
I've tried a vertical mouse, many trackballs and the rollermouse and, in the end, I think that my favorite of them all are the trackballs. However, one thing that annoys me about them is that most tend to have a base that forces you to tilt your wrist and fingers upwards and, in the case of Kensington's ones, also have buttons which are not so friendly to press, being horizontal instead of opposing the thumb vertically like on the Microsoft Trackball Explorer.
As there's not any negative slope trackball that I'm aware of, I'm sort of interested in making one myself. Here the wrist and arm would be horizontal and the fingers would fall naturally into a groove where the ball sits. It's mostly the casing that I'm interested in trying to get made out of plastic, perhaps from a place like shapeways, but I was wondering how to go about doing this.
I've seen many people here do very creative things, and I was wondering if one of those people would have a helpful hint for me. I was going to get some modeling clay so I could fool around with creating the shape but wasn't sure where to go to after that, such as 3D scanning the clay model into some modeling program...? I'd then use the innards of a Kensington slimblade (as I would prefer to use the twist-to-scroll feature rather than the blue scroll wheel I illustrated here).