(Magnet replacement)

This is an attempt to replace magnets and springs. After continuous iteration and testing, we finally succeeded. It’s a perfect replacement.

I eventually designed a pair of flexible material holders with an inclined angle for insertion, one at the top and one at the bottom, using two 15mm TPU pieces as elastic support. After testing TPU 95A (Fusrock), the feel of pressing with two pieces is the best. Due to the potential differences in rigidity and elasticity among different brands of materials, I have designed six reserved holes. This allows for controlling the pressing feel by, for example, increasing from two to three pieces of material, enabling customization of the desired feel. I hope my alternative design solution can help you quickly utilize the "Ret retractable Ballpoint Pen" provided by @wuguigui.

Regarding printing, it is best to use a 0.2mm nozzle for finer details.

Here is the translation:

I eventually designed a pair of flexible material holders with an inclined angle for insertion, one at the top and one at the bottom, using two 15mm TPU pieces as elastic support. After testing TPU 95A (Fusrock), the feel of pressing with two pieces is the best. Due to the potential differences in rigidity and elasticity among different brands of materials, I have designed six reserved holes. This allows for controlling the pressing feel by, for example, increasing from two to three pieces of material, enabling customization of the desired feel. I hope my alternative design solution can help you quickly utilize the "Ret retractable Ballpoint Pen" provided by @wuguigui.

For printing, it is best to use a 0.2mm nozzle for finer details.

Here are some failed attempts during the process