Light beam won't cut it (pun intended)
Even the colour of flesh is close to wood.

I find it hard to believe this thing can detect a dry skinned finger from
wet wood without false triggering.

His information stats the thing reacts in 5 milliseconds...maybe the
electronics but after spending a lifetime of calibrating speeds on
electronic and mechanical relays I doubt that chunk of metal hardly starts
to move in less then 20 milliseconds.


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"Dave" wrote in message news That's why I suggested some type of beam of light being broken as a
stop mechanism. Sort of like the mechanism of an automatic door
opener. It detects movement and operates. All that would remain is for
it to distinguish between flesh and ignore wood/everything else.