BB Assassin Pen

Disclaimer: Some parts may have durability issues and can be challenging to print. In certain cases, parts may break during or shortly after printing. Please take this into account before starting the project.I am working on improvements and plan to release a more durable version in the future.1. Pen disassembly and part preparationFind a standard ballpoint pen with an ink refill (ink tube) that has an outer diameter of approximately 3 mm.Most common ballpoint pens use this size.Disassemble the pen and remove:The ink refillThe internal springNote:The total length of the ink refill should be around 107 mm, which is a standard length.A longer or stiffer spring will result in a stronger firing force.2. Attaching the ink refill to the printed partInsert the ink refill into the designated hole in the printed part (as shown in the image).Important:The part must grip the ink refill securelyYou may glue the refill in placeAlternatively, slightly crimp the end of the ink refill so it fits into