K40 Build: Part 1

I was looking for a laser cutter/engraver to enable me to add a little polish to some of my projects and add new capabilities.  When looking at capabilities I knew I wanted one with all options: air assist, power Z-axis (table), good DSP controller.  Looking at the machines that have all of this capability and the prices start around $3K.  I started looking for a cheaper alternative and, like many others, decided to start with the "cheap Chinese laser" K40.  I went into this fully aware of its shortcomings, and planned accordingly.  I bought one off of eBay for < $800 delivered. 

The most important part of this was to make sure it has a PWM capable power supply as I wanted to keep that.  If you are looking, make sure the PSU looks like the one available on the LightObject site or the ones that typically come with the newer K40 machines.

40W Laser PSU that comes with newer K40 laser machines

Perusing the various build sights I decided on a shopping spree at LightObject.com.  I got:

• DSP upgrade kit for D/K40 small machine
• Power table/bed for K40 small laser machine
• Mini 2 Phase 1.5A 1-axis Stepping Motor Driver to drive the power table
• 2412S DC-DC 12V (2watt) Isolated Power Module to drive a 12V fan

I then did a little shopping on Amazon to beef up the air extract and add some lighting:

• Ledwholesalers 16 Ft 5 Meter Under Cabinet Lighting NaturalWhite LED Flexible Ribbon 300 3528 Leds, 2026nw  to light the cabinet
• HitLights LED PCB Strip to Strip Connector, 2 Conductor, AnyAngle Turn, For SMD3528 LED Strip Lights (4 Pcs Pack) to connect the LEDs across the case corners
• Ledwholesalers 30 Watt LED Power Suppply Driver Transformer120 to 12 Volt DC Output, 3207 to power the LEDs
• Rule 240 Marine Bilge Blower (4-Inch, Inline) to beef up the air extract
• Sabrent AD-LCD12 LCD Monitors 12V 6A 72W AC Adapter PowerSupply to run the bilge blower
• Dundas Jafine FD420ZW Flexible White Vinyl Duct, 4-Inches by20-Feet to route to window vent

Then I hit up Home Depot for some venting accessories:

• Deflect-o Skinny Duct 4 in. Dryer Venting Duct for making a window vent
• 4” dryer clamps (4)
• 1/8” x 12” x 24” Plexiglas to replace god-awful orange one
• Watts 1/4 in. x .170 in. x 20 ft. PVC Tubing for the air assist

Then finally to Harbor Freight:

• 1/6 Horsepower, 58 PSI Oilless Airbrush Compressor for the air assist.

Plus various bits and pieces like heat shrink, proto board, metric screws, tacos, wire, more wire, cable ties, masking tape, bandages, spare lenses and mirrors, beer, you name it.  Needless to say, I was a little bit above $800 by now, but still well below the $3k mark.  If you look at this list you’ll notice I don’t have anything for water cooling.  Right now I’m using 4 gallons of distilled water in a Home Depot bucket but will be upgrading to a PC type water cooling solution.

As part of all of my research, I compiled a list of useful documents from people that have “been there, done that” with the K40.  I started with the install guide from Marco at the LightObject forums.  I also found a handy wiring diagram that made wiring up the DSP box a breeze.

Next up will be the unboxing and teardown.