Simple Tips on Wiring a Stepping Motor

In previous articles we have gone over how to choose a best stepper motors online for a particular application. This article goes into detail on how a stepper motor is wired.

A stepper motor can come with assortment of wire configurations. The type of motor you’ve selected will determine the wire setup. Most commonly stepper motors come with four, five, six, or eight wires.

To begin, if your stepper motor only has four wires, this means it can only be used with a bipolar driver. You will notice each of the two phase windings has a pair of wires, use your meter to identify the wires.

Find the wires that have the continuity between them and connect these to the stepper motor.

Like the four wire motor, six wire stepper motors have a pair of wires for each winding. However, it also has a center-tap for each winding as well, this gives it the option to be wired as bipolar or unipolar.

With your meter, divide the wires into sets of three that have continuity to each other, next identify the center taps. If you are connecting to a unipolar driver use all six of the stepper motor wires.

A bipolar driver will require you use only one end wire and one center tap of each winding. With a five wire stepper motor the wire setup is very similar to the six wire driver, the main difference being the center taps are connected together internally, bringing it out as one wire. This will make the motor only function as a unipolar driver. Also, the windings will be impossible to identify without trial and error, the best you can do is try to identify the center tap wire since it has half the resistance.

Finally there is the eight wire stepper motor, which is much like the six wire. The difference being that the two phases are split into two separate windings. When this is done it allows for the stepper motor to be connected as a unipolar stepping motor, as well as three different bipolar combinations.

What stepper motor technology is best for this application?

As outlined in our original parameters, the final design must be inexpensive and have simple drive architecture. Stepper motors satisfy both of these requirements. However, minimizing this machine’s overall volume is also important, so a stepper isn’t recommended: The 17.64-W minimum power requirement at the load (not including system losses and instantaneous peak power) would necessitate a large stepper. A brushless motor solves the problem of design footprint, but adds cost and complicates the drive architecture.

The third option — a dc-brush gearmotor with an in-line planetary gearhead — provides a small footprint, simplified drive, and relatively low cost. Adding a leadscrew for rotary-to-linear conversion keeps gear reduction stepper motor
 output speed at around 1,000 rpm, which reduces generated heat at the leadscrew and nut-thread interface.

Gearmotor output

3. What’s the velocity, reflected inertia, and reflected load at the gearmotor output shaft (acting as the leadscrew input)?
Step one: Calculate the peak linear velocity of the application with its ¹/₃-¹/₃-¹/₃ motion profile:

where v_pk = peak linear velocity, m/sec.

Step two: Calculate the minimum pitch needed to keep the leadscrew speed at about 1,000 rpm:

where p_min = minimum leadscrew pitch, m.
For one typical linear stepping motor, the closest pitch in an 8-mm screw diameter is 20.32 mm.
Step three: Calculate the peak shaft speed of the leadscrew (in rad/sec) for a linear velocity of 0.3 m/sec:

The leadscrew we select is TFE coated, 275-mm long, 8 mm in diameter with a 20.32-mm pitch, and paired with a freewheeling nut. Assume the leadscrew efficiency, ηs, is 86% and its inertia, J_s, is 38.8 × 10-7 kg-m².
Step four: Determine the total reflected inertia, JT, back from the load to the leadscrew shaft:

where J_L = reflected load inertia, kg-m²; m = mass, kg; and p = leadscrew pitch, m.
Step five: Determine the shaft torque needed to accelerate the load inertia T_a:




where T_J = torque required to overcome load inertia, Nm; T_f = torque required to overcome friction, Nm; T_g = torque required to overcome gravity, Nm; a = linear acceleration,
m/sec²; Θ = load orientation, with horizontal = 0° and vertical = 90°; m = mass, kg; g = gravitational constant = 9.8 m/sec2; p = leadscrew pitch, m; v_f = final linear velocity, m/sec; v_i = initial linear velocity, m/sec; t_f = final time, sec; t_i = initial time, sec; and α = angular acceleration, rad/sec2.

WHERE TO GET 3 AXIS CNC CONTROLLER

Advantage of CNC router machine

Function: A more economical model CNC machining center, suitable for routing,relief, drilling, cutting, edge chamfering, etc.

Construction: Whole machine table adopts high strength thick steel pipe welded. Whole working table cast by resin sand. The annealing and other heat treatment methods ensure that the whole structure is tested to the limit for sturdiness and reliability.
Spare parts: Features world top class mechanical and electronic components, e.g. German rack and pinion, Taiwan rail and ball screw, Taiwan reducer, French Shneider electrical components, which guarantee stable performance and high quality.
Precision: Excellent spare parts, accurate precision detection instrument, which make sure the machine with perfect location and working precision.
High-speed: Adopt reducer direct design, high torque, high-energy, X axis dual motor drive, runs smoothly with high efficiency.
Table: Double adsorbable countertops, material in HPL, large suction by slots.
Tool magazine: Carousel tool magazine for optional. 

Main configuration

Working Area	1300*2500*200mm
Spindle	CE Standard Changsheng 3.0kw Water Cooling Spindle
Motor And Driver	Leadshine Stepper Motor And analog Stepper Driver
Control System	RichAUTO A11 DSP System
Transmission	X,Y Axis Germany Helical Gear Transmission;Z Axis Taiwan TBI Ball Screw Transmission
Working Voltage	380V/220V  3Phase/1phase
Inverter	Taiwan Delta  Inverter
Body	Heavy Duty Body 8mm Thickness
Guide Rails	Taiwan Hiwin 20mm Guide Rails
cnc kit	4 axis cnc kit	3 axis cnc kit

Advantages over servo motors

Closed loop-capable stepper motors merge the benefits of stepper and servo motor technology. They run more quietly and have a lower resonance than stepper motors, provide position feedback and control, feature short settling times, and exhibit no step loss at all. They are an alternative to stepper motors if energy efficiency, smooth running and a high load tolerance are required.Compared to servo motors, they have advantages due to their high torque at low speeds, short settling times, correct positioning without back swing and a lower price for sizes that are often smaller.

Closed loop step motors from Nanotec are an alternative to servo drives in many cases, such as in winding applications or conveyor belt drives. Not only can the rotational speed and position be more precisely controlled, but the torque can be controlled as well (in torque mode, as typically required in winding applications). Closed loop stepper motors combine the benefits of both worlds. They achieve the highest maximum torque, the best efficiency and optimum dynamics, but also feature the lowest torque ripple and exceptionally smooth running.

In torque mode, the closed loop stepper motor functions analogously to a spring, whereby the spring tension characteristic curve can be set via a potentiometer. Thus, the closed-loop stepping driver a stable force, even when the motor counteracts a force while at a standstill. When the force declines, the motor begins to turn proportionally to the declining force up to the current and torque setpoint values. Thus, closed loop stepper motors prove ideal for any type of winding, stretching and pressing applications.

Driving a Stepper as a 2-Phase Brushless Motor

To achieve the highest performance, the stepper motor can be treated as a 2 phase brushless servo motor. Current to the motor will then be controlled as a function of the error signal just as with standard servo motors. Galil refers to as 2 Phase Brushless mode, or 2PB. Figure 7 details the stepper motor system being driven in this mode. Now, rather than step pulses, a torque command signal (brown line) is generated by the controller to be fed to one of Galil's internal amplifiers operating in 2PB mode in order to control the position of the motor. times. A stepper motor driven in 2PB mode is analogous to a classic servo motor attached to a speed reduction gearbox.

Closed Loop Stepper Control

By leveraging Galil's methods of closed loop stepper control, the various shortcomings of stepper motors can be overcome. The endpoint position can be adjusted for inaccuracies with stepper position maintenance mode, the position can be dynamically adjusted with closed loop microstepping, and lastly the stepper motor can be treated as a 2-phase brushless servo to further increase the performance and efficiency of the motor. If you have questions on which mode of closed loop stepper operation is appropriate for your application, contact our Applications Engineering department at oyostepper.com.

APPLICATION ON NEMA 17 Steppering Motor FOR 3D Printers

Stepper motors are brushless dc motors that use multi-toothed electromagnets to define the position. The electromagnets are fixed around a centralized gear. NEMA numbers define the standard dimensions of a faceplate for mounting a motor.  NEMA 17 stepper motors are stepper motors with a 43.2mm x 43.2mm (1.7 inch x 1.7 inch) faceplate. They are heavier and larger than a NEMA 14, but their size is what ensures more room for higher torque. NEMA 17 is the most common size for stepper motors used in 3D printers. They can be designed and manufactured to have different mechanical and electrical specifications to suit the 3D printer that you want to build.

When looking for a NEMA 17 stepper, remember that the name is merely the frame size standard, which defines the dimensions of a mounting faceplate. You need to make sure that you are getting the right stepper based on the motor’s electrical specifications. A high torque NEMA 17 stepper that can provide 200 steps per revolution (1.8-degree step angle) is one of the options to consider for 3D printers. Be sure to check the model and specifications of your 3D printer before you buy a NEMA 17.

Some companies can manufacture and design custom NEMA 17 stepper motors for your 3D printer. The service comes with custom winding and housing to suit specific dimensional and application needs. You can choose different lead wires and include lubricant and bearing options in case you need parts for high temperature and humid operations.

Custom NEMA 17 stepper motors are ideal for custom 3D printer applications that require a specific lead length, shaft size, frame size, or body length. You can order NEMA 17 steppers online. Look for a reputable supplier of small electric motors with years of experience working for a range of industries. This way, you can be sure to get high-quality stepper motors at the right size and at a reasonable price.

Nema 17 Stepper Motor Bipolar L=48mm w/ Gear Ratio 100:1 Planetary Gearbox

What’s the difference between servo and closed-loop stepper motors?

Servo and stepper motors have similar construction and share the same fundamental operating principle. Both motor types incorporate a rotor with permanent magnets and a stator with coiled windings, and both are operated by energizing, or applying a dc voltage to, the stator windings, which causes the rotor to move. However, this is where the similarities between servo and stepper motors end.

Drive methods for stepper motors
Stepping motors have 50 to 100 poles and are two-phase devices, where servo motors have between four and 12 poles and are three-phase devices. Stepper motor drives generate sine waves with a frequency that changes with speed … but with an amplitude that is constant.



Servo drives, on the other hand, produce sine waves with variable frequency and amplitude, allowing them to control both speed and torque.




Control methods for stepper motors
Traditional closed-loop stepper motor move when they receive a command to advance a certain number of pulses, which correlate to a distance. Steppers are considered open-loop systems because they lack a feedback mechanism to verify that the target position has been reached. Servo motors also move on receipt of a command signal from their controller.