Pneumatics Question

Do you have to have one solenoid for each actuator, or can you have one solenoid controlling multiple actuators?

while you can not have more than one solenoid powering a acuator, the rules do not prohibit multiple acuatorss per solenoid, as far as I can tell. However, this will slow down each of your acuators, as the flow rate will be restricted. Why do you want to do this?

Why would the flow rate be restricted? All that is being changed is that the air flow is being split after going through the solenoid instead of before. If we did this we could save a solenoid.

You’re trying to move twice the air through the same opening. That’s going to have an effect; your actuation will be slowed down somewhat, as only so much air can get through at the same time, and you have the same pressure to push air through with. For, say, a 3/4" bore/1" stroke cylinder, like might be used for shifting, that effect would be negligible. But when you get to more of a 1/5" bore, 12" cylinder, say, there will be a noticeable effect on speed.

The actuators are the 3/4 x 3/4" cylinders used for the Andy Mark supershifter. So if the effect is negligible, using one solenoid would be okay?

Probably. The reason it’s negligible (or close to it) is that you have a fairly small volume of air to move, and small volumes tend to move faster than large ones in this type of case.

OK, thanks.

For many applications, it makes sense to use one solenoid instead of 2.

Shifting is one example - it is important that both transmisssions shift at the same time. So having a single solenoid controlling the shift ensures that both will be energized together. If you have separate solenoids, and one sticks or fails (bad connector, bad signal, etc.) you can end up with one side of the robot in hi and one in low.

Other examples could be any system where it is important that both cylinders (or more) be in the same condition.