Linear Actuator Selection

The accelerated and efficient development of machinery is impossible without simple but powerful elements. Those elements are linear actuators. Nowadays, there are myriads of devices that turn different types of energy into linear motion; butut it is rather tricky and challenging to pick the right tool. Different qualities, sizes and technologies of the available options complicate the selection. Narrowing down a huge list of options, you can mistakenly overlook the most suitable ones. This small mistake can lead to undesirable consequences; a device can fail to perform the simplest tasks.
We have analyzed the specifics and pitfalls and come up with this article on how to select the linear actuator for your specific project. Take a look at the facts that will help with your choice.

What a User Expects from a Linear Actuator

First of all, let us clarify the main features we would like the linear actuator to have:

Great efficiency

You are looking for an actuator to become a part of a mechanism that either lifts, pulls, or pushes weight, or performs any other similar action. So you have to be sure that the chosen actuator is able to handle this task.

High adaptability

External factors such as humidity may change. It is necessary to find an actuator that easily adapts to changing conditions and doesn’t lose productivity.

Seamless integration

An actuator is just a single small part of the whole complex system. Integration capabilities must be considered.

Affordable price

Here, we mean not only the actuator’s price but the maintenance costs as well. All factors such as product quality, efficiency and energy use contribute to the overall product price. The important thing is to analyze them and come to the best choice.
Unfortunately, none of the existing actuators come with a label saying “This option demonstrates better efficiency than the others” or “It is really adaptable, we promise”. To find out how powerful the chosen actuator is, you need to have a proficiency in mechanics. Or, you can take a look at the information below and find out more about the key actuator characteristics.

5 Characteristics of Linear Actuators That Will Help You with Your Choice

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Take into account the following characteristics to select a linear actuator:

Speed

The mechanisms you build demand a certain actuator speed. Each actuator has a special feature called critical speed. It may vary depending on materials and dimensions, but what is crucial, the actuator’s speed must not exceed it.
Screw-type actuators demonstrate high speed along with impressive efficiency. But in this case, you should pay attention to the screw whip which may cause premature wear.

Capacity

There are 3 main types of actuator capacity:

  • – Radial load capacity;
  • – Axial load capacity;
  • – Moment capacity.

Load capacity is highly important as it allows calculating the actuator’s service life. But you should not underestimate the other factors: each of them must meet the requirements.
Pay particular attention to the actuator’s design and sizing. Appropriate sizing is one of the most important things for the right choice, as the actuator’s size defines what load it can handle.
Analyze load positioning carefully to reveal all possible weaknesses. Let’s analyze the two most common cases:

Load atop

A load should press on the actuator’s surface along the defined axis so the force applied is the same at every point. The load should be supported by either by actuator’s or system’s elements.

Vertical application

In this case, it is extremely important to watch the positioning of the load. The lead-screw should be self-locking.

Stroke length

You can use linear actuators for distances of 5 ft to 50 ft and more. And here, you must decide on a suitable stroke length. The newest actuators are made of cutting-edge materials that require little maintenance. In turn, stroke is powered with a linear motor that has its own characteristics as well. When selecting an actuator, analyze those characteristics and make sure they can help you to achieve the goal.

Actuator’s duty cycle

The duty cycle of the mechanism you build depends completely on the duty cycle of the actuator you choose.
In case of high-duty-cycle application, you should avoid leads screws. The construction of the lead screw combines stainless steel and plastic; thus, it wears over the mechanism’s lifetime.
Our recommendation is to choose a ball-screw actuator. It is based on rolling friction and lasts much longer. A planetary roller screw even meets the requirements of huge serious projects which allow no failure. And the budget option is a simple belt drive.

Environmental conditions

Earlier, we mentioned that it is important to choose actuators that easily adapt to changing conditions. However, there are some things to keep in mind. A dirty environment can damage some actuators, and a clean room will be contaminated with the others.
Actuators to use in a clean environment:

  • – Rodless actuators, because the screw is vulnerable here.

Actuators to use in a dirty environment:

  • – Metal-to-plastic screw actuators as they contaminate the air with small particles;
  • – Rod-style actuators as their screws are built-in and safe from any contamination.

10 Questions to Answer Before Making a Choice

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Take a look at the following questions to make your linear actuator selection impeccable:

  • – How much force do you need?
  • – How far do you need it to move? And in what direction?
  • – How fast should it move?
  • – How should it be mounted?
  • – Will the environmental factors change?
  • – What type of motor do you plan to use?
  • – What type of power supply do you plan to use?
  • – Do you need it for long-term operations?
  • – Will you take care of safety mechanisms? And how?
  • – Will the environmental factors change?
  • – What is your budget?

Final Thoughts

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The best tips to select a linear actuator are right here:

  • – Define the key features it must demonstrate;
  • – Be aware of all the basic characteristics of the tool you choose;
  • – Answer the above questions and build a clear picture of what you actually need for your future project.

These tips will provide you with valuable help when selecting actuators. Of course, the task is still challenging. So if you have some doubts or have faced some issues, just let us know and we will take care of them.

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