Thursday, 9 November 2017

Feedback Actuators


We understand that it can be a little complicated to distinguish between actuators. There are position feedback actuators, limit switched actuators, internally controlled actuators, RC actuators, and that's just the micro stuff. When you move into larger actuators there's a whole different host of options and styles for you to choose from.

Today, I'm going to walk you through what a position feedback actuator is, how it works, and what types of applications they are intended to be used in.

What is a Position Feedback Actuator?

Simply put, a feedback actuator is capable of telling you what position it is at. Position feedback actuators can be operated the same way as -S series actuators using reversing polarity on the positive and negative leads. However, because they don't have end limit switches, the feedback signal is intended to be used with a device that can stop the actuator at it's end limit. Running a feedback actuator into it's end stop can reduce it's lifespan considerably.

How Do Feedback Actuators Work?

Feedback actuators feature an internal potentiometer. This potentiometer sends out a position signal that can be read by our LAC board. It is possible to monitor the position of a feedback actuator remotely using our LED position indicator.

How Is A Feedback Actuator Different From A Standard Actuator?

A standard linear actuator has 2 wires and is very simple to operate. When you apply appropriate power to the 2 wires, the actuator will extend. Reversing polarity on the two leads will cause the device to retract. Generally, they feature end limit switches and are designed to stop when they hit their end stroke. Running them to the end of their stroke is considered normal use and typically,  shouldn't shorten the life of the device.

How Can I Spot A Feedback Actuator

There are two ways that you can tell if an Actuonix device is a feedback actuator. The first is by looking at the model number. All of our feedback actuators end with a 'P', for example 10-210-12-P. The other way you can tell is by looking at the lead. 'P' series actuators all feature a 5-wire plug. 
position feedback actuator

Why should you choose a feedback actuator

A feedback actuator is the best choice for applications where you want to remotely monitor the position of your actuator. Using a position feedback device with our Linear Actuator Control Board also gives you control over how you drive your actuator and how it functions.

Using the LAC Board you can control your actuator via:


  • RC Input
  • PWM
  • Voltage
  • Current
  • USB
This setup also allows you to adjust your actuator's:

  • Speed
  • Sensitivity
  • Extend limit
  • Retract limit

As you can see, using a feedback actuator can be a little bit more complicated than a standard device, but it offers a lot more flexibility when it comes to adjustment and customization.

All of our feedback actuators can be found here.




Tuesday, 31 October 2017

How To Use A Linear Actuator Control Board With Arduino

Arduino linear actuator control


Over the past few years, our support department has been receiving more and more questions about how to use a linear actuator with Arduino. We have never officially offered Arduino support. We have a couple of resources on our website and we've directed many people to Robot Geek and a couple of other Arduino pros.

The problem with this is that none of those resources cover how to drive a -P series linear actuator via Arduino and a Linear Actuator Control (LAC) board.

I thought it was time that I did a basic tutorial on how to accomplish this. I'm going to show you how to make the physical connection between the two boards, as well as cover a couple of common issues that our customers have. This will serve as the basis for any additional learning you may want to do with Arduino and linear actuators.

We'll start by going through the things that you will need to operate an actuator via Arduino.

1. -P Series Micro Linear Actuator

Our -P series micro linear actuators are designed to be operated via our LAC board. Using the board's RC input mode, you can effectively control your -P series actuator as you would an RC linear servo.

You can only use -P series feedback actuators with the LAC board. -R, -S and -I actuators will not work.

2. LAC board

As mentioned above, our LAC board was developed parallel to our -P series actuators, and the two are meant to be used together. The LAC board will also work with some larger actuators that offer position feedback. We do not sell such actuators however and can not offer support for this usage.

3. Arduino Board

We often use an Arduino Mega or an UNO around here for various experimentation and testing.

3. Source of Power

You will need either a battery or a power supply to power both your Arduino board and your LAC board. The power supply for your LAC must match the voltage of the actuator and the power supply for your Arduino must be appropriate for the board.

4. Potentiometer Or Another Way To Drive The Actuator

You will need a control mechanism of some type if you want to drive the actuator manually. You can also cycle the actuator using code, which is what we have done here. The code used to drive the actuator in our example is a modified version of the 'servo-sweep' example found in the Arduino library.

Why use an LAC board with Arduino

Using an -R series linear actuator is the simplest way to drive a linear actuator via Arduino. The -R actuators use the same 3-wire connector as a standard hobby servo. The LAC board however, offers a couple of advantages over just using Arduino and an -R series micro linear servo.

The first is that the LAC board allows you to monitor the position of the actuator using the position feedback signal. This is ideal for situations where you can't see the actuator, but want to monitor where it is along it's stroke.

Another reason to use an LAC and -P series device is that the LAC board offers you direct control over certain aspects of how the actuator functions. The LAC has 4 pots on it that allow you to control speed, sensitivity, and both extended and retracted end-of-stroke limits.

Of course, this setup might just happen to be what you have on-hand. If that's the case, keep reading and I'll show you how to get your setup working via arduino.

Wiring The LAC To The Arduino

There are a few things to understand when you're trying to use an LAC via Arduino:

  • First, as mentioned above, you are going to need an external power supply. You can use the same power supply to power both your Arduino board and your LAC board provided the input voltage of your Actuator and your Arduino is the same, but each board must be powered directly.
  • Second, the Arduino and LAC must share a common ground to function correctly. This is the most common issue our customers have when trying to drive their actuators this way.

Below is a wiring diagram showing how we've connected the  LAC board to our Arduino Uno.

linear actuator control board via arduino


The actuator is plugged into the board as usual. We're using the RC output on the LAC to connect the Arduino board via standard RC cable (red/black/white). The red wire has been cut at the LAC as it's not used. The black wire runs from the RC plug on the LAC to gnd on the arduino board. This is the common ground we mentioned before. The white RC wire runs from the RC output on the LAC to pin-9 on the Arduino.

That's it for interfacing the LAC and arduino, but now you need power. We have powered the LAC with a 12V power supply (this matches the 12V actuator) into the + and - terminals on the X6 block, as per the LAC datasheet.The Arduino board is powered by it's own 6V power supply with positive plugged into the -vin terminal, and - plugged into -gnd.

As for code, we used a slightly modified version of the Servo-Sweep example found the Arduino software.

As you can see, this is a relatively basic way to cycle the actuator in and out.

If you are so inclined, you can use your own code and a switch of your choosing to actuate the device another way. This could be via a push button, proximity sensor or any other Arduino-compatible sensor you choose


Below is the code that we used for this example. It is the basic Servo-Sweep example code from within the Arduino software. The only part we modified is the delay.

#include <Servo.h>

Servo myservo;  // create servo object to control a servo
// twelve servo objects can be created on most boards

int pos = 0;    // variable to store the servo position

void setup() {
  myservo.attach(9);  // attaches the servo on pin 9 to the servo object
}

void loop() {
  for (pos = 0; pos <= 180; pos += 1) { // goes from 0 degrees to 180 degrees
    // in steps of 1 degree
    myservo.write(pos);              // tell servo to go to position in variable 'pos'
    delay(30);                       // waits 15ms for the servo to reach the position
  }
  for (pos = 180; pos >= 0; pos -= 1) { // goes from 180 degrees to 0 degrees
    myservo.write(pos);              // tell servo to go to position in variable 'pos'
    delay(30);                       // waits 15ms for the servo to reach the position
  }
}


Tuesday, 17 October 2017

Opening And Closing Windows With Linear Actuators

Opening Window With Linear Actuator


It's becoming a fairly popular project to automate household windows. Using linear actuators is the most cost-effective and simple way to achieve this.

There are a lot of reasons that you may want to consider automating your home windows, skylights or vents.
  • To prevent your home from getting too cold at night
  • If it is in a difficult to reach spot
  • To keep bugs out at certain times of day
  • For noise abatement if you live near a railroad or airport
  • Just for fun!
Automating your home's windows, skylights or vents is a project that anybody can take on. With only a few basic tools you can create a system that will open windows with the push of a button, wireless remote or even on a timer switch.

Related article: Choosing The Correct Actuator For Your Application

If you're up for taking on a more difficult project, you can use an arduino board to control your actuator. This will open up dozens of new ways that you can control your actuator setup. You can use motion sensors, clap sensors, light sensors, voice command, bluetooth or other inputs to determine when your device opens and closes. This can be particularly useful if you're not home often.

We do not officially support arduino. We do however offer a few helpful resources here. The best place to go for arduino support are the arduino forums.

Step 1

Measure the distance that your window must travel, and select an appropriate actuator.

Our micro linear actuators are small and discreet, making them ideal for applications where you don't want a massive device in your face every time you go to your window

That said, our actuators have a maximum stroke of just under 12". This will be plenty for windows that swing up or out, but you may want more stroke for windows that slide. 

Step 2

Decide how much force and stroke you need and order the actuator and switching mechanism that you want to use. As mentioned above, this can be a simple button or rocker switch, a remote control or an arduino setup.

Step 3

Mount the actuator. Mount the device appropriately for the window you intend to open. Actuonix actuators come with a hardware mounting kit so you won't have to buy anything extra for mounting. Ensure that the actuator has space to move freely and not bind up at any point along it's travel path.

Step 4 

Wire up your switching mechanism according to the data sheet for the switch you're using. You are going to need a power source for this. For indoor applications, most customers use one of our DC power supplies rated at a voltage appropriate to your actuator, either 6V or 12V. 

Related Article: How To Make A DIY Remote Controlled Door Lock

This is one of many household tasks that can be automated using linear actuators.

If you have a project idea and need help choosing the best device to suit your needs, give us a shout via email or phone. Our dedicated sales professionals will be happy to help you choose the best product for you. If our products aren't the best fit for your application, we will always try to recommend another company that can help you out.

Friday, 13 October 2017

2017 FRC Team Sponsorship Winners


The time has come to announce the winners of our 2017 FRC team sponsorships! 

In early 2017, we started looking for new ways to actively support young engineers and robotics enthusiasts. This lead to the creation of two brand new programs - our Scholarship Program and Our FRC Sponsorship Program.

The Actuonix Motion Devices FRC team sponsorship program is brand new for 2017. It was designed as a way for us to give back to the engineering and robotics communities. 

For several years now, we have supported our local FIRST Tech Challenge team and we're excited to reach out to the larger FIRST community and offer more teams the opportunity to win financial and product sponsorships.

I have to say that choosing the winning teams was not easy. We received a big stack of applications that we had to sort through and try to do our best to choose according to demonstrated financial need, teams that had a plan for how to use our products, and of course, those that followed the instructions and applied according to the directions given.

And so, now it's time to announce the winners...


$500USD Financial Sponsorship


Team 6314 - DM Robotics from Scottsdale, Arizona.

Team 1729 - Team Inconceivable! from New Ipswitch, NH.


$250 Product Sponsorship (In-store credit)


Team 6619 - GravitechX from Livermore, California.

Team 2585 - Bellaire Robotics from Houston, Texas.

Team 5618 - From Plessisville, Quebec.

Thanks to all of the teams and mentors who took the time to apply and share this opportunity with other teams. We appreciated all of the interest we got in this opportunity and are looking forward to continue supporting FRC (and FTC) teams moving forward.

Winners will be contacted in the near future to tell them how to take advantage of the sponsorship.

Friday, 29 September 2017

Using Linear Actuators For Realistic Animatronics




Building animatronic displays was once solely the domain of professionals in movies and television. These day, there are hobbyists and professionals all over the world working with animatronics. Motion-enabled elements can be found in Halloween and Christmas displays, museums, and of course, just for fun. It's an art that has come a long way in the last couple of decades.

Making robots, puppets and displays move is complicated. It requires skillful use of drive mechanisms, linkages, controllers and mounting techniques. Builders want their projects to move in a smooth, fluid manner to create the illusion of realism. The options available for creating linear motion used to be expensive, complicated to work with or unrealistic in the way they move. 

In 2004 when Actuonix invented the low-cost micro actuator, we opened up a new realm of possibilities to builders of animatronic displays. Of course linear actuators are not new. They have been around for decades in different configurations such as:
  • Hydraulic
  • Pneumatic
  • Electromagnetic
Though these types of actuators have their place, hydraulic and pneumatic tend to be more expensive and complicated than electric actuators. Electromagnetic actuators (such as those found in power door locks) are cheap and easy to come by, but they tend to be underpowered for a lot of projects and lack the ability to stop mid-stroke.

Related post: Micro Linear Actuators in Prosthetics

Electric micro linear actuators allow builders to create smooth linear motion without complicated motor controllers or clunky rods and fittings to convert rotary motion to linear.

Control options

One of the primary advantages of using linear actuators for animatronics is that they offer a wide range of control options. Actuonix offers four series of actuators, each with a unique control method.

S-series - Controlled via reversing polarity. This is great for applications where your prop is controlled by a physical switch or remote control system. They come in 6V or 12V and can run off of a battery or a power supply.

P-series - These offer position feedback and are intended for use with our linear actuator control board. They're ideal for applications where you need to remotely monitor the position of your actuator. They also offer the ability to set custom stroke limits, adjust speed and sensitivity.

R-series - By far the most popular with hobbyists. R-series linear servos have the same 3-wire plug as RC linear servos. If you're familiar with using standard rotary servos via RC or arduino, these are for you. They're just $70 and there's nothing on the market quite like them.

I-series - Our I series actuators feature an internal position controller and several input modes including R/C. They're best suited for industrial applications or enthusiasts who wish to design their own controller.


For a closer look at more of the available options and the pros and cons of each, check out this article by Steve Koci. Steve is a long-time animatronics enthusiast and expert in the field.


If you're considering your options for a project and want some help choosing the best linear actuator for your needs, contact our sales team, we'll be happy to assist you.


Monday, 18 September 2017

Rod vs Rodless Actuators


Rod and Track (rodless) actuators ultimately perform the same function - they move loads back and forth. Depending on your application however, there can be significant advantages to either rod or track actuators in your design. 

Rod Actuators

Rod actuators are more common than track actuators. In fact, 90% of our product lineup are rod actuators. Simply put, any actuator functions by extending a rod out of the device to drive motion is a rod actuator.
These are ideal for applications where the load you are pushing is either very light weight, or not primarily supported by the actuator. Rod actuators are intolerant of side loads by design. Because of this, it's important that when using this type of device, your load is either supported by a guide device such as a linear slide rail or by some other means.

Rodless

A rodless or track actuator does not have a rod that extends from the device to push or pull the load. Rather, it has a carriage or block to mount the load to, and it carries the load along the length of the actuator. Electric rod actuators can be driven via lead screw or belt. All of our track actuators screw driven.
There are a couple of main advantages to using a track actuator. First, they take up less space overall. For example, if you use a rod actuator, the unit has to be long enough when retracted to fit the rod inside the device. Add to that the length of the rod when it extends from the device. On larger actuators that adds up to significant length. Track actuators carry the load along the length of the device and thus can be used in applications where less space is available.
The second main advantage of using rodless actuators is that the actuator itself is capable of supporting the load. This not only saves you space in your design, but also saves you the cost of a slide rail.

What's right for you?

Do you know what type of actuator is ideal for your application? If you need a hand selecting a device that will work for your application, give our sales team a call. Linear motion is all we do and our sales professionals can help you pick the device that's going to work well with your design.


Thursday, 7 September 2017

Linear Actuators and IP Ratings


When selecting a linear actuator for a project, there are many different things to consider. Stroke, speed, physical dimensions and force requirements are the most common, but there are other things that you may need to account for when choosing an actuator to include in your design. Some customers require their actuators to be dust proof, waterproof or water resistant. These customers typically want to know what our actuators carry for an IP rating.

What is an IP Rating?

IP which stands for International Protection Marking (or Ingress Protection Marking) is a universally recognized system of rating the degree of protection provided against intrusion for mechanical casings and in our case, electrical devices. Simply put, it's a rating for how resistant a product is to water and dust. 

The ratings system is designed to give consumers more detailed information about the types of environments that a product is suitable for than vague terms such as "waterproof" or "water resistant".

How IP Rating Works

Simply put, an item that carries an IP rating will have the letters 'IP' followed by two numbers, for example, IP24. There are other designations that can follow the numbers, these represent additional, more specific testing. For the purposes of electronic devices, just understanding the basic numbers will do just fine. There is a drop-test component to the IP numbers as well, but at this time it is not yet widely used.

The first number indicates how much protection the enclosure provides against foreign objects. This could mean parts, wires or dust. This is rated on a scale from 0 through to 6 with zero being no protection at all, and 6 being completely dust tight.

The second number represents the level of protection that the enclosure offers against the ingress of water. This is rated on a scale from 0-8 with zero being no protection whatsoever and 9k being protected against close-range, high-pressure, high-temperature spray downs.


linear actuator IP rating


Why Are IP Ratings Important?

You don't want to buy a linear actuator, or any electrical device that can not withstand the conditions that it will be subjected to. Understanding how IP ratings work is important to make sure that you choose a device that offers adequate or superior protection to what you require.

Do Actuonix Actuators Carry an IP Rating?

Yes - all of our rod actuators carry an IP rating of 54. The solid object rating of 5 means that our actuators can be expected to protect against all but a very limited ingress of dust and should not effect the operation of the device.

The moisture rating of 4 means that our devices are protected from water splashes from all directions, but not complete submersion, high-pressure spray or prolonged exposure.

If you have any questions about our IP ratings or need help choosing an actuator that is appropriate to your application and operating environment, please give us a call. Our sales professionals can help you identify your needs and direct you to the product that will best suit your application. If you require a custom solution, we offer a custom micro actuator design service

Looking for more information on IP ratings, check out this Wikipedia article for a more in-depth explanation of how IP ratings work.