|
Thanks for that.
your analogy of the snail on a plate was brilliant.
I worked out the clock freq required for a 1.8deg stepper motor using a worm and 360tooth gear as below.
would this be correct?
Earth's Rotation 23h 56m 4s = 86164.091 secs
Thats 360 deg of the RA shaft in 86164.091 secs
360 tooth gear requires 360revs of the worm to turn 360 deg
I need to turn 360 deg of the gear in 86164.091 secs
Thats 0.004178075 deg in 1 sec of the gear
that’s 1.504106856 deg in 1 sec of the worm
with 1/16 stepping of a 1.8 deg stepper, 1 step turns 0.1125 deg
I need 1.5041086856 deg in 1 sec
which is 13.36983872 steps in 1 sec
therefore clock freq should be 13.36985 Hz.
I presume further gear reduction is required to achieve this rate, mechanical errors, clock drift, etc will all add to accuracy errors.
|