Twist bladder for Platypus Pens Model 20

I make and sell fountain pens and have recently released a model which features a novel filling system using a twist bladder printed from flexible TPE. The bladder has survived over a hundred thousand actuations and so it is unlikely to need replacement. However the long term stability of the TPE used (eSun eLastic) has not yet been proved. I intend to supply free replacement bladders on request, but in case I am unable to do so in the future I am providing this file here so that customers can print their own bladders at need.

The older file is gcode with my settings for eSun eLastic and header and footer specific to my Prusa MK4, and the updated files (updated design) is gcode without any header or footer code. The gcode can be run on other printers and with other filaments, but adjustments to the settings in the gcode will likely be needed, so slice a model (any model) in your slicer with settings for the filament and printer that you are using and copy the preliminary and finish gcode into the files supplied here.

Why supply gcode and not an STL? Well the gcode is created mainly without an STL and so I do not have an STL or any other 3D model to supply. The topmost portion of the object was made with a STL from an OpenScad model that was sliced in PrusaSlicer, but the flexible part of the bladder was constructed algorithmically with software that I wrote to make gcode.

In order to be fully functional the bladder needs to be printed from a fairly soft flexible filament. The eSun eLastic is supposed to be 80A Shore hardness, and I have also printed the model successfully using Recreus Filaflex 83A, which is a TPU rather than TPE. As I mention above, if you print with a filament other than the eSun Elastic that I use you will likely need to edit the gcode to put in the correct temperature.

The bladder can be glued to the end of the ink reservoir with a TPU-based glue like the original “Gorilla glue”.

You can see my pens at my website.