, it’s half the price of any other new laser in the UK of similar spec.

Owning one of these is not for everyone:
  • It is missing important safety features
    • No lock on the lid to prevent opening the lid while running
    • No lid switch to cutoff the laser when the protective lid is lifted
    • The front panel is likely not earthed properly
    • No temperature sensor/cutoff for water coolant reservoir
    • Poor/non-existent seals in the casing (fire risk, smell of burning materials)
  • The control hardware and PC software are locked to a USB dongle
  • Both of the limit switches misfire causing the machine to grind
    • X is a microswitch with a loose arm
    • Y is an IR beam sensor which is poorly aligned
  • The PC software is Windows XP only
  • The PC software (and/or control hardware) cannot cope with complex designs and will randomly skip entire paths

  • It is mechanically good
  • It is optically good
  • It’s hackable - it’s just a CNC bed with a PWMable death-ray! What Could Possibly Go Wrong?
  • I’m not dead/blind yet

I’ve owned the machine for about 9 months. Today, it works well enough for everyday use.
I have spent less money than buying a better laser cutter. But, it’s still not as good and it’s taken a lot time to get to this point. If you want a general purpose laser cutter for hobby or home use and have no interest in fiddling with it - do not buy a DC-K40III.

That said, I can’t resist a bargain and I like a challenge.

I’ve run with the original control hardware, attempted (and ultimately failed) to replace it with an OSHW board. Currently, I’m using it with a “drop-in” semi-open control board - giving me a limited feature set, but good reliability.

I’ve added air assist (compressed air at the cutting point), joystick control and a laser crosshair for calibration.

This blog will record some my my experiences and projects with the laser.