Ergonomic replacement for Bic ballpen

This a replacement for a Bic ball-pen tube, with an ergonomic triangular profile, and small indentations for the fingers, that automatically corrects the hand grip. The proper way to hold it is illustrated in the pictures: that point on the arrow tip is to be hold top between your thumb and index finger; the middle finger passes along the back.

The regular pen.stl is for a right hand of regular size. The pen_smallhand.stl is useful if you have small hands: same width but the indentations are nearer to the point.

If you are left-handed, just mirror the model.

The original Bic cap has a circular profile, that more or less fits the original hexagonal tube. You can use the original cap with this pen, but it does not fit so well. So I've added a custom cap that fits quite snugly. There are two versions: one with the clip and one without it (I find the clip useless, and it tends to break anyway).

The triangular profile provides three almost flat surfaces, ideal for customization, as seen in the picture (name not actually included in the STL model). You can add your name and nobody will accidentally take your Bic-3D-printed ball-pen, thinking it is theirs!

How to print

The pen should be printed vertically, with the flatter face to the bed (obviously). Since it is quite tall with a small footprint, a brim is strongly recommended.

Beware that the flat face at the bottom (top face when writing) has a venting hole, if you print an inner brim you will have to cut it open or your ball-pen will eventually stop writing.

The clipless cap can be printed vertically in both orientations, The clipped cap should be printed with the clip up. A brim is also recommended, particularly for the clipped one.

No supports required.

Designed with OnShape, model available here.