Bistable Mechanism Minified Fidget Toy

thingiverse

This is a 4x3cm condensed version of the BYU_CMR's bistable demo print showcased at https://www.thingiverse.com/thing:3163115/. This print took just 15 minutes to complete. It has a very pleasant feel when switching states, similar to sliding a power switch. This was achieved using SVG inkscape and then extruding it via the plugin found here https://inkscape.org/~arpruss/%E2%98%85openscad-cookie-cutter-file-output The cookie cutter scad file was modified with these values: featureHeight = 2.5; minFeatureThickness = 0.1; Key points noted during development include: * I chose an extruded thickness of 2.5mm and a spring width of 0.5mm, which provides the right wall length for flexibility when using a nozzle size of 0.4mm. Rigidity is crucial for the mounting points on the flex springs. Without it, the moving mass can easily spring back without latching. Initially, I tried leaving the top off to make access easier, but PLA is too flexible. At this compact size, it's difficult to get the spring to buckle correctly. To address this issue, I added a curve instead of making the spring longer artificially so that it buckles and latches more easily. It was discovered that you need the curve to extend beyond the mass for proper buckling, rather than from the frame. If you squeeze the frame, you can reset it to its default position temporarily by warping the frame. This highlights the importance of rigid mounting points, which can be achieved on a silicon chip but are challenging with a 3D printed PLA structure.