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Re: Hydraulics and Pneumatics

Posted: January 17th, 2010, 11:48 am
by Uncle Fester
DS, as usual. speaks (writes?) great wisdom. At Mission I ran at an invitational yesterday, a hose broke loose off a car windshield washer pump after running out of distance to push a syringe. Water sprayed over thirty feet and nailed a bunch of HS students with quite a bit of water. never saw so much squealing and running. the girls were upset too. :lol:

Absolutely the best worth-the-penalty boundary violation I have ever seen in 19 years.

Re: Hydraulics and Pneumatics

Posted: January 17th, 2010, 12:03 pm
by Dark Sabre
And this is why you have the switch that the syringe hits have both NO and NC circuits. You use the NO circuit to trigger the next action and the NC circuit to turn off the pump! :lol:

Re: Hydraulics and Pneumatics

Posted: January 19th, 2010, 8:34 am
by aubrey048
ONCE AGAIN, I have a question. Can someone define an enclosed hydraulics system? Is water falling out of an uncorked hole in one cup into another cup to set off a reaction enclosed? The water never LEAVES the system entirely. Thanks in advance. I really appreciate it. :)

Re: Hydraulics and Pneumatics

Posted: January 19th, 2010, 11:35 am
by Dark Sabre
It sounds like you may have already read the recent FAQ about hydraulics.

If I understand your setup, you are releasing water from one cup into another and presumably using the weight of that water to initiate some action.
To the extent of my understanding, they would define two syringes hooked together as "entirely enclosed" since there is no water exposed to atmospheric pressure. I don't think that pouring water from one cup to another is at all "enclosed".

Looking at, for example, hydraulic brakes:
There is a reservoir that the system draws from that is essentially open to the air. It is usually covered by a plastic cap to prevent spillage, but it isn't sealed against pressure or anything.
The fluid is drawn through the master cylinder setup and taken to high enough pressures to provide the force on your car's brakes.
To me, like the windshield-fluid pump setup that I advocate, it is a clear demonstration of hydraulics. The part of the system where force is actually being transferred (where the hydraulics is happening) is enclosed and pressurized, but there is the "open" reservoir that the system draws from. I dunno. :?: :?:

Either way, I don't think pouring water between two cups is enclosed.

Re: Hydraulics and Pneumatics

Posted: January 19th, 2010, 3:14 pm
by aubrey048
Thanks again for answering my question, Dark Sabre!!! Now I'm going to go fix up step F. :oops:

Re: Hydraulics and Pneumatics

Posted: January 21st, 2010, 6:18 pm
by ROFLcopter
What would be an example of a simple hydraulic or pneumatic system? it's getting close to our invitationals and we don't know what we're doing yet

Re: Hydraulics and Pneumatics

Posted: January 21st, 2010, 7:06 pm
by Primate
ROFLcopter wrote:What would be an example of a simple hydraulic or pneumatic system? it's getting close to our invitationals and we don't know what we're doing yet
I think it was mentioned somewhere in this thread, but two syringes hooked up end to end are never a bad option. Just make sure you have enough force on both ends to get the system to work. You could also look into getting a windshield washer pump and using that instead of one of the syringes. Dark Sabre's written a nice tutorial on that.

Good luck!

Re: Hydraulics and Pneumatics

Posted: January 22nd, 2010, 3:00 pm
by aubrey048
I have two questions, again. :!:

A) If one (theoretically) tilted a closed box with water in it and two electrical wires, and the water closed the circuit, would this be considered a hydraulics system? By definition hydraulics is just anything "operated by, moved by, or employing water or other liquids in motion." (Dictionary.com)

B) If A) was considered hydraulics, could we use mercury instead? A teammate brought up the example of the old thermostats where the mercury tube tips when it is cold and the mercury closes the circuit to heat up the building.

Thanks again!!! :D

Re: Hydraulics and Pneumatics

Posted: January 22nd, 2010, 3:14 pm
by penclspinner
aubrey048 wrote:I have two questions, again. :!:

A) If one (theoretically) tilted a closed box with water in it and two electrical wires, and the water closed the circuit, would this be considered a hydraulics system? By definition hydraulics is just anything "operated by, moved by, or employing water or other liquids in motion." (Dictionary.com)

B) If A) was considered hydraulics, could we use mercury instead? A teammate brought up the example of the old thermostats where the mercury tube tips when it is cold and the mercury closes the circuit to heat up the building.

Thanks again!!! :D
A) If I were a judge I would not count your above example as hydraulics. This page better explains what you are looking for. Basically there has to be a transfer of force involved in your hydraulics. In your example the liquid would not be transmitting the force from one point to another.

B) I would not advise using mercury either due to its poisonous nature, in addition to being against the Mission Possible Rules 3E.

Re: Hydraulics and Pneumatics

Posted: February 2nd, 2010, 7:05 pm
by Flavorflav
If your hydraulic system had a small leak, would consider that it was no longer an enclosed system?