It was a bit of a pain to design a flat part that can fold around a curved armrest and fit the vertical spikes in the frame, but I think it worked out pretty well. It's really easy to print and it fits on a MK3S bed. You probably want your filament to be something flexible, I don't think PLA would be flexible enough. I printed mine in PETG and it seems to do the job just fine. TPU could possibly be better, but didn't test that. I installed mine when the print was still warm but I'm not sure if that makes a difference.
UPDATE: I printed another pair in TPU, and they feel a lot better. I uploaded a new 3MF for the TPU version. It has a more solid body that I filled with 15% gyroid infill. I didn't print any top layer on it. (Picture attached of the PETG and TPU parts)
I used a 0,6mm nozzle with 0,4mm layers but I think anything will work.
The author marked this model as their own original creation.