Vacuum

[EricH]

Originally Posted by scottydoh

I know its legal to charge the pneumatic system prior to the match, but is it legal to create a vacuum or suction and store it in a tank prior to a match?

(We would plan on using the venturi generator from last years KoP)

I think it would be very hard to do that. Also, is the venturi even legal this year?

[scottydoh]

Thats what I was wondering...

[robogeek753]

Yes, the venturi generators from last year are legal as per Rule <R87>. However, they don't work in such a way that you could "pre-charge" a tank, when you open a solenoid valve letting air through them they create the vacuum, rather than having a "vacuum tank". In addition, those things are serious on the air usage, so if your going to use them for extended periods of time, you need the compressor on-board.

--NOTE-- We used them last year to pick up the tubes, worked pretty well, but the skin of that ball is going to be much harder to use vacuum cups on.

[GearsOfFury]

Still allowed... <R87>

For the purposes of the FIRST competition, a device that creates a vacuum is not considered to be a pneumatic device and is allowed. This includes, but is not limited to, venturi-type vacuum generators and off-the-shelf vacuum devices (as long as they are powered by provided or permitted motors).

[Elgin Clock]

I'd like to see one with only one point of contact on a Trackball that actually would work. I don't think it will.

The reason I say this, is because the fabric outer covering of the Trackballs will not result in a very good seal as the nice one layer vinyl tube would last year.

If you tried this, you would probably need 2 or more on quite opposite sides of a ball, and in that case, why even bother adding the venturi mechanism when you basically have a gripper with 2 points of contact anyways?

[robogeek753]

Originally Posted by Elgin Clock

I'd like to see one with only one point of contact on a Trackball that actually would work. I don't think it will.

The reason I say this, is because the fabric outer covering of the Trackballs will not result in a very good seal as the nice one layer vinyl tube would last year.

If you tried this, you would probably need 2 or more on quite opposite sides of a ball, and in that case, why even bother adding the venturi mechanism when you basically have a gripper with 2 points of contact anyways?

Kind of what I was thinking...

[DonRotolo]

Vacuum can be used for many things besides picking things up.

If you can figure out a way to store vacuum in a sealed tank (think solenoid valves) and prevent the vacuum from 'leaking' out through the venturi (think timing of air supply), then yes, you should be able to store vacuum prior to a match, by "charging" the tank in the pits, sealing it up.

Of course, this is merely my opinion, I cant say if it is legal or not, but this has been done by teams last year.

Don

[scottydoh]

thanks, thats what I thought, just trying to convince a mentor that it won't work...

[Peter Matteson]

Originally Posted by Don Rotolo

Vacuum can be used for many things besides picking things up.

If you can figure out a way to store vacuum in a sealed tank (think solenoid valves) and prevent the vacuum from 'leaking' out through the venturi (think timing of air supply), then yes, you should be able to store vacuum prior to a match, by "charging" the tank in the pits, sealing it up.

Of course, this is merely my opinion, I cant say if it is legal or not, but this has been done by teams last year.

Don

We did this in 2004 the only year it was technically legal. Note the solenoid use rule, R60, and the above quoted R87:
A vacuum is not a pnuematic system.
The solenoid rule clearly states that you can only use solenoid valves for pnuematics.
Vacuum is not equal to pnuematics therefore solenoid valves used to contain the vacuum are not allowed.

[jgannon]

Originally Posted by Peter Matteson

Note the solenoid use rule, R60 [...] The solenoid rule clearly states that you can only use solenoid valves for pnuematics.

I'd venture that not only is that not clear, it's most likely wrong.

<R60> Items specifically PROHIBITED from use on the ROBOT include:
* Electric motors and/or servos different from, or in addition to, those in the Kit Of Parts, with the exception of those specifically permitted by Rule <R59>.
* Electric solenoid actuators (note: electric solenoid actuators are NOT the same as pneumatic solenoid valves – the latter are permitted, the former are not).

<R60> prohibits the use of electric solenoids, meaning electromagnetically controlled linear actuators. It notes that pneumatic solenoid valves, such as the ones found in the KoP, are legal. It makes no mention as to restrictions of their application... as such, you can use them in your pneumatics, you can use them as part of your end effector, you can use them as ballast, you can use them as non-functional decorations, and if you can make it work, you can most certainly use them to control a vacuum.

[Peter Matteson]

Originally Posted by jgannon

I'd venture that not only is that not clear, it's most likely wrong.

<R60> prohibits the use of electric solenoids, meaning electromagnetically controlled linear actuators. It notes that pneumatic solenoid valves, such as the ones found in the KoP, are legal. It makes no mention as to restrictions of their application... as such, you can use them in your pneumatics, you can use them as part of your end effector, you can use them as ballast, you can use them as non-functional decorations, and if you can make it work, you can most certainly use them to control a vacuum.

I will again point out that the rule quite clearly states that vacuum is not considered pnuematics. Therefore you would be using the solenoid for a purpose other than pnuematic. I think this is quite clear.

Also you want to use vacuum solenoids not pnuematic.

[roboengr]

The next thing on the valves is the pilot control of a valve. valves require a air pressure to work. Just keep that in mind. Dont use a venturi! It is not enough use a bima cylinder on a fisher price motor. the rest you will have to figure out.

Has anyone tried to use a vacume on the nylon cover? Tell the success or failure, please. I am not sure how much leakage there must be to over come in volume.

[jgannon]

Originally Posted by Peter Matteson

Therefore you would be using the solenoid for a purpose other than pnuematic. I think this is quite clear.

Peter, <R60> only talks about what parts are allowed to be on the robot. It says nothing about how they are allowed to be used. Whether the solenoids we are allowed to use will physically work for this application is up for debate, but please don't spread misinformation when the rules say something else.

[Peter Matteson]

Originally Posted by jgannon

Peter, <R60> only talks about what parts are allowed to be on the robot. It says nothing about how they are allowed to be used. Whether the solenoids we are allowed to use will physically work for this application is up for debate, but please don't spread misinformation when the rules say something else.

I am not spreading mis-information. We clearly disagree on the interpretation of the way this is written and both feel strongly that the way it is written agrees with our case. As such anyone who wants do this should directly ask about it through the FIRST Q&A system.

[Alan Anderson]

Originally Posted by Peter Matteson

I am not spreading mis-information.

As it turns out, you are.

The rule you are quoting, <R60>, is forbidding electric solenoid actuators. It's not saying anything about legal or illegal ways to use pneumatic solenoid valves. Ironically, the parenthetical comment that is intended to clarify the meaning is apparently what's leading you to misinterpret it.

Do you know what electric solenoid actuators are? They're the sort of thing that you find in chime doorbells, where an electric current causes a magnetic field to move a metal rod.