The next time you need large plastic springs, this is something you should consider [PattysLab]Method of making plastic springs from replacement filaments. The basic process is simple: wrap a 3D printer filament tightly around a steel rod, secure it, wrap it in kapton tape, and then heat it. After cooling, what remains is a reasonably working spring, apparently with all of the benefits of annealed plastic.
The basic process may be simple, however [PattysLab] has a number of tips to help you get the best results. The first is to use a 3D printed jig to anchor one end of the filament to the steel rod, and then use an electric drill to tightly wind the filament. After he has wrapped the plastic with Kapton tape (wrap it against the direction of the spring winding so that the subsequent pulling off of the tape does not pull the spring apart), he hangs it in a preheated oven at 120 ° C for PLA and 160 ° C for PETG. How long will it stay there? [PattysLab] use the following method: when the spring is coiled, a few inches of filament protrudes to serve as a visual indicator. When that segment of filament sags, this is its cue to begin the retrieval process. After cooling, a compression or tension spring is created, depending on how it was wound up before heating.
[PattysLab] shared a short video on this Reddit post showing both feathers in action, and the process is covered in the video embedded below.
This method clearly works for [PattysLab] and doesn’t require any unusual hardware or equipment, but should anyone want to add a little more finesse to the process, this scientific approach to annealing plastics used in 3D printing could come in handy.