Solenoids

How do I switch the default direction on a single acting solenoid?

I dont know that you can, because it only has one port, with double acting itd be easy as plugging into the other port, however you cant do that with a single acting solonoid

Edit: maybe if you took the 3 wire connector, and switched the red and black spots? Idk, it’s an idea and idk that its be legal

Are you also using a single acting actuator? If you are, you can effectively switch directions by changing to a double acting actuator with a rubber band contracting it. (Plug the other end up.)

Please don’t do that.

@jpearman lol sorry

Single acting solenoids are like single acting cylinders: powered one way, spring return to their default (closed for solenoid, retracted for cylinder) state. This is another reason to spend your money on double acting pneumatics as they are more versatile.

In my industry experience, I prefer double acting cylinders because I have had springs break inside a few non-repairable Bimba cylinders at about 1,000,000 cycles, while double acting cylinders just keep on running, and running, and running…

okay thanks for the inupt, would it be feasible to plug a 2 wire connector into the solenoid, and flip it before it goes to the driver cable?

Maybe we don’t understand what you’re trying to do. You must know that air won’t flow backwards just because you switch solenoid polarity, so you can’t be asking that. Presumably, you’ve examined the single-acting cylinder and determined how it works and how it can’t be changed, so that’s not it.

Are you asking this:

The solenoid valve does not allow air to flow unless and until it is energized. How do I change it so air flows all the time until I energize it?

If that’s what you’re asking, two things:

  1. Switching polarity won’t switch the action of a simple solenoid. For a standard (non-magnetic) solenoid, there is only “energized” and “not engergized;” the spring-action comes from a physical spring, not a magnet as in some specialty devices, so the activation doesn’t change with direction of current. And:
  2. There is almost certainly no reason you would need to do this. If you need the solenoid valve to allow flow most of the time, turn it on when your code starts, and use programmatic control to turn it off periodically.

So, it’s not clear exactly what you want; only that the existing answers haven’t satisfied you. A more detailed question might be helpful.

I was using a single acting solenoid on a double acting piston. And i wanted the piston to be expanded when the cortex is off while being pressurized. For my design the piston needs to be expanded at the begining while be pressurized. If i could use rubber bands to keep it expanded it would be fixed as I could put the piston fitting on the top hole.

A single-acting solenoid can’t do this:

When de-energized, the input port is blocked off, and the output port is routed to the exhaust. When energized, the input port is routed to the output port and the exhaust port is blocked off. So no matter how you try to re-wire it, the cylinder will get no pressure when the solenoid is de-energized.

A double-acting solenoid switched the input port from output 1 to output 2 when energized, while the other output port is routed to exhaust; therefore you have pressure on either one side or the other side of the cylinder at all times.

Thanks

You can activate the solenoid in pre auton so that upon power up the piston extends.