Lasercutter@lab

overview page machines and technologies@our labs

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, acrylic glas.
• 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)

Step 1: Creating the Illustrator File

Create a new file with dimensions of 400 mm x 300 mm (this is the size of the laser bed) and with a RGB-profile.
Color the outline of the objects to be cut in RGB red:
R = 255; G = 0; B = 0



Set the outline thickness to 0.01 pt.
if you are using inkscape or coreldraw instead of illustrator, set the line for cutting as "hairline".

Step 2: Printer settings and thickness of material

Go to printer settings:
File > Print > Setup (Drucker VLS2.30DT) > Settings
Here you should see the graphical interface of the laser software for the first time.



Choose the right material from Material Database (in this case: Natural Materials > Wood > Medium Density Fiberboard). Enter the material thickness (here: 3mm). Than confirm by clicking: Apply > OK > Drucken > Drucken

To determine the thickness of your material, use the calipers (Messschieber).

Step 3: Universal Control Panel

Open up the software of the Laser Cutter (UCP).

Step 4: Activate/move laser

To activate the laser, click the On/Off-Symbol (top right-hand side of the user interface). The machine will start the homing process, wait till it is finished before opening the cover.
Upon activation, the object to cut will be automatically imported from Illustrator.



There are two more important buttons on the right-hand side of the user interface to be used frequently:

• Click the first one to move the laser to a specific point (1).
• The other allows you to reposition the object (the drawing) itself within the size of the laser bed and on the specific area of the material where you would like to cut or engrave (2).

This is particularly helpful if you are using scrap material and/or if you want to save material and space.

(1):


(2):

Step 5: Laser bed alignment

It is important to set the distance between material and laser properly. Follow these steps to adjust it correctly:

• Position the Material: Place the material on the laser bed. Check if the laser head is higher than the material itself for avoiding collision.
• Navigate the laser head to the position above the material where you would like to cut or in the middle of the surface.
• Use the Distance Tool: Retrieve the distance tool from the designated box next to the laser pc and place it on the material next to the laser head.
• Adjust the Laser Distance: Lift the protective plate above the laser head. Use the arrow keys on the machine (right hand side next to the machine cover) to slowly raise the laser bed until the laser aligns with the notch on the distance tool (The front panel of the laser head should be positioned directly above the indentation of the distance tool: see images below)
• Be careful to place the distance tool not directly under the laser head (danger of collision)!!
• Take out the distance tool and place it back into the designated box.
• Close the protective plate and the machine cover too.

Refer to the images below for visual guidance.

Step 6: Adjust settings

We need to change a few settings in the software before we can start laser cutting.



Go to > Settings. The window you see is identical to the one accessed via Illustrator’s print settings.

If the settings for the material or material thickness were not applied properly, enter them again and confirm with > Apply.



Do not close the window; instead, navigate to the > Manual Control tab. Select the red tab to adjust the Power, Speed, and PPI settings for laser cutting. As a general rule, it is advisable not to run the laser at 100% power. The appropriate settings vary depending on the material (and its thickness) as well as the specific project. Here's a good starting point for cutting 3mm MDF:
Power: 90%
Speed: 5.1%
PPI: 250
Confirm the entered values by clicking Set > Apply > OK.

Step 7: Switch on the fan

Always ensure the ventilation is turned on before starting the laser!

Step 8: Laser

You can start the laser process via the start-button of the user-interface.

Always stay with the machine during laser cutting and observe the process carefully and avoid looking into the laser directly. When the process is complete, switch off the ventilation and open the cover. Carefully remove the workpiece.

Step 9: Clean the laser

After each use, the laser module must be cleaned. To do this, loosen the small screw on the laser head. The cover will automatically detach from its mounting. Thoroughly clean the inside of the cover using pipe cleaners or moist wipes, then secure it back in place by tightening the screw.

If you are lasering a lot of MDF or other material which generates a lot of fumes, the mirror/ lenses have to be cleaned: Talk to us.

Step 10: Document your process

Finally, enter the selected settings into the provided notebook, along with a comment on the final result (e.g., “everything OK,” “didn’t cut through,” etc.).

This allows for a good documentation and helps others using the laser :-)

Don't hesitate to ask for support, if in doubt!

Useful Links/ Boxmakers

some first links for templates eg of boxes and boxmaker editors online see here