Lasercutter@lab

overview page machines and technologies@lab

Working with the lasercutter

Technology

Laser cutting is a digital manufacturing technology that works with 2D vector files. Our cutting device is a CO2 laser, 30 watts, which works with a gas mixture. The cutting process begins when energy is supplied to the mixture, which is then passed through various mirror lenses that focus the laser.

The laser beam is directed through a nozzle directly onto the material due to the arrangement of the mirrors. When it comes into contact with the surface, it vaporizes the material following the drawing lines of the vector file. The part of the material that is melted by the laser is called the kerf and must be taken into account in the design.

Main aspects of lasercutting at our machine VLS2.30

The Lasercutter VLS2.30 can only be operated after an introduction.

If interested please write an email to Karin: lingnau@khm.de

Coming back for the first time after the introduction please make another appointment, for discussing the project and possible support.

Anytime: If you have any questions, e.g. about material selection or settings, even after the introduction, ask again!

Main interface and machine specifications

Datei:VLS230 main info www.pdf

Material size

max. 40,5 cm x 30,5 cm

Material

• Important: PVC or materials containing PVC are not allowed! PVC is generating toxic gases!
• Grey cardboard or other sooty cardboard should also be avoided.
• Unknown composition of a material or object can be discussed, but are not permitted to be used just like that.
• For tests/models/mockups basic materials and rest material can be used: simple paper cardboard, MDF, paper in general, thin wood, ... later on acrylic glass, ...(for first tests some material is available).
• A detailed material list will be compiled later.

Parameters

The material database of the lasercutter uses different parameters to create cuts or engravings: The most important ones are:
POWER and SPEED.
They can be set as a percentage between 0 and 100%.
The POWER laser parameter describes the output power of the laser. 100% is maximum power. High power is generally needed for example for dark wood engravings or stamp engravings. Low values are used for materials such as paper.

The SPEED laser parameter describes the speed of the laser head movement. Fast speeds lead to short exposure times, slow speeds lead to long exposure times. Large-scale engravings are most often engraved at high speeds between 80 and 100%, photo engravings with lots of detail e.g. on wood, the set speed should not exceed 10%. In most of the cases a speed setting of 90% is sufficient.
The different settings affect the quality and the appearance of the laser cut. Note that cutting and engraving speeds are not comparable. Basically, cutting is slower than engraving. A "high" cutting speed is 10%.

For testing the right parameters for engraving a gray scale test pattern should be lasered, for testing cutting depths and overall outcome of cuts a test pattern e.g. with lines should be lasered before using the final size and layout. (Example templates will follow)

File formats

• Formats of vector programs (*.ai, *.dwg, *.svg...) --> or prepare a *.pdf --> to open or to import into the programs on the PC
• Illustrator (*.ai), and Inkscape are installed on the computer. CorelDraw (*.cdr) and other Vector formats can be imported.
• The lasercutter is instructed via a driver software and interface on the PC, like a "printer driver".

Some notes and tipps

• Remove double lines in the file or overlaying forms (white is not registered).
• Pay attention to the correct line thickness, e.g. red/cut = 0.01 for Illustrator/Inkscape or hairline for CorelDraw = thinnest possible line.
• RGB red = cut, RGB black = etch/engrave, RGB blue = mark/scribe

• Carry out or check dimensions and alignment of the work piece with closed lid (laser adjustment is moved slightly forward at the top edge when lid is open).

Cleaning

A "small" cleaning is performed after each user change, so that the next user finds a clean workplace and can immediately start working with the laser cutter.

• Clean nozzle inside/outside with paper towel and cotton swabs
• Clean laser cutter from the inside/outside with a soft cloth
• in case of small parts: clean the inside of the machine with the hand vacuum cleaner

A larger cleaning is performed when there have been many work passes, a lot of material has been lasered or a lot of smoke has been produced. Also at regular intervals by arrangement.

• Remove the material table in the laser cutter, clean it and empty the material residues (use the big vacuum cleaner, for pieces lying on top use the hand vacuum cleaner)
• also check for smaller pieces and dust/powder residues in the machine itself

The cleaning serves the general clean and secure usability of the device, avoidance of fire hazard and destruction of the lens by strong smoke development or material remainders in the device.

• Only after consultation: Remove and check lenses, clean with cleaning fluid and cotton swabs if necessary.

Thank you!

Laser process (cutting/engraving), in brief

• have the material cut to workspace size beforehand
• copy file to desktop, remove USB stick from PC!
• prepare laser files (different procedures depending on the software, more information after consultation or later here on the wiki)
• adjust lasercutter settings for the corresponding material:
  • Measure material thickness
  • set Z-axis at the machine (move the cutting board/work surface with the up/down arrows on the right side of the machine)
  • check the settings in the laser cutter driver for speed and power and right dimensions of the material.
  • Set special features if necessary
• start the fume extractor
• then start the machine and the process in the driver interface on the PC
• cut/engrave material under observation(!). Do not leave during the process!
• clean the laser cutter afterwards

• enter date, name, material, comments... in the list
• if a material has not yet been lasered or has been lasered with new settings, leave a material sample with corresponding setting values.
• ask for support or if in doubt!