Air Bellows origami structure

thingiverse

Air bellows that folds along inner edges origami style as it compresses so PP is filament of choice. Update May 2020: Added rounded bellows edge stl file. Cetus tool chain has firmware bug when printing vase that rounds small Z changes to zero, causing lots of grief. I finally converted printer electronics to Duet2 controller board and kept mechanical only. Now I can print round vase structure. Latest stl file slices better and I can print much thinner bellows wall (about 0.3mm) using thinner layer height. Slice and print in Vase mode. I used Prusa slicer to create gcode for Cetus printer that has 0.4mm nozzle. Slice with 0.2mm layer, 0.6mm paving width, 8mm brim, and default 3 layer center for vase bottom is fine (design is open tube at both ends), becoming top bellows seal. This print is thin and weighs about 35gr. I printed PP at 255C to reduce sideways extrusion forces during layer printing. Layer adhesion is great using fan print cooling and no heated chamber. My glass build surface was 60 to 80C. If brim lifts, use packing tape on bed. To speed up initial test prints, set slicer bottom to zero layers and then stop print after first full fold to inspect all folding edges for weak spots or holes. Adjust slicer settings and test print again. When you think you have correct slicer settings, add back 3 bottom layers in slicer and go for it. 3D printer air pump conversion? Print takes about 3kg or 5lbs of force to compress and full stroke has volume of about 2 liters. 3D printers with Z axis threads should be capable of compressing this bellows if mounted on build plate. My printer uses Z axis belt so force is limited to under 2lbs and no joy for me. 10 sided open end needs custom thing with intake and exhaust reed valves. PP shrinks on cooling and my bellows measures 144mm across flats. For attaching your custom thing, I would think some packing tape or cable tie or both. Stay safe, -Peter