Another 3D Print - Star Wars Tie Fighter

Last week suddenly I heard a noise and I saw the extruder of the 3D printer I build hanging on only one screw. I tried to fasten everything again, but I had no luck what so ever. So before I could do any more printing I had to take the whole extruder apart, fasten the screws a but more and put it back together. That was a little setback, but unfortunately it didn't end there. After that I had to recalibrate the head distance and I had no luck in that.

The material just didn't want to stick to the heated print bed anymore. I tried cleaning with alcohol, rubbing it a bit with sand paper like I did before, but no luck. Then I started looking on some forums for a solution and I found one. Painters tape! Very cheap stuff that you can just stick on the print bed and after that I printed like a charm. I guess by now you would have guessed from seeing the pictures of a print in progress.

The model I printed came from ThingiVerse and it is a tie fighter from Star Wars. I really like the look of that model. It consisted of three separate printable parts that you eventually have to glue together. But before I got to this point there was some more trouble. After the first print was finished, the material was stuck to the painters tape so well, that I couldn't get it off. I printed in PLA and that is quite fragile, so I could not use too much force since then the material would break.

So again I went to look for a solution and I found one. The tip was to use a spraycan with compressed air, put it up side down on purpose so that the stuff coming out is frozen. This cools the object to quickly that it shrinks a bit and pops loose. And guess what? It worked :) I will go and look now though for blue painters tape since they say this is less sticky. So that is worth the experiment. All in all the model is done and I really like it. But again I found out that printing on a DIY 3D printer is not so easy as it looks. Ah well most important thing. It still works. Up to the next project.

First 3D Printer Output

Last time I promised to show you the first thing I outputted on the Velleman K8200 3D Printer. Well here it is. It is actually kind of a puzzle that you have to put together. It was originally designed for laser cutters to be made of wood or metal, but someone transformed this into an STL and put it on ThingiVerse. This site is filled up with nice projects, but I decided this would be a nice first test. So here is a picture with all the finished parts.

And this is what it looks like when you put it all together. It is actually a Tyrannosaurus Rex model. I think it looks quite neat. I printed it in transparent PLA and in thick layers that turns out to be a bit white. It is made with 50% infill and the nice thing is when there is light on it you can see the honeycomb structure inside. I think it is quite cool. Well this was the first print as I promised. A very decorative and non functional make :)

And here is another picture of it. I probably should have taken it from the other side, but I didn't think of that ;)

I did print a lot of other stuff in the mean time, but nothing is quite finished yet. I'm still very busy with other stuff and don't get to printing too much unfortunately.

I will try to update you all soon on that, but first things first. Work is taking up a lot of time at the moment.

Velleman K8200 3D Printer (Part 6)

I know it has been a while since I wrote on here and that some of you are waiting on the final part of this series about the Velleman K8200 kit. I have been very busy lately with my new company Virtiso BV and didn't have much time for anything actually. But today finally I found some time to catch up on here. First of all here is a picture of the finished printer doing its first test prints. As I wrote before though this didn't go as I planned.

On the picture on the right you can see what happened on my first test prints. I was quite puzzled and had no idea what to do next, since the manual ended here. I started reading a bit on several forums and started asking around. The first thing I learned (and it is in the manual now) that you really need to roughen up the print bed a bit with some sand paper. It is just to smooth as it comes. Secondly you really need to clean it with some alcohol. This has to be 70% the least, but more is better. This is because when you touch it with your fingers it will become greasy.

And then I think the hardest part was calibrating the print head Z distance. The head needs to be exactly 0,25 mm from the bed. And in every direction. So you need first to level the print bed with the screws below and then you need to turn a screw that touches a microswitch to calibrate it. I tried to do that on eyesight, but that really is impossible. You need a tool like you see in the picture on the left. I don't know what it is called in English though but it consists of small metalic blades that you can use to 'feel' the distance of the head to the bed. When you can put the 0.2 5mm blade just in between and you feel some friction it is OK. Then don't forget to securely fasten the calibration screw since it will come loose from vibration.

And then you need to calibrate the software settings as well depending on your material and print object. It took me about as long to calibrate the printer as it took me to build it. So do keep this in mind. Printing in 3D is not as easy as it looks at first sight. It takes time, skill and a lot of patience :) Then I had another problem that turned out to be the USB driver on windows. I finally swapped to a RaspBerry Pi running Octoprint and in the picture on the right is the first part that was finally printed successfully. What it is I'll show you in a later post ;) This concludes the building series. I hope to post some stuff that I printed over time on here. I'll keep you updated when I can.

Velleman K8200 3D Printer (Part 5)

Another very critical and not so easy part of building the K8200 3D printer is assembling the hot end. This is where is plastic eventually will be heated to 190 degrees C with PLA and even higher with ABS. To keep the temperature steady a tiny NTC has to be inserted in a very small whole in the heater. The wires are about as thin as a hair and you have to solder them to the thicker wire, put heat resistant tube around it and make sure none of the leads touch each other and don't touch the copper either.

If you make a mistake here or don't insert the NTC resistor properly in the whole your temperatures will be off and your prints will fail. You need a lot of patience here :) On the right is a picture of the whole hot end. It is actually up side down. Eventually the plastic flow from the little hole on top of the copper nozzle. This is the print head and it will be about 0,25 mm from the print bed. Another remark is in the manual that you need to tighten all of this very good to prevent leakage that will be unrepairable and will cost you a new hot end. So again. Patience and check and double check everything.

The it is time to install the control board and solder all the wires. Not a very exiting job but again you need patience and some soldering skills. The manual is quite extensive about which wire goes where and shows a lot of pictures. So if you follow along carefully you can't go wrong there. When you are finished you wrap everything up neatly with some tie raps and you can do some sanity checks with your multimeter to see if there is no short circuits anywhere.

And then you are done building, but not finished by far. The first step is calibrating the stepper motor voltages. You need a multimeter and a very small screw driver for this and again patience :) Then you test the switches with the multimeter and measure the NTC's. And then the famous smoke test. Hook up the power, watch the leds and see if nothing smokes. When that is done it is time for some actual testing from the software and seeing if all the motors run and if the calibration works. So far so good. I'm happy to say that everything was working for me the first time. But the story isn't over yet :) The hardest part turned out still to come. More on that soon.

Velleman K8200 3D Printer (Part 4)

Next part to build was the extruder. This is the mechanical part that feeds the filament (plastic material) in to the extruder. It holds one motor and some gears. The tricky part here is to put a spring in that has quite some tension to it. And this also holds the last motor. It is very essential that everything runs smoothly again. The manual also talks about some bolts that need to be 'tight' and some that cannot me 'too tight'.

All very relative right. I thought as longs as it runs it must be OK. Then you have to attach it to the frame. I found out that this is not easy. You have to put some rings in between and they kept falling our every time I tried to screw it on. I think I did this 10 times over. But well. It is on now. This actually concludes most of the mechanical moving parts. Everything still runs fine so I'm quite happy so far.

Then you have to assemble the heated print bed. There are two tricky parts here. First of all you have to solder on a NTC on the backside. Not easy since it is a SMD component and it is very small. Luckily I did this before, but you need some skills and a good soldering iron for this. It is essential that you solder it as flat as possible or you will get into trouble later. Also the screws are actually to large. They stick out of the bed. Try to avoid that since the print head will only be 0.25 from the bed and the screws can be higher. You don't want to hit them since the software doesn't know the screws are there.

Then you finally get to install the mysterious part that you build the first. And suddenly you understand its purpose. It only holds the spool of filament later on. So the detailed description given about the measurements here make no sense at all since all the spools I've see so way are way smaller that this. But a well.. It fits :) I did have one spool laying around and of course it fitted easily. OK so far for the mechanical part. After this it will be electronics and lots of wiring.

Velleman K8200 3D Printer (Part 3)

I didn't have much time lately to continue this report, but now I did so here it continues. Next part in building the printer was constructing the frame. It is made of clever aluminum struts held together by 90 degree angled clamps. I never saw this stuff before, but it is really cool you can build anything with this I guess. Tricky part is you really need to read the manual here since you have to insert some square nuts in there that you will need later.

After that you insert the X/Y carriage that was constructed before. Aligning is a careful job as well. It has to be positioned very well. The cool thing is after this you are able to move it around and get a sense of what it will be like when it is printing. I was quite happy that everything seemed to move very smoothly so I could go on to the next part. Down side is now that it is getting quite a large piece to work on so I had to continue my work on the floor.

Then you start building your way up. These two assemblies on the left and right will eventually move the print extruder assembly up and down. So this is for the Z movement. On the left is another motor with a long piece of threaded material attached the drives an embedded bolt. On top you have to apply quite some force to screw on a lock tight bolt. It is quite difficult to hold it all. You have to be especially careful not the damage the thread since it will make smooth movement problematic later on.

And the last part is to install another piece of aluminum strut on top to hold everything together. I didn't follow the manual here on purpose. The bar is supposed to go lower with a bracket on top, but I thought it didn't look as nice and I preferred to mount it like this. I could not think of any problem this would create since the whole construction was still rock solid. And it really necessary I could always change this later on. So far so good. Everything still running smoothly also by turning the motor for the Z movement. It is really starting to look like a real machine already :)

Velleman K8200 3D Printer (Part 2)

And here is the correct tool. Life if so easy when you have the right equipment. With this tool snapping the O-rings in place was a matter of seconds work. So do your self a favor and get one of these. Velleman is quite clear by the way in the manual as well about the tools you need, so go check this before you start your build and get frustrated. OK enough about the tools lets continue with the build.

After the this you need to construct the other carriage and these two go together with some rods. It is very important that you get this very straight for a smooth movement later on. So you are advised to tighten all the screws while moving the carriage so that it aligns during screwing. Don't apply too much force since it will twist the part then. I found also that adding a little teflon spray helped to make thing evens more smooth.

After this you have to install the first motor. In total there will be 4 motors in the whole printer. One for the X, Y and Z movement and one for the extruder later on. The most difficult part in this step is cutting the timing belt. You have to count an exact number of tooth and not more one or less. If you screw up here you can order a spare part :) I think I recounted about 5 times  before I finally cut it and still wasn't sure :)

Here is the complete X/Y carriage including the motor and the belt. Eventually the heated print bed will be attached on top of this whole construction. Well so far I am happy with the result. I'm not that skillful in mechanics but it all runs very smoothly. Before I called it a day I did read the rest of the manual to estimate how far I could get the next day. But I was pretty sure it was going to take at least 3 days to build this thing. So far for day 1. To be continued..

Velleman K8200 3D Printer (Part 1)

Another thing that has been on my mind for a long time was building my own 3D printer. I had been looking on the internet for several projects, but none of them were very clear. I found some kits, but they were a bit expensive, then just a week before my holiday I visited my local electronics store to pick something up and there was this 3D printer kit from Velleman on the counter. Complete and ready to take and for a price I thought was really interesting so I couldn't resist it and took it home including some PLA print material. The kit is called the K8200 and I started building it right away. I took picture along the way so I thought it would be nice to share this experience with you as well on my blog.

Here is the content of the box. A lot of small bags with parts, some metal parts and some electronics. I was expecting a bit manual, but I couldn't find it at first, but when I read the documentation that came along they pointed to a website. On there is the real build manual and it is rather extensive. A lot of detailed pictures. For the first step I made the mistake to print the pdf, but that were way too many pages, so I continued the build next to my PC to read a long on the screen.

The first part to build is rather simple. It is just a rod with some nuts and rings on it. At first I didn't understand what it was supposed to do, but later on in the build project I found out that this is the spool holder. The plastic material is delivered on spools as you can see in the very first picture and this thing sticks on top of the printer later to feed the material into the printer and make the spool rol turn on its own axis. Nothing fancy but still an important piece :)

The next part to build is the carriage that will hold the print bed later on. I immediately ran into trouble there. On top in the picture you see some ball bearings and below that some O-rings. You have to put these rings around the ball bearings and slide them into the black plastic parts. You need a special tool for these o-rings and I didn't have it. So I tried to get them on using other tools, but that is really impossible. Then my wife was smart enough to see this and ask me what I was doing. I said I didn't have the right tool and that it was Friday evening and the shops were closed. Luckily my wife is better into shopping as I am and told me the hardware store was open all evening :) Oh. I just spend 1 hour for nothing. I short trip to the hardware store and 15 euros further I had the right tool. To be continued in part 2.....