Single-acting pneumatics


For the life of me I just can’t seem to get the single-acting pistons to work! I pump it to a 100psi, upload the program, and when I send a value of HIGH (i’m using pros) I see the tube to the pneumatic tighten up a bit indicating a flow of air, but nothing happens to the piston itself!

Could the spring be causing this issue?


Have you checked that the solenoid is not backwards? Do you have a photo of your setup and all the components?

It is essentially like this image but without the tire pump fitting:

Is your regulator turned up so it provides air pressure down the line?

Without air being supplied, can you still move the piston’s rod back and forth by hand? One possibility that would match your description is that teflon tape or something has come loose inside the tubing and perhaps blocked the line to the piston, but I kinda doubt that is the case.

Are you sure your air supply cylinder (reservoir) is actually getting inflated? I’ve seen kids try to pump up their reservoirs by hand, and give up trying to pump thinking their reservoirs are fully pressurized when in fact they were not getting the reservoir’s inflator valve to open up because their pump connection did not properly depress the little metal doo-hickey located inside the inflator valve.

I even took out the regulator to supply maximum pressure, but when it was in I had it set for maximum pressure (turned all the way to the right). And I can move the piston back and forth without air.

And I have an electric air pump. When I’m done pumping it reads 100psi, so I know that I am pumping it all the way.

When you fire the solenoid, can you hear a flow of air if you disconnect the tubing from the piston?

By chance are you using a double-acting solenoid to control a single-acting piston?

The tubing between the cylinder and soleniod?

If you disconnect the pneumatic tubing that leads from the solenoid to the cylinder (a.k.a. the actuator or “the piston”), and then fire the solenoid, can you sense air flowing out of the free end of the pneumatic tubing?

I can’t think of any other way to be absolutely certain you are getting not only the air pressure but also the air flow that you might need to move the cylinder (a.k.a. the actuator or “the piston”).

Finally had time to try this: yes, there is a flow of air.

Is it a small ‘wind’, or a strong burst that lasts a few seconds and then stops when the tank is empty?

Well since you say your setup looks like the one in the picture then i’m guessing you don’t have the fittings with the built in regulator used in the double acting kits. So is your piston rode possibly bent? Or are there notches in the metal on the rode? These can also lead to pistons not functioning correctly.

It’s a small wind.

Edit: and no the rod is not bent. I can take out the rod by hand very well.

Nevermind! I can’t believe it… I was supposed to take out the red thing??? And yet the instructions said no such thing…

Anyhow, after two days of trying to solve it it is now solved. Thank you everyone for your help :smiley:

The red thing is placed there to teach us all to forever be patient and compassionate toward all beings less intelligent than ourselves.