RE: [CAD_CAM_EDM_DRO] Optical mouse for DRO anyone?

> Has anyone had success using an optical mouse or it's
> components to make a DRO or an accurately reading scale? If
> so, can you share any tips, links, or other info?
>
> TIA, Chris

Do you want the good news or the bad news? Well, it's mostly bad news.

I do recall people dismantling the old ball mice (usually serial), and
hacking up something to turn the wheels in those. This fact that everyone
isn't hacking up their old mice, coupled by the fact that digital calipers
are dirt cheap probably means their success rate isn't high, or it's just
not worth the effort.

Have a rummage around for Honeywell mice; instead of a ball, they had two
wheels on the bottom of the mouse, directly driving the slotted wheels
inside. Worked well, no ball de-junking sessions, bit of flop commercially.
I think they figured it out just as optical mice came out.

The resolution of most mice sucks. A typical mouse is supposed to be 1/100"
- 1/400" resolution, and 'gamer' mice have higher resolution, up to 1/4000".
That doesn't sound too bad, except I think there's a bit of marketing plus
'that number doesn't mean what you think' in there. The newer mice take
more readings per second, but that doesn't mean they can detect a movement
as small as 1/4000". It just means that when you do move the mouse in order
to shoot something, it reacts faster. Then again, who knows?

The real downside is that mice are USB these days, and good luck building an
interface for that. You're stuck with having to plug your mouse into a PC
(although you might be happy with that). There are serial port optical
mice.

On top of that you get to deal with everyones favorite, dirt.

Tony