Yet Another AA to C Battery Adapter

thingiverse

This simple project enables users to utilize AA size cells in appliances designed for C size cells by providing a battery adapter. The construction consists of two thin cylinders that are not entirely closed, but joined together by two tight turns which form a small gap. This design is inherently flexible and forms a spring-like structure that encloses the AA cell. On top and bottom, the outer cylinder is chamfered, while the inner cylinder is only chamfered on the top and has a brim on the bottom, preventing the inserted battery from slipping out. To insert or remove the battery, it's easiest to slightly spread the gap with two thumbs, widening the cylinders so that the battery cell slides in or out easily. Given the springy nature of this design, ABS material is the preferred choice for printing. The OpenScad source code for this project utilizes the snakeline approach, a library that extensively employs OpenScad's child concept. Each curve is coded as a single statement where each subsequent child adds another segment starting at the point and direction the last segment ended. The SCAD source is fully parametrized, allowing it to be easily adapted for other sizes if needed. Print settings include using a 0.40mm nozzle with a 0.25mm layer height and a 0.56mm extrusion width on a DIY box-frame Prusa i3 printer without rafts or supports. Notes from the original print include using a clear mirror without Kapton tape, thoroughly cleaned with acetone and double concentrated lemon juice. The thickness of the springy cylinders is twice the extrusion width by default. If you have significantly different extrusion widths, modifying the eh and ew parameters in the SCAD file may be necessary to achieve optimal spring strength, requiring a rebuild of all STLs needed.