|
|
|
 Earlier this week it took me a little bit too long to realize that the reason my pen wasn't writing correctly was that it was actually a screwdriver. I'm going to have to ask for a few nights of honest sleep before signing off on a report. - EricVanWyk [more] |
 |
|
|||||||
|
||||||||
My favorite time of the year!
Here's a clever mount for the vent valve using a 1/2" E-clip and some 3/32" polycarbonate. Surprisingly secure.
Discussion
view entire thread
06-02-2014 10:11
trilogy2826
Re: pic: It's systems integration time!
That is really clever. It's amazing how such a simple thing can make you so happy.
One valve that I found a few years back is McMaster 6790T42
http://www.mcmaster.com/#catalog/120/481/=qkrfx0
Under Brass push button valves. With a normally closed action, you'll never have to remember to close the valve again. I think this would still work well with your mounting method.
06-02-2014 10:51
ToddF
Re: pic: It's systems integration time!
That's really cool. I love the idea of using a spring loaded valve for the dump valve. I hope that someday they will become legal to use.
06-02-2014 11:14
EricLeifermann
Re: pic: It's systems integration time!
|
Originally Posted by ToddF
That's really cool. I love the idea of using a spring loaded valve for the dump valve. I hope that someday they will become legal to use.
|
06-02-2014 11:14
apalrd
Re: pic: It's systems integration time!
|
Originally Posted by ToddF
That's really cool. I love the idea of using a spring loaded valve for the dump valve. I hope that someday they will become legal to use.
|
They meet all the requirements of R89.
06-02-2014 12:20
ToddF
Re: pic: It's systems integration time!
It violates R77.B:
"The only pneumatic system items permitted on 2014 FRC ROBOTS include the items listed below. ...
B: Pneumatic pressure vent plug valves functionally equivalent to those provided in the KOP."
A momentary push button electrical switch is not functionally equivalent to a toggle switch, which must be actuated in both directions.
A spring-loaded single-acting pneumatic cylinder is not functionally equivalent to a double acting pneumatic cylinder, as it returns to its retracted position without actuation.
A spring loaded push button pneumatic valve is not functionally equivalent to a rotational ball valve, which must be actuated in both directions. For the purposes of a dump valve in a FIRST robot, the functionality of being spring loaded makes it better than a ball valve. From an air flow perspective, they may flow the same, just as electricity doesn't care whether it is switched by flipping a switch or pushing a button. But, to the operator, they are very different. If it were functionally equivalent, there would be no reason to use it. (Other than cost and availability.)
I suggest a question to Q/A. I'd love for them to rule the push button dump valves legal.
06-02-2014 12:29
EricLeifermann
Re: pic: It's systems integration time!
|
Originally Posted by ToddF
It violates R77.B:
"The only pneumatic system items permitted on 2014 FRC ROBOTS include the items listed below. ... B: Pneumatic pressure vent plug valves functionally equivalent to those provided in the KOP." A momentary push button electrical switch is not functionally equivalent to a toggle switch, which must be actuated in both directions. A spring-loaded single-acting pneumatic cylinder is not functionally equivalent to a double acting pneumatic cylinder, as it returns to its retracted position without actuation. A spring loaded push button pneumatic valve is not functionally equivalent to a rotational ball valve, which must be actuated in both directions. For the purposes of a dump valve in a FIRST robot, the functionality of being spring loaded makes it better than a ball valve. If it were functionally equivalent, there would be no reason to use it. (Other than cost and availability.) From an air flow perspective, they may flow the same, just as electricity doesn't care whether it is switched by flipping a switch or pushing a button. But, to the operator, they are very different. |
Do they both not serve the same function? They both allow and prevent the release of air pressure.
06-02-2014 12:32
ToddF
Re: pic: It's systems integration time!
|
Originally Posted by EricLeifermann
Do they both not serve the same function? They both allow and prevent the release of air pressure.
|
If one component includes a function which differentiates it from another, and makes it more desirable for a particular application, by definition, they are not equivalent.
06-02-2014 13:06
amesmich
Re: pic: It's systems integration time!
|
Originally Posted by ToddF
One allows you to forget, and leave it permanently open. The other does not. They are not functionally equivalent.
If one component includes a function which differentiates it from another, and makes it more desirable for a particular application, by definition, they are not equivalent. |
2. No they are not equivalent but they are FUNCTIONALLY equivalent. They serve the same purpose via slightly different methods. More than one compressor is leagal for first. They are both FUNCTIONALLY equivalent but they certainly are not the same one is heavier and can be viewed as a disadvantage.
06-02-2014 13:10
AGPapa
Re: pic: It's systems integration time!
|
Originally Posted by amesmich
1. Any valve can be forgotten about and be left open or closed so I dont see the difference there.
|
|
Originally Posted by trilogy2826
With a normally closed action, you'll never have to remember to close the valve again.
|
06-02-2014 13:21
apalrd
Re: pic: It's systems integration time!
Guys, you're over analyzing this.
A manual valve is a valve, it releases the pressure in the system when manually actuated. IMHO, the function is to release pressure when actuated manually, and both valves do that.
Not sure why we have to read so hard into this.
06-02-2014 13:35
Gregor
Re: pic: It's systems integration time!
|
Originally Posted by amesmich
More than one compressor is leagal for first. They are both FUNCTIONALLY equivalent but they certainly are not the same one is heavier and can be viewed as a disadvantage.
|
See R77J and R79.
06-02-2014 13:47
amesmich
Re: pic: It's systems integration time!
|
Originally Posted by Gregor
R77B does not apply to compressors.
See R77J and R79. |
I didnt realize the valved closed by itself. I agree with the above post, reading too much into it.
10-02-2014 11:22
ToddF
Re: pic: It's systems integration time!
|
Originally Posted by apalrd
Not sure why we have to read so hard into this.
|
For example, a small pneumatic cylinder actuated by a legal solenoid valve could be used to push the button on a high flow spring loaded push button valve (McMaster 6859K31 for example) that fires a pneumatic catapult.
Another example would be a weight which is held up by a motor that has power as long as the robot is operating. In case of a dead robot, the weight drops on a push button valve, which ejects the ball from the robot.
edit: Never mind. Just found Q235.
10-02-2014 11:28
Sparky3D
Re: pic: It's systems integration time!
|
Originally Posted by ToddF
I'm concerned with whether spring loaded push button valves are legal because there are some really cool things that can be done with them. This year there is no rule that says pneumatic cylinders must be actuated by solenoid valves.
|
10-02-2014 11:38
EricLeifermann
Re: pic: It's systems integration time!
|
Originally Posted by Sparky3D
Actually, the Q&A already dealt with the alternate uses of manual valves (Q235). You are only allowed one, and it can only be used to vent pressure for the system.
|
"No. Per R89 only one pressure vent plug valve may be used on the ROBOT which, when manually actuated, must vent to the atmosphere to relieve all stored pressure."
Bolded for my emphasis, doesn't state that the valve must be manually actuated to prevent air from being relieved. Though this question was asked about a different topic, its answer allows for spring actuated relief valves.
10-02-2014 11:39
ToddF
Re: pic: It's systems integration time!
We must have cross posted. 
Full disclosure: We are going to install one and let the inspectors decide.
10-02-2014 11:53
Nate Laverdure
Re: pic: It's systems integration time!
|
Originally Posted by ToddF
Another example would be a weight which is held up by a motor that has power as long as the robot is operating. In case of a dead robot, the weight drops on a push button valve, which ejects the ball from the robot.
|
28-04-2014 08:50
ToddF
Re: pic: It's systems integration time!
|
Originally Posted by ToddF
Full disclosure: We are going to install one and let the inspectors decide.
|
We swapped valves and competed with a valve with a handle.
28-04-2014 09:08
Al Skierkiewicz
Re: pic: It's systems integration time!
|
Originally Posted by ToddF
That's really cool. I love the idea of using a spring loaded valve for the dump valve. I hope that someday they will become legal to use.
|
view entire thread
Tags
loading ...