FlexLinks remix

thingiverse

The FlexLinks Cross-Axis Flexural Pivot produced by the BYU CMR group at https://www.thingiverse.com/thing:2987817 is a brilliant mechanism that seamlessly integrates with Lego Technic parts and can be manufactured using a laser cutter. At present, PETG filament is my go-to choice for printing the FlexLinks. However, to ensure optimal results with PETG, I need to print the first layer closer to the bed than ideal, which causes it to spread out into an "elephant foot." Consequently, when I print STL files from https://www.thingiverse.com/thing:2987817, I find it challenging to fit technic pins without trimming the bottoms of the holes. Apparently, the BYU group deliberately chose not to make their FlexLink STLs the same thickness as equivalent technic parts in order to facilitate compatibility with laser-cut sheet material and avoid having to create a recessed lip on standard technic holes. Having previously developed openSCAD tools for creating Lego parts at https://www.thingiverse.com/thing:2738552, I decided to refactor the Flexlink parts in openSCAD. This allows me to adjust the width of the flexible segment and vary the size and positions of the beam segments (with their respective holes). The pieces are now produced with the standard thickness of technic pieces and feature the standard stepped rims on at least one side. As a result, I can print flexLinks that no longer require trimmed holes, even when "elephant foot" is present. While I haven't quite achieved the same level of curvature on the beam segments as the BYU group did, it's possible that this difference may actually be a feature rather than a bug, making it easier to distinguish between the two versions.