2018年9月4日星期二

THE STEPPER MOTOR CONTROLLER YOU CHOOSE MATTERS!

Equally the stepper motor controller that you use will have a major impact on the mechanical performance you are able to achieve using the motor. If the controller is not able to deliver more power than the motor can handle then it is unlikely that you will be able to achieve the maximum possible mechanical performance from the motor.

As an example of this, our stepper motors with integrated controllers have higher powered controllers the bigger the motors get.

See the table below for an overview of frame sizes.




WHAT NEXT?
If your interest in motor sizes was purely academic then we hope we have helped. If you have any questions about this please do not hesitate to get in touch and we will do our best to help.

Alternatively if you are looking for a motor and aren’t sure which is best for your application then you could start by having a quick look at our standard range.

We offer a range of stepper motors of different sizes which are available in geared or standard format.

As always, if you have any questions about choosing the right motor or the pros and cons of a long stack NEMA 17 versus a short stack NEMA 23 MOTOR(for example) then you can get in touch with us via online chat, phone or email.

2018年9月3日星期一

A Small and Llight Gearbox for a Stepper Motor

I wanted to build a small and light gearbox for a stepper motor (used as excuse: for building a light extruder for a 3D printer - didn't trust the bowden setup, and the scavenged driver might not have enough torque for a direct drive - real cause: playing around with the lasercutter :-)

DIY PLANETARY GEARBOX FOR NEMA17 STEPPER MOTOR


I decided to use POM (polyoxymethylen), since it's quite strong, self lubricant and you can cut it with a lasercutter... if you have a good ventilation: Burning POM produces formaldehyde, not the best product for your health. So using a CNC mill might be more healthy.

On the other hand, we have now a three stage filtering system especially for formaldhyde, and a just fine tuned laser cutter - perfect for fine teeth.

I used apart from the laser cutter:

- POM (i used three different thicknesses, 2,3 and 4mm to get a really small and light version, but using only one (4mm) thickness is also possible)

- 3* bearings 3mm inner diameter, 7mm outer diameter, 3mm height

- 1* bearing 5mm inner diameter, 10mm outer diameter, 4mm height

- 3* 3mm hexagon socket head screw 12mm long, with 12 washer and 3 nuts

- 1* 5mm hexagon socket head screw 30mm long (but trimmed down) and 3 nuts (small height)

- 2* 3mm hexgon socket head screw 40mm long with 2 washers

- NEMA17 stepper driver (5mm diameter axis)

- MK8 drivegear for 5mm axis


2018年8月20日星期一

JVL QuickStep closed-loop integrated stepper motors

They do this with greater efficiency and less motor heating because motor phase currents are regulated up and down according to need. Performance of the closed-loop steppers are similar to servo motors, but with higher torque and often without need of gearboxes, reducing costs.

JVL QuickStep closed-loop integrated stepper motors


Oyostepper is a true closed-loop control system that compensates step angle errors during a movement and correct errors within a full step. If load becomes too high speed is lowered and position errors will always stay within two full-steps. Smart digital design and very high update rates (36 MHz) means there is no need of any manual adjustment or setup. It works like a perfect stepper motor benefiting from the servo motor technology. Advantages compared to open loop steppers include position feedback and control, fast and easy commissioning with no tuning needed, no stalling or step losses, faster positioning and more cycles per second and more. Advantages over servo motors include very high torque at low speed, often three to four times higher in the same motor flange size; very high ratio of inertia, often up to 40:1; faster commissioning, with no tuning needed, same price as open loop steppers and total stiffness at standstill, with full holding torque.

See more:
https://www.playbuzz.com/item/243ef9d0-b027-49ef-bc83-9354d49f451f

2018年8月16日星期四

Spectrum External Motor Planetary Gear Motor

For the DIY'r, these gear stepper motors allow you to drive a dolly or other custom motion control accessory through the M3/M4  ports on the side of your spectrum.



The 14:1 Motor has:
  Efficient stepper motor planetary gear Drive
  8 mm mounting shaft
The Direct Drive Motor has:
 5 mm mounting shaft

Both Motors have a short lead spectrum connector with strain relief. This allows you to plug into the AUX port of the spectrum with no soldering or crimping.

Extension cables are not included and are needed.

Motor Speed

14:1: Strong enough to do video and timelapse moves up slopes and vertical. Slower motor.
Direct Drive: Our fastest motor and what we pair to the shark slider for interviews. Great for all horizontal moves and turbo mode.

ADVANTAGES OF A CLOSED-LOOP STEPPING MOTOR SYSTEM

2018年8月10日星期五

How to make 5-Axis CNC Machining

Whether you’re sculpting a masterpiece from marble or milling a blisk from titanium, the basic principle is the same: start with a block of material and remove the unnecessary bits until the target object is all that’s left. Of course, the details of that process are much more complicated, especially for 5-axis machining.


What is 5-axis CNC Machining?
In the simplest terms, 5-axis machining involves using a CNC to move a part or cutting tool along five different axes simultaneously. This enables the machining of very complex parts, which is why 5-axis is especially popular for aerospace applications.

However, several factors have contributed to the wider adoption of 5-axis machining. These include:

A push toward single-setup machining (sometimes referred to as “Done-in-One”) to reduce lead time and increase efficiency
The ability to avoid collision with the tool holder by tilting the cutting tool or the table, which also allows better access to part geometry
Improved tool life and cycle time as a result of tilting the tool/table to maintain optimum cutting position and constant chip load.

What are the Axes in 5-Axis?
We all know the story about Newton and the apple, but there’s a similarly apocryphal story about the mathematician and philosopher, Rene Descartes.

Descartes was lying in bed (as mathematicians and philosophers are wont to do) when he noticed a fly buzzing around his room. He realized that he could describe the fly’s position in the room’s three-dimensional space using just three numbers, represented by the variables X, Y and Z.
This is the Cartesian Coordinate system, and it’s still in use more than three centuries after Descartes’ death. So X, Y and Z cover three of the five axes in 5-axis machining.

What about the other two?
Imagine zooming in on Descartes’ fly in mid-flight. Instead of only describing its position as a point in three-dimensional space, we can describe its orientation. As it turns, picture the fly rolling in the same way a plane banks. Its roll is described by the fourth axis, A: the rotational axis around X. (1 axis cnc kit  or mini 4 axis cnc kit)



(Image courtesy of Hurco North America.)

2018年8月8日星期三

Design of Controlling System for Linear Stepper Motor Based on DSP2407

into linear micro-step motion directly. In condition of open-loop, it can provide accurate and reliable straight-line displacement, velocity and acceleration control, and it can be used to constitute an open-loop system without feedback. However, due to its structural characteristics, there were some shortcomings as follows [1-2]:

(1) It can not automatic accelerate and decelerate smoothly as DC motor and AC motor, out-of-step or blockage will appear probably in circumstance of high speed and large variation.

(2) Its Whirling speed is not steady enough, step angle is overlarge, especially, and concussion phenomenon will appear occasionally.
Focus on shortcomings of linear step motor, this paper carry out two optimization for the application of its driver: control the process of acceleration and deceleration when speed (pulse frequency) of system fluctuate largely; Providing subdivision function for the system, which can promote positional accuracy and steady degree at lower speed; Theoretical analysis and experimental results show that system’s dynamic and static performance has been improved noticeably by optimization design.


2 Control System Configuration
As the core of the system control unit TMS320LF2407A was used to achieve a signal generating.TMS320LF2407A was a powerful general-purpose I/O port and PWM
336 H. Zheng and W. Cui output function, it can output a 16-way PWM waveform. PWM frequency change can be realized stepper motor speed and position control [4-5].

Control signal was used to set up the linear stepper motor operation mode and software integration of the motor control the start and stop, the positive/negative
circumrotate, acceleration/deceleration and location and orientation. Display circuit with real-time display in the operation of the motor speed, and other parameters. The system schematic was shown as Figure 1.
Design of Controlling System for Linear Stepper Motor Based on DSP2407


3 Acceleration/ Deceleration Control Arithmetic hybrid stepper motor started from a low frequency, run at high speed after the uniform. When approaching of another terminal location, the stepper motor run slowdown, and then it could accurately stop in the terminal position. Starting vibration and mechanical impact of route end is restrained effectively. The process can be a variety of variable speed control mode time curve.

Line acceleration/deceleration control Curve was shown as Figure 2 (a). Plans in the segment AB, BC, CD, were on behalf of acceleration, uniform and deceleration. The
letter ‘N’ was behalf of line


2018年6月7日星期四

Which Has Higher Stopping Accuracy - Stepper Motor or Servo Motor?

Customer Inquiry: Looking for a motor with good stopping accuracy. How much of a difference is there between stepper motors and servo motors?

Assumption: The AC servo motor NX Series is equipped with a 20-bit encoder, thus it should have a fine resolution, and good stopping accuracy.

First, it is necessary to clarify the difference between resolution and stopping accuracy: Resolution is the number of steps per revolution and it is also called a step angle for stepping motors. It is needed when considering how precise the required positioning needs to be. Stopping accuracy is the difference between the actual stop position and theoretical stop position.

Stepper Motor vs Servo Resolution and Stopping Accuracy

Does this mean that the AC servo motor equipped with a high accuracy encoder has better stopping accuracy than hybrid step motor?

Not quite. In the past there was no issue with the concept of "stopping accuracy of servo motors being equal to encoder resolution within ±1 pulse." However, recent servo motors are equipped with the 20 bit encoder (1,048,576 steps) which has a very fine resolution. Because of this, errors due to the encoder installation accuracy have a huge effect on stopping accuracy. Therefore, the concept of stopping accuracy has slightly started to change.

Source:
http://obd2newsfrance.blogspot.com/2018/06/basics-of-stepper-motors-you-should-know.html