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 is this 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.