Model requires a one or more 5x2 mm magnets to be pressed into the end. Use more magnets for a stronger pen. The fit is tight, a lighter might be needed to heat the tip of the pen up to install the magnets. When all magnets are installed the pen can hold itself at 90 degrees on a metal surface.

Fusion file is included in case you need to adjust anything. A little superglue can be used to secure the magnets once assembled for peace of mind. 

12-5-24 - Replaced with STEP file

Print vertically with magnet holes facing up for best results. printed with PLA at 0.3mm, 2x.84mm walls, 15% infill with brim and tree supports for best adhesion. 

Magnets can be dangerous to kids, ensure they cannot come loose from the pen and be swallowed.