W
W. Watson
- Jan 1, 1970
- 0
I'm looking at the manual of a stepper motor device that turns a focus knob
on a telescope. It talks about micro step pause, step size, cycles and
counts. The software program allows one to specify the # of pauses from 1 to
20, and steps (step size, microsteps) from 1 to 255.
The description is quite baffling. How do these two numbers figure into one
rotation of the stepper motor shaft? Apparently, they produce a rotation
measured in microsteps, which relates to the number of milliseconds in a
microstep. There seem to be too many terms here, cycles, steps, microsteps,
pauses, stepsize. Apparently, it is a small shaft that is geared to the
larger focuser shaft. I quote the manual:
"MicrostepPause. The RoboFocus processor pauses between its microstep moves
for a chosen number of milliseconds. Thus, the longer the microstep pause,
the slower the stepper will move. If the pause is set too small, the pulses
may be too fast for the stepper to follow and movement will cease or be
erratic. A stepper period of about 4 is a good choice for most motors. You
may want a longer period (slower stepping) if you want to perform
diagnostics on the system.
StepSize (Microsteps/Step). The stepping motor goes through four microsteps
before it completes one full electronic/magnetic cycle. One full cycle is
small fraction of rotation of the output shaft (depends on the gearing used
in the particular motor). The RoboFocus controller counts microsteps
internally, but you can set how many microsteps equals one control program
count. This configuration item allows you to set the number of microsteps
(1-255) that will be made when you tell the RoboFocus to move one step
(count). By changing the microsteps per count setting, you can change the
“fineness” of the focus positioning.
Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA)
(121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time)
Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet
--
"Summertime,
And the livin' is easy
Fish are jumpin'
And the cotton is high ..." -- G. Gershwin
Web Page: <home.earthlink.net/~mtnviews>
on a telescope. It talks about micro step pause, step size, cycles and
counts. The software program allows one to specify the # of pauses from 1 to
20, and steps (step size, microsteps) from 1 to 255.
The description is quite baffling. How do these two numbers figure into one
rotation of the stepper motor shaft? Apparently, they produce a rotation
measured in microsteps, which relates to the number of milliseconds in a
microstep. There seem to be too many terms here, cycles, steps, microsteps,
pauses, stepsize. Apparently, it is a small shaft that is geared to the
larger focuser shaft. I quote the manual:
"MicrostepPause. The RoboFocus processor pauses between its microstep moves
for a chosen number of milliseconds. Thus, the longer the microstep pause,
the slower the stepper will move. If the pause is set too small, the pulses
may be too fast for the stepper to follow and movement will cease or be
erratic. A stepper period of about 4 is a good choice for most motors. You
may want a longer period (slower stepping) if you want to perform
diagnostics on the system.
StepSize (Microsteps/Step). The stepping motor goes through four microsteps
before it completes one full electronic/magnetic cycle. One full cycle is
small fraction of rotation of the output shaft (depends on the gearing used
in the particular motor). The RoboFocus controller counts microsteps
internally, but you can set how many microsteps equals one control program
count. This configuration item allows you to set the number of microsteps
(1-255) that will be made when you tell the RoboFocus to move one step
(count). By changing the microsteps per count setting, you can change the
“fineness” of the focus positioning.
Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA)
(121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time)
Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet
--
"Summertime,
And the livin' is easy
Fish are jumpin'
And the cotton is high ..." -- G. Gershwin
Web Page: <home.earthlink.net/~mtnviews>