i actually want to call this bic vortex.. since it is been used. i better call this BicGripVortex as the parts required is from bic stic grip
i made this mod as after making some bictory with bic stic grip, i found out that i have lots of tubes left behind. Therefore i decided to use up these spare parts and make a pen which could spin well.
length:19.8cm
center of gravity/balance is almost at the center.
good for infinities
lightweight but have momentum
below are the parts required to make this mod.
2. bic stic grip tubes
1. ink tube with grips and stuff
2. anyball grips
2. grips that i got from nowhere. (you can try g2 or pilot super grip)

here are the steps to make this mod.
step1: remove the grip of the ink tube and stuff and cut on the region where it is stated on this picture.
important!!!stick the near pen tip region (with reference to the illustration on top, the right part) onto a bic stic grip tube (body) dont push in too much, leave half for the other side... this side is stuck.
the reason to cut on that place is because that area could PERMANENTLY get stuck onto the tube (body). like shown in the picture below.

step2: take the body with the stuck joint and link it with the other body

step3: put in the grips. the pilot super grip or g2.. then the anyball grip.

The final product...

as shown.. the center of balance/gravity is at the center

alternatively, you can put on the sides bic caps instead of the grips.. making it a longer pen (25cm)


a video of making this is shown
here, but it is not as detailed.. no cutting scene...
cutting scene can be found
here.
have fun....