Triggering solenoids after match?

I read through the manual before asking, and I did not see anything that would indicate that this is illegal. Can you manually trigger a solenoid after the match to for example release the rope (does not require robot re-enabling)? If this is illegal can anyone point me to the rule that states this? Thanks!

There is no rule against it, as long as it is safe.

If by manually, you mean pressing the little button that causes it to switch, of course. Some also consider it safer to completely depressurize your robot on the field(through the manual valve). I would suggest putting a small T-connector right next to the piston the solenoid in question would actuate(if it is exposed) and put a switch there.

We did this for our climber in 2013. It is not explicitly illegal (this year or then), though sometimes you’ll get pushback from safety folks. This varies by person, and there’s no one way to definitely convince everyone. We would vent the air in that case. Of course that was 10 feet off the ground, so safety objections at 4 feet may be less impeding. Also note that if you’re on your own rope, you’re allowed to just remove the rope with the robot on it.

It is a requirement for any FRC pneumatic system to have a pressure release valve. It is something that most drive teams will do at the end of each match. This will make the cylinders stop exerting pressure and make them easy to put into whatever state you want them for the sake of releasing the rope.

I don’t really care if a robot is 10 feet, 4 feet, or 2 inches off the ground. If it’s in an unstable position, you shouldn’t have your hand or arm buried in its guts while you’re removing some of its support. If someone isn’t paying attention or loses their grip when the weight hits them, you’re in a bad position and liable to get hurt. If everyone has their hands on the outside of the robot, the worst case for dropping it is a toe or foot injury.

So if your solenoid is easily accessible from the outside without shoving your hand through any mechanisms or framing, fine. If it’s buried inside your robot, then dump the air with the dump valve that had better be on the outside of the robot. If you don’t want to dump your air after every match, I suggest you place your solenoid accordingly.


The only thing I would add: using a muffler or flow controller on your pneumatic system vent is really nice for two reasons: (1) it’s significantly quieter than a direct dump, and (2) all the pneumatic mechanisms will relax slowly and safely.

We use a pokey stick to push the button from outside the robot. We can always make a new stick.

That’s one way that we do that. The other way that we actuated our hood safely last year (so that we could lift it off the tower) was by having two people holding the robot while another person pressed the button on the solenoid.

The system that we used last year also had the benefit that actuating the shooter hood didn’t actually effect the system - the hood was already up, since the entire weight of the robot was on it. Pushing it just made sure that it wouldn’t try to move down as we were lifting off the robot.

I would have been much more scared to vent the robot than to manually trigger the solenoid - both the elevator and the pivot had pneumatically actuated disc brakes, and 120 lbs of suddenly falling robot is terrifying!

I wouldn’t want to reach deep inside my robot guts and trigger a solenoid from a stable position on a flat floor. Please don’t bury actuators you intend to manually power in any way inside anything that might be construed at as pinch point. Altitude has nothing to do with that (though it does compound other problems).

As for venting, I’d have to map it, but there ought to be a legal vent valve setup where: 1) the main upstream valve vents the entire system (as required), 2) a downstream valve(s) vents only its own section (potentially venting rather than actuating a single solenoid). Just food for thought.

This has to be rigged up where the main valve is guaranteed to dump the entire system no matter what’s going on with the downstream valve. It’s pretty much allowed by R82-H:

H. Shutoff valves which relieve downstream pressure to atmosphere when closed (may also be known as 3-way or 3-way exhausting valves).

You need to be a little careful on the sizing, since there is the standard of releasing pressure in a “reasonable” amount of time. 15 seconds is probably not reasonable.