Re: Cannibalize a mouse to create digital setting circles.

mltza!espector@mltsa.att.com
Mon, 20 Mar 95 09:30:28 GMT

This sounds a Good Idea. Mice are much cheaper than precision encoders. My PC friends tell me that the resolution of mice is measured in "Mickeys" per inch (sic). This is the number of pulses the thing generates per inch of travel, along each axis. The resolution is actually quite good - 800 is a normal number.

Without even dismantling the mouse, putting it against a shaft or wheel of diameter D, and M Mickeys per inch will give:

pi x D x M pulses per rev. This is a lot of pulses.

I don't how repeatable this would be - a rubber ball pressing against a smooth surface may give a rather variable gear ratio. (This doesn't matter for normal mouse useage).

Regards

Edwin Spector edwin.spector@att.com