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Actuele versie: http://oud.fablabamersfoort.nl/en/book/open-control-laser-cutter

Open Control Laser Cutter

By jorisammerlaan. Last update on 30 Jan 2018.

Start

  1. Download the latest version of VisiCut: visicut.org/downloads (choose the top one from the list)
  2. At start-up choose Netherlands, Amersfoort: FabLab
Or go to Edit> Settings> Download recommended settings... and select it there.
 
You can also add the laser cutter separately: LAOSlaser machine instellingen.
You can also add the machine settings via a file: Add machine settings via file.

Preparation

Start with a digital design in a drawing program. For engraving you can make bitmap drawings, with eg PhotoShop or Gimp. Vector drawings enable use of all modes. You can create them with programs such as IllustratorInkScape or CorelDraw. You can also scan drawings that you can then make suitable for laser cutting.
 
If you do not have any software yourself, we recommend using Inkscape. This is easy to learn to use and open source.
Some tutorials for Inkscape: Basisgeavanceerdvormen.
 
Tip, if you want to cut out letters, it is useful to use stencil fonts.
 
By giving shapes different colors you can eventually use other options for these on the laser cutter. With the standard "mapping", the color red is cut, black and bitmaps are engraved and blue marks (cutting lighter). See Mapping for more info.
 
Be aware that the laser cutter requires about another 5cm on both sides of the design for engraved parts to allow the laser head to sweep. Therefore, you cannot use the full horizontal range of the machine in this mode.

Setting up the machine

Place the material under the laser cutter. The laser focuses its power at a certain point, however because the materials can vary in thickness, you have to focus the laser properly.
 
Large laser cutter

First you have to loosen the lower part of the laser head. This is done by loosening the larger, flat, copper nut, at the front of the head. To be able to adjust the height easily, we have a blue piece of transparent plexiglass plastic with adhesive tape. You have to place this between your material and the laser head (place the piece of plastic on the side, as on the picture), then you can "drop" the laser head and tighten it again. Make sure that the material is as flat as possible. Since we often use sheets of 50 cm by 30 cm, this just does not fit on the plate. It rises a half-mm to the right. If it needs to be really precise, then it is better to shorten the sheets 2 cm.
Kleine lasersnijder
 

By turning the large yellow wheel under the machine you can move the platform up or down. There must be about 6.9 cm between the material and the highest point. The easiest way is to use the blue sample piece.

Place the sample piece on the material and place the platform at such a height that the top of the plastic coincides with the upper metal plate at the top of the laser head:

VisiCut 

Open your file in VisiCut. VisiCut supports file formats such as svg, dxf, jpg, png etc. File formats such as ai, cdr, eps, pdf are not supported. You can also drag files into VisiCut.
Select the laser cutter you want to use under Lasercutter.
Behind File you can see the file you have selected. Here you can also add multiple files. 
More information about Visicut can be found on the official Visicut wiki.

1. Laser cutting a test pattern

It is useful to first laser cut a test, afor instance to find out which settings you need to get through the material.
Better results can usually be obtained simply by repeating the cutting task, rather than increasing the power or lowering the speed
 
Amongst the selection of examples in Visicut there is a square. 
  1. Open a test pattern: File> Examples> block.svg set the size to 5x5mm;
  2. Under Mapping, choose: Cut everything;
  3. Set the speed to 1 and the power between 20 and 80, lower power gives a better result;
  4. Click on Execute.
2. Mapping

Here you can determine how parts of the drawing are assigned to which profile. The profile determines what the laser cutter does. The standard profiles are:

  • Cut: meant to cut things out. (default: red)
  • Engrave: meant to engrave things. (default: black / bitmaps)
  • Mark: actually the same as engraving, but then somewhat shallower, meant to mark things. (default: blue)
The default mapping is "Cut red, engrave black and bitmaps, mark blue". Which of course means that the machine is going to cut out the parts in red, engrave the black parts and bitmaps, and mark the blue parts of the design.
There is an experimental mapping "Cut layer cut, engrave layer engrave, mark layer mark", which allows you to assign different profiles to differently named layers of your design. Use "cut", "engrave" or "mark". This does not always work.
You can also simply select "Cut everything" or "Engrave everything".
Be aware that in engraving the colour is also used to determine the intensity of the laser. This means black is completely engraved, but green is not, because green is less dark than black.

Advanced options:

  • If you want to do more complex things, you can also create a mapping under "map by single property", where you choose how drawing properties such as (fill / line) color, line thickness etc. are translated into profiles. Under Advanced mapping you have even more freedom. If you want to create more than 1 engraving or cut profile, because you need a different part of a drawing for a different intensity, you have to create an extra profile, this can be done via Edit> Settings> Manage laserprofiles.
  • In addition to the settings that you can fill in with laser settings, there are even more advanced settings. Because of the way this was programmed, these are only available with mapping. You can usually find this by clicking on the gear. This is only possible when you use a ... everything, Map by single property or Advanced mapping. Here you can eg settings in which resolution should be engraved, in which order things should be lasered and what Dithering algorithm should be used. You can adjust the defaults under Edit> Settings> Manage Laserprofiles. N.B. Our laser cutters only support the following resolutions: 100, 200, 300, 500, 600, 1000 or 1200 dpi (no intermediate values).
  • When engraving, the laser head must reach speed before it burns away material consistently, otherwise it burns deeper on the sides. To facilitate this you can increase the setting Additional space per grid line under Edit> Settings> Manager laser cutters ...> a specific laser cutter. 20mm appears to work well.

3. Position

You can drag and enlarge your drawing with the mouse, or you can enter this  information manually under the heading Position (the tab between Mapping and Laser Settings).

4. Laser Settings
Now you have to set which settings are used per profile. This encompases at least the power and speed. Here you can enter the settings that succeeded best with the test pattern. The best thing is always to find the fastest setting.
The settings:
  • power: how much of its power should the laser cutter use.
  • speed: at what fraction of its maximum speed should the laser cutter move.
  • engrave bottom up: Whether the laser cutter has to engrave the drawing from bottom to top.
  • engrave unidirectional: Whether the laser cutter should engrave only in one direction.
NB If you do not work on your own computer, it is a good idea to save your settings for yourself somewhere. But keep in mind that the laser tube slowly deteriorates and that there can be a lot of variation in material.
Example: cutting 4mm plywood (wood)
Use the values ​​of power = 39 and speed = 0.3 to cut the wood completely.
 
Advanced options:
By pressing the + you can give the laser cutter multiple operations per profile. For example that he has to cut twice.
In addition to these settings, there are even more advanced settings, see Mapping.
 

5. Execution

The big red button
At the top you see a big red button. If you want to stop the laser cutter while it is running, press it. The laser cutter then stops cutting. If it goes wrong, you can also use this button.
 
After pressing it, the button is locked, rotate the button to unlock it again. The laser cutter will reset itself.
 
Stay with it!
Do you use the laser cutter? Make sure there is someone there at all times! If the machine overheats, a fire may occur.
 
Start
Send your job to the laser cutter by pressing Execute in VisiCut. Now you can have the laser cutter do the job by pressing the blue joystick on the laser cutter.
 
Positioning using the camera
The camera can be used for positioning new jobs on an already used sheet of material, allowing re-use of uncut sections. Take a picture of the plate. The camera position is slightly out in relation to the cutting bed, by 3cm vertically (up), and 1.5cm horizontally to the left. Move the plate down 3 cm and 1.5 cm to the left in reference to the photo. See also attached picture.
 
 
5. Uitvoeren

De grote rode knop
Bovenop zie je een grote rode knop. Wanneer je tijdens het snijden de lasercutter wilt stoppen, druk deze dan in. De lasercutter stopt dan met snijden. Wanneer het mis gaat kun je deze knop ook gebruiken.

Na indrukken is de knop vergrendeld, roteer de knop om deze weer te ontgrendelen. De lasercutter zal zichzelf resetten.

Blijf erbij!
Gebruik je de lasercutter? Zorg dat er ten allen tijde iemand bij staat! Er kan brand ontstaan.

Start
Stuur je opdracht naar de lasercutter door op Execute te drukken. Nu kun je de lasersnijder de opdracht laten uitvoeren door op de blauwe joystick bij de lasersnijder te drukken. 

Positioneren met de camera

De camera kan goed worden gebruikt voor het positioneren op een reeds gebruikt werk zodat de niet gebruikte delen alsnog worden gebruikt. Maak een foto van de plaat. De camera zit er 3cm verticaal omhoog en 1,5 cm horizontaal naast. Plaats dus de plaat 3 cm omlaag en 1,5 cm naar links ten opzichte van de foto. Zie ook bijgaande foto.

Troubleshooting guide

I no longer see my design in visicut
Visicut gives a preview of what it is going to do. If your drawing, for example, consists of colors that the current "mapping" does not use, you will not see anything. If you only want to cut or engrave something you can also select Cut everything or Engrave Everything.

The job is not sent to the laser cutter
When the laser cutter gets an order for the first time, something goes wrong. Wait a moment until VisiCut says it is successful and then press Execute again.
 
The laser cutter does not respond
If the laser cutter does not react at all, even if you move the joystick you can restart it, for example by pressing the emergency button. Then turn this knob to unlock it. The laser cutter resets itself. Resend your file if necessary.
 
Resolution of ... is not supported
The laser cutter only supports a number of specific resolutions and no values ​​between them. Our (LAOS) laser cutter only supports: 100, 200, 300, 500, 600, 1000 or 1200 dpi. Issue to make this clearer in the interface: VisiCut issue #169
 
White or transparent colors are also engraved
With Greyscale shift, which can be set under a raster laser profile, you can set the brightness of what you want to engrave. If this is lower than 0, it will also engrave transparent and white. At the moment this is not clear to see, current issue about this: VisiCut issue #167.
 
Sending the order takes a long time
When an order is to be engraved, a lot of data has to be sent quickly, so this can be a reason.