Laser Cutter guide 2.0
The laser cutters have a working area of 1200x900 mm. You may cut up to 6mm thick materials - over 6mm we prefer you use the CNC Plexiglass/acrylic, plywood, HDF, MDF, wood, cardboard. Cloth can also be cut. You must ask a Technology Guru before cutting any plastic you are not 100% sure whether or not is plexiglass/acrylic - some plastics give off poisonous fumes or damage the machine.
It is required to have watched this safety video before using the lasers:
Do not leave the laser cutter while the machine is cutting, due to fire hazard. You can make agreements with other users to keep an eye on each others' cutting jobs, but leaving the laser unattended is dangerous and will result in immediate expulsion.
Keep fumes in the room to a minimum - do not open the lid immediately after cutting is finished. Instead, open it 2 cm and give the ventilation 10 seconds to suck the smoke out and slowly open the lid.
Throw away leftovers in the containers outside the basement door, as specified on signs. Leave only useful leftovers on the shelves. Do not leave materials anywhere else.
The workflow for laser cutting is in three steps.
- Draw a model in CorelDraw (or Inkscape, AutoCAD etc.), and
- Export the model to a DXF file.
- Import to RD-Works (the Lasercutting software) and Cut.
Below is a step by step guide describing the two last steps: How to get from an existing Vector file to a finished cut out model. If you want to learn how to draw your own vector files, come down to the lab!
Step 1: Export the model to a DXF file
Open your model from the menu: file -> åben (open)
It should look something like this:
Mark each shape in the model individually, and right click with the mouse on a color from the left column in the color menu, to give each shape individual colors. This will allow cutting out the different shapes in the prefered order.
It should look something like this:
Next step is to export the model. This is done by choosing export in the file menu. file -> export:
Now choose a name and a location for the file, and make sure the file type is DXF. Then press Export:
After creating your drawing, export it as .DXF on a memory stick.
Open RD-Works and import your file. Let’s assume it looks like this:
If you want to engrave some areas on your drawing and cut others, keep reading. If you only want to cut, you ca skip to step 7.
In this example, the eyes and mouth are to be engraved while the contour of the face will be cut through. Thus, they should be on different layers but by default, everything is on the same layer. Firstly, select all the shapes to be engraved and change their colour (bottom-left corner).
A new layer has just been created and can be seen on the top-right side, containing all light blue shapes. Double click on it to edit it.
In the new window, change the Processing Mode from “Cut” (default) to “Scan” (as in the picture above).
By each of the machines, there is a table with proper values for speed and power for all materials used by FabLab and looks like this:
We chose 4mm HDF for this project and the values for engraving are speed: 400 (mm/s) and power: 30 (%). These values can be inserted in the pop-up window from step 5 or on the right-hand site menu and can be adjusted for lighter or darker shades.
Note that the light-blue layer is labeled as “Scan” now and the areas enclosed by this layer’s shapes are filled. Do the same for all the others layers that will be engraved. For areas with different shades within the same drawing, create or assign them to layers with different settings.
Choose “Cut” and insert the appropriate values for power and speed (see picture at step 6) for all layers that will be cut through.
Note that “minPower” is the laser power on corners and “maxPower” means the intensity everywhere else. These values are listed but can be slightly adjusted if needed.
Get your material and check the thickness to make sure you are using the right settings in RD-Works. After, place it in the machine.
Adjust the distance between the laser head and the material (focal distance) by unscrewing the highlighted nut, sliding up or down the lens’ housing and using the nearby plastic spacers to get the correct space between laser and material. When you have the right distance, fasten the nut again (not too tight!)
Once the Laser cutter is powered on, you can download the file from PC to the laser cutter using the "download" option in the lower right corner. Press “OK” to all three pop-up windows that show up.
The software will fit the drawing in a virtual rectangle and the top-right corner will be marked with a green square. This is where the laser cutter will start from IF the position is set to “Current position” (right below “download” button).
By using the arrow keys on the front panel of the cutter, position the laser head where you want it to start on the material to be processed.
Press “Origin”. To check whether the drawing fits on the sheet, press “Frame”.
Place weights to ensure a constant level of the material and check the focal distance once more to avoid material waste.
Always make a small scale test in cardboard first! All variables can change with time and this is a chance to adjust the settings for best results with minimum waste.
The size of the drawing can be easily adjusted in RD-CAM in mm or %.
Before starting to job, make sure you know where the following are located and how to use them:
- Pause button (first action in case of fire) CO2 fire extinguisher
ONLY USE LAST STEP IN REAL EMERGENCY SITUATIONS:
- Foam fire extinguisher (this one will destroy the laser cutter).
As a rule of thumb, if a fire occurs, pause the machine. If the fire does not die out within 4-5 seconds, take the material out and put out the fire by “jumping” on it or using a fire extinguisher. After the fire is out notify the staff about the accident.
Press “Start” and enjoy the show!
Upon completing the job, clean: empty the laser cutter and the bottom tray. Turn off the machine. Place the pieces that can still be used back on the shelf and discard the remaining.
Thank you for keeping the space nice and tidy and have fun laser cutting!