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Unread 25-02-2010, 13:16
grosh grosh is offline
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Pressure not building up?

We did not get our robot wired until the last minute so we only got about an hour to test our pneumatic system. Now the robot has shipped...HELP!

The compressor kicked on and, when we plugged the hose running into the working side of the system, it would fill the system with 120psi. However, when the hose was connected to a 6 SMC solenoid manifold the air ran out the exhaust ports. No pressure would build up at all.

Specifics:
-We are using three 3/4" double acting cylinders to pull back our kicker.
-We are running 2 solenoids per cylinder to increase the exhaust volume. 6 SMC solenoids (4 x 24v & 2 x 12v)


We have never used a manifold before. Could we have issues with the manifold?

The pressure never built up on the working side. Doesn't their have to be a minimum amount of pressure for the solenoid to set themselves? If true, how do we overcome this?

We had to use two solenoid breakouts because we needed 12 connections for our 6 solenoids. Is it an issue to combine 12v and 24v?

Thanks for your help! We don't have our robot to test with so we are relying on the graciousness of the chief delphi community to help us before our regional.
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Unread 25-02-2010, 13:26
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Re: Pressure not building up?

It certainly sounds like a plumbing problem with the manifold.
I'd imagine you just have the pilots, cylinder, and exhaust ports mixed up.
You did install manifold gaskets for each of the solenoids?

The pressure should feed through the manifold into the pilots for each solenoid providing the initial pressure required.

You don't happen to have a spare manifold and solenoids do you?
You don't need a control system, or even a full pneumatic system to investigate the manifold fully.

There are no issues with mixing 12VDC and 24VDC solenoids segregated by separate solenoid breakouts.
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Last edited by Mark McLeod : 25-02-2010 at 13:30.
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Unread 25-02-2010, 13:30
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Re: Pressure not building up?

Our team had slight problems related, but this was because we made a variable pressure kicking system using a couple values and somewhat complicated arrangement of plugging in hoses to slots in the valves.

To solve the losing pressure I would start off with checking to make sure all the tubes are long enough to fit in the valves with space, also make sure that the hoses are fully inside the valves or quick-connects in your pneumatic system. Then from there, if you are still losing pressure, well if your losing pressure from the exhaust then your plugging of the valves isn't done correctly.

Hope I Somewhat helped. I know that pneumatics can be a pain.
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Unread 25-02-2010, 14:31
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Re: Pressure not building up?

Quote:
Originally Posted by grosh View Post
We did not get our robot wired until the last minute so we only got about an hour to test our pneumatic system. Now the robot has shipped...HELP!

...............

Thanks for your help! We don't have our robot to test with so we are relying on the graciousness of the chief delphi community to help us before our regional.

I would suggest that as soon as you get to your first event, uncrate your robot, then proceed directly to the pit announcer and ask for some help from another team on pneumatics. You can spend a lot of time running around in circles on a problem like this. I'm absolutely sure there will be a pneumatics guru or 12 standing around at each event. I would also find the lead Inspector and explain your situation. Most Lead Inspectors know the field of teams and who to call on for such problems.

Nip it in the bud ..........
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Last edited by Ed Sparks : 25-02-2010 at 14:33.
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Unread 28-02-2010, 22:46
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Re: Pressure not building up?

What he ^^ said.

Sometimes, the valves get hung up 'in the middle' and never allow pressure to build up to switch it to one side or the other.

The fix is to hold your finger over the exhaust port that's "leaking" and let pressure build up to 20 PSI or so, that'll be enough for it to pick one side or the other and stop leaking. You might have get six hands (one for each valve).
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