So we have a problem with our clamp, and it’s the at our pistons simply aren’t strong enough. There should be pictures included of our design. The other teams didn’t know either, and he have a competition very soon. Could anyone help us?
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Increase the arm length, so there would be more power (type 1 lever). Also I suggest adding rubber bands to increase to retraction strength.
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I dont think this will make it stronger but if you were to screw the shaft collar onto your piston and run a longer screw across the mogo to make a more secure connection. Really the only ways i could think of would be to add more pistons, make a longer lever arm for the effort side, and check for any leaks
The issue is you aired up both ends of the piston together. Big no no, but understandable if you don’t fully understand pneumatics. I’m based off the images the pistons extend to clamp the goal and i’m assuming you’ve tested them to where they do extend out to clamp the goal. That would make sense because even if you apply air to both sides of the cylinder at the same time the extending side has more surface area on the piston meaning it has more force out powering the retracting side, but is still highly underpowered. You need to apply air to the bottom end of the piston only to extend the piston in turn clamping the goal, then you could have a separate air hose the goes to the top of the piston to retract it and unclamp the goal.
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forgot about bands that is a good way to add more power
Wow, good catch! I didn’t even notice that 
Yeah @9537zFodder that probably means you haven’t read this article:
Here’s also a jank, really “rough” basic diagram of how pneumatics works:
Right now, here’s what yours is doing:
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I agree with the fact that you should power the retracting side, but can you elaborate on this part?
My team uses 2 pneumatic cylinders together, so I don’t want it to fail.
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“confused piston does nothing”
I love this line
Besides, you know what, this isn’t even an embarrassing mistake to have made on OP’s behalf, it’s genuinely interesting to see this have happened for the first time personally.
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For example on my robot the pistons retract to clamp, so if you look down to them you’ll see I have air fittings coming out of each retract port, which I then connected both into a t-fitting. But also for the goal unclamp part, I only powered one of the pistons extend ports because unclamp doesn’t require much power at all so its a waste of air to power both cylinders for unclamping.
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Thanks for this, but does that mean we should remove one of the pistons? I’m personally fine with doing that but would prefer not to if there is a solution.
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No what I meant was keep the two pistons, and air them up to clamp the goal, but you only technically need to air one of the two pistons up to release the goal.
This first image is just an image explaining what i’ve meant by extend and retract ports.
This second image is an example of what your setup should look like. The extend ports are aired together using a t-fitting and then go into one of the outputs on the solenoid, then the retract port of one cylinder is left open without a fitting, then the other retract port is aired straight into the second output on the solenoid. This setup allows for you to use the power of the two pistons for clamping but only use one pistons worth of air to unclamp the goal. Hope this makes sense
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Hey this is another member of the team we just fixed the problem so no more need to post
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what I did last year was use a constant loop so the pistons are constantly pushing or pulling
Now that the OP has resolved the pneumatics problem, here is an additional suggestion for strong mobile goal clamps… Look up an over-center locking mechanism. You can find info online or on this forum. You may not need or like it, but some of my teams put it to good use during Tipping Point.
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One thing I do if they lose strength over time is to just have a wait function in the program that pushes out the piston again while it is out so that the pressure does not decrease too much after holding for a long time, I just check if it is still out then wait like 8 seconds then send it again
If your pistons dont hold over time then that means either the piston itself has a leak or somewhere in the tubing in the pneumatic system there is a leak. No saying what you do doesnt work just stating that pistons should not lose pressure in normal working conditions.
I believe this is not how air cylinders work. The program simply sends a command to the solenoid to open or close a valve, and the pressure of the air is what pushes out the piston, not the code or solenoid itself. I think telling the code to “push out the piston” again while it’s extended wouldn’t change anything, but please correct me if I’m wrong.
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good line, but theoretically not accurate. The ‘blind’ side of the piston (the side opposite of the rod) will have a larger surface area for the compressed air to act upon than the rod side area (which would be the area of the piston MINUS the area of the rod).
Therefore the piston should extend but will not be with as much force as it would if plumbed correctly.
Think of the piston force extending normally. It would be calculated by the area of the piston times the air pressure. To retract, it is the area of the piston minus the area of the rod then multiplied by the air pressure. The retract force is always smaller than the extend force. In this case there is still a delta extending force and the rod should move out.
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Let me counter that with another line of thinking:
Think of a system where the piston at both ends is connected to the reservoir. The inside of the piston and the reservoir form a closed system from which matter cannot enter or exit. Therefore it stands to reason that the pressure at both ends of the piston should be in equilibrium, and any movement of the piston would simply only cause movement of air from one end of the piston to another.
In this scenario, where is the energy which supplies the force for the piston to extend or retract? I am genuinely curious. Had there been two air tanks, isolated from each other and each attached to one end of the piston, I could see the logic behind it, but to me, when they are connected to each other, it seems that it would just balance out.
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