Re: Rule 105 Pneumatic Cylinders

[FRC2150]

The answer from GDC fails to take into account that the larger stroke lengths (12" and 24") for the 1.5" cylinders were included on the order form in 2004. The 2007 Parts Use Flowchart clearly indicates that a previous year's cylinder can be used even if it is not identical to those on the custom order form. If you really intend to disallow the 12" and 24" stroke 1.5" cylinders, you also need to change the 2007 Parts Use Flowchart. I think that would be the wrong way to resolve the conflict.

The problem started with a change to the 2005 Pneumatics Manual that omitted the 12 and 24 stroke lengths for 1.5" cylinders from the order form, but left the comma following the 11 stroke length. The comma still appears after the 11 stroke length on the 2007 order form, and it still suggests that additional stroke lengths are available but not visible. I suspect that the omission was an unintentional glitch caused by Adobe Acrobat. It makes no sense to delete these stroke lengths if they are available from Bimba, especially since the same stroke lengths are available for 2" cylinders.

The Bimba web site continued to offer the 12 and 24 stroke cylinders in 2005 as it does in 2007. Teams pointed out that the 2005 Manual indicated that any cylinder size available on the Bimba website was OK. After a long discussion on the forum about whether the manual, the pneumatics manual or the Bimba website should take precedence, teams were ultimately allowed to use the 12 and 24 stroke cylinders in 2005. The resolution was summarized in the following excerpt from 2005 FRC Team Update 08:

"Question & Answer Items of Note

> #1335 and #1385

There has been significant discussion regarding pneumatics, in particular what Bimba cylinders were allowable. The revised answer to #1335 and the answer to #1385 follow:

#1335
CORRECTED ANSWER 2/3/2005 AT 1330.

CORRECTED ANSWER
The manual is correct. It tells you to go to the Bimba site for all of the available sizes.

Old Answer
The pneumatics manual takes precedence.

#1385
WE APOLOGIZE FOR THE OBVIOUS CONFUSION WE HAVE INFLICTED
UPON TEAMS, PARTICULARLY BY OUR ANSWER TO #1335. We were correct in our answer (the manual takes precedence) as it points you to the Bimba site, but we were far from clear. We will clarify the answer to #1335.

As the Pneumatics Manual states very clearly on P19...
Please check the Bimba web site for available strokes in each bore size.
These are the cylinders you can use."

I can not understand why the conflict between the order form and Bimba website is still not resolved after 3 years. Why not just restore the two missing stroke lengths to the order form and be done with it?

LeRoy Nelson
Lead Mentor, Team 2150
2005 Southern California Woodie Flowers Award

[GDC]

Please remember that rules from prior FIRST Robotic Competitions do not apply to the 2007 competition. Under Rule <R105>, the only pneumatic cylinders permitted are those that are identical to those shown in the table on the "FIRST Free Pneumatic Components Order Form". Rule <R106> and availability listed on Bimba's website do not override this. Therefore, any parts scavenged from prior year robots, as permitted by Rule <R106>, must still be in compliance with Rule <R105>.