Proper way to connect a solenoid

[rkoripalli]

My team is adding t-shirt cannons to our robot for the offseason, and we are using sprinkler valves as solenoids to fire them. We have little experience with pneumatics, we managed to get the compressor working with no trouble; however, we don't know the proper way to connect the solenoid so that we can fire. We tried connecting it to a Spike and switching the spike on, but it was unsuccessful. What is the correct way to do this?

[gr8dragon]

There is a solenoid module and breakout for the cRio (much like the analog) to which solenoid can be connected. Inside of the program they will need to be fired using the Solenoid class.

[rkoripalli]

Originally Posted by gr8dragon

There is a solenoid module and breakout for the cRio (much like the analog) to which solenoid can be connected. Inside of the program they will need to be fired using the Solenoid class.

Thanks, we will definitely try that, we would've done that earlier, but we are in the process of moving all of our parts so we don't have the breakout right now.

[magnets]

If you're using valves that aren't the typical FRC type (like sprinkler valves), I'd recommend using a spike relay instead of the solenoid module/breakout. Then you would use the relay class/vi instead of the solenoid one when you program it.

[rkoripalli]

Also, is there some time of sensor that gives feedback on what psi the compressor is at? We want to be able to adjust how far we can shoot the shirts by changing how much pressure is in the tanks.

[rkoripalli]

I can say that the solenoid does work, we were able to fill up the air tanks with the compressor, and fire a t-shirt a very good distance by connecting the solenoid directly to a battery

[rkoripalli]

I've found out that it is in fact a 24v valve, what would you guys suggest based on that?

[bardd]

Originally Posted by rkoripalli

I've found out that it is in fact a 24v valve, what would you guys suggest based on that?

As far as I know, there's no way of getting 24V except hogging the cRIO's power, and I wouldn't suggest that. Is there a way for you to get a 12V one?

[magnets]

If you were able to successfully operate the valve using the KoP 12V battery, you should be able to do it with a spike relay, wired the same way your compressor is set up.

[rkoripalli]

Originally Posted by bardd

As far as I know, there's no way of getting 24V except hogging the cRIO's power, and I wouldn't suggest that. Is there a way for you to get a 12V one?

As of right now we're open to anything. We're actually planning on building 4 cannons, but we only have one right now. If its possible we would like to get the 24v one working though

[bardd]

Originally Posted by rkoripalli

As of right now we're open to anything. We're actually planning on building 4 cannons, but we only have one right now. If its possible we would like to get the 24v one working though

Working with the 24V isn't different than 12V, and like Scott said, if it worked with the battery it'll work on the robot. The thing is since you're not using the solenoid's specifications it might fail or work poorly. Also, it's bad practice to not supply the component's specifications, that's why I suggested getting another.

Other than the tips in my original post, there's not much I can say, based on your description. Do you think you could post a picture of the system you built?

[rkoripalli]

Originally Posted by bardd

Working with the 24V isn't different than 12V, and like Scott said, if it worked with the battery it'll work on the robot. The thing is since you're not using the solenoid's specifications it might fail or work poorly. Also, it's bad practice to not supply the component's specifications, that's why I suggested getting another.

Other than the tips in my original post, there's not much I can say, based on your description. Do you think you could post a picture of the system you built?

I won't be able to post a picture today because I don't have access to the robot right now. It's at another members house,I'll ask him to post one later today

[rkoripalli]

In terms of code, I am using Java commandbase. I have "public static Relay cannon = new Relay(4);" in RobotMap. I also have a command setup to fire. In the initialize i'm doing "RobotMap.cannon.set(Relay.Value.kOn);" where cannon is the name of the Relay and RobotMap is the place where it is defined. I can verify that the command is running because I have a debug statement which is printing when I push the button to run it.

[rkoripalli]

Do you guys know of a way to use a non spike relay on the bot? We only have two working ones and one is on the compressor, we want to have 4 cannons and our team is short on cash so we really don't want to spend the $35 for each new spike

[tr6scott]

From the link I posted, they were talking that they were reliably firing the solenoids with 9vdc batteries, so I would wire it with a spike to the 12v battery. Let it run, and monitor how warm it gets, just to watch for early failure.

Not sure how much to spend on an analog pressure sensor, but we use these in industry. http://www.ifm.com/products/us/ds/PN2024.htm with good success.