Frequency (speed) of linear scale
17 Sep 2021 07:27 #220863
by Jonas
Frequency (speed) of linear scale was created by Jonas
I see that there are two types of linear scales. The glass and the magnetic.
Looking at the magnetic ones they specify a speed for example of 2 meters per second. And then there is also a max frequency that is 300 kHz.
I would think that the 300 kHz would limit a 5 um scale. For example if the balls screws are 5 mm per rotation and the scale is 5 um per step. Then there will be 5 mm / 5 um = 1000 steps per revolution of the stepper. I guess that is good since I see that rotation encoders that fit on the stepper axel can be 1000 steps per revolution as well.
But if there is 1000 steps per revolution and a max frequency of 300 kHz that would mean that stepper could only spin at max 300 rpm so that the linear scale could keep up.
The 2 meter seems like a mechanical limit then?
Looking at the magnetic ones they specify a speed for example of 2 meters per second. And then there is also a max frequency that is 300 kHz.
I would think that the 300 kHz would limit a 5 um scale. For example if the balls screws are 5 mm per rotation and the scale is 5 um per step. Then there will be 5 mm / 5 um = 1000 steps per revolution of the stepper. I guess that is good since I see that rotation encoders that fit on the stepper axel can be 1000 steps per revolution as well.
But if there is 1000 steps per revolution and a max frequency of 300 kHz that would mean that stepper could only spin at max 300 rpm so that the linear scale could keep up.
The 2 meter seems like a mechanical limit then?
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17 Sep 2021 13:21 - 17 Sep 2021 13:26 #220888
by Aciera
Replied by Aciera on topic Frequency (speed) of linear scale
Those 300kHz is probably the maximum output frequency of one channel. Full resolution requires the receiver to combine both channels to a full quadrature signal
So really the 2m/s is the maximum axis speed your sensor can keep up with and the max. frequency is relevant for the receiving electronics.
That is how I would read that.
So really the 2m/s is the maximum axis speed your sensor can keep up with and the max. frequency is relevant for the receiving electronics.
That is how I would read that.
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Last edit: 17 Sep 2021 13:26 by Aciera.
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17 Sep 2021 13:34 #220889
by Jonas
Replied by Jonas on topic Frequency (speed) of linear scale
Thank you.
Seems very resonable. Got me worried for a while.
Seems very resonable. Got me worried for a while.
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