Now that I am sure that version 3 of my extruder prototype can handle PLA without any problems, it is time to test new materials. A raw material with this suitable grain size which is available in almost any household is sugar. So let's turn on the printer and check the temperature needed to melt this material. According to the display on the printer, this is the case at around 170 degrees Celsius. It can be seen that the grains change from solid to liquid almost instantly. This video sequence shows the real speed of the process. So let's put that exotic 3D printing material into the hopper and heat up the hot end. As soon as the dial temperature was reached, I started the extruder motor to squeeze the sugar out of the nozzle. However, this looked very different from the way PLA exits the extruder. Instead of forming a sugar string, this material trips out of the nozzle like water. This is because of the significantly different chemical composition which corresponds to a very different physical properties. Sugar is the generic term for a whole range of different sweet tasting substances. The household sugar used here consists of sucrose. As wept the conveyor screw for a wood screw without a wire at the tip because the helical ridge must dive deeper into the melting zone to properly forward the sugar grains. In the third attempt, the printing finally worked. I'm using my universal cure for better teaching, my cheap glue stick. The file to be processed is the small gear on the stepper motor of the extruder. The temperature of the hot end is set to 181 degrees Celsius. The print speed is 10mm per second. As you can see, a color change occurs in the hot end. The sugar exits the extruder in a slightly brownish color. The reason is the caramelization reaction that takes place at temperatures above around 140 degrees Celsius. A pleasant smell spread in my video studio that made me feel hungry. The top surface of the gear is not as smooth as when printing with ordinary plastics. The reason is the surface tension in combination with the significantly lower viscosity of the molten sugar. The tip of the nozzle is always surrounded by a drop of liquid sugar. With that it is surprising that the only 3mm small teeth of the gear become clearly visible. The tiny gear is far from being perfect, but not too bad for a first try. At the top, the tendency of the liquidified sugar to form droplets can be clearly seen. On the other hand, however, you can also see the layering of the print. For the next attempt I use a sugar solution for better adhesion on the print bed. The brown color of the solution comes from the fact that I also disolved a piece of the gear printed before. To make the water evaporate faster I set the print bed to 80 degrees Celsius, which is the temperature I use during the following prints. First an octagonal base plate with a diameter of 100mm is printed. The sugar now sticks much better to the print bed. Again I started with 10mm per second as print speed. During the first layer I increased the speed to 30mm per second, which still works well. When assembling the extruder I forgot to seal a gap on the inside with adhesive tape, so sugar grains keep falling out of the hopper. At 30mm per second the end made extruder prototype starts getting louder due to vibrations of the mechanics so that the sugar crinkles down. The base plate is printed nice and smooth at the higher speed. Now you can see sprints of printed sugar on the surface. Obviously, the melted sugar has no longer enough time to form droplets before solidifying. The next step is to print 1.8mm thin walls on the 1.75mm thick base plate. With an extrusion width of 0.45mm this corresponds to a total of 4 passes per layer. The sugar walls are clear enough to look through them. The walls grow higher but at some point you can see that the top edge is getting rough. I guess that this is caused by the weak mechanics that tends to vibrate. You can clearly hear the clutter of the printer. Not much later it happens as it has to happen, while scratching with the nozzle over the rough edge a piece of the thin wall breaks out. When the extruder passes over the missing piece in the wall it can be seen that sugar is completely unsyutiful for bridging gaps. When keeping the low viscosity and the high surface tension of sucrose in mind the non-existent bridging capability is no surprise. So in the next test run the print speed was set to only 10mm per second for the walls in order to keep the vibrations of the mechanics low. If the base plate is also printed at this low speed it becomes just as bad as with the gear wheel. Here too sugar droplets will form on the surface. With the reduced print speed it can be seen that the caramelization leads to darker color. The walls are amber and no longer quite as transparent. Again a prop of sugar forms around the tip of the nozzle. The individual strands cannot be seen on the upper edge. The individual layers in the walls on the other hand can be clearly identified. There are 50 shades of brown in the different layers. The hand made extruder has so called dead spots which are corners in the extruder where the sugar stays in place a little longer until it is flushed out of the nozzle. Longer caramelization leads to darker color of the sugar. All in all I am satisfied with the result. The walls are quite smooth and no cracks can be seen anywhere within the layers. The extruder seems to convey the sugar fairly consistently. It's nice that the transparent sugar walls also allow a view on the inner structure. With the print speed of 10mm per second it seems like the printer has no problem with the printer material so let's try 20mm per second. Obviously that works fine too. But only for a few layers. The printer has not yet started to print rough edges but shortly after increasing the print speed a piece of the wall broke out. This happened when the print head was on the opposite side. Obviously due to the increased printing speed higher tensions build up in the walls while the sugar was shrinking when cooling down which finally led to a crack. Even in slightly caramelized form, household sugar is still damn brittle. This has also been shown before. When the print bed cooled down after the previous print cracks appeared in the base plate. Even a successful print would have led to self-destruction after the bed heating had been switched off. An attempt to print the base plate with a heated bed turned off also failed. With that cracks formed in the material during printing. Pure sucrose is therefore only suitable for special use cases in 3D printing. But there are gigabytes of sugar recipes available that could be worth testing. A 3D printer with a heated weld chamber will result in better prints. As with all materials in 3D printing you must keep the properties of sugar in mind in order to be able to achieve good results. The cone printed here has an angle of 45 degrees and a wall thickness of again 1.8mm. The diameter at the base is 100mm and the print speed is set to 10mm per second. As usually there are high resolution photos of the prints made in this video available on my website. Have a click. There you can also see how the print of this cone ended. And if you would like to support further research on my direct granulite extruder you are welcome to click the donate button on my website. Many thanks to all the great people that already made use of it. Thanks for watching and I'll be back.