For making a 3D printed pen you are going to want to have these materials.

• Pen Cartridge (Standard cartridge found in any BiC Pen)
• Access to a 3D printer
• Epoxy or any Super Glue
• Electrical Tape
• Sandpaper or File

After you have your materials, you are going to print the parts for your pen using a 3D printer. After printing, you want to sand off the rough parts so you can squirt epoxy or other super glue into the divots in the pen. Then place a pen cartridge into the pen and clamp the cap pieces together good. The epoxy or super glue will keep the cartridge in place. Now, test your pen and use it.

It relates to engineering because you are building products and you have to follow the rules of the engineering design process: creating, testing, and evaluating the product and researching to make sure you make the pen in the best possible way.