3D: Extrusion (Potterbot)
The Potterbot for biomaterial extrusion involves loading a syringe with the prepared biomaterial, ensuring it has the optimal consistency for printing. The extrusion is performed under controlled pressure, and the biomaterial is carefully layered to form three-dimensional structures. Prepare for this fabrication technique by creating or scanning a 3D model. This method provides a versatile approach to creating intricate designs and allows for precise control over the final Biomaterial form.
Since most biomaterials shrink in size when they dry, prepare to print your biomaterial on a fabric surface to avoid cracking during the drying process. Depending on your print size, drying can be done in a freeze dryer, dehydrator, or on a warm sunny windowsill.
Contact email@example.com to book a consultation time before using the Potterbot. Before approaching this fabrication technique, consider whether your final form can be achieved by using 3D: Mold making, 2.5D: folding, or other fabrication techniques within this grid.
Video summary: https://vimeo.com/888141304
Step One: Fill a syringe with the prepared biomaterial to load into the tube. Extrude the biomaterial manually on a scale. The pressure it takes to extrude needs to be between 25 and 30 pounds, and the clay should have a slightly sticky texture - this is optimal for printing with the PotterBot.
Step Two: Once you have the biomaterial recipie at the correct consistency, roll it into spheres that fit into your hand. Press the spheres one on top of the other, pressing down with the palm of your hand. Smooth out the top of the tube after each sphere to ensure minimal air pockets.
Step Three: Fill the tube and leave about three inches of space at the bottom.
Step Four: You also need about two inches of space on the top. Dig out your biomaterial paste just past the holes around the tube. You are now ready to assemble.
Step One: Insert the nozzle on the end of the tube with approximately two inches of negative space. Put the screws in - you must alternate sides when putting in the screws. Put in two on one side and then rotate to the other side. Do not overly tighten the screws; they do not need to be tight, just fully inserted.
Step Two: Once the nozzle is fully installed, flip the tube to the other side. The rod will fit into the black attachment, align the holes, and screw them in - same as step one. You will have to use the drill with the provided attachment to reverse the rod and get the holes to align. Drill slowly, and be sure not to reverse the rod outside of the motor.
Step Three: Place the silver cover over the rod, screwing it in on either side. Note: only two screws for this are provided, and they must be screwed in diagonally from one another.
Step Four: Place the fully assembled extruder into the stand and tighten the strap. Note: you will need to have the strap placed close to the nozzle so it does not crash into the print bed.
Step Five: Flip the switch located on the back of the stand. Plug in the black cord to the motor. A green light will appear when it is on. You are now ready to prepare for print.
Prepare for Print
Step One: On your computer, connect to 3DP-10; the password is 12345678. Type in the IP address 192.168.42.14. The web browser interface will appear once you have typed in the IP address. The green button on the top left will let you know you are connected to the PotterBot.
Step Two: From the menu on the left, select Jobs Files. Find the prime G-code and start a prime. Keep priming until a steady flow of clay is extruding.
Step Three: Prepare a surface to print on (such as a bat, board, or fabric swatch) and place it on the print bed. If you want your piece to have a base, roll out a slab onto the surface. If not, then smear some material on the surface to ensure adhesion. Press four small pieces of material around the print surface so that it does not move during the print.
Step 4: Return to the Jobs Files and select Print Start Location Standard to set the Z height. When the Print Start Location Standard is started, the PotterBot will move to the center of the print bed. Once it stops moving, hold the tube and unlock the straps to adjust the height. Use caution - the tube will be heavy. The ideal height of the tube will allow a fettling knife to fit between the tip of the nozzle and the print surface. You are now ready to print.
Step One: Once you have the correct Z height, upload your G-code file to the web browser interface under the Jobs tab and select it to print.
Step Two: Print! On the web browser interface, you can monitor and control your print's speed and extrusion rate as it is in progress. Note: once the print has finished, there is no need to reset the Z - as long as you use a print surface (a bat or board) that is the same thickness as the one you used in your initial print.
Step One: Once you have finished printing, run the retract G-code (image 31) for approximately 20 seconds to relieve the pressure on the tube. Select the emergency stop button when you are done retracting. Note: if you did not finish the tube and plan to finish printing later, you must still retract it - the pressure will push the water in the material to the bottom of the tube, making it unfit for printing. Run the prime G-code when you resume printing.
Step Two: Remove the extruder from the stand by unplugging the black cord and unlocking the straps.
Step Three: Remove the silver cover and use the drill to reverse the rod slowly. Note: keep material off the rod once it is exposed and avoid touching it. Check that the rod is properly greased regularly.
Step Four: Unscrew the attachments on each end of the tube - starting with the motor and then the nozzle.
Step Five: Place the motor and rod attachment on a clean surface. Use the silver cover to push the nozzle attachment from the tube.
Step Six: Clean the biomaterial residue from all of the equipment and organize it.
Biostructures - spatial design strategies for biomaterials