Inspired by this post, I have designed a set of 3d printed accessories for a platypus quickdraw filter. They include a two piece attachment which allows for a small circle of cloth or filter paper to act as a pre filter, an attachment for a lifestraw activated carbon filter and barbed attachments for both the dirty and clean sides of the platypus, which allows for the filter to be converted for use in a gravity filter system.
The design of the quickdraw with O rings and gaskets on every outlet make this relatively simple and leak free. The major concern is the porosity of 3d prints and their potential to hang on to bacteria. This could be dealt with in a few ways. I’ve tried coating a few parts in a food safe epoxy, which is the best solution and works pretty well but is a little tedious. Alternatively, I expect you could just keep the dirty/clean ends separately and not worry about it throughout the trip and bleach them in between trips.
The files I have ready have been uploaded here: https://www.printables.com/model/391570-3d-printed-accesories-for-platypus-quickdraw.
