K40 enhancements and modifications

There are a number of things that people have done to make their K40 lasers more usable, more convenient, and/or reliable.

Added Power Supply

The K40’s stock power supply is adequate, just barely, for K40 operations. If you add stuff on (like LED strips for viewing the lasing through the window while engraving, or for better visibility to set up stock to work on) it may cause issues because the power supply is just barely able to put out the power.

There is a cheap alternative that will let you add on many more electrical mods. I bought a Mean Well RT-85D power supply for US$25.79 from Jameco Electronics. This supply provides 24Vdc at 2A, 12Vdc at 1A, and 5Vdc at 6A. This is plenty to provide all of the +24V the K40 needs for its X-Y motors, vastly more +5V than it needs for the logic and controls, and also gives you 1A of 12V for anything else, like maybe those LED strips. It takes the 24V and 5V loading off the stock power supply entirely, and so the stock power supply is not running so near the edge of the power cliff. There are probably other 2- and 3-output power supplies that would do much the same. A 24V and 12V supply would do most of this, and maybe be cheaper.

Moveable bed / table

Several people have built DIY powered Z beds / tables. Some are only hooked up to buttons on the front panel, others are software-controlled. The M2nano board cannot support a software-controlled Z table. Some other controllers have an extra stepper driver or can use an external stepper driver to control height from software.

Rotary axis


Enhancement suggestions

@donkjr maintains a spreadsheet to help compare levels of machine, also suggesting classes of useful modifications and their relative value.

He has listed the following modifications and described their value:

  • Verify system and subsystems grounding
  • Interlocks for cabinet covers disables laser with user access
  • Laser coolant flow monitoring interlocks laser firing with water flow
  • Laser Cooling Pumping
  • Laser Cooling Pump
  • Vent cabinet for contaminated air removal and better cutting
  • Air assist blows air on cut line for better cutting
  • Moveable floor to change focus for various size objects
  • Rotary accessory to allow the marking of cylinders
  • Beam finder: LED added to the laser head
  • Cabinet lights adds better lighting to marking cutting area
  • High Capacity 24VDC supply for add on electronics
  • High Capacity 12VDC supply for add on electronics
  • Alternate Controller for Open source compatibility
  • Power fuses for better electronics protection
  • Upgraded pot and postion display
  • Upgraded optics
  • Remote control of air and cooling subsystems
  • Monitor laser tube temperature
  • An indicator that tells the user if interlocks are open

@funinthefalls is selling an upgraded “BeamBuddy” High Resolution Laser Head for Chinese laser engravers aimed at engraving (not cutting).

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