Living with the lasersaur
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Sarah
After a year with the Lasersaur, pro's and con's, mods, problems and general experiences with the DIY open soure laser cutter.
 I'm Sarah. I love lasers a lot besides FPGAs. In the FabLab of Karlsruhe, which the FabLab is oriented at the ideas of the FabLab idea of the MIT. We got funding for a laser sour. The laser sour is an open source project. You can see it on the screen. It's a huge machine. It's this size. I want to talk about it. I want to talk about what you've done, what went wrong, what was bad in the original design, what we have tried to make better, where we fell in, what mistakes we made. I want to encourage other spaces to also build lasers sour because it's quite a bang for the buck. I mean, five to six Ks, you get a hundred watt machine. It's not that much. My background is laser marking development, laser system development. As you can see, this is a professional industrial laser system, which is in a production line. Some parts pass by, they get a barcode marked on and continues. This is what I've developed for the last two and a half years. It's a Yuc laser. It operates at the wavelength of 1064 nanometers, which is near infrared, which is perfect and amazing for metals. You can engrave, you can do a lot of things also with plastics. This machine got me started into the laser world and gave me the passion for laser marking. I love it when I've seen it a lot of time. It's like the washing machine and kids effect. You put a kid in front of the washing machine when it runs and the kid stares like this. This is the same with the laser beam. I can't stop watching. I love it. The machine, what I'm going to talk about, the structure. I want to talk about the laser saw itself. Then I want to get into it in the detail how the beam runs. The pros and cons of the original design. This is very important. It is not what we've done, but this is what's out of the box. What we've done in mechanically or in electrically ways, then there's a very painful issue that's calibration and one last which hasn't made it into the talk yet is what you shouldn't do. By the way, this is the tube. This is the actual laser tube from our laser saw. We had a small mishap, so I could bring it here. It's toast. The laser saw runs with this CO2 laser tube. It has 100 watt optical laser power, which is quite a lot. It goes through 12 to 15 millimeters wood with a hot knife into butter. This is quite impressive. Also acrylic and other plastics. The CO2 laser is with the wavelength of 1064 nanometers. They're very, very good at organic materials like wood or paper, leather, skin. I made some experiments with pig skin. It goes right through. It smells like, if you don't want to smell, acrylic, plastics, but what's totally, totally, this is a strong warning to everyone who plays with lasers. Don't use PVC or any other chlorine-containing materials. This will decompose. This will reorganize the molecules of the chlorine and you will have a fume of HDCL, hydrochloric acid. This will make your machine from the inside rusty immediately. Don't do. You see the website, lasersower.com. The plans are online. You can download them. There's a forum where you can have access to what other people did. I haven't been into this community too much, but it seems to be quite interesting. The working area is quite large. You have 1 meter 20 times 60 centimeters. This is huge. You can put a large piece of wood or plastic in and do whatever you want. This is amazing. Also the speed, we've tested it with 10,000 millimeters minutes. Cutting speed, this goes like what? The wood is cut into pieces. Quite impressive. About the CO2 itself. This tube with 100 watt optical power is about a grand with the power supply. The lasers I use for my work, it's a 20 watt system. They are in the range of 6 kilo euros. This is a totally different story. You can have a lot of energy for quite a little money. For example, the laser cutting systems for metal working for these sheets of metal, they use CO2. Normally CO2 doesn't work very well with metals, but you can throw a lot of energy into it. Then you can cut metal. You need 1 to 3 kilowatt of light. It's cheap, you can afford it. It has quite a high efficiency compared to other gas lasers. You don't need 10 kilowatts to get 500 milliwatts optical power out of it. Conclusion, happiness from a tube. We go to the path of light. On top you see this tube. Then to the right, you see the first mirror which stands still. This is the first mirror in the mounting where the laser itself goes like this and stands still. Then the M2 is the second mirror. This is on the Y axis which moves and the mirror M3 is on the X axis. This deflects the beam down side through the lens. Painful to calibrate, I will come to it later. That you have a rough idea how the setup is. It is basically this classic plotter principle, you have the XY thingy going around. This is done by stepper motors. You don't need any big machines, any big stepper motors. You can have the small NEMA, I don't know, 17 whatsoever, to operate the system. Pros, not so beefy on the price. You can do it in your space. Which is an awesome idea. You need to have three, four, five, six people who know what they do. You need to have some electrically experience. You need to have some mechanically experience. Off you go. By the parts, build yourself. We had a lot of fun. We had the mechanical group. We had the electrical group. I was in the electrical group because of my experience with laser safety. The user interface is quite easy. This is in the stock. There's a board. There's plugged in a Beaglebound black. There runs a web server which you access via browser and you put in SVG files. What's nice is you can have many colors of SVG files. To every color you assign is specific energy like speeds, marking speed and percentage of energy. You can engrave in the first run, then in the second run you cut out the drill holes. In the last run you cut out the outlines. It works. It has its flaws. We try to mod. I don't know if we have it on GitHub yet. We try to implement the... to see how long does the job last. How long is the tube on? We can see how much every user has to pay. We are right now thinking about one euro per minute because filter systems are quite expensive and the tube itself doesn't last until Kingdom comes. If you can download the software, I don't have any screenshots, but you can tinker with it runs on... it's a Python thingy running. I'm not into software. I'm a hardware person. Coming to the contrary sides. First of all, it has no z-axis. No electrical z-axis or z-axis. You have this honeycomb aluminum flat bed where you put your material on and then you have a tube which is... too far. Oh, thanks. On the left-hand side, right-hand side picture, you see the third mirror. You see the head where it is basically the tube with a holder and you can adjust the tube. This way you can adjust the focus which means you can have sort of a z-axis. This is only about 50 millimeters. I've seen other machines where you can adjust the height of the table electrically. Some have done... you can tilt it which is very nice, but the design of the laser is how it doesn't have it. Something to go into and do a redesign. Then they use in the original design patch cables, ethernet patch cables you get from your supplier. It has nothing to do with ethernet, with the protocol or with the speed. The thing is you have a very cheap cable. You can get in quite some distances and you have readily made a connector onto. Again, nothing about network. It is just DC running through and very low, very static signals. The only point was the connectors on the suggestion of the board, RJ45, so everything is made cheap. The con of this solution is the cables are very stiff. If you use it in a drag chain, you go backward and forward. Try it with a network cable. Do it 100 times, bend it, and you will have a cable break. Some mechanical details were not so nice. One we realized is that it can flex. It has no diagonal stiffings. It is stiffened the whole frame. If you lift up one side, it goes like this. It is not adjusted anymore. We had some problems in the lab because it is an old slaughterhouse and we got the cooling room and the floor is not flat. It goes to the middle of the room where there is a drain. We pushed forward the laser and did our adjustments for a couple of days. Yes, it works. We pushed it back and nothing worked. If some of you are mechanically inexperienced and know what you have to do, then don't use this original design. In the suggestion, they left open how to handle the air. When you cut with a laser, when you do anything material processing with a laser, you will have fumes. If you have small particles, they are just there and you need to get rid of them. The easiest way is you have one hole on the other side and you have a fan on the other side and it sucks the air through. We did it basically this way and we got a lot of vortexes going around. It is like in a snowstorm where you have in one end of a house suddenly, Germany is called Schneevia, a lot of snow and the other side is there is no snow and just by the wind. We have a lot of dust in the machine which is in one corner and the other area, it is nothing and the mirrors are dirty. So there is a lot of room for errors. We haven't figured it out yet perfectly. It became better. We have another fan with I don't know how many cubic meters per hour, I think one and a half thousand cubic meters per hour of air flow. This makes it a bit easier and makes it a bit better and we have a filter system. But realized when the filter becomes clogged, the air flow isn't that much anymore and we start again having these vortexes. So there is a lot of room to think about. The original design doesn't care about the EN 6,850 which is the standard for laser systems. It starts with the emergency stop switch. It continues with an interlock circuitry and it is not safe. You can't use it out of the box. You can use it alone at home in your basement or in the garage if no one else comes. Then you can do whatever you want. But not as soon as there are more people involved who might also not know about laser systems. So that's a bit weak. I mean they come from America. This design is American. I don't know. These standards are quite strict. They are similar to the 6,850 standard. They should have followed it. So this is one of the mechanical things. When you see this is the holder for the big boom which goes in Y-axis and there is this other piece which goes in X-axis. There are three long screws into the extruded aluminum profile and they are quite long. After some time of operation we realized it got a bit loose. These screws they warped a bit. So suddenly we could turn this boom and immediately you have fun with adjustment of the beam. So room for improvement. Then it comes to electrical. Yes. We have the problem that when you switch on the laser source and you fire the integrated Beaglebone black crashes. We didn't know why. It was okay and some days it was really bad. So you make a single shot and everything is crashed. It took us a while. I grabbed my oscilloscope from work and connected it to the Pools with modulator to output from the Beaglebone via an AVR which does the G code interpretation into the stepping step commands and into the PWM Pools with modulation to the laser source. What you see on the bottom line, the pink one is the signal that I saw on the PCB going out of the laser source. At first you see it is a 5 volt logic. It looks nice and then we have a lot of bursts going up and down, up and down, minus 5, minus 7 volts and plus 10, plus 12 volts. I forgot the other traces. We realized the power supply is sort of firing back. There are a lot of EMI problems. The power supply fired back. This is what the pink line is what comes out of the AVR. It goes back on the AVR and makes the AVR crash. Yeah. I don't want to talk about E-waste out of the box. No, I'm not going to talk about E-waste out of the box but it comes close to it. By the way, this electronics, this stock electronics is done. It is open source. Yeah, that's fantastic. It is still open source and have no clue about what you do. It is done in fritzing. If anyone who knows about fritzing, you can have, it is very good if you have a bread pot, if you have three resistors and two LEDs and connected maybe to some embedded board, go with it. That's fine. As long as you have more and you do a larger schematic and are crazy enough to make a PCB out of it, no way. Don't do it. You can't click like in other EDA programs like E-eagle or CAD or whatever. You click on a trace and it is highlighted and it says which name it has. On fritzing, you click on it and you just see it is just highlighted between two junctions. There is no consistency between the schematic and the PCB itself. I had to connect this board. We had difficulties with the time. We had the deadline. The laser saw was a university project or institute for technical upshadowing. It was a scientific project and we had a strict deadline. We couldn't develop a known board. We had to use this and we had to live with it. I had to connect it and I got so cranky so many times. I was close to through a closed window and smashed everything into pieces. Painful. Enough of the rant. Yes. What you see on the left-hand side is, I did try to bring it into E-eagle to make pictures. What you see is basically how it looks like. You have the AVR, you have two wires, two traces to the RJ45 connector. Nothing else. No protection. No nothing. For the inputs, for the end switches. So X and Y have end switches and for the big door. You have also switches. For the end switches, at least you have a pull-down resistor. So this is something I wouldn't consider publish to publish. Because the solder stop was black. You couldn't see any traces. And with a loop and a lot of guessing, I put in an inductor against EMI distortions. I had the capacitor and the Xenode diode to at least cut these tremendous normals over an undershoot and it works much better. Still this is a workaround and it was a lot of work to get the SMD components onto this board and a lot of scratching, cutting of copper traces and so no fun. Really no fun. So we did something. Why is this sleepy? What we did in modifications is this is a beam catcher. This is for the beam going from the first to the second mirror. In case the first mirror is not adjusted, you don't know where it's going to shoot the beam. We have this ceramic tire so that if you don't hit the second mirror spot on, the beam doesn't go somewhere else. So if the hood is closed, nothing will happen. An acrylic is for the unfocused beam is quite safe. You see what happens. You smell it. It works. But we use the ceramic tiles on many places. Nothing happens if you shoot. We also use the ceramic tiles on the floor. We first had captain. Captain is a fantastic material. If you have a PCB and you go through the solder wave and you want to have some holes, you don't want to be filled with solder. So you have this captain type and you stick it onto and nothing happens. Very thermal resistant but not good for a laser. Someone had the idea. It wasn't me. I said, oh, yeah, let's stick captain on it. When you shoot with a laser, it makes funny things, funny films and toxic things. So we use the ceramics. What you can see on the floor is where the laser was going on, cutting through wood. It is compressed air through this tube. There is a lens and there is the nozzle and you put in some compressed air so that no fume goes onto the lens to make it dark and to blow away all the fumes and to cool the spot where the laser beam goes into the material that nothing ignites. Heat plus wood plus oxygen, fire. So it goes through the wood and leaves some traces on the tires. Quite impressive. So what else did we do? It's a bit tricky to see that we did a beam labyrinth. When you close the hood, according to the original design, and you open it a little bit, there's a possibility that the beam goes through and goes into room where you stand. So it's just an aluminum angle we screwed on one of the extruded aluminum. Just sort of make it safer. Then we changed the tube holder. It's so funny. The original design was you had an aluminum piece of metal and another one and it goes like clock. And there's this delicate glass tube inside. So no, we did something else. And the benefit is we can adjust it in height, which is very important for the process of calibrating the laser. Then we tried to improve our airflow system. This was a test on the left-hand side. We tried to split the intake and air into what goes above the cutting area and below to get away the fumes. We are still not finished yet. On the other picture, you see the dust from cutting wood. This is what I told about the vortexes and leaving dust traces everywhere. So then we did, when you operate a laser and do some material, you cut through something, you will have or engrave it, you will have a lot of dust. And this dust can be very toxic and this dust can be smelly, can stink. And you don't want to let it go, let it out, you don't want to have it in your lab or in your space and you don't want to let it out unfiltered. So we designed a filter system which has five stages, going from, going finer and finer until the two black things are, this way, are active carbon filters which filter the last smelly bits and pieces. This works quite well. You have to maintain it, you have to look for the filters. When one filter gets clogged, you see it that you again have these vortexes. So the, reduces the pressure and the airflow. And we changed the out, these area for suction that we cut out. One side, the air stream goes in and on the other side in the floor it goes down and sucked out to the bottom. What else? I mentioned few traces on the mirrors are very bad because you lose energy. The mirrors will heat up. It's not good. We tried to 3D print covers for the mirrors. This is one of our latest iteration with this long glass tube. If someone has a better idea, I'm open to any suggestions. It makes it a bit better. We have less traces on the mirrors. On the left hand side you see the original design. It is just the mirror holder and the tube. You have a lot of air and space around for any dust and fumes and smoke. It gets a bit better. We are still not at the end from where we want to go. So electrically we made some electrical changes. We haven't changed the board, the electronics board yet. It is still in discussion. We have a lot of ideas floating around. A lot of different theories how this laser has to be made. But we did some changes compared to original design. First of all we use an E-stop relay which prevents an automatic... That we don't have an automatic restart. So you do something, you hit the E-stop switch. The beam will go out immediately and the motors from the X and Y axis stop working immediately. It is not emergency off. It is an emergency stop. So the electronic still is alive. You get data back. You can do something. But the idea behind it is that the dangerous thing is shut down. The machine itself. The dangerous parts are shut down. Our relay is from DOL. We got it from eBay for affordable money. It is something to do. We made an interlock circuitry. Interlock circuitry means that if not all the conditions are fulfilled you can't have a laser beam. So if you interrupt this interlock circuitry like you open the hood or the door then the beam will go off immediately. So you can do it laser chop and why the job is running. You open the hood and the beam is stopped immediately and the X and Y continue working doing their thing. You can put away something. What you've forgotten you can close it. The beam will continue. So also when you switch off the chiller I will come to cooling later. That's the reason why the tube is here. And also the air system. The compressed air which goes into the tube is within the interlock circuitry and as well as the suction system. So you simply don't want to have that fumes in the system. We did it once. I don't know how it came. We had it once. Someone came up with a big piece of acrylic or whatever polycarbonate material. Can we just do a quick cut? I don't want to use a table saw or circular saw whatsoever. Yeah sure. Put it in. It was still in construction, closed the door and we haven't had the extraction in the interlock circuitry. We forgot to switch on the fan. And immediately the chamber was filled with this yellowish fumes and it took us half an hour in winter time to get all the smoke out of the lab. You don't want to have this. Once we changed from these patch cables which are easy to break to something nicer, we actually used Urflex from Lab Carbon which is a very nice cable which is very suitable for drag chains. You can go around back and forth a million times. It doesn't break very, very thin, very fine, flexible, thin wires. Excellent cable. No, I'm not related to lab carbon. This is our electrical operating panel. On the right hand side you see the main switch for power mains, the chiller switch and for the laser source. And you see the E-stop switch and the green button is the release, the E-stop relay. So processes you switch on the machine, then you open the padlock which we use according to EN6850. You need to have a for class four laser system. You need to have a switch, a key switch or a num pad or something like that only people are allowed to use the laser, actually can use the laser. So remove the laser, the key padlock, release the E-stop switch and push on the green button and you're good to go. And when you actually want to do something, you switch on chiller. The moment is quite, the chiller is quiet. You switch it on right after you switch on the machine and then air is quite noisy. You just switch on air when you actually want to laser something. So there is sort of an E-stop functionality on the web front and on the web side, but it has nothing to do with an E-stop, with a serious E-stop. So in panic when something goes wrong, you don't want to click somewhere and find a button. Where was a button? Where was E-stop? Up top right corner. Okay, let's click. Oh, shit, missed. You want to have a serious one and it stops the danger immediately. So then we ran into these troubles with the EMI problems from the laser source and we had the idea that our Beaglebone was defective, that something destroyed something on the board. It is just three volts tolerant, the IOs and if there comes something more, it is very itchy on this issue, then it dies. So on the larger piece, you see the AVR and the rest of the electronics, which does the G-code interpretation and this is connected via our receive and transmit, it's a standard serial connection on TTR level and then it goes to the Beaglebone and then it goes via Ethernet to the outside world and we took out the Beaglebone and we have another embedded on board and we simply replaced it. This works. So calibration. Calibration is pain in the neck, seriously, straightforward, takes days, makes a lot of gray hairs. It's necessary. You need to calibrate the system. You need to calibrate the system where the laser is going to stand finally. As I said before, we have the floor in the lab is not horizontally, not leveled, but it goes slightly downwards. You need to have it in that place if you don't have a perfectly leveled floor. You need to level everything. Go with this water level, check out diagonal, horizontal, vertical axis, all these needs to be leveled. And then you need to have the beam coming from the tube. This is the fun part. It goes to the first mirror. It has to hit the first mirror from the height in the middle and then you go to the second mirror and it has to hit it on all positions in the same height and then you go to the third. So it is a lot of opening, closing screws, going back again, again, again through the cycle until you have it all. The beam goes and runs on pain. We did something to help to calibrate this laser. This is basically how the mirror holder looks like. The beam comes from here and you have this piece of aluminum and this way and you have the actual mirror goes a bit inside. It is a bit like a mirror frame. As we stick it in a label, I come from the labeling industry, we stick a thermal sensitive label onto this frame and the actual mirror is not the same height. It is three millimeters deeper. So you need to do some calculations and you see on the left-hand side, this is actually in vertical and you see that the beam doesn't hit it in the middle but it has to hit it a bit below. What you did is, these are shots from onto this thermal sensitive paper and here you see on the left-hand side what it just meant, the beam holder and the mirror and it is behind the front of the mirror holder. So the two images, the two shots on the thermal sensitive papers are quite okay. We stick this paper onto the mirror holder and with a fingernail or with a back of a knife, you just mark it so this is this sort of circle, this funny polygons. So that we then have a tool, it is printed on foil and on the right-hand side you see this, it looks like a fingerprint. But if you center it on the spot where the beam hit the paper, you can see how far off you are from how far you have to adjust the mirror. So this is your maker shot, you put it down, two millimeters too far, okay, then you open the screw, lift the mirror holder for two millimeters, you do again the same shot. Next days, I want to put these files on my website and also ask a file on the talk. Yeah, it's difficult to describe. If someone wants to know how it works, FabLab is in Karlsruhe, we are very open to visitors, please come to visit and we can show you. So things you should not do, you should not fry your tube, it's expensive. This one is fried. Very simple reason, totally stupid reason. The chiller is a system, it has a water pump, it has two water pumps, so it's redundant. It has a cooling system with a compressor and everything, it is a fantastic machine. But if the plug this year slips out, then you're done, then you're finished. It happened five minutes after first time laser on this day, at my just piff, light was off and water run through the whole machine and I don't know how much water is inside, but the pump was fortunately not functioning, so it didn't continue pumping water through the electronics of the laser system. Yeah, expensive, expensive experience. This is something you should avoid, always check your cooling system and always check the water security, besides all other things. Great. If you like you can contact me, Sarah at laserlady.org, soon you will see this talk on this website, soon you will see the talk from the GPN 15 on this website. You can contact me if you have any questions, feel free. I want to thank all the guys here at the camp for this awesome time. I want to thank the FabLab Karlsruhe and I also want to thank the ITAS Institute for Technique Folgenabschätzung in Karlsruhe, which did the funding and which helped us a lot and we had a lot of fun together, as you can see on the picture below. We have some time left. I'm out of slides now. If you want to know something, feel free now. We can do for the Q&A. We have a lot of time because this is the last talk in this tent for the camp 2015 and at first thank you for your patience and thanks for listening. Which talk is doing the Q&A? Thank you, Sarah. We have some people here. I'll start over on my right. At Hackerspace Hack42 we have a Laos laser. We have had quite some issues with the accuracy of the code itself that it doesn't calculate the laser precision correctly. Do you have any problems like that in laser, Sarah? That just works fine all the time? It works fine because it works with absolute positions. When you switch on the machine you have to run the homing cycle, which means it goes in X and Y axis. On the top left corner there is zero, zero. It goes to the first end switch and goes to the next end switch. Then it knows here is zero. Then you can do whatever you like. It knows where the head is. Is it that? Was it your question? My question was that with Laos you could get, for example, you do an entire run and you go back to the zero position but it's not exactly at zero position. It makes a small error during the cycle. No, this doesn't happen with laser, Sarah, electronics. Sometimes it really happens that you can do a lot of things with parameters right or wrong. Let's say you go through three millimeters, would you choose a thousand millimeter speed? Let's say not to treat the tube bad, you go with 50%. Then you run. Afterwards you see if it goes through or not. You have the feeling no, it didn't work. Then you can do the same run, the same job again and again as long as you don't touch anything inside like you move a piece of wood, nothing happens. It goes exactly the same contours, exactly the same traces. But I wouldn't recommend this hardware very much. We've used the Laos hardware and the hardware itself is basically from what I hear from you in quality roughly the same as the laser saw. Also no inherent safety in it at all. What we're going to do is, as I mentioned before, we want to do our own laser bars. With my experience in laser safety there will be an FPGA for all the safety circuitry and some more benefits. What we actually want to do with the laser is doing big data. We want to monitor the temperatures of the mirror of the tube of water in, water out, water flow, how many times or how long the laser tube is running and this and that and that and that. We want to integrate it into our lab net and store the data on the server so we can see slow changes for example in the temperature of a mirror. We can see, well, it's time to clean. So we get some more experience, more data for having experience. Yeah, the Laos. I heard the name Laos, but maybe I have seen it, but I can't remember. But if you say it's the same, no, I don't say. If it's the same type of board, there are some other smoothie boards I heard. The Haas should be okay in support of laser, but they all don't have laser safety circuitry. Was it, did I answer your question? You answered it fine, thank you. You're welcome. Okay, and we have another question over there. Hello, I'm leaving standard FabLab Brussels. Thank you for the interesting talk. Another FabLab, yes. We don't have a laser store yet. I worked with one in Antwerp. You just answered my first question about the controller. My second question would be if I want to build it on a smaller budget as a student project, where would you compromise? At the tube. Do a 60 watt instead of 100 watt. Yes. 100 watt is fun. Sure. I mean, nothing replaces power so good like more power. Everyone knows it. Same like memory. But you can do a lot with a 60 or 50, sometimes 40 watt tube. This is about 1,000 to 1,200 euros, you can have it cheaper. What I just learned is that you can have, let's say 100 watt in this size, or you can have 100 watt in smaller size, larger, I don't know, but in a different size and it's cheaper, but the beam quality is less. It's not so nice. I mean, you have seen the images on the papers, the small shots. It was just a small shot with very low energy on the paper to get this, to get a bit, to see where the laser beam goes. It looks like a donut, so the energy distribution in the beam is like this. The beam doesn't go out collimated. It's like glasses. So the beam widens up. And the way how much, how far it widens up, this is one quality parameter. And the cheaper the tube, the more you have this. I would go with a high quality, but less energy tube. You want to have a high quality or you want to have the beam as good as possible. You kind of have a lot of energy, but if the beam is crap, then you have problem adjusting the system and makes it fun. And you can compensate less energy with slower motion of the head. You don't need to run 8,000 millimeters per minute, what you can do with this tube. But then you go on 2,000 millimeters or you go with 100 or whatever. I would save the money on the tube. Get a good quality, but you don't need that much energy. And I think there is no linearity in how big the machine is. If you have an aluminum profile, if you have it one meter or 80 centimeters, there is a big difference. So go big, build the machine in the full size, but with less energy. It doesn't hurt. Yes, thank you. You're welcome. Okay, then we have another question over here. Yeah, please. Hello, my name is Arvid and I wanted to thank you for your nice talk. It's very interesting. We in our Hacker Space are planning to build LaserSaur 2. So I wanted to ask, we are not really sure how much it will cost us. So I wanted to ask you how much are the costs only for the materials if you doesn't broke anything. And the second question is how many people were you to build that up and how many men hours or woman hours, sorry, you put into it. I thought it. The pricing. As far as we know, we've been between five and a half and six grams, five and a half and six thousand euros. And this was 1,100. So just take this out of the calculation. You will be good with four and a half case. But you can do if you think twice about the design, there are some, there is some room to save some money to make things more intelligent, more smarter. You will find better solutions. It is quite cool if you have some mechanical engineering guys or girls. It is not the end of what's possible in the design. And yeah, I find another board. Sorry, I forgot the two last other questions. The second question was how many hours you put into the project until everything was running. We had two building weekends, meaning we met on Friday afternoon. We had the mechanical group and we had the electrical group. The mechanical group had about two weekends building, which means beginning Friday afternoon, working until late night, two, three, four o'clock. Next day, Saturday, meeting in the morning about 10, working late, having supplies of Marty, of pizza, what's necessary, and working late, and on a Saturday, not so much, but working until 10 o'clock in the evening. So we had about two weekends this style and one, as far as I remember, one weekend for the electrical system. So we've been, I don't know how many guys have made the mechanical setup. I think it was four to five guys. I don't know if they've been there all the time together or if they did shifts from the electrical side. We've been three to four guys and we tried to distribute the work. One was working on this area and the other one. This area and we tried to get the cables around. Because you stand in cables, you have wires around and around and open ends and you, yeah. I would say if you're focused, if you have everything ready, a theme for good weekends, or let's say one week of vacations from morning to evening, you can do it. Okay, same. Yeah, please. Okay, then we have one more question over there. You got plenty of modifications to the laser-zower design. So in which website can you find them? Out. In non. I don't know where we got the laser holes, the laser tube holes in plastic parts. I don't know where we bought all the parts. We bought the electronics at the Nordtards labs. Nord labs. It is the webshop around the laser-zower where we got some special water cut aluminum parts. They have these, if you get a sheet of metal, eight millimeters thick aluminum with some special parts. And there you get also the mirror holders and you get also the tube and also the electronics. One thing I forgot about the mirror holders, one thing we want to modify we haven't done yet is it is nice. You can pan until the mirrors, but you can't move them up and backward and forward. You can't move them in the three axes. This is something very, very important for calibrating the laser. Because otherwise if you want to change something, you have to open an M4, M5 screw because it is an aluminum profile. And you open the screw, you shift it two millimeters in one way and you close the screw. You can all imagine what happens. You have to start from the beginning. Yeah, we haven't found these mirror holders yet. We got a lot from this Nord Labs web shop. The electronics we're going to build, we will publish open source, of course. But I don't think we will sell them. Maybe we sell the PCBs. I don't know. It's not decided yet. And eBay is a fantastic source. This emergency stop relay is from eBay. The three switches are from eBay. The emergency stop switch was from eBay. You have to look. On which website you plan to publish source? First of all, it's fablab minus calzwood.de. This is where I live. This is my space and then I guess it will be published on GitHub. Something. Thank you. You're welcome. I think that concludes the questions. There's no more. Okay. It's really over then. Thank you very much. Thank you all guys. Thank you.
 I'm Sarah.  I love lasers a lot besides FPGAs.  In the FabLab of Karlsruhe, which the FabLab is oriented at the ideas of the FabLab idea  of the MIT.  We got funding for a laser sour.  The laser sour is an open source project.  You can see it on the screen.  It's a huge machine.  It's this size.  I want to talk about it.  I want to talk about what you've done, what went wrong, what was bad in the original design,  what we have tried to make better, where we fell in, what mistakes we made.  I want to encourage other spaces to also build lasers sour because it's quite a bang for  the buck.  I mean, five to six Ks, you get a hundred watt machine.  It's not that much.  My background is laser marking development, laser system development.  As you can see, this is a professional industrial laser system, which is in a production line.  Some parts pass by, they get a barcode marked on and continues.  This is what I've developed for the last two and a half years.  It's a Yuc laser.  It operates at the wavelength of 1064 nanometers, which is near infrared, which is perfect and  amazing for metals.  You can engrave, you can do a lot of things also with plastics.  This machine got me started into the laser world and gave me the passion for laser marking.  I love it when I've seen it a lot of time.  It's like the washing machine and kids effect.  You put a kid in front of the washing machine when it runs and the kid stares like this.  This is the same with the laser beam.  I can't stop watching.  I love it.  The machine, what I'm going to talk about, the structure.  I want to talk about the laser saw itself.  Then I want to get into it in the detail how the beam runs.  The pros and cons of the original design.  This is very important.  It is not what we've done, but this is what's out of the box.  What we've done in mechanically or in electrically ways, then there's a very painful issue that's  calibration and one last which hasn't made it into the talk yet is what you shouldn't  do.  By the way, this is the tube.  This is the actual laser tube from our laser saw.  We had a small mishap, so I could bring it here.  It's toast.  The laser saw runs with this CO2 laser tube.  It has 100 watt optical laser power, which is quite a lot.  It goes through 12 to 15 millimeters wood with a hot knife into butter.  This is quite impressive.  Also acrylic and other plastics.  The CO2 laser is with the wavelength of 1064 nanometers.  They're very, very good at organic materials like wood or paper, leather, skin.  I made some experiments with pig skin.  It goes right through.  It smells like, if you don't want to smell, acrylic, plastics, but what's totally, totally,  this is a strong warning to everyone who plays with lasers.  Don't use PVC or any other chlorine-containing materials.  This will decompose.  This will reorganize the molecules of the chlorine and you will have a fume of HDCL,  hydrochloric acid.  This will make your machine from the inside rusty immediately.  Don't do.  You see the website, lasersower.com.  The plans are online.  You can download them.  There's a forum where you can have access to what other people did.  I haven't been into this community too much, but it seems to be quite interesting.  The working area is quite large.  You have 1 meter 20 times 60 centimeters.  This is huge.  You can put a large piece of wood or plastic in and do whatever you want.  This is amazing.  Also the speed, we've tested it with 10,000 millimeters minutes.  Cutting speed, this goes like what?  The wood is cut into pieces.  Quite impressive.  About the CO2 itself.  This tube with 100 watt optical power is about a grand with the power supply.  The lasers I use for my work, it's a 20 watt system.  They are in the range of 6 kilo euros.  This is a totally different story.  You can have a lot of energy for quite a little money.  For example, the laser cutting systems for metal working for these sheets of metal, they  use CO2.  Normally CO2 doesn't work very well with metals, but you can throw a lot of energy into it.  Then you can cut metal.  You need 1 to 3 kilowatt of light.  It's cheap, you can afford it.  It has quite a high efficiency compared to other gas lasers.  You don't need 10 kilowatts to get 500 milliwatts optical power out of it.  Conclusion, happiness from a tube.  We go to the path of light.  On top you see this tube.  Then to the right, you see the first mirror which stands still.  This is the first mirror in the mounting where the laser itself goes like this and stands  still.  Then the M2 is the second mirror.  This is on the Y axis which moves and the mirror M3 is on the X axis.  This deflects the beam down side through the lens.  Painful to calibrate, I will come to it later.  That you have a rough idea how the setup is.  It is basically this classic plotter principle, you have the XY thingy going around.  This is done by stepper motors.  You don't need any big machines, any big stepper motors.  You can have the small NEMA, I don't know, 17 whatsoever, to operate the system.  Pros, not so beefy on the price.  You can do it in your space.  Which is an awesome idea.  You need to have three, four, five, six people who know what they do.  You need to have some electrically experience.  You need to have some mechanically experience.  Off you go.  By the parts, build yourself.  We had a lot of fun.  We had the mechanical group.  We had the electrical group.  I was in the electrical group because of my experience with laser safety.  The user interface is quite easy.  This is in the stock.  There's a board.  There's plugged in a Beaglebound black.  There runs a web server which you access via browser and you put in SVG files.  What's nice is you can have many colors of SVG files.  To every color you assign is specific energy like speeds, marking speed and percentage  of energy.  You can engrave in the first run, then in the second run you cut out the drill holes.  In the last run you cut out the outlines.  It works.  It has its flaws.  We try to mod.  I don't know if we have it on GitHub yet.  We try to implement the... to see how long does the job last.  How long is the tube on?  We can see how much every user has to pay.  We are right now thinking about one euro per minute because filter systems are quite  expensive and the tube itself doesn't last until Kingdom comes.  If you can download the software, I don't have any screenshots, but you can tinker with  it runs on... it's a Python thingy running.  I'm not into software.  I'm a hardware person.  Coming to the contrary sides.  First of all, it has no z-axis.  No electrical z-axis or z-axis.  You have this honeycomb aluminum flat bed where you put your material on and then you  have a tube which is... too far.  Oh, thanks.  On the left-hand side, right-hand side picture, you see the third mirror.  You see the head where it is basically the tube with a holder and you can adjust the  tube.  This way you can adjust the focus which means you can have sort of a z-axis.  This is only about 50 millimeters.  I've seen other machines where you can adjust the height of the table electrically.  Some have done... you can tilt it which is very nice, but the design of the laser is  how it doesn't have it.  Something to go into and do a redesign.  Then they use in the original design patch cables, ethernet patch cables you get from  your supplier.  It has nothing to do with ethernet, with the protocol or with the speed.  The thing is you have a very cheap cable.  You can get in quite some distances and you have readily made a connector onto.  Again, nothing about network.  It is just DC running through and very low, very static signals.  The only point was the connectors on the suggestion of the board, RJ45, so everything  is made cheap.  The con of this solution is the cables are very stiff.  If you use it in a drag chain, you go backward and forward.  Try it with a network cable.  Do it 100 times, bend it, and you will have a cable break.  Some mechanical details were not so nice.  One we realized is that it can flex.  It has no diagonal stiffings.  It is stiffened the whole frame.  If you lift up one side, it goes like this.  It is not adjusted anymore.  We had some problems in the lab because it is an old slaughterhouse and we got the cooling  room and the floor is not flat.  It goes to the middle of the room where there is a drain.  We pushed forward the laser and did our adjustments for a couple of days.  Yes, it works.  We pushed it back and nothing worked.  If some of you are mechanically inexperienced and know what you have to do, then don't use  this original design.  In the suggestion, they left open how to handle the air.  When you cut with a laser, when you do anything material processing with a laser, you will  have fumes.  If you have small particles, they are just there and you need to get rid of them.  The easiest way is you have one hole on the other side and you have a fan on the other  side and it sucks the air through.  We did it basically this way and we got a lot of vortexes going around.  It is like in a snowstorm where you have in one end of a house suddenly, Germany is called  Schneevia, a lot of snow and the other side is there is no snow and just by the wind.  We have a lot of dust in the machine which is in one corner and the other area, it is  nothing and the mirrors are dirty.  So there is a lot of room for errors.  We haven't figured it out yet perfectly.  It became better.  We have another fan with I don't know how many cubic meters per hour, I think one and  a half thousand cubic meters per hour of air flow.  This makes it a bit easier and makes it a bit better and we have a filter system.  But realized when the filter becomes clogged, the air flow isn't that much anymore and we  start again having these vortexes.  So there is a lot of room to think about.  The original design doesn't care about the EN 6,850 which is the standard for laser systems.  It starts with the emergency stop switch.  It continues with an interlock circuitry and it is not safe.  You can't use it out of the box.  You can use it alone at home in your basement or in the garage if no one else comes.  Then you can do whatever you want.  But not as soon as there are more people involved who might also not know about laser systems.  So that's a bit weak.  I mean they come from America.  This design is American.  I don't know.  These standards are quite strict.  They are similar to the 6,850 standard.  They should have followed it.  So this is one of the mechanical things.  When you see this is the holder for the big boom which goes in Y-axis and there is this  other piece which goes in X-axis.  There are three long screws into the extruded aluminum profile and they are quite long.  After some time of operation we realized it got a bit loose.  These screws they warped a bit.  So suddenly we could turn this boom and immediately you have fun with adjustment of the beam.  So room for improvement.  Then it comes to electrical.  Yes.  We have the problem that when you switch on the laser source and you fire the integrated  Beaglebone black crashes.  We didn't know why.  It was okay and some days it was really bad.  So you make a single shot and everything is crashed.  It took us a while.  I grabbed my oscilloscope from work and connected it to the Pools with modulator to output from  the Beaglebone via an AVR which does the G code interpretation into the stepping step  commands and into the PWM Pools with modulation to the laser source.  What you see on the bottom line, the pink one is the signal that I saw on the PCB going  out of the laser source.  At first you see it is a 5 volt logic.  It looks nice and then we have a lot of bursts going up and down, up and down, minus 5, minus  7 volts and plus 10, plus 12 volts.  I forgot the other traces.  We realized the power supply is sort of firing back.  There are a lot of EMI problems.  The power supply fired back.  This is what the pink line is what comes out of the AVR.  It goes back on the AVR and makes the AVR crash.  Yeah.  I don't want to talk about E-waste out of the box.  No, I'm not going to talk about E-waste out of the box but it comes close to it.  By the way, this electronics, this stock electronics is done.  It is open source.  Yeah, that's fantastic.  It is still open source and have no clue about what you do.  It is done in fritzing.  If anyone who knows about fritzing, you can have, it is very good if you have a bread  pot, if you have three resistors and two LEDs and connected maybe to some embedded  board, go with it.  That's fine.  As long as you have more and you do a larger schematic and are crazy enough to make a PCB  out of it, no way.  Don't do it.  You can't click like in other EDA programs like E-eagle or CAD or whatever.  You click on a trace and it is highlighted and it says which name it has.  On fritzing, you click on it and you just see it is just highlighted between two junctions.  There is no consistency between the schematic and the PCB itself.  I had to connect this board.  We had difficulties with the time.  We had the deadline.  The laser saw was a university project or institute for technical upshadowing.  It was a scientific project and we had a strict deadline.  We couldn't develop a known board.  We had to use this and we had to live with it.  I had to connect it and I got so cranky so many times.  I was close to through a closed window and smashed everything into pieces.  Painful.  Enough of the rant.  Yes.  What you see on the left-hand side is, I did try to bring it into E-eagle to make pictures.  What you see is basically how it looks like.  You have the AVR, you have two wires, two traces to the RJ45 connector.  Nothing else.  No protection.  No nothing.  For the inputs, for the end switches.  So X and Y have end switches and for the big door.  You have also switches.  For the end switches, at least you have a pull-down resistor.  So this is something I wouldn't consider publish to publish.  Because the solder stop was black.  You couldn't see any traces.  And with a loop and a lot of guessing, I put in an inductor against EMI distortions.  I had the capacitor and the Xenode diode to at least cut these tremendous normals over  an undershoot and it works much better.  Still this is a workaround and it was a lot of work to get the SMD components onto this  board and a lot of scratching, cutting of copper traces and so no fun.  Really no fun.  So we did something.  Why is this sleepy?  What we did in modifications is this is a beam catcher.  This is for the beam going from the first to the second mirror.  In case the first mirror is not adjusted, you don't know where it's going to shoot  the beam.  We have this ceramic tire so that if you don't hit the second mirror spot on, the beam doesn't  go somewhere else.  So if the hood is closed, nothing will happen.  An acrylic is for the unfocused beam is quite safe.  You see what happens.  You smell it.  It works.  But we use the ceramic tiles on many places.  Nothing happens if you shoot.  We also use the ceramic tiles on the floor.  We first had captain.  Captain is a fantastic material.  If you have a PCB and you go through the solder wave and you want to have some holes, you  don't want to be filled with solder.  So you have this captain type and you stick it onto and nothing happens.  Very thermal resistant but not good for a laser.  Someone had the idea.  It wasn't me.  I said, oh, yeah, let's stick captain on it.  When you shoot with a laser, it makes funny things, funny films and toxic things.  So we use the ceramics.  What you can see on the floor is where the laser was going on, cutting through wood.  It is compressed air through this tube.  There is a lens and there is the nozzle and you put in some compressed air so that no  fume goes onto the lens to make it dark and to blow away all the fumes and to cool the  spot where the laser beam goes into the material that nothing ignites.  Heat plus wood plus oxygen, fire.  So it goes through the wood and leaves some traces on the tires.  Quite impressive.  So what else did we do?  It's a bit tricky to see that we did a beam labyrinth.  When you close the hood, according to the original design, and you open it a little bit, there's  a possibility that the beam goes through and goes into room where you stand.  So it's just an aluminum angle we screwed on one of the extruded aluminum.  Just sort of make it safer.  Then we changed the tube holder.  It's so funny.  The original design was you had an aluminum piece of metal and another one and it goes  like clock.  And there's this delicate glass tube inside.  So no, we did something else.  And the benefit is we can adjust it in height, which is very important for the process of  calibrating the laser.  Then we tried to improve our airflow system.  This was a test on the left-hand side.  We tried to split the intake and air into what goes above the cutting area and below  to get away the fumes.  We are still not finished yet.  On the other picture, you see the dust from cutting wood.  This is what I told about the vortexes and leaving dust traces everywhere.  So then we did, when you operate a laser and do some material, you cut through something,  you will have or engrave it, you will have a lot of dust.  And this dust can be very toxic and this dust can be smelly, can stink.  And you don't want to let it go, let it out, you don't want to have it in your lab or in  your space and you don't want to let it out unfiltered.  So we designed a filter system which has five stages, going from, going finer and finer  until the two black things are, this way, are active carbon filters which filter the  last smelly bits and pieces.  This works quite well.  You have to maintain it, you have to look for the filters.  When one filter gets clogged, you see it that you again have these vortexes.  So the, reduces the pressure and the airflow.  And we changed the out, these area for suction that we cut out.  One side, the air stream goes in and on the other side in the floor it goes down and sucked  out to the bottom.  What else?  I mentioned few traces on the mirrors are very bad because you lose energy.  The mirrors will heat up.  It's not good.  We tried to 3D print covers for the mirrors.  This is one of our latest iteration with this long glass tube.  If someone has a better idea, I'm open to any suggestions.  It makes it a bit better.  We have less traces on the mirrors.  On the left hand side you see the original design.  It is just the mirror holder and the tube.  You have a lot of air and space around for any dust and fumes and smoke.  It gets a bit better.  We are still not at the end from where we want to go.  So electrically we made some electrical changes.  We haven't changed the board, the electronics board yet.  It is still in discussion.  We have a lot of ideas floating around.  A lot of different theories how this laser has to be made.  But we did some changes compared to original design.  First of all we use an E-stop relay which prevents an automatic...  That we don't have an automatic restart.  So you do something, you hit the E-stop switch.  The beam will go out immediately and the motors from the X and Y axis stop working immediately.  It is not emergency off.  It is an emergency stop.  So the electronic still is alive.  You get data back.  You can do something.  But the idea behind it is that the dangerous thing is shut down.  The machine itself.  The dangerous parts are shut down.  Our relay is from DOL.  We got it from eBay for affordable money.  It is something to do.  We made an interlock circuitry.  Interlock circuitry means that if not all the conditions are fulfilled you can't have  a laser beam.  So if you interrupt this interlock circuitry like you open the hood or the door then the  beam will go off immediately.  So you can do it laser chop and why the job is running.  You open the hood and the beam is stopped immediately and the X and Y continue working  doing their thing.  You can put away something.  What you've forgotten you can close it.  The beam will continue.  So also when you switch off the chiller I will come to cooling later.  That's the reason why the tube is here.  And also the air system.  The compressed air which goes into the tube is within the interlock circuitry and as well  as the suction system.  So you simply don't want to have that fumes in the system.  We did it once.  I don't know how it came.  We had it once.  Someone came up with a big piece of acrylic or whatever polycarbonate material.  Can we just do a quick cut?  I don't want to use a table saw or circular saw whatsoever.  Yeah sure.  Put it in.  It was still in construction, closed the door and we haven't had the extraction in the interlock  circuitry.  We forgot to switch on the fan.  And immediately the chamber was filled with this yellowish fumes and it took us half an  hour in winter time to get all the smoke out of the lab.  You don't want to have this.  Once we changed from these patch cables which are easy to break to something nicer, we actually  used Urflex from Lab Carbon which is a very nice cable which is very suitable for drag  chains.  You can go around back and forth a million times.  It doesn't break very, very thin, very fine, flexible, thin wires.  Excellent cable.  No, I'm not related to lab carbon.  This is our electrical operating panel.  On the right hand side you see the main switch for power mains, the chiller switch and for  the laser source.  And you see the E-stop switch and the green button is the release, the E-stop relay.  So processes you switch on the machine, then you open the padlock which we use according  to EN6850.  You need to have a for class four laser system.  You need to have a switch, a key switch or a num pad or something like that only people  are allowed to use the laser, actually can use the laser.  So remove the laser, the key padlock, release the E-stop switch and push on the green button  and you're good to go.  And when you actually want to do something, you switch on chiller.  The moment is quite, the chiller is quiet.  You switch it on right after you switch on the machine and then air is quite noisy.  You just switch on air when you actually want to laser something.  So there is sort of an E-stop functionality on the web front and on the web side, but  it has nothing to do with an E-stop, with a serious E-stop.  So in panic when something goes wrong, you don't want to click somewhere and find a button.  Where was a button?  Where was E-stop?  Up top right corner.  Okay, let's click.  Oh, shit, missed.  You want to have a serious one and it stops the danger immediately.  So then we ran into these troubles with the EMI problems from the laser source and we  had the idea that our Beaglebone was defective, that something destroyed something on the  board.  It is just three volts tolerant, the IOs and if there comes something more, it is very itchy  on this issue, then it dies.  So on the larger piece, you see the AVR and the rest of the electronics, which does the  G-code interpretation and this is connected via our receive and transmit, it's a standard  serial connection on TTR level and then it goes to the Beaglebone and then it goes via  Ethernet to the outside world and we took out the Beaglebone and we have another embedded  on board and we simply replaced it.  This works.  So calibration.  Calibration is pain in the neck, seriously, straightforward, takes days, makes a lot of  gray hairs.  It's necessary.  You need to calibrate the system.  You need to calibrate the system where the laser is going to stand finally.  As I said before, we have the floor in the lab is not horizontally, not leveled, but  it goes slightly downwards.  You need to have it in that place if you don't have a perfectly leveled floor.  You need to level everything.  Go with this water level, check out diagonal, horizontal, vertical axis, all these needs  to be leveled.  And then you need to have the beam coming from the tube.  This is the fun part.  It goes to the first mirror.  It has to hit the first mirror from the height in the middle and then you go to the second  mirror and it has to hit it on all positions in the same height and then you go to the  third.  So it is a lot of opening, closing screws, going back again, again, again through the  cycle until you have it all.  The beam goes and runs on pain.  We did something to help to calibrate this laser.  This is basically how the mirror holder looks like.  The beam comes from here and you have this piece of aluminum and this way and you have  the actual mirror goes a bit inside.  It is a bit like a mirror frame.  As we stick it in a label, I come from the labeling industry, we stick a thermal sensitive  label onto this frame and the actual mirror is not the same height.  It is three millimeters deeper.  So you need to do some calculations and you see on the left-hand side, this is actually  in vertical and you see that the beam doesn't hit it in the middle but it has to hit it  a bit below.  What you did is, these are shots from onto this thermal sensitive paper and here you  see on the left-hand side what it just meant, the beam holder and the mirror and it is behind  the front of the mirror holder.  So the two images, the two shots on the thermal sensitive papers are quite okay.  We stick this paper onto the mirror holder and with a fingernail or with a back of a  knife, you just mark it so this is this sort of circle, this funny polygons.  So that we then have a tool, it is printed on foil and on the right-hand side you see  this, it looks like a fingerprint.  But if you center it on the spot where the beam hit the paper, you can see how far off  you are from how far you have to adjust the mirror.  So this is your maker shot, you put it down, two millimeters too far, okay, then you open  the screw, lift the mirror holder for two millimeters, you do again the same shot.  Next days, I want to put these files on my website and also ask a file on the talk.  Yeah, it's difficult to describe.  If someone wants to know how it works, FabLab is in Karlsruhe, we are very open to visitors,  please come to visit and we can show you.  So things you should not do, you should not fry your tube, it's expensive.  This one is fried.  Very simple reason, totally stupid reason.  The chiller is a system, it has a water pump, it has two water pumps, so it's redundant.  It has a cooling system with a compressor and everything, it is a fantastic machine.  But if the plug this year slips out, then you're done, then you're finished.  It happened five minutes after first time laser on this day, at my just piff, light  was off and water run through the whole machine and I don't know how much water is inside,  but the pump was fortunately not functioning, so it didn't continue pumping water through  the electronics of the laser system.  Yeah, expensive, expensive experience.  This is something you should avoid, always check your cooling system and always check  the water security, besides all other things.  Great.  If you like you can contact me, Sarah at laserlady.org, soon you will see this talk on this website,  soon you will see the talk from the GPN 15 on this website.  You can contact me if you have any questions, feel free.  I want to thank all the guys here at the camp for this awesome time.  I want to thank the FabLab Karlsruhe and I also want to thank the ITAS Institute for  Technique Folgenabschätzung in Karlsruhe, which did the funding and which helped us  a lot and we had a lot of fun together, as you can see on the picture below.  We have some time left.  I'm out of slides now.  If you want to know something, feel free now.  We can do for the Q&A.  We have a lot of time because this is the last talk in this tent for the camp 2015 and  at first thank you for your patience and thanks for listening.  Which talk is doing the Q&A?  Thank you, Sarah.  We have some people here.  I'll start over on my right.  At Hackerspace Hack42 we have a Laos laser.  We have had quite some issues with the accuracy of the code itself that it doesn't calculate  the laser precision correctly.  Do you have any problems like that in laser, Sarah?  That just works fine all the time?  It works fine because it works with absolute positions.  When you switch on the machine you have to run the homing cycle, which means it goes  in X and Y axis.  On the top left corner there is zero, zero.  It goes to the first end switch and goes to the next end switch.  Then it knows here is zero.  Then you can do whatever you like.  It knows where the head is.  Is it that?  Was it your question?  My question was that with Laos you could get, for example, you do an entire run and you  go back to the zero position but it's not exactly at zero position.  It makes a small error during the cycle.  No, this doesn't happen with laser, Sarah, electronics.  Sometimes it really happens that you can do a lot of things with parameters right or wrong.  Let's say you go through three millimeters, would you choose a thousand millimeter speed?  Let's say not to treat the tube bad, you go with 50%.  Then you run.  Afterwards you see if it goes through or not.  You have the feeling no, it didn't work.  Then you can do the same run, the same job again and again as long as you don't touch  anything inside like you move a piece of wood, nothing happens.  It goes exactly the same contours, exactly the same traces.  But I wouldn't recommend this hardware very much.  We've used the Laos hardware and the hardware itself is basically from what I hear from  you in quality roughly the same as the laser saw.  Also no inherent safety in it at all.  What we're going to do is, as I mentioned before, we want to do our own laser bars.  With my experience in laser safety there will be an FPGA for all the safety circuitry and  some more benefits.  What we actually want to do with the laser is doing big data.  We want to monitor the temperatures of the mirror of the tube of water in, water out,  water flow, how many times or how long the laser tube is running and this and that and  that and that.  We want to integrate it into our lab net and store the data on the server so we can see  slow changes for example in the temperature of a mirror.  We can see, well, it's time to clean.  So we get some more experience, more data for having experience.  Yeah, the Laos.  I heard the name Laos, but maybe I have seen it, but I can't remember.  But if you say it's the same, no, I don't say.  If it's the same type of board, there are some other smoothie boards I heard.  The Haas should be okay in support of laser, but they all don't have laser safety circuitry.  Was it, did I answer your question?  You answered it fine, thank you.  You're welcome.  Okay, and we have another question over there.  Hello, I'm leaving standard FabLab Brussels.  Thank you for the interesting talk.  Another FabLab, yes.  We don't have a laser store yet.  I worked with one in Antwerp.  You just answered my first question about the controller.  My second question would be if I want to build it on a smaller budget as a student project,  where would you compromise?  At the tube.  Do a 60 watt instead of 100 watt.  Yes.  100 watt is fun.  Sure.  I mean, nothing replaces power so good like more power.  Everyone knows it.  Same like memory.  But you can do a lot with a 60 or 50, sometimes 40 watt tube.  This is about 1,000 to 1,200 euros, you can have it cheaper.  What I just learned is that you can have, let's say 100 watt in this size, or you can  have 100 watt in smaller size, larger, I don't know, but in a different size and it's cheaper,  but the beam quality is less.  It's not so nice.  I mean, you have seen the images on the papers, the small shots.  It was just a small shot with very low energy on the paper to get this, to get a bit, to  see where the laser beam goes.  It looks like a donut, so the energy distribution in the beam is like this.  The beam doesn't go out collimated.  It's like glasses.  So the beam widens up.  And the way how much, how far it widens up, this is one quality parameter.  And the cheaper the tube, the more you have this.  I would go with a high quality, but less energy tube.  You want to have a high quality or you want to have the beam as good as possible.  You kind of have a lot of energy, but if the beam is crap, then you have problem adjusting  the system and makes it fun.  And you can compensate less energy with slower motion of the head.  You don't need to run 8,000 millimeters per minute, what you can do with this tube.  But then you go on 2,000 millimeters or you go with 100 or whatever.  I would save the money on the tube.  Get a good quality, but you don't need that much energy.  And I think there is no linearity in how big the machine is.  If you have an aluminum profile, if you have it one meter or 80 centimeters, there is a  big difference.  So go big, build the machine in the full size, but with less energy.  It doesn't hurt.  Yes, thank you.  You're welcome.  Okay, then we have another question over here.  Yeah, please.  Hello, my name is Arvid and I wanted to thank you for your nice talk.  It's very interesting.  We in our Hacker Space are planning to build LaserSaur 2.  So I wanted to ask, we are not really sure how much it will cost us.  So I wanted to ask you how much are the costs only for the materials if you doesn't broke  anything.  And the second question is how many people were you to build that up and how many men  hours or woman hours, sorry, you put into it.  I thought it.  The pricing.  As far as we know, we've been between five and a half and six grams, five and a half  and six thousand euros.  And this was 1,100.  So just take this out of the calculation.  You will be good with four and a half case.  But you can do if you think twice about the design, there are some, there is some room  to save some money to make things more intelligent, more smarter.  You will find better solutions.  It is quite cool if you have some mechanical engineering guys or girls.  It is not the end of what's possible in the design.  And yeah, I find another board.  Sorry, I forgot the two last other questions.  The second question was how many hours you put into the project until everything was  running.  We had two building weekends, meaning we met on Friday afternoon.  We had the mechanical group and we had the electrical group.  The mechanical group had about two weekends building, which means beginning Friday afternoon,  working until late night, two, three, four o'clock.  Next day, Saturday, meeting in the morning about 10, working late, having supplies of  Marty, of pizza, what's necessary, and working late, and on a Saturday, not so much, but  working until 10 o'clock in the evening.  So we had about two weekends this style and one, as far as I remember, one weekend for  the electrical system.  So we've been, I don't know how many guys have made the mechanical setup.  I think it was four to five guys.  I don't know if they've been there all the time together or if they did shifts from the  electrical side.  We've been three to four guys and we tried to distribute the work.  One was working on this area and the other one.  This area and we tried to get the cables around.  Because you stand in cables, you have wires around and around and open ends and you, yeah.  I would say if you're focused, if you have everything ready, a theme for good weekends,  or let's say one week of vacations from morning to evening, you can do it.  Okay, same.  Yeah, please.  Okay, then we have one more question over there.  You got plenty of modifications to the laser-zower design.  So in which website can you find them?  Out.  In non.  I don't know where we got the laser holes, the laser tube holes in plastic parts.  I don't know where we bought all the parts.  We bought the electronics at the Nordtards labs.  Nord labs.  It is the webshop around the laser-zower where we got some special water cut aluminum parts.  They have these, if you get a sheet of metal, eight millimeters thick aluminum with some  special parts.  And there you get also the mirror holders and you get also the tube and also the electronics.  One thing I forgot about the mirror holders, one thing we want to modify we haven't done  yet is it is nice.  You can pan until the mirrors, but you can't move them up and backward and forward.  You can't move them in the three axes.  This is something very, very important for calibrating the laser.  Because otherwise if you want to change something, you have to open an M4, M5 screw because it  is an aluminum profile.  And you open the screw, you shift it two millimeters in one way and you close the screw.  You can all imagine what happens.  You have to start from the beginning.  Yeah, we haven't found these mirror holders yet.  We got a lot from this Nord Labs web shop.  The electronics we're going to build, we will publish open source, of course.  But I don't think we will sell them.  Maybe we sell the PCBs.  I don't know.  It's not decided yet.  And eBay is a fantastic source.  This emergency stop relay is from eBay.  The three switches are from eBay.  The emergency stop switch was from eBay.  You have to look.  On which website you plan to publish source?  First of all, it's fablab minus calzwood.de.  This is where I live.  This is my space and then I guess it will be published on GitHub.  Something.  Thank you.  You're welcome.  I think that concludes the questions.  There's no more.  Okay.  It's really over then.  Thank you very much.  Thank you all guys.  Thank you.
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