Re: mouse encoder

At 01:12 22/08/2001 +0000, you wrote:

>Why use a 1/16 end mill. Use something much smaller (say .01 dia.) and you
>can do a whole lot more slots (about 450+ on a 3 inch disk).

1) The disc I wanted to use was big enough to take 60 1/16" slots (and
needed to be that big for the space I was putting it in)

2) 1/16" was the smallest cutter I had to hand.

But you are right - the cutter can be as small as you like for the
application concerned. Be aware though, that a given sensor will have a
minimum slot size/spacing - corresponding to the size of the aperture over
the IR sensor. Go smaller than this, and the sensor "sees" more than one
slot at a time. This is actually the third reason why my slots were that
big. And as others have pointed out, for a quadrature encoder, the slot
size/spacing is critical in order to generate the correct waveform.

Regards,
Tony