Wednesday, January 22, 2020

Motion Controller and Driver Selection Tips You Should Know

Motion Controller
The first thing that should be checked when selecting a motion controller is compatibility with other system components such as the PLC/PC, stepper driver and voltage sources.Motor speed is controlled by the pulse rate (pulses per second) supplied by the driver via the controller.Depending on the speed required, one must ensure that the motion controller can output the corresponding pulse rate to reach that speed. The motion controller must be able to output this pulse rate, and the stepper drive must be able to receive this pulse rate and send over to the SMLA. The equation for determining required pulse rate is shown in the following page.

Motion Controller and Driver Selection Tips You Should Know

• Linear speed: desired linear travel speed (in/s)
• Lead: lead screw for stepper motor travel per one full revolution of the screw (in/rev)
• Motor steps per rev: how many steps per one full revolution of the motor (steps/rev). All SMLAs are 200 steps per revolution.
• Pulses per step: pulses per step (pulse/step). SMLAs are 1 pulse per 1 step.
• Microstep: Micro-stepping resolution (micro-step/step)
After calculating the required pulse rate, it may come to light that your PLC, PC or microcontroller is capable of sending out this frequency to the stepper drive without the need of a separate motion controller.

Stepper Drive
Like a controller, the user should select a drive based on its ability to interface with all other components in the system – specifically the stepper motor and controller. For Thomson standard SMLA stepper motors, a drive must be able to allow the connection of a four-wire, bipolar motor. Electrical properties of the system must also be taken into consideration. Items such as desired output current to the motor, max input voltage from the power supply, and motor inductance will need to be reviewed.Just like a controller, required pulse rate will also need to be considered to ensure the driver is capable of driving the motor to the required speed.

There are many unique stepper motor drives out there that offer various micro-stepping resolutions. Depending on your requirement, micro-stepping may be worth considering, specifically if a smoothmotion is required. Micro-stepping essentially takes the standard 200 steps per revolution of the SMLA motor and breaks down each step to smaller increments such as from ½ step, ¼ step and even all the way to 1/256 step. Figure 7 illustrates the difference between full-stepping and micro-stepping.

Figure 7: Simple illustration comparing the motion between full stepping and micro-stepping.An important thing to note about micro-stepping is that it does not improve positional accuracy by goingto finer resolutions. A typical rotational accuracy for a stepper motor is approximately +/- 0.09 degreesregardless of micro-stepping resolution.

Final Considerations
Ultimately, experience is the best tool at one’s disposal for building a stepper motor-based system.The guidance mentioned above should only be utilized as a way of getting in the ballpark for a system build.Some experimentation with trial and error may need to be conducted to get a completely functional system. Always utilize the help of an experienced system designer and add a decent margin to system calculations when possible. When it comes to SMLA selection, Thomson can help recommend a product to get the performance you need. PLC, motion controller and drive manufacturers will also have dedicated engineers to help assist you in selecting one of their products.

Additional benefits of linear stepping motors

Additional benefits of linear stepping motors

Linear stepping motors are an excellent solution for positioning applications that require rapid acceleration and high-speed moves with low mass payloads. Mechanical simplicity and precise open-loop operation are additional features of the Compumotor microstepping linear motor systems.

Additional benefits of linear stepping motors

High Throughput – The motors are capable of speeds to 100 ips and the low mass forcer allows high acceleration.
• Mechanical Simplicity – The need for leadscrews or belts and pulleys is eliminated. The mechanical design is preengineered.
• High Reliability – Fewer moving parts and a friction-less airbearing design results in a longer, maintenance-free life.
• Long Travel – Length of travel is limited only by the length of the platen; increasing length causes no degradation in performance.
• Precise Open-Loop Operation – Unidirectional repeatability to 2.5 microns without the added expense of feedback devices.
• Small Work Envelope – A linear motor is usually smaller in all three dimensions than comparable systems where rotary motion is converted to linear.
• Easily-Achieved X-Y Motion – The assembly of X-Y gantry systems is readily accomplished.
• Multiple Motion – More than one forcer can operate on the same platen with overlapping trajectories.

Construction of a Linear Step Motor
A linear hybrid stepping motor operates on the same electromagnetic principles as a rotary hybrid stepping motor.The moving element is called a forcer. The stationary part is called the platen. The stator or platen is a passive toothed steel bar extending over the desired length of travel. All permanent magnets, electromagnets and bearings are incorporated into the armature or forcer. The forcer moves bidirectional along the platen, assuring discrete locations in response to the state of the currents in the field windings

Monday, January 20, 2020

What is the maximum speed of a stepper motor?

What is the maximum speed of a stepper motor?
Modern stepper motors can reach rotation speeds of up to 1500 RPM, taking into consideration that the motor torque curve decreases considerably with the increasing of the step frequency. If a screw of 4 mm is run at 1500 RPM, we obtain a displacement speed of 1500*4mm=6000mm/min or 6 m/min. Therefore, in practice, the stepper motors runs at max 600 RPM because the torque decrease above that values.

What is the maximum speed of a stepper motor?

14hs13-0804s or 17hm08-1204s

Related Questions:
What temperatures are stepper motors able to run at?
Most stepper motors are made with Class B insulation. This allows the stepper motor internal wiring to sustain temperatures of up to 130 degrees Celsius. With an ambient temperature of 40 Celsius, the stepper motor has a temperature rise allowance of 90 Celsius. Stepper motors can run continuously at these temperatures.
What applications would a bipolar stepper motor be used for?
A bipolar stepper motor is best used in a situation that would require high torque at low speeds.

What is the difference between a Unipolar and a Bipolar stepper motor?
The main difference between unipolar and bipolar hybrid stepper motor is the center tap connections. A unipolar motor is wound with six lead wires, each of these having a center tap. These would be used in applications needing high torque with high speed. Whereas a bipolar stepper motor has four lead wires but has no center tap connections. Bipolar stepper motors are used when you require high torque at low speeds.

What applications would a unipolar stepper motor be used for?
A unipolar stepper motor would be best used in an instance where you would require a motor with high speed and high torque.

Tuesday, December 31, 2019

When to apply external Non-Captive and Captive Step Motor Actuators

When to apply external Non-Captive and Captive Step Motor Actuators

A common way to generate precise linear motion is to use an electric motor (rotary motion) and pair it with a lead screw to generate a linear actuation system. Depending upon what this linear actuator interfaces with it can be constructed in a number of different ways.

Here we will discuss several different ways to combine a lead screw and nut with a stepper motor to create a linear actuator system. The stepper motor is frequently used in motion control as it is a cost effective technology that does not require position feedback to operate correctly.

When to apply external Non-Captive and Captive Step Motor Actuators

3 Different Styles
There are three different styles of linear actuators that are commonly used they are the external nut linear actuator style, non-captive style and captive style. There are many reasons to use a certain style of linear actuator, the three main reasons for selecting one style over another are:

Size 23 stepper motor.
Stroke What is the amount of linear travel required?

Interface Point:
How will the actuator be mounted and how will the load be attached?
Options: What other options might be required from the linear actuator?

External Linear Actuator
The simplest way to envision this combination of parts is to simply affix the lead screw onto the shaft of the motor. The nut that rides on the lead screw must be restrained from rotating so that linear motion will be generated. This type of actuator  is commonly referred to as an external linear style actuator.

Non-Captive (through screw) Linear Actuator
Another option is to locate the nut inside the motor and allow the screw to move linearly through the actuator. In this case the screw must be prevented from rotating to generate the linear motion.This style of actuator is commonly referred to as a through screw or non-captive linear actuator.

Captive Linear Actuator
In instances where the application does not have a mechanism to prevent the rotation of either the nut or the screw a third style exists. This style locates the nut inside the actuator body just like the non-captive actuator above but on the front side a linear spline is attached to the screw, this linear spline engages a front sleeve that is rigidly fixed to the actuator this prevents the rotation of the screw and provides linear output. This style of actuator is referred to as a captive style actuator.

Friday, December 27, 2019

Block Diagram of a Stepper Motor System

A stepper motor actuator is a mechanical device which produces force, as well as motion along a straight path. A stepper actuator uses the core principles of a stepper motor, with some slight modifications. With the stepper actuator, the shaft of a normal stepper motor is replaced with a precision lead screw, and the rotor is tapped to convert it to a precision nut that is adjusted to the lead screw. As the rotor rotates, the lead screw rotates up and down the precision nut, allowing for linear motion. Minimizing outside mechanical systems to convert rotary into linear motion, greatly simplifies rotary to linear applications. The stepper actuator design allows for high resolution and accuracy, while minimizing extra mechanical components.

Block Diagram of a Stepper Motor System
Block Diagram for Stepper Motor System
Figure 1: Stepper Actuator System
Physical Properties of a Stepper Actuator
The physical properties of stepper actuators are made up of the same core properties of a stepper motor, with some modifications. The shaft of a normal stepper motor is replaced with a precision lead screw and the rotor is tapped precision nut that interacts with the lead screw to allow for linear motion. The stator and rotor laminations are comprised of silicon steel which allows for a higher electrical resistivity and lower core loss. There are a variety of magnets used: ferrite plastic, ferrite sintered and Nd-Fe-B (neodymium magnet).
Figure 2: Physical components of a PM stepper actuator with a threaded shaft and a mounting plate.
Figure 2: Physical components of a PM stepper actuator with a threaded shaft and a mounting plate.
Figure 3: Illustration of the threaded shaft with the pitch and lead.

Figure 3: Illustration of the threaded shaft with the pitch and lead.

How do Stepper Actuators Work?
A stepper actuator is driven by a stepper motor driver and/or controller, which provides the instructions to manipulate the stepper actuator to start or stop. The driver and/or controller sends the proper signal pulses to the windings of the stepper actuator, causing the rotor (Economy Linear Stepper or Precision Linear Actuator) to rotate and the lead screw to extend or retract. By the use of instructions, a stepper motor controller designates how far and how fast the stepper actuator should extend or retract. A controller can be pre-programmed or controlled in real time by inputs predefined on the stepper drive or controller.

Monday, December 23, 2019

Some Knowledge on Braking Stepper Motor With Physical Principle

The brake stepping motor is mainly suitable for the vertical movement of the driver. The brake is externally connected to 12~24 VDC. When the stepping motor power and the braking torque start, there is a fixed motor shaft effect, and the stepping motor can still be locked.

There are now 57, 56, 110 series two-phase or three-phase stepping motor brakes available. A brake that electromagnetically forms an air gap is suitable for all areas where heavy objects must be moved to limit deceleration or limitation in a short time and generate braking torque even when power is supplied. Was interrupted. The braking force is generated by a compression spring or permanent magnet, and the DC24V voltage must be connected to all the brakes to form an air gap.

The integrated brake is operated by plug connection under severe environmental conditions (IP54), and the defects of fast, connected, brakeless stepper motors are widely used in semiconductor devices, bookbinding machines, packaging machinery, textile machinery, CNC machine tools, and biological Analyze light detection instruments, various workstations, optical inspection equipment, laser focusing devices, cone conveyors, and vehicle inspection equipment. At the same time, the company provides control cards, stepper motor systems, linear motors, voice coil motors, various reducers, machine vision, ultra-high temperature, low temperature, vacuum, explosion-proof motors, CAN bus controllers and other industrial automation products, to undertake various automation Project development.

Saturday, December 21, 2019

Some Knowledge of Stepper Motor Driven Linear Actuators

Actuators are devices which facilitate motion, and are fitted in components or tools which require movement. Commonly, stepper motor actuators are of the linear type, and hence the name. A stepper motor actuator produces force and motion along a linear or straight path. They share most of the properties with stepper motors, although there are some differences. A stepper motor has a shaft, while a stepper actuator has a precision lead screw and precision nut which together facilitate linear motion. They also have a stator and a rotor just like stepper motors, which in fact have improved resistivity as they are laminated with robust metal coatings such as silicon steel. The driver or controller of the stepper motor controls the movements of stepper motor linear actuators, in terms of switching on or off, speed, and rotation. The controllers translate the signals and clock pulses they receive into phase currents for stepper actuators to interpret and act.

Stepper Motor Driven Linear Actuators

Applications of Stepper Motors:
Stepper motors are used in a wide range of industries from manufacturing and security to medical and electronics. Here are some application areas of stepper motors:

Automated machine tools
Automotive gauges
Surveillance equipment such as cameras
Zooming functions in digital cameras
Medical imagers and samplers
Blood analysis machines
Dental photography equipment
Fluid pumps
Hospital beds
Stretchers and incubators

If you require actuators and stepper motors for your application, ensure you source them from a reliable manufacturer and supplier. Venture Manufacturing Co. makes superior quality and technically perfect linear actuators and more. On certain types of actuators, Venture Mfg. offer stepper motor actuators and brushless DC motors.

How to prevent this problem of extra steps on stepper motor
Application to Speed Control of Brushless DC Motor

Motion Controller and Driver Selection Tips You Should Know

Motion Controller The first thing that should be checked when selecting a motion controller is compatibility with other system components ...