K40 Laser Cutter

Chinesium K40 Laser Cutter

Location: Electronics Room Ownership: Mag Laboratory Status: Fully Working / Upgrades Pending Usage Restrictions: Laser Cutter Qualification
Laser Cutter
Brand: Chinesium Model: K40 Quality: Prosumer/Professional Cutting Area: 315 x 225 mm Materials: TODO

Getting Started

Welcome on your laser cutter journey. We at MAG Laboratory are proud to host the venerable and storied K40 laser cutter machine. As we should all know, each K40 machine is a unique snowflake upon this world not only because each factory K40 is manufactured differently but also because each K40 owner will apply different modifications to their machine.

Read at least the "General Use" section of the K40 user manual (link).

When following the example speeds and power levels given below, use Power (mA) over Power (%) when possible.

General Advice and Precautions

⚠ Always use the air assist.

⚠ Always operate with lid closed.

⚠ Do not let machine run without water cooling.

⚠ Do not place hand along laser path.

⚠ Ensure laser cooling water temperature is acceptable.

Software Support

The preferred file format is .svg. Inkscape (link) can be used to create and edit svg files it is under active development, so be sure to update your inkscape.

Materials

Recommended Materials

Material	Comment
Acrylic	Cuts well. Turns into combustion byproducts immediately!
MDF	Mostly turns into smoke. Ash may be an issue. Use air assist to clear the ash.
Laser Rubber	Ash may be an issue. Use air assist to clear as much ash as possible.
Acetal Plastic	Apparently works if the plastic has additives.
Leather	Cuts / Engraves.

Banned Materials

Material	Comment
PVC	Combustion byproducts are literally hydrochloric gas. Do not cut.

Feeds & Speeds

This section contains a sample of feeds and speeds gathered from various projects over the lifetime of the machine. Beware that different factors will affect cutting performance including but not limited to: machine age, air temperature, water temperature, and cutting location.

Brandon's 1/8" (3.2mm) Edge-Lit Acrylic

Feeds and Speeds:

Path Category	Feed	Power	№ Passes
Raster Engrave	100mm/s	8%	1
Vector Engrave	28mm/s	7%	1
Vector Cut	8mm/s	18%	1

Raster Settings

Setting	Value
Line Width	0.008 in
Engrave Bottom Up	✅
Halftone	✅
...	...

Acrylic orientation should be such that the raster engraving is vertical when the sign is placed on the LED base. The light reflects better inside the acrylic and provides more consistent lighting of the design in this manner. The axis of the acrylic that is facing up should be parallel to the raster lines to look the best.

Brandon's 3/16" (4.6mm) Edge-Lit Acrylic

The parameters for 3/16" acrylic are mostly the same as the 1/4" acrylic with the exception of the final vector cut from the mother sheet.

Additionally, current change compensation can be applied to this process because the laser current is now being recorded.

Path Category	Feed	Power (%)	Power (mA)	№ Passes
Vector Cut	5.9mm/s	18%	14 to 13.5mA	1

Brandon's Name Tag on 1/4" (6.4mm) MDF

The following section is written for cutting a name tag on 1/4" MDF. The whole name tag should be covered in blue tape to prevent the char from the laser from bleeding over the white paint.

Feeds and Speeds:

Path Category	Feed	Power (%)	Power (mA)	№ Passes
Raster Engrave	100mm/s	8%	N/M	1
Vector Cut	4.4mm/s	42%	17.9mA	2

Raster Settings

Setting	Value
Line Width	0.003 in
Engrave Bottom Up	✅
Halftone	✅
...	...

Brandon's Cork Coaster

The following section is written for cutting 90mm (diameter) x 5mm (thickness) coasters. Note that the coaster is not cut to size because it is precut into the final dimensions.

Feeds and Speeds:

Path Category	Feed	Power (%)	Power (mA)	№ Passes
Raster Engrave	100mm/s	7%	N/M	1

Raster Settings

Setting	Value
Line Width	0.003 in
Engrave Bottom Up	✅
Halftone	✅
...	...

History

The K40 is a complex machine with a history of previous activity. This section is where the laser cutter upgrade history is documented.

Gallery

• 

  Lid On

• 

  Interior (pre-air-assist)

• 

  Cutting Neoprene

• 

  Interior (with air-assist)

• 

  Cutting Assembly in the K40

• 

  CO2 Laser Tube

• 

  Laser Power Supply

• 

  Laser Cutter Control Boards

• 

  Laser Cutter Open

• 

  Interior (air assist)

• 

  Air Assist Pump

• 

  Water Temperature Thermometer

Aluminum Air Assist

2021-05-03 "Cloudray" aluminum air assist nozzle installed

Laser Tube

The laser tube was replaced after being broken from a loss of cooling incident on 2021-03-17.

Laser Path

The focusing mirror was broken on 2021-01-26 and subsequently replaced on 2021-02-01.

Air Assist Upgrades

https://www.maglaboratory.org/w/images/9/98/K40DragChainBracket.stl

File:K40DragChainBracket.stl

User:BLu added a drag chain for the air assist on 2021-01-24.

The air assist pump and PLA nozzle were installed on 2021-01-31.

Alignment

User:BLu first aligned the laser on 2020-12-24.

Acquisition

The K40 laser cutter was purchased by User:BLu on 2020-12-03 and arrived at MAG Laboratory on 2020-12-07.

Laser Guidance

2023-12 Two visible lasers are installed to denote the cutting location of the CO2 laser. The two lasers form a crosshair that marks the location where the CO2 laser beam should hit.

The files for the laser bracket with laser guidance can be found at https://github.com/blu006/blu_BOB_and_MISC/tree/main/2023/laser_bracket

The only vitamins are the existing M3 mounting screws that came with the k40, a square screw, and an M3 internal hex socket head bolt.

Future Upgrades

The K40 is due for many future upgrades including but not limited to:

• height adjustable table