On Mon, 08 Feb 2016 22:24:02 -0500, Micky
wrote:


That's my question. Even at the highest downward force setting, I believe
that the door will eventually reverse when it hits an obstruction. The

Assuming that circuit is working.

The two passenger trains that hit each other head on in Germany today,
the 9th, had a safety system so that they couldnt' do that. I guess
it didn't work. 10 dead, 80 injured.

"He says the stretch was fitted with a safety system designed to
automatically stop trains to prevent such a crash and it's not clear
why it didn't function."

And as for setting the photocells to work at 2 feet above the floor:
with 2 more mirrors one can have the same photocell work at 2 feet and
5 inches at the same time.