--- In Losmandy_users@..., "Sean Houghton" <shought1@s...>
wrote:
The Astro-Physics mounts use servo motors which have 0.05 arc
second steps,
the G11 and G8 use stepper motors which have 0.5 arc second steps.
The new
Losmandy goto system replaces the stepper motors with servo motors
that have
0.1 arc second steps.........
Hello group,
The information on the Gemini Goto drive is somewhat incorrect. The
servos have an approximate resolution of 0.1 arc sec they are in fact
a DC motor that has a smooth an continuous rotation.
The system resolution is 0.1 arc sec, meaning that that is how
(theoretically)accurate the position of the system can be set. This
has nothing to do with how the motor moves.
The existing drives are indeed stepper based, and under some
circumstances can set up a harmonic vibration which can be seen on
nights of very good seeing through large aperture scopes.
Regards
Peter Ward
Advanced Telescope Supplies
