Makers' Alliance Wiki

Current Status: Sort of operational (It's a K40…)

Specifications:

• Power output: 40 W (theoretically, anyway)
• Cutting area: roughly 12“ x 9”, Cuts 1/8“ material well, thicker could be problematic. Might need multiple passes, etc.
• Coolant: currently a mix of distilled water and a few drops of algicide.
• Exhaust: Fume extraction via a BOFA AD-Access fume extractor/filter

Fixes/Upgrades implemented:

• There is a somewhat goofy spring-loaded material holding mechanism installed. Theoretically, it will keep materials at the right focal distance from the lens.
• Jumpered water break detection since detector is seemingly NFG.
  • Test again with new coolant pump to make sure it wasn't just low flow?
  • Tested again. Maybe backwards? Maybe NFG.
• Air Assist was installed. Air assist pump should be much less rattly than it was before (attached to cart with some neoprene between the cart & pump)
• Lens got cracked and was replaced.

Fix needed:

• need to replace K+/K- cable. We should have a pile of the correct kind in the through-hole connector bin (hooked up to thermistors, but one can be sacrificed for this)
• Figure out proper solution to water break sensor (a: try better pump? b: replace sensor?)

Laser does work.

Software: MeerK40t is what we've been using lately, though it has trouble parsing certain SVG files in the past. It's also installed on the Lenovo computer above the SLA printers, which is normally plugged into the laser. K40 Whisperer has also been good in the past.

Usage: It's not ready for random production jobs yet, so DON'T USE IT WITHOUT PERMISSION. We're getting there…

• How to format your SVG drawings for K40 Whisperer/MeerK40t: https://www.youtube.com/watch?reload=9&v=9wYvbenigtk
• Basic concept- using K40W, move the head over the upper left hand part of your work. maybe use the “laser test” button to make sure you're actually over the work. and then choose whichever of your engrave/cut options (do engraves first, and cut last).
• Specialized documentation: HOWTO Inkscape for the Laser

Safety considerations: https://techbravo.net/hosting/knowledgebase/4191/CO2-Laser-Engraver-Safety.html

• NO ABS - Cyanide gas is bad for you!
• NO PVC OR VINYL-BASED MATERIALS - Chlorine gas is bad for you!
• Wood and Acrylic are OK.
• ATX Hackerspace has a recommended list of materials here- don't consider it gospel just yet, but a series of recommendations.

Power levels:

• Wood (engraving) - 8% does a fine job on the random wood pieces we've tested with.
• wood (cutting) - 11% was sufficient to cut 3mm baltic birch plywood?
• Acrylic - 25% was great for engraving, but slightly insufficient for cutting (the cut edges did snap off easily, though). 33-35% should be good for cutting at 10mm/s.

(these numbers should be revisited)

Upgrades to consider in the near term:

• A better material holding mechanism.
• Thermometer & flow meter for cooling pump (i.e. https://www.amazon.com/Thermometer-Cooling-Liquid-Cooler-System/dp/B074SDFW51/ref=sr_1_3?s=electronics&ie=UTF8&qid=1521656040&sr=8-3&keywords=LED+Thermometer+3+Way+Flow+Meter+FlowMeter+For+Water+Cooling+Liquid+Cooler+System) ordered, but not installed?
• Better coolant flow detector? The one it came with is either non-functional, or our pump isn't pumping hard enough. Flow meter definitely needed
• E-Stop button (do we have one on hand?)
• Smoke detector/CO detector nearby?

Upgrades to consider eventually?:

• improved controller board (Smoothie? DSP?)

Documentation dump:

• Information about the power supplies used in these: https://www.everythinglasers.com/forums/topic/power-supply-info/
• more power supply info: http://donsthings.blogspot.com/2016/06/k40-s-laser-power-control-interface.html
• Person who has done tons of mods: https://techbravo.net/k40/