This might sound really unusual, but I have been meaning to experiment with pneumatic actuators for a long time. For my random robotics and DIY projects, motion is typically accomplished with gear motors or servo motors, but there are certain types of movements and actions that could be easier or better done with pneumatic cylinders and valves.
In a pneumatic actuator system, you have a source of pressurized air, one or more valves to control the movement of air, and cylinders that use pressurized air to provide motion of some kind.
I briefly worked with pneumatics back in high school, when our team built a robot to compete in the 2001 FIRST Robotics Competition. In the years since then I wanted to start experimenting with pneumatics, but there hasn’t really been a good time to get started.
Recently I began work on a project where pneumatic cylinders would have come in handy, but due to timing I went down another route. However, this gave me a good excuse to finally get into pneumatic systems.
Maybe my first test project will be a ping pong ball launcher or an automatic tablet stand for my toolbox. I have a few robotics project ideas, but really need more hands-on experience before I could get there.
I figured that there are three approaches that would help me gain more experience with pneumatic actuators and components.
- A la carte components
- Vex pneumatics kit
It might seem silly, but Lego’s Technic building kits and accessories are very good at teaching about mechanical systems. However, there is a disconnect between what can be done with Lego pneumatic components and what can be with “real” ones. Plus, I am pretty capable at learning theory on my own, and was more interested in strengthening my hands-on and practical experience.
A la carte components would probably be best, but there would be a lot of data sheets to go sort through. Which brand of cylinder would be best – Bimbo? Amico? Which fittings brand – SMC? Which valve? Tubing size?
Initially, I want to experiment with different configurations, control methods, flow rates, actuation speeds, and so forth. Technical specs are not quite important to me right now.
So what I did was start off with a Vex pneumatics kit.
Vex, an Innovation First brand, designs and manufacturers robotics prototyping and learning components for different levels of experience. I bought a lot of Vex components years ago when Radio Shack stopped carrying their products, and use them every now and then for quick robot and mechanism builds.
Their pneumatics kit comes with an air tank (which is actually a sealed non-actuating double-acting cylinder), a simple regulator, control valve, 5V solenoids with built-in drivers, and two double-acting cylinders. I also purchased an add-on single-acting cylinder and solenoid combo.
I could have spend a little less if I skipped the solenoids and pieced together a starter kit using similar industrial components, but the Vex starter kit helped demystify the basics.
The air tank is filled using a manual pump or powered air compressor via Schrader valve. It only takes 3 or 4 pumps with my bicycle pump to get the 10 cubic inch tank up to 100 PSI.
There are ways to connect small air compressors to the system, including 12V auto/tire models, but thus far I’m happy to use a bike pump.
What I like about the Vex kit is how it’s simple but capable enough for me to learn and experiment with. Most of the components are industry-standard, which provides for better hands-on experience and allows for easier implementation with additional standard products.
The solenoids that come with the Vex kits require the use of a microcontroller (such as an Arduino) to send digital signals to the solenoids. That’s how I’ll control them in the future, but I also ordered a range of manual and mechanical valves and flow control accessories to give me a feel for what can be done without the need for a microcontroller.
These aren’t the types of products you often see outside of industrial settings, mainly because of cost, but also because of complexity. The Vex system doesn’t really help with either very much, but it’s still a very nice way to springboard into working with pneumatic actuators, valves, and components.