[simpits-tech] Zero point on a two needle altimeter

[Matt Bailey]

Interesting ideas on this subject! One thing to keep in mind, the
relationship of the turning of the hands of an altimeter is always the
same, the hundreds needle always makes 10 revolutions per one revolution
of the thousands needle etc. So you really only need one connection to
the motor and sensor (perhaps on the hundreds needle, for precision) and
just drive the other needles off that, using gears or pulleys. Also, if
you had a way to measure the position of the ten thousands needle, your
software would always know where that needle was and hence where the
other needles are...only problem might be resolution since there is so
much difference between this needle and the hundreds needle, for
instance. But without having to count the number of revolutions for this
needle, you would get a range of 100,000 feet. Quite sufficient for
anything other than very high performance fighters (like the F-104) or
spacecraft.

	-Matt Bailey