Stepper Motor

Overview

Stepper Motor

A stepper motor (or step motor) is a brushless, electric motor that can divide a full rotation into a large number of steps. The motor's position can be controlled precisely without any feedback mechanism (see Open-loop controller), as long as the motor is carefully sized to the application.

How Stepper Motors Work

• Basic animation on Wikipedia - 4 poles, multiple teeth - advance of 1/4 tooth per phase - so the resolution is number of teeth*number phases =25*4=100 in the example - [1]
• See good overview. Note that steppers are typically made of 2-rotors of opposite polarity - [2]
• Microstepping
• Difference between 2 phase and 5 phase stepper motors - [3]
• Comparison of stepper motor to brushless DC motor - [4]
• Note that the combination of poles and phases determines the full step resolution. If you have many poles and 2 phases, you can advance in a number of steps proportional to the product of number of poles and number of phases. You can have many poles and 2 phases, or many poles and many phases - and each can give the same resolution. The ultimate resolution is determined by the number of poles and microstepping - where microstepping is activating the 2 rotors out of phase
• https://www.motioncontroltips.com/faq-what-are-stepper-drives-and-how-do-they-work/

Holding Torque vs Moving Torque

• 125 oz in hold for nema 17, example - [5]

Gecko Drives Tutorial

Good start.

Voltage

Running steppers at higher voltage produces more torque. 20x rated voltage is ok. [6]

Gecko Drives Tutorial

Good start.

Voltage

Running steppers at higher voltage produces more torque. 20x rated voltage is ok. [7]

Lifetime

The typical lifetime for a stepper motor is 10,000 operating hours. This approximates to 4.8 years; given the stepper motor operates one eight-hour shift per day. The lifetime of a stepper motor may vary in regards to user application and how rigorous the stepper motor is run.[8]

See Also

• Open Source Stepper Motor
• Stepper Motor Controller
• Rotary Encoder
• Open Source Stepper Motor Controller
• Open Source Stepper Motor Controller Problem Statement
• Torch Table Bill of Materials
• Motor
• Wikipedia: Stepper Motor
• [9]
• Stepper Overview Youtube Video

Torque Tests

Test 1

This test used Nema17 stepper motors driven by A4988 driver boards http://reprap.org/wiki/Stepper_torque

Summary: All motors perform well at speeds < 100 revs/min. Dynamical torque starts to drop off at speeds higher than 300 rev/min. The higher the rated current and the lower the inductance, the better the performance at high speeds.

inside a stepper motor

• http://www.homemodelenginemachinist.com/index.php?topic=6748.0
• http://www.robotgear.com.au/Cache/Files/ProductImageOriginals/676_The%20inside%20of%20a%20bipolar%20stepper%20motor.jpg
• http://www.bg-cnc.com/wordpress/wp-content/uploads/2011/01/631.jpg
• http://www.designworldonline.com/articles/5409/267/New-Stepper-Motors-Beat-Corrosion-Without-Seals.aspx
• https://www.cdli.ca/courses/isys1205/unit02_org05_ilo07/b_activity.html
• http://electronics-control.info/Stepper_types.htm
• http://electronic-schematic.blogspot.com/2011/04/circuit-for-driving-stepper-motors.html
• http://www.cibomahto.com/2008/02/thing-a-day-day-20-dissecting-stepper-motors/

Types of Stepper Motors

• 17PM-K402 - Hybrid 2 and 4 phase - 6 volts rated - [10] - RAMPS wouldn't run it.
• 12 V rated - [11] - RAMPS wouldn't run it

Sourcing

NEMA 34

• 360 in lb - 0.6" shaft, 6x planetary gear - $84 - [12]
• 75 in lb - $77 - Ebay - [13]

Driver

• 5A TB6600 driver - $14 each - [14]
• 4A TB6600 driver is typically $8 - [15]

Small

• 3A - $6 each - [16]
• 4A - $9 each for 5 - [17]
• 4A - Single - $11 - [18]

By Origin

• MAE Ametek - made in eu
  • https://www.ametekmae.com/product/motor-solutions/stepper
  • https://www.amazon.com/MAE-Stepper-Motor-HS200-2231/dp/B017UU1AN8
• Oriental Motor - made in japan
  • https://catalog.orientalmotor.com/item/2-phase-bipolar-stepper-motors/

Links

• Stepper Motor Inductance