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Laser-Cutting at the FabLab Munich


Laser cutting at the FabLab Munich. Hi everybody! Today we spend some time in a different workshop for a change. I am here at the FabLab Munich. This fellow here is Peter, who is a member of the FabLab and he is going to show you a few things about laser cutting. First question: What is the FabLab and what can we do and see here? The FabLab is basically a club, but there is also a special philosophy connected to it. The FabLab club here in Munich was founded in 2010 and was the second FabLab in Germany at the time. The basic philosophy of the FabLab is “make, learn, share”. This means that while you work on your projects here you also learn something on the go and share that knowledge with others. This is the reason why we are here today, because i want to share my knowledge about that. When i came here for the first time a few years ago i was mainly curious about the 3D printing technology. I did not know much about the FabLab before. I was standing in this workshop and felt like a child at Christmas Day and knew right away that i want to participate in this.Very quickly i discovered the laser-cutting technology here. Initially i was also interested in milling when i retired from work and almost bought a CNC milling machine in order to mill my own parts for the scale modelling hobby. That did not happen, because i realized that it is much easier to master the laser-cutting method for my purposes. One can create amazing things with the laser and thats what i want to show you today. What is this all about? There are a few things i want to show you for the start, so you know what i do with the laser and maybe it sparks your interest. I use the laser for scale modelling, so i can build an entire model from scratch. This is a truck trailer i have produced, using actual data of the real thing. Thats what i am working on right now. So this is your scratch building project? But you don´t do it the classic scratch building way with plastic sheet, instead you use different materials and the laser cutter as a tool. Exactly. That is the only difference here. All of this is about scratch building really. The materials might be a bit different, but we get to that later. One thing for the start: Most people come up with an idea for a scratch building project and start with the drawings. I used to do it this way as well in the past. However, if we plan to use the laser we need to think it through first. Okay, so i have an idea. Next i have to think of the tools i want to use. If we use the classic approach for scratch building, with some plastic card like you said, i just need enough plastic sheet, a tool for cutting it, a ruler and a good drawing. Thats how one would normally do that. It is not as complex as the approach i have chosen. If i decide to use a different tool, let´s say a laser, then there is a necessity to think about the material i want to use. Different materials require different procedures and all of that affects the result. When the material has been chosen, i will talk about the materials in more detail soon, i can come up with a conecpt to build the thing i have in mind. When that is out of the way i can actually plan the process. There we think of how many parts we need for our object we want to build. Do we need only one material or several? For example, my trailer is mostly made out of Bristol cardboard, the carriage and wheels will be made out of resin. The axle mountings will be made out of milled polystyrene. Photo-etched parts will be required for the tail light mounts. Some struts towards the front will be done with polystyrene rods. This leads us to the layout of the drawings and how it all gets arranged in a reasonable way, and only then i can go to the last step, which is the production. The material i usually use is Bristol cardboard. It is very rigid. It is often used for strong business cards, boxes and has applications for architecture models. The reason for its relative rigidness are its three layers. It has a top layer, a bottom layer and a lightweight fibre layer in between. All of these layers are glued together and create a fairly rigid cardboard sheet. I have here 0.1mm and 0.7mm thick material. There is also 0.5mm, 0.35mm and 0.18mm material out there. This means that i can use this material for a lot of different things. It also allows me to get fairly close to in-scale thicknesses of the parts. One thing i have noticed when i hold the sheets is the fact that it feels almost exactly like a plastic sheet. The cardboard has indeed a very even surface. Because of that it is sometimes used as a canvass for airbrushed pictures and drawings. Maybe not for the most fancy ones, but it is stable enough to work with it. However, one can use very different materials for laser-cutting besides cardboard. In this little box here i have a few examples. This is acrylic glass with a reflecting side. It looks just like a glass mirror, but it is made out of acryl and can therefore be cut with a laser. What a lot of people like to use is core-board, or the most popular material MDF or HDF. On YouTube you can find a lot of people who work a lot with this stuff and create amazing things with it. However, for my own purposes it is to thick and coarse, so i can not use it for my model. It is very strong, though. Just to show you a few more examples, i have here a few types of felt. I don´t have any use for it, but one can create amazing things with these and the laser. More suitable for my purpose is thick acrylic sheet, all white and feels like plastic. This leads us to the question a lot of people have: Why don´t you use polystyrene? Polystyrene can not be laser-cut with the same precission as cardboard. Let me show an example. This is a grille, made out of 0.5mm thick Bristol cardboard. I cut out all these little holes there with the laser. The precission of the laser allows us to create highly delicate parts. What you see here is a shroud i made the same way, normally one would use photo-etched parts for that. This is a shroud for a 1/24 scale truck model. This is the amount of precission i can get with the Bristol cardboard, this is not possible with polystyrene. What is the problem with polystyrene? Does it melt away or is there something wrong with its internal structure? It is melting very quickly. It just melts away. You end up with round and molten edges and that is the opposite of what i want to achieve. I need fine and precise cuts. Now i want to back and tell you how it all came together for me. I had the idea to build a certain type of truck trailer. I started with a PDF file of the company. These days it is not that easy to find such files anymore, the companies became more reluctant about that, but if you collected them over the course of some years you have all the data you need. This is the original drawing of the company and i scribed it into a sheet of Bristol cardboard with the laser. This leads us to the three main procedures that are important for me: I can cut, the results of that i have shown you earlier, i can scribe, which is basically cutting, but with less power, so i don´t cut all the way through the cardboard, and finally it is possible to engrave something. Since we are already talking about engraving, this label here got engraved. We talk about that more in detail later. So, i made the decission back then to use a laser, the material is the Bristol cardboard, the concept was to think about the material and how to use it, the planning was about the individual parts and different materials and finally i ended up with a drawing, which looked a bit like this. The next thing i want to show you are the results you get when you engrave the material. Up to know we only talked about cutting. The quality i get by engraving is so much better than anything i could do with milling. I need a deck for my trailer. There are two possibilities for this. The real trailer comes in two variants, one is a combination of wood and a metal frame. The frame is made out of steel, the deck is covered with wood. The second version features an aluminium deck, which is riveted on to the frame. What you see here are my first test pieces. This made me curious about all the engraving part of it, so i got into it quite a bit. This led to a second field of interest for me, which is building a diorama. Some years ago i had the idea to use a cardboard kit of a warehouse to build a 1/24 scale diorama. The brick wall of the kit did not look very good due to the lacking texture. It was very obvious and annoying, because there were no gaps between the bricks. It was not good. I decided to put it aside and i did not pursue that any further. Recently i had the idea to use photos as a basis for engraving textures into the cardboard. This showed me that i end up with a really nice brick wall texture when i engrave the brick wall texture. This sample here got painted with a white primer, just as a start for further experiments with paints. So i picked that idea up again. This is the engraved warehouse wall for my diorama as it stands right now. This is the gate of the delivery zone, with a window and two doors cut out of the wall. As you might now, when you start with something it is hard to stop again. I took this a few steps further and tried to replicate other textures, mainly using photos to aid the process of engraving the photos into the material. Here i did a wooden floor or wall section. It looks and even feels very realistic. Here i have a damaged concrete road section. It is rough enough. Here i have weathered doors and wall sections of old buildings, which look very realistic to me. You can see them up close now. All of that is fun, but it kept me away from my trailer project for a while. The time i have spent on that is not gone, but it is missing for the work on the trailer. One side note for you right now, but i guess we will touch on that towards the end again: Michael has mentioned a few models shows, where we are going to exhibit our work. If you want to see and touch these parts in real life you should go to the shows in Ried, in Lingen or our own PMVA club show in Augsburg/Haunstetten. I will bring along all of that stuff there. Of course i will be open for discussions with you there as well. Let´s get to the software part now. What is typical for most laser-cutters out there is the compatibility with the drawing software “Corel Draw”. You can also use the version “Corel Draw Home & Student”, which is way less expensive. Thats what we work with to draw our parts. The laser is implementing everything we draw there into cutting, scribing and engraving, depending on our drawing. What is good about Corel Draw is its compatibility with the ordinary printer drivers that are out there, which are also used for laser-cutters. We have two of these machines here, one is called “Zing” and the other “Trotec Speedy”. It works just like any laser or ink jet printer you know, the software operates the same way. What you see here is the Corel Draw work space. Of course we always start with an empty screen. There is a prepared test drawing. This here is a really relevant point. I had to learn this the hard way. What you see here is my main drawing in the A0 format. I used to draw each section individually, but i ended up with huge problems in the chain dimensions. What i do now is having only one complete drawing with all the parts in it. The individual parts i want to cut with the laser get deduced from that and copied into separate drawing layouts. These drawings are the pre-stage of the actual cutting process. When we move on to engraving it looks like this. You might recall these images from the laser engraved parts i have shown you earlier. These photos serve as the imput data for the laser, so it can engrave the material. As i said, you have seen these two doors perviously in detail, thats how they started out on the computer screen, before they got sent over to the laser.
This finishes the input section. Up to now we have talked a lot about the planning procedures, drawings and the general background, so it is time to move on to the machines and the production. I mentioned before that we can use two machines here. The big one on the right is my favourite one. I mostly use that one. It has a big working surface (80cm x 50cm) and a lot of power, 120 Watt to be precise. The smaller machine at the back, called Zing, is not equally good. It only has 40 Watt of power. The working space is maybe just two thirds of the big one. The big one is called Speedy, a Trotec Speedy 360. The next things are shown on that machine. One or the other of you guys might want to have such a machine at home now. However, i would like to warn you about this: Don´t buy any of that Chinese junk you can get for 300€ at Amazon or Ali Baba. They are usually called “laser engravers”. These small machines have no safety features at all. If you care for your health better don´t touch them. There are two hazards: These machines have no screening against the laser beam. You will see later how the laser is burning the cardboard, but it can harm you severly as well, despite the lower energy, if the laser beam gets deflected and protrudes outside the machine. You can injure your eyes or other things due to a sudden reflection. This is a thing that can not happen with proper machines, because they have several safety features. The second threat is the absence of offtakes. When you laser-cut something you burn material. Everybody, who has some idea what that means, will understand that burnt residue is not welcomed by your lungs. It can cause severe problems. A laser-cutting machine without a proper offtake is diabolic in my opinion. What is somewhat acceptable are the offtakes of slightly more expensive cutters, which have at least an extractor hose, where you can blow the fumes outside your window. There is no filter connected to them, which should be the case though. As long as you can make sure that neither you or somebody else is exposed to these fumes you extract this way it is alright, but please, keep in mind that safety is the highest priority. Now we can start with the prodution. I already placed a cardboard plate in the machine, which we will cut. The software driver has connected with the machine and the hardware gets initiated. You see that the laser cutting head has moved, so the machine is ready. Now we have to lift up the plate. The reason behind that is to get the optimal distance between the laser head and the cardboard. The laser has the greatest power at a certain distance. For that purpose i use a magnetic distance piece, which i use to determine the optimal distance. I attach it and lift up the plate a bit further, until it touches the distance piece. I always have to do that, no matter what the material is. Now i have the optimal distance between the laser head and the cardboard, so the laser beam is in focus and has the maximum power at the right point. Now we choose a starting position of the laser. It gets indicated by the red dot of course. That is the area where we are starting to cut. Alright, what you see here is the second program we work with. The first program we used, as you might recall, is Corel Draw. There are a bunch of open windows at the bottom of the screen. The second program belongs to the laser cutter. It translates the data of Corel Draw into something the laser-cutter can work with. I now connect the software with the laser. The connection has been successful, i can tell that by the beeping sound, the ready sign on the screen and the marked out current location of the laser head on the screen. In order to show you how that works i go back to my drawing. I simply select a few main frame beams of the trailer, which i want to cut out. For that i create a printing job, as if i had a normal ink jet printer connected to my computer. I then select the laser-cutter driver. Because i do not want to print everything i just select what i want down here. Next i check my basic parameters, namely size, the material (i saved the data required for that a long time ago already) and the type of procedure. The other options right here are not important at the moment. What i will choose here is the option “optimized geometry” and “cutting internal parts first”. That just means that everything in the middle gets cut first and the last step is cutting the outer edge. This prevents misalignment. If you cut the outside parts first something might just shift a bit and everything else would be off. Alright, i send it now to the driver. At the right hand top corner the print job i have created should show up now. There it is, you can see it. I see also a depiction of the object i have chosen. Now i just drag that file to the working space and there it is. I get information on how long the cutting process will take. Now we can start. In order to show you the three main working procedures at once, which are cutting, scribing and engraving, i have a little test piece, which we are also cutting now. Here you see the finished part we just made. It cut out perfectly. Even the most delicate sections got removed. On the first sample it did not quite work, it seems like the power of the laser was set a bit too low. With that being corrected you can see that even such small and intricate parts are quick and easy to produce. I hope you liked what you saw here. Yes, it was indeed very interesting I hope you guys enjoyed it as well. I talked a lot, i don´t know whether or not it was too much, but it is an interesting and complex subject. Maybe you have at least seen that one can do a lot with these machines. This is not yet the end of it all, there are much more possibilities. In any case, we are pushing the boundaries of what is possible a bit further. Exactly. Companies were able to laser-cut in the past and produce model kits this way, now we can make that ourselves. If you are interested in that, just look up where the next FabLab is for you. There is a list on Wikipedia. There are FabLabs everywhere in Germany. Most of them have machines like that. If you have questions, you know how to contact Michael and he will be able to contact me. As i said before, you can see my work at our model show in Augsburg/Haunstetten, in Ried or Lingen. Thank you. You are welcome! Thank you very much for taking the time to show us everything. Your personal expertise in the subject is of particular interest. Everybody knows that laser-cutters and 3D printers exist. What was interesting to me was how you deploy these machines for your truck trailer project in particular. I am looking forward to see this project proceed in the next months and maybe even years, or how long it might take in the end to see it all finished – yes, thats right i must admit. I have to say that i know your trailer from a very early stage and it is really fascinating to see how it slowing taking shape. You bring it along to model shows very often and people who go to these shows can see the progress. You also bring along the “dead ends” which did not work, so people can see and learn what works and what does not. I really like that. Thank you. Alright, you guys heard the man. The FabLab in Munich is an interesting contact point for you. There are of course plenty of other things you can do here. We did not get to talk about 3D printing at all for example. You can also work with wood and metal here or even design your own T-Shirts. As you can see, there is tons of stuff here for every taste. Alright, so far, so good. We meet again and thank you guys for watching, your Hamilkar Barkas.

Cesar Sullivan

3 thoughts on “Laser-Cutting at the FabLab Munich

  1. Hallo Michael.
    Danke für dieses sehr interessante, informative Video.
    Es ist einfach faszinierend, was damit möglich ist. Und was noch möglich werden wird, denn da ist lange noch nicht das Ende erreicht.
    Ich arbeite in 1:87 schon länger mit 3D + LaserCut und bin einfach davon begeistert.
    Die jetzt vorhandenen Möglichkeiten sind fast grenzenlos, die aktuelle Grenze ist meistens das liebe Geld und das eigene Können. Da ist dann wieder gut, das es so etwas wie diese Lab's gibt. Da kann man sich dann handfeste Hilfe holen.
    Ich hoffe sehr, das Du diese Serie fortsetzt und uns über Neues auf dem Laufenden hältst.
    Danke für diese ½ Std Wissenserweiterung. 👌👌👏👏

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