Recently, I made and published this mod on SweSpin, the swedish pen spinning board. I've done it only with four types of Pilot pens. Here are the pics:










I've used four Pilot pens, as I said. Pilot G1, Pilot G2, Pilot BPS and Pilot Supergel.
The pen is originally a Pilot G1, without the ink tube ant the small plastic thing in the end of the pen. The cap is from a Pilot Supergel, with the clip gone. Inside there is a tip from the BPS, and one half of a Pilot G2 grip. The grip's width is reduced so it would fit in. Inside the pen there is an insert, and in the front of the pen the other half of the G2 grip is. Under the tip there is a small lead clot for the balance.
Length: 18 cm
Weight: 12 g
The Center Of Pen is less than 5 mm from the Center Of Gravity.
Colours: Black, Blue, Red, Green
Used pens: Pilot G1, G2, BPS and Super Gel.
I sell these for a price under the real production price in Sweden, maybe i can sell outside the country aswell.