digital-brain/content/zettels/stepper_motor.md

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title = "Stepper Motor"
author = ["Dehaeze Thomas"]
draft = false
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category = "equipment"
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Tags
:
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## Errors between steps (micro-stepping) {#errors-between-steps--micro-stepping}
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For a two phase stepper motor, there are (typically) **200 steps per revolution** (i.e. 1.8% per step).
Between each step, even when using some micro-stepping, there are some position errors that are due to non-perfect magnetic and electromagnetic fields.
The period of this error is corresponding to 200 period/revolution.
Then scanning, this can lead to high frequency vibrations.
This is what is typically limiting the accuracy of the stepper motor (usually specified in between 3% and 5% of the step increment).
This is approximately corresponding to **1mrad**.
<div class="exampl">
Consider a stepper motor with 200 steps by turn attached to a ball-screw with a pitch of 1mm per turn.
A rotation of 1 turn per second will induce vibrations at 200Hz with an amplitude of \\(1\\,\mu m\\).
</div>
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Note that this error is not a pure sine, it also has some harmonics with corresponding periods of 1/100 revolution and 1/50 revolution.
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This error should repeat every turn and can be calibrated provided it is repeatable over time.
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One way to reduce these errors is to use a ball-screw mechanism with a smaller pitch.
The price to pay is smaller velocity.
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## Manufacturers {#manufacturers}
| Manufacturers | Country |
|--------------------------------------------------------------------------|----------------|
| [AML](https://arunmicro.com/) | United Kingdom |
| [Sanyo](https://www.sanyodenki.com/catalogs/servo/stepping_systems.html) | |
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## 2 phase VS 5 phase stepper motor {#2-phase-vs-5-phase-stepper-motor}
<https://www.orientalmotor.com/stepper-motors/technology/2-phase-vs-5-phase-stepper-motors.html>
## Bibliography {#bibliography}
<style>.csl-entry{text-indent: -1.5em; margin-left: 1.5em;}</style><div class="csl-bib-body">
</div>