Solid 3D printed concrete will be a powerful tool for designers and architects. In the fall of 2014, my colleague Alan Cation and I created a mobile 3D printer that, as part of the CCA Master of Architecture studies, can print large objects with sawdust. We decided that while sawdust is a very good material to test our technology, we would really prefer to print concrete. However, in order to use our mobile 3D printer with concrete, we must first understand the behavior of concrete as a powder bed printer material. OK, put on your dust cover and boiler set and calibrate your digital calipers and it\'s time to get dirty. What can you get from this structure :- Introduction to how gcode and CNC technology work we will create a CNC machine, but you do not have to deal with any dangerous parts of the CNC Operation ( Read: No spindle). Since we are using a self-built solution to control machines, you can get a close look at how we can convert computer geometry into gcode instructions. - Go deep into how the powder bed printer works and you will feel like a 3D print champion. From understanding geometric constraints and possibilities to how to dig print without breaking the print, you will walk all the way through the powder bed 3D printing process. - The power of 3D printing in concrete! Don\'t let our architectural bias limit your imagination when we focus on printing sculpture/structure/building objects! Finally, you can use this fully printed cool jar, outdoor furniture and sandcastle, which is the way we teach this technique: while we will show you in particular how we make this thing work, there are many ways to make this particular cat skin ( It\'s not that we let the cat Peel). Replace, experiment, share your findings! This is a list of the things that are most needed for hardware setup: gantry- Alas, an important aspect of building a 3d printer is getting a gantry! To gain control, we used an improved shapcnc CNC machine. Here is how the linked shapoko is assembled. We expanded the gantry to a 4\'x6 \'aluminum rail. Plastic CNC machine tool aluminum rail expansion micro controller- As a micro-controller, we use arduino uno boards for both gantry control and for the storage of adhesives by pumps. The programming of the micro-controller will be introduced in the instructable later. Shapoko also provides information on how to set up wiring for the motor controller, which is equipped with an uno board and a stepping motor shield. The Peristaltic pump needs its own uno plate and motor shield. We also have a file for 3d printing the motor holder. 1 Arduino uno boardDC motor shieldA a bunch of wires- Stranded and solid-core end actuators- The end actuator consists of a peristaltic pump with a pipe, nozzle, 3\' aluminum guide rail and a reservoir that holds the adhesive. It is possible to motorize the z axis, but we found that it is faster to manually control the Z axis height during our printing process. We have also attached. Stl files for 3d printed parts. Spray bed-aluminum extrusion-squirming pump tube The print bed is an optional method. We built one for a certain amount of material to accommodate, but there is no need to have one during the printing process. To build our printing bed, we CNC milling plywood. If you decide to build one, here is what you need, otherwise you can put the gantry on the post. 2 sheets 4\' x 8 \'- 1/2 \"plywood2 sheets 4\' x 8 \'- 3/4 \"the plywoodAcrylic sheet gantry assembly is well documented in a link found above. As for the print bed, steps can be found in the drawings here if you choose to build. If not, the gantry can be installed on the 4 pillars that extend out the ground. DXFs for print beds can be found here. The post is the first thing to assemble, then the frame, and the post is added to the frame. Adhesive reservoir and bracket for Peristaltic pump mounted on X- The shaft of the machine, the arduino board is installed in Y-axis. You need a ton of sand (literally) And half the cement. If you print something in a smaller size, you can use less of these materials. To print 3 objects with a volume of 2\'x\' 3\'x\' 1, we used 1,000 of sand and 500 of cement. We use 30 sand fine aggregate sand and white cement in most prints, the ratio of sand to cement is 2:1. We used this method because of fine aggregate sand, and the coarse aggregate can use a ratio of 3:1. The adhesive we use is a soil hardening agent called polyphosphorus, with 5 gallons of barrels. The Poly takes effect through the evaporation process, so the concrete will initially solidify, and when it digs, the Poly will make the material stronger. It is also convenient to have too many 5 gallon barrels and tarps. Now that you \'ve addressed the need for hardware and materials, it\'s time for the CNC to move. If you have followed our advice so far, you have been given a modified and extended Shapeoko 2 CNC machine with a reservoir and reciprocating pump tied to it, Since we also need to control a worm pump and manually cut the layer height of the toolpath, we chose to run our machine using Rhino, grass grasshopper and Firefly. The attached grasshopper script acts as a gcode \"translation \". It accepts surfaces and solid objects as inputs and turns them into a series of instructions to be followed by CNC machines. These instructions are simple coordinates, g- Drive the shielding of the stepping motor and then convert to the signal driving the stepping motor. What a wonderful time to live Download the attachment and look around. Once we start rolling, it\'s easier to understand what\'s going on. So you should have built your machine, mixed materials and software downloads so far. It\'s time to start lifting concrete. The printing process can be described as a repetition of the following steps: 0. Before you start, you need to measure the overall height at the bottom of the bed (in millimeters) And enter it into the script of the marker point. If you would like to explain why, please read the second step quickly and come back. Also, create a physical \"origin\" location to re- Calibrate your machine in case your computer crashes randomly while printing. Believe me, you will want to do this. 1. Add concrete and level the bed: the amount of concrete you need to add depends on how big your bed is. We found a 3 \'x2 \'print and we added about 4 quarts of mixed concrete for about 6mm floors. In order to get a good combination between layers, keep each layer below 10mm. Leveling the bed itself is a process. The practice here is perfect. Just get as close to it as possible. Smooth uniform motion is better than short ups and downs. Also, try to change the angle of the material you sweep out. We chose to keep our bed with the rest angle of concrete. If you are doing this, make sure that every time you add more material, you sweep the material off the side of the bed in order to create more support for the sand at the next level. Set the origin in grasshopper to stay away from printing and leave it there until it is ready for a height check. 2. Read the layer height and enter it into the script. Move the CNC stand to the middle of the print ( Height check settings). Then use a laser ruler (like this one) , Measure the distance between the top of the compartment and the powder bed. Usually, in powder bed printing, there is a machine after each layer to level the bed precisely, so the height of the layer is known. Then, subtract this number from the overall bed height and find the current height in the model. Because we have low resolution and large scale, we don\'t need ( We don\'t actually) So much control So instead of matching our bed height to our model, we just match our model to our height! Brilliant! 3. Make sure you have enough glue in the reservoir for her to tear open. Set the machine to run and switch the switch to stop the counter reset. Sit down now and watch your machine do all the work for you. I found this to be a great time to measure more material on the next floor, put on new work gloves, make sure your dust mask is intact and think about the futility of being there. 4. Rinse and repeat your machine to the origin to clear the bed and level the bed. Nice work! You 3D print in concrete! General precautions :- Keep the bed level! Take your time and it will make your life easier. While this printing technique is very forgiving, divots in the bed and any other deviations spread the adhesive pool away rather than directly penetrating down. It will make your print more beautiful, I promise. See the video above and see how I did it. - Make sure your design fits the rest angle of the sand. You will save materials and time if you plan ahead. We have found sand/cement about a 35-Angle 40 degrees. - If you have a work light installed by the bed, the shadows it projects can help you find uneven spots more easily. Now that you have finished your printing and have cured it for about 12 hours, you can dig it up. From the top, slowly dig out the unfixed concrete and carefully feel the edges of the print. We found small plastic cups to be the best choice for digging as they are all soft enough to not damage the print and have enough concrete to use. If you let your print stay longer, it will continue to heal and gain strength. Traditional mixed concrete usually gets full strength after 24 days, but this is far from the traditional mixture, so hopefully your print will initially be more like a weak plaster mixture to gain strength as Poly The pavement and concrete continue to solidify. If you have gone so far, the job is also good! Post your results and findings in the comments below and let us know how your printing is progressing.