Pneumatic's Rules confusion

[dlavery]

Originally Posted by Nitroxextreme

im really confused now
i have a contact at another team and he says that in the past they can use other pnuematics as long as the team pays out of their pocket

Also i heard that one year they allowed a team to use all SMC pneumatics

Rules from prior years DO NOT APPLY to this year! So even if teams were allowed to use SMC products in the past, that is irrelevent as far as this year is concerned.

With regard to the allowed pneumatics for this year, read <R90> and <R91> very carefully.

Originally Posted by Kautz

There are no 1/2" bore cylinders on the order sheet only 3/4", 1-1/2" and 2" bore.So you can not use 1/2" bore cylinders of any stroke?

That would appear to be correct. 1/2" bore pistons are not available this year on the Pneumatic Components Order form (nor were they available last year). Under <R90> we can only order pistons identical to those on the order form, which include only 3/4", 1-1/2" and 2" bore pistons. Therefore, 1/2" pistons would not be legal.

Originally Posted by jrocket567

It does seem a little more confusing than last year.. the best I can understand it is that you can use as many cylinders, rotary actuators, etc as you want, as long as they are listed on the custom order sheet.. but the thing that is throwing me off is the flow chart.. it states that you can use any pneumatic devices off of previous year's bots.. so if I have a 1/2in bore (they are not on the list this year) on last year's bot, can i take it off and use it this year??

1/2" bore pistons were not legal items last year (they are not listed on page 19 of the 2004 FIRST Pneumatics Manual - only 3/4", 1-1/2" and 2" bore pistons were allowed). Based on that, the flow chart and the rules seem consistent. You could use any legal pistons or valves from last years pneumatics kit (all the elements of the 2004 pneumatics kits are included in this years kit, except we get two double solendoid valves instead of a single and a double, and the Texas Instruments pressure transducer is missing), and they would be permitted under <R91>.

-dave

[Steve W]

Dave maybe you can find the answer to this question. I asked on the Q&A if you could use 6ft coiled connector hoses that are off the shelf. Now according to the rules they are connectors and off the shelf. They are not storage devices. Last year for some reason they were disallowed. They are the same diameter as the current hose that we receive in the KOP. The safety issue that we are concerned about is better because coiled hose does not flop around on the robot or swing in open air. When I asked the question all that was answered was check the flowchart. Why does FIRST not give us a yes or no answer. There is nothing worse than building and getting to a regional to find out that something is disallowed.

Thanks in advance for any clarification.

[dlavery]

Originally Posted by Steve W

Dave maybe you can find the answer to this question. I asked on the Q&A if you could use 6ft coiled connector hoses that are off the shelf. Now according to the rules they are connectors and off the shelf. They are not storage devices. Last year for some reason they were disallowed. They are the same diameter as the current hose that we receive in the KOP. The safety issue that we are concerned about is better because coiled hose does not flop around on the robot or swing in open air. When I asked the question all that was answered was check the flowchart. Why does FIRST not give us a yes or no answer. There is nothing worse than building and getting to a regional to find out that something is disallowed.

I can't give you an official ruling on the connector hoses, only FIRST can do that. But I will say that with our team I tend to be very conservative when it comes to determining if something is in compliance with the pneumatics rules or not. In general, if it did not come in the pneumatics kit or it is not explicitly (rather than implicitly) permitted under <R90> or <R91>, then we don't use it. We try to keep ourselves out of trouble by not over-interpreting the definitions.

With that in mind, as I read <R90> and note where it says you can use an unlimited number of "connecting fittings" I put the simplist interpretation on that phrase that I can. A fitting is a simple, monolithic piece used to connect two other parts with dissimilar physical interfaces, such as the bag of brass fittings that come with the kit. A connector hose is not a single fitting, it is an assembly of two (or more) fittings and a hose. So let's then go through the flow chart for each of the individual parts of the assembly. Each of the individual end fittings would safely fall through the flow chart, and would seem to be OK to use. But the hose is another matter. It falls through these logic blocks: it is a pneumatic component; it is not an air cylinder; it is not a purchased fitting, valve or purchased air cylinder; and it is not a piston or valve from last years robot. Therefore, the hose itself would be illegal. Double checking with <R90> and <R91>, we see that "tubing" is not explicitly listed as an "unlimited" item. So, in the case of our team (and as mentioned above, we take a very conservative approach to the pneumatics rules), we would say that the connector hose failed the flow chart test and would not use it.

This is my opinion only, which is being provided at no cost and is therefore worth what you have paid for it. Your mileage and interpretation may vary.

-dave

[Steve W]

Dave, thanks for your reply. Even though you say I get what I pay for I believe it to be of more value. When you see me next be sure to collect your $0.02.



I guess I don't understand the logic all together. As sold off the shelf the "hose" is sold as a connector hose which I understand from some sides may be seen as stretching (no pun intended) the term. For an safety point I am totally lost as why FIRST wouldn't want someone to use this off the shelf product.

Maybe I will ask the question again to get a yes or no answer rather than "let's see what happens" rule.

Thanks again for your insight.

[BillCloyes]

I'm not trying to get into a debate on grammar, just clarification on the second half of <R90>:

Originally Posted by <R90>

...you may purchase additional air cylinders or rotary actuators, however, they must be identical to those listed on the Pneumatic Components Order form, and obtained from a Bimba or Parker Hannifan distributor.

Does this mean (A) or (B)?

(A):
"...they must be:
- identical to those listed on the Pneumatic Components Order form
- obtained from a Bimba or Parker Hannifan distributor

Or

(B):
"...they must be identical to those:
- listed on the Pneumatic Components Order form
- obtained from a Bimba or Parker Hannifan distributor

At least if i read this correctly...
(A) means that cylinders MUST be Bimba/Parker BRAND (only in sizes listed on the order form) while (B) means the cylinders could be other brands, provided they are otherwise (size/type/style) identical to Bimba/Parker (only in sizes listed on the order form).

I only ask because if we could use other brands (rated the same and visually identical to Bimba ones) that are carried by places like McMaster Carr or MSC teams could order, receive, and implement them MUCH faster.

My experience with FIRST says that (A) is correct, but my common sense says that (B) should be correct.

-Bill
(I know already that it is usually unwise to try to apply common sense to FRC rules )

[Nitroxextreme]

For example, can we use a modified off the shelf gripper? Keep in mind the pneumatic portion is in its original unmodified condition and is a COTS item.


Bah, I'm so confused

Thanks

[Mr. Van]

I think this is the idea: You can not use anything that rookie teams do not have access to. This means any 1/2" pistons. (As far as other off the shelf pistons, I'd tend to think that if you can't order it with the FIRST form, it is not legal.

The rules also clearly state that compressed air may only be stored in the two tanks (one from the kit, one available from IFI). This means that coils of tubing, extra large hoses, etc. that exist on the robot in order to store more air are not allowed. This is probably why the 6ft coiled connector hose was not allowed last year.

-Mr. Van
Coach, 599

[Steve W]

Originally Posted by Mr. Van

The rules also clearly state that compressed air may only be stored in the two tanks (one from the kit, one available from IFI). This means that coils of tubing, extra large hoses, etc. that exist on the robot in order to store more air are not allowed. This is probably why the 6ft coiled connector hose was not allowed last year.

-Mr. Van
Coach, 599

I would have to challenge the fact that coiled hoses store any more than straight hoses that are coiled to allow for expansion. Secondly, you can only have 60 lbs of pressure in the tube which means that it is not really a storage device with any pop.Maybe, just maybe you might be able to fire 1 small cylinder with the air in the hose but without much force.

[Mr. Van]

Originally Posted by Steve W

I would have to challenge the fact that coiled hoses store any more than straight hoses that are coiled to allow for expansion. Secondly, you can only have 60 lbs of pressure in the tube which means that it is not really a storage device with any pop.Maybe, just maybe you might be able to fire 1 small cylinder with the air in the hose but without much force.

Of course, if the tube is coiled in order to allow expansion, then I would agree it should be legal.

-Mr. Van
Coach, 599

[ngreen]

Originally Posted by Mr. Van

Of course, if the tube is coiled in order to allow expansion, then I would agree it should be legal.

-Mr. Van
Coach, 599

Has anyone got a ruling on this. I tried to read Q & A which didn't seem to give a clear answer except looking at the flow chart. The flow chart is not really specific on definitions. I don't think it offers any safety risk when it is rated for 200 psi. It is 1/4" which is the same as the other stuff. If you have a moving part it offers no extra storage and might possibility be less total tubing.

I hope FIRST offers at least offers a more clear cut rule regarding off the shelf tubing.

[gosling2003]

So I was reading above that 2 air storage tanks are allowed on the robot this year. One is provided and the other apparently we can order. Is it allowed for the second cylinder instead of ordering it to use one of the tanks from last year, since our team never used it in the first place? The old tanks are identical to the new ones so I don't see any reason why we can't use them. Can anyone clarify?

Also, only a max of 2 tanks are allowed right? We can't use more than 2 even if they are identical?

[Chris Fultz]

Read rules:

R02 "only in the two Clippard Instruments tanks provided in the kit" and

R87 "you may not use extraneous lengths of pneumatic tubing to increase the storage capacity of the air storage system.".

You only got Clippard tank in the kit, so you can get another one free, or use one from 2004. They are identical and pass the other rules.

You cannot use coiled tube or big coils of tubing.

The specific question was asked, and answered, in the 2004 Q & A.

[BillCloyes]

Originally Posted by Chris Fultz

...You only got Clippard tank in the kit, so you can get another one free...

Perhaps I overlooked something...How/what/when/where do we get the second Clippard tank for free?

Sorry if this seems like a remedial question, but any info on this would be much appreciated.

-Bill

[Steve W]

Originally Posted by ngreen

Has anyone got a ruling on this. I tried to read Q & A which didn't seem to give a clear answer except looking at the flow chart. The flow chart is not really specific on definitions. I don't think it offers any safety risk when it is rated for 200 psi. It is 1/4" which is the same as the other stuff. If you have a moving part it offers no extra storage and might possibility be less total tubing.

I hope FIRST offers at least offers a more clear cut rule regarding off the shelf tubing.

Watch for question ID 1407. I hope that this will give us our answer.

Chris, last years rules do not apply. Besides there were regionals were coiled tube was allowed. The question stated above should answer our questions. You can make coiled tube but it tends up 2x the size of the purchased and holds more air. It also does not tend to hold its shape as well.

[Chris Fultz]

Originally Posted by BillCloyes

What about other cylinders (that do not "do" anything) except hooked to the pneumatic system (per the rules) are added as "dead weight" to better place a robots CG.... Don't they also behave as a 60 psi air storage unit?
-Bill

If they are hooked up "per the rules" they will not function as a storage device, they will function as a pneumatic actuator. The rule clearly states only the two provided cylinders can be used as storage devices. Not extra hose, not extra coils, not the robot frame, not spare pneumatic actuators.

And if the other cylinders are added as "dead weight", why would you hook up pneumatic lines to them and risk the air loss unless you were planning to use that air, clearly in violation of the rules.