Legality of pnumatic ball launcher systems

[JesseK]

I'm curious as to if you can depressurize an end of the cyllinder such that it's actually less than atmospheric pressure, theoretically achieving the same results but also technically within legality of all of the Q&A answers. Depressurisation would be achieved in a similar (but reversed) manner to what's described.

[jskene]

Update #6 says that the rules say that a solenoid must be connected to a cylinder with 1/8" tubing. I can find no reference to this in the rules.

We were planning to connect the valve directly to the cylinder, using "off the shelf" 125 psi fittings, as permitted in rule R88.

Is anyone aware of any rule in section 8.3.9 that would preclude this?

Also, we are planning to store air in the Clippard tanks downstream of the regulator, at 60 PSI, instead of 120. Is anyone aware of any rule that would preclude this?

[EricH]

Originally Posted by jskene

Also, we are planning to store air in the Clippard tanks downstream of the regulator, at 60 PSI, instead of 120. Is anyone aware of any rule that would preclude this?

Nope. You will get less air in the system, but that is your choice.

[IndySam]

Originally Posted by jskene

Also, we are planning to store air in the Clippard tanks downstream of the regulator, at 60 PSI, instead of 120. Is anyone aware of any rule that would preclude this?

Question, why would you want to do this? I can't think of any advantage to it.

[JesseK]

It would seem that a tank that simply stores air would allow for faster response times if it's closer to the target consumer than all other consumers, espeically during times of large air consumption. Not sure of how much performance gain there is overall, but if the target consumer is short stroke and/or timing critical I can imagine it's a big enough difference.

[IndySam]

Originally Posted by JesseK

It would seem that a tank that simply stores air would allow for faster response times if it's closer to the target consumer than all other consumers, espeically during times of large air consumption. Not sure of how much performance gain there is overall, but if the target consumer is short stroke and/or timing critical I can imagine it's a big enough difference.

No, the limit is the size of the pneumatic line. You would be much better served by having a tank at 120 back stream. You could buy a second regulator and run the one important cylinder off of that.

[jskene]

Thanks for your replies regarding the legality of using the Clippard tanks for low pressure storage.

How about the first question?:

Update #6 says that the rules say that a solenoid must be connected to a cylinder with 1/8" tubing. I can find no reference to this in the rules.

We were planning to connect the valve directly to the cylinder, using "off the shelf" 125 psi fittings, as permitted in rule R88. Is this legal?

[EricH]

Originally Posted by jskene

Thanks for your replies regarding the legality of using the Clippard tanks for low pressure storage.

How about the first question?:

Update #6 says that the rules say that a solenoid must be connected to a cylinder with 1/8" tubing. I can find no reference to this in the rules.

We were planning to connect the valve directly to the cylinder, using "off the shelf" 125 psi fittings, as permitted in rule R88. Is this legal?

The applicable rules are:

<R87> Additional pneumatic system items specifically permitted on 2008 FRC ROBOTS include:
[...]
 Additional 0.160” inch inside diameter pneumatic tubing functionally equivalent to that provided in the Kit Of Parts, with the pressure rating clearly factory-printed on the exterior of the tubing (note: alternate tubing colors are acceptable).
[...]
<R88> There is no limit to the number of solenoid valves, pressure regulators, pressure gauges, and connecting fittings that may be used on the ROBOT. All such devices must be “off the shelf” pneumatic devices rated by their manufacturers for pressure of at least 125psi.

I don't see anything against this. (I am also not on the GDC.)

[SteveJanesch]

I'd think the main disadvantage in using a vacuum in a cylinder for energy storage is that you only get -15 psi (negative one atmosphere) pulling pressure at best, or a quarter of the pushing pressure available with a +60 psi line. You just can't pump it down any more than that.

Steve