Very confliting data on pneumatics

Competition Rules/Strategy
1

Rule 105 states that you must use pneumatic cylinders that are identical to the ones on the Pneumatic Components Order Form. The Pneumatic Components Order form also states to check the Bimba web site for available strokes in each bore size. Both the online Free Pneumatic Components Order Form and the online Bimba Product Catalog list more choices for stroke length than are listed on the printed order form from the Pneumatics Manual.

This question was asked on the Q&A syatem and the responce was:

As specified in Rule <R105>, additional pistons “must be identical to those listed on the Pneumatic Components Order form (i.e. same part numbers).” Parts 1724-DP and 3118-DXP are not available on the Pneumatics Components Order Form, and therefore are not permitted.

Even more conflicting is the data provided by the 2007 FRC Pneumatics Manual.

It states:

You will again be able to order custom cylinders from Bimba for your robot this year. You have a choice of 3/4” bore (diameter), 1-1/2” bore and 2” bore. You can order the amount of stroke you require.

Anyone have any clue what gives?

I will have our teams communication officer contact first Q&A system about this inconsistancy.

  • Bochek
2

You could ask for a specific resolution on Q&A, or you could find a way to make one of the cylinders on the order form work for you, and avoid potential problems at inspection time. I’d go for the easy way out…just use what’s on the form…but I’m lazy.

3

our design calls for a 2" bore 12" stroke cylinder. i was assuming we could get them for free from bimba but i am getting a little worried.

We will find out the outcome tomorrow hopefully.

  • Bochek
4

As I read the form, that cylinder is one of the allowed options and its designation would be M-3112-DXP.

5

yeah, it does show up on the bimba online order form

6

That is correct, So My team is free and clear, but what about the 1-1/2 bore 12" stroke and 24" stroke cylinders?

Just trying to clear up the confusion.

  • Bochek
7

If they’re not on the order form, you might be wise to design the robot to use alternates that are on the order form, just to be safe. Perhaps use 2" bore cylinders with a lower regulated air pressure on that circuit.

8

As I read the form, those are not allowed. But you should ask on the official Q&A, since anything you see here is unofficial.

9

It sounds like FIRST is saying the form in the manual has the only ones that are acceptable to use. There is a miscommunication between Bimba and FIRST, what really needs to be asked on the Q&A is what is the true form, the online one or the manual one.

I’m betting its the one from the manual.

10

Yes but that is still conflicting with what the pneumatic manual states, saying that you can order any stroke required.

11

you may use any cylinder on the form. all bimba’s cylinders are custom and normal stock items. any cy;linder not on the list will be rejected on inspection. you may not use any others than the list. some teams in the past have used 1" bore and 3/8" bore and have passed inspection because the inspecters are looking mostly for safety issues. it is up to each team to learn the rulesand follow them so as to live up to the spirit of FIRST. no one that i know of has intentionally used any illegal parts. some teams have been called to the carpet for the wrong cylinders and were not allowed to use them in competition which nreally hampered the function of the design.

isuggest that you really redesign now and get your design to work with the specified cylinders.

any q’s e-mail me and i hope this helps

12

The FIRST Q&A system has answered this.

In short: NO, you can NOT use any cylinder bore-stroke combination UNLESS it is shown in the 2007 FIRST Pneumatics Manual. (IOW, the FIRST Manual takes precedence over the Bimba ordering system.)

Yup, there was an error on the Bimba website, that allowed teams to order other combinations. That was unfortunate. However, I read in another thread that Bimba has sent out letters apologizing to teams that did order illegal combinations for the error, and are offering free exchanges for “legit cylinders”, as defined by the manual. (Yea Bimba, for acting so quickly on this!) :smiley:

Here’s the Q&A entry’s answer, when someone from team 63 noted that 1.5" x 24" (1724-DP) and 2" x 18" (3118-DXP) were “orderable”, and asked this very question:
>—
> Re: Rule 105 Pneumatic Cylinders
> Posted by GDC at 01/13/2007 12:20:05 am
> As specified in Rule <R105>, additional pistons “must be identical to those listed on the
> Pneumatic Components Order form (i.e. same part numbers).” Parts 1724-DP and 3118-DXP
> are not available on the Pneumatics Components Order Form, and therefore are not permitted.
>—

Therefore, in this context, the “Pneumatics Components Order Form” is the one in the Manual, and NOT the one on the online ordering site.

So… Be sure to design your pneumatics system to ONLY use cylinder bore-stroke combinations from the 2007 FIRST Pneumatics Manual.

I hope this helps, and good luck to you!

  • Keith McClary
    Chief Engineer, Team 1502, “Technical Difficulties”