"the bat" - a mechanical 3D input device - 1990

My "bat" is a mechanical device for 3D input.  You reach into a tetrahedral "cage" and grasp the "bat", whose movement is transmitted to the computer.  I designed it, but never completed a physical prototype.

I did start work on a virtual prototype in 1996 using World Up, so that you can see how it really looks and operates in 3D. To the right is a screenshot from the work-in-progress:

Details: Consists of a tetrahedral cage with a hand-held "bat" suspended on wires from each corner of the cage. Advantages:

Sensors at each corner of the cage track the distance of the bat from the corner. These 4 distances can be run through a matrix operation to get a 3D position.

The "bat" name has been used by some other, unrelated people as well - strangely, apparently all Canadian, including:

When designing tetrahedral structures, it may be handy to consult my tetrahedra data sheet.

I'd be delighted if somebody actually turned this into a product someday. Just let me know and i'll send you a copy of all my notes. Here are a few snippets:

Tetrahedral cage with a hand-held "bat" suspended on wires from each corner

Each corner has a simple assembly with a wire spool and optical shaft encoder. The encoder could be inline or be on a second axle as shown.

I built my prototype with steel bars and acrylic platforms in each corner, but the epoxy wasn't strong enough to hold it together when the cage was moved

The user holds on a "bat", can be any ergonomic shape - the ones i built were snub-tetrahedra

Hewlett Packard was nice enough to give me some HEDS-5500 series "quick assembly optical encoders", but i never finished the wiring or electronic interfacing.

"3D display without true 3D manipulation (6DOF hands) is an exercise in frustration."
  - Timothy Poston