So my team’s robot has an adjustable tray that we control using pneumatics. We use two air tanks with two double-acting pneumatics. With this, we only get 10 shifts (1= up and down). This is enough at all in a match. Does anyone have any ideas to increase it without adding more tanks?
Use rubber bands as tensioners. Also, there are ways to regulate the pressure using the little screw on this part.
maybe try adding more tubing.
Uhhh… not sure how that would help. Adding more tubing (after the solenoid) would mean that you lose a lot of that air when you compress/decompress. This would only worsen the situation. If you add tubing before the solenoid, so it acts like a “reservoir,” I doubt you’d see much of a difference, as the volume the tubes hold isn’t that much.
But perhaps you’re thinking of something different.
First thing I would try is asking one of your founding members if their high school team would lend you a tank for worlds because he has one just sitting there.
I would also recommend adjusting your regulator - you can significantly increase the amount of strokes by doing this.
Do you need active control going both ways? You could use single-acting cylinders to push against gravity, and let the spring take care of the downward motion (i’m assuming your tray rotates upward and downward)
That’d be nice if you could lend us a tank. If we could also find some other ways to improve the amount of shifts without adding extra weight, that’d be the best.
For the pressure regulator idea, that doesn’t work. We’ve already tried it.
I mean I’ve seen some great robots that use two air tanks and have dozens of shifts. I don’t think there’s a leak in our tubing. So, it must be something else.
Hehe. I think I’m on your brother’s team… But yeah, the spring wouldn’t be strong enough to lift up a few sacks. We could add rubber bands I guess.
The piston is pulling to move the tray up and pushing to move the tray down.
How much tubing is there between your solenoids and your pistons? This should be kept as small as possible. I k ow it’s harder with double acting pistons, but with single acting pistons we keep that tubing length as close to zero as possible. Any air that goes into this piece of tubing is expelled from the system.
You can use a handful of rubber bands to retract the cylinder and use it as a single acting cylinder.
What does your pneumatic circuit look like? Depending on how much force you need, you could run the pneumatic actuators in series through one valve. This should halve the air you need.
When is your next VEX meeting. I live like a mile away. I will stop by with a tank and see if seeing it in person gives me any ideas.
Nah it’s fine. Russell has the same bus as me, so maybe he can drop it off. That way you won’t have to drive. I might post some pics if my team lets me.
Yeah. We figured this was the problem. Thanks we’ll try this.
Your 10 actuations makes sense. The piston pages says you get 40 total activations and you have 2 pistons. 40/2=20 then you need to extend and retract 20/2=10
Here is what I am going to suggest. This is something Oats over in New Zealand does to create a plug.
https://dl.dropbox.com/u/90045276/plug.png
at the 2 locations I poorly scribbled on take out the tubing double it over itself and put a zip tie. Like creating a not in a hose this will stop air from being used to lower the platform so you have a single acting piston that only retracts so you don’t have to use double the air.
We are using 2 air tanks though… But yeah we’ll also try what you recommended. Thanks!
EDIT: We only have 1 solenoid, so your idea won’t work. Thanks still.
Remember all the tubing between the soloniod and piston is air you throw away every single actuation. As seen in the picture you want this to only be a few inches of tubing not something you split into 2 pistons. Why don’t you have each piston on its own soloniod like it is designed to be?
We only have 1 solenoid 
Yes the less tubing between solenoid and piston the less air you throw away http://db.tt/GG9MiJ8L
How do you only have 1 soloniod?
Did you buy pistons from plccenter?