If you're new to the world of robotics, you might be wondering "what are micro linear actuators?" Simply put, they are small
devices that convert rotary motion into linear motion. They work
in much the same way as large-scale actuators, but are physically
smaller in size. This makes them more suitable to tight spaces and applications where weight must be kept to a minimum.
There is no hard and fast rule for what
makes an actuator 'micro' but generally speaking, micro linear
actuators have a stroke of less than 300mm and offer less than
100lbs of maximum force.
You'll find these devices in thousands of applications across dozens of industries including robotics, aerospace, medical devices and radio control. RC linear servos are also compatible with arduino and thus becoming more popular with the DIY crowd.
Benefits
Of course the main benefit of micro
linear actuators is their relatively small size. Size, weight and
cost restrictions have kept linear actuators out of consumer products
for a long time. Actuonix changed that in 2005 with the development
of the first affordable, reliable micro linear actuator.
Electric micro linear actuators are slowly replacing pneumatic and hydraulics as the preferred solution for all types of automation applications.
The main advantage of Actuonix micro linear actuators is their tiny size. They're also very simple to mount compared to standard rotary hobby servos. Our micro linear actuators are also capable of higher forces. With max forces of up to 67lbs, Actuonix devices have the power it takes to drive your projects.
Design
Electric micro linear actuators fall
into one of two categories: inline or side by side. Inline actuators
are typically thinner and a little bit longer than their side by side
cousins. They are ideal for small spaces. Below is an example of an inline actuator and a side by side actuator
Side by side actuators tend to be more
powerful due to the added space for a larger motor. They have a larger cross section but also have a shorter installation length, which can be better for some applications.
The shaft of a miniature linear actuator
can be either circular or square in shape. They will typically be
constructed of aluminum or another high-quality metal. There are
exceptions here, our PQ12 is constructed of plastic and is tough as
nails with a max force of over 11lbs!
Difference between micro linear
actuators and servos
Micro linear actuators and linear
servos are very similar and the term you use can depend on the
industry you're working with. R/C and robotics hobbyists will be more
familiar with the word 'servo' as rotary servos have been popular in
those spaces for many years. The term actuators tends to be used more by industry and the scientific community.
For the purposes of this article, I'm
referring to all products as 'actuators' with the exception of our
'R' series, which is a direct plug-and-play replacement for rotary
servos. The 'R' series are micro linear servos.
Control
Most micro linear actuators are a
simple 2-wire 12v device that is operated by reversing the polarity
of the applied voltage. Simple and effective. This is great for some
basic automation projects.
Actuonix Motion Devices leads the micro
motion industry when it comes to control options. We offer 4
different control options off the shelf to better accommodate the
needs of our clients.
Our S series is the simplest micro
linear actuator that we offer. As described above, they use a 6V or 12V input
and are controlled by reversing the polarity. Our S series actuators come
with end of stroke limit switches to prevent motor damage.
The P series micro linear actuator, has an internal position feedback sensor instead of limit switches. This sensor allows you to connect a position controller of your choice to automate the actuator. We offer a control board called the LAC board which allows you to adjust the speed,
set end limits and adjust the sensitivity.
Our R series linear servos are a direct
plug-and-play replacement for regular rotary servos. They will work
with most R/C receivers as well as arduino, VEX and Raspberry Pi.
The I series micro linear actuator has
an embedded internal position controller that will allow you to send a variety of position commands which the actuator will follow. Designed for the industrial and scientific market, it can accept an analog voltage, PWM voltage, 4-20 mA current from a PLC, and RC signal inputs.
What are Micro Linear Actuators used for?
The potential applications for micro
linear actuators are endless. Any project that requires linear motion
but has space or weight restrictions is an ideal candidate. Below,
I've listed a few examples of industries or groups that commonly use micro linear actuators to give you an idea of how versatile they are.
Robotics – OEM companies and
hobbyists alike use micro linear actuators in everything from
mass-produced robotic hands to carefully-crafted, home-built R2D2
models with full functionality.
Radio Control – Linear actuators
are a popular choice among RC enthusiasts. Sliding canopies,
retractable landing gear, excavator and bulldozer control as well as
automated dump truck boxes are common
Arduino – Our micro linear
actuators drive thousands of arduino projects from animatronic
Christmas and Halloween displays, to auto-closing chicken coops.
Industrial – Thousands of
potential applications
Choosing the right Micro Linear
Actuator for your project
Start with stroke. Measure how far you
need the actuator to drive to accomplish your goal. Next is force or speed,
how much force do you need or how fast does it need to move? Remember these two factors are linked because for any actuator the more load you add, the slower it will go. Use our speed vs. force charts to pick the gear ratio that is most suitable for your application.
Now that you have a good idea what you
need in terms of physical capability, you need to decide how you will
control the actuator. Do you want a basic 12V reversing polarity
setup, or do you need to control your end limits. Do you plan to use
arduino?
If you need help choosing the correct
micro linear actuator for your project or product, send us an email
or call our sales department and we'll be happy to help you choose
the micro linear actuator that will best suit your needs.