Vacuum

[NoRemorse]

Ok, I was wondering if it was legal to use a venturi style vacuum genorator. Its just a little box then when positve air pressure is blown over it, it creats negative air ressure at the other end. Probably wont use it anyhow, but it is somthing we are looking into and would like to know the legality of!

[Skabana159]

If you can make one with off-the-shelf parts, or ones that you have machined, and only motors from the kit, then yes, it would be legal.
However, if there was any motive force, in say the fan/blower, it would be an illiegal motor.

[NoRemorse]

What if it IS an off the shelf part all together

[KenWittlief]

you could probabally do what you are talking about, but I dont think it will create much vacuum.

in the past teams have used a pair of pnuematic cylinders to create vacuum. have a pressurized cylinder pump a second one to draw a vaccum at one end.

[NoRemorse]

Well, 2 points

Vanturi style is what they do in industry and create MUCH more vacuum, i just got home from prototyping

We were planning on using the cylenders, even thogh they create less vacuum, they reqire a NON-continuous flow

[BananaMango777]

you can also create a vacuum using a kit motor and a cam arrangement which repeatedly creates a draw/push stroke, then you retain the vacuum using a no-return valve on one side of the cylinder. This is something our team has been looking at this season :D
I think that this might be more successful than what you are proposing, I believe that some teams did this last year as well to develop a vacuum, with a fair amount of success.

[NoRemorse]

well, we need somthing with a quick vaccum produced to take out the air in our large cup, the cup is larg to allow for sloppy driving and positioning, lol

the ventri works WAY better than i thouht it would, you people should puick one up just to try it, ive seen them lift #30 boxes at my dads works. pretty impressive!

[KenWittlief]

yeah but what were they powered with? the compressors we have are pretty whimpy - something like 1/8 HP or less (rough guess) and they dont supply a large volume of air.

please dont let me discourage you- definately try the venturi and see how it works - Im only tossing out options for your consideration

[NoRemorse]

i know its not a good idea bc lack of volume of air, im just sayin, dont underestimate its power! try it out, i was REALLY impressed!

[andy]

I do not think that you have enough compressor "umph" to efficiently implement a venturi vacuum generator. I also would quicly discount centrifigal vac pumps (there heavy- upwards 100 lbs) and turbo molecular vacs (expensive-upwards $15000).

I would try to drive a pnumatic cylinder with a cam on a motor with one way valves that seems like the easiest, lightest, most cost effective solution.

good luck!
-Andy

[Rickertsen2]

I do not think that you have enough compressor "umph" to efficiently implement a venturi vacuum generator. I also would quicly discount centrifigal vac pumps (there heavy- upwards 100 lbs) and turbo molecular vacs (expensive-upwards $15000).

I would try to drive a pnumatic cylinder with a cam on a motor with one way valves that seems like the easiest, lightest, most cost effective solution.

good luck!
-Andy
But since one way valves arn't really legal either, you can use a double solenoid in place of one, as long as you know when the cylinder is extending and retracting. Rather that use a cam, why not put two cylinders parallel to each other and link them together, driving one, while using the other to generate a vacuum. As far as the practicality of generating a vacuum on a FIRST robot or the usefulness of doing so: impractical and useless, but its still interestign to discuss.

[NoRemorse]

"We were planning on using the cylenders"

I realize all this, and had already butlt the prototype for it before I even posted. I just wanted to know the legality of it.

[ahecht]

[QUOTE=Rickertsen2]But since one way valves arn't really legal either, you can use a double solenoid in place of one, as long as you know when the cylinder is extending and retracting.[QUOTE]

Actually, the flow restrictors in the pneumatics kit only restrict flow in one direction (the direction with the small arrow). Therefore, if you tighten it all the way down, it functions as a one-way valve.

[TomWx]

Q&A hass said that Vacuums are not allowed, but suction cups are. As of right now, there are several different followup questions as far as using pneumatics and fans to create a vacuum. Tehse questions stand unanswered. It is clear however that venturi-style vacuum generators are not allowed.

[tenfour]

We tried this last year and got very little suction as a result of little air flow out of the compressor.

There is also a rule against custon pneumatics.

Why in the heck would you want a vacuum anyways?

[pras870]

To clarify, you cannot use an off the shelf vacuum. My team comtimplated this last year, and found that it was in fact illegal. Instead, we bought a festo suction cup, which created suction through a vacuum. Now I know this contradicts what I said, but it was not in fact a vacuum. We simply used 2 of the largest cylinders we could get (I think it was a 2" bore?), we used 1 to raise our arm, and the other cylinder was right next to it, with it's output valve connected to the cup. So simply, when you move the arm down, it created a vacuum/suction in the cup. However, you cannot keep constant pressure like this, so you basically had to keep pumping the arm up and down to keep the suction. I'm assuming you want to create some sort of vacuum to grip onto the big ball, and without using an actual vacuum, this simply isn't possible.

[NoRemorse]

That is exactly what we have done, and were planning to do from the beggining.

[tenfour]

That is exactly what we have done, and were planning to do from the beggining.

Just a word to the wise about sucking on the HDPE. Its nearly impossible after the rough gameplay scratches the nice smooth surface......we had this ahppen and ruin a sub system.

[Levaman]

To all this year's comptetitors: This years game presents many chances to use vaccum systems or similar devices. I'll leave it to you to figure how far this can go.

Good Luck. :D

[KenWittlief]

I searched the entire set of documents FIRST gave us and the word 'vacuum' does NOT appear in any of them

creating a vacuum to pick up a ball really has nothing to do with the pnuematics FIRST supplies - the pnuematics are designed to be linear actuators to move structural components

vacuum would be used in this game to grab or attach to a ball or platform

I want to ask FIRST directly on the Q&A website about this. The robot rules say we cannot use anything else to compress air, except the compressor, but it says nothing about creating a vacuum.

There are commerical off the shelf devices that will generate a vacuum, that we could power with one of the motors in the kit of parts - as soon as I can get my hands on our teams Q&A password I will ask this question directly

"can we use commerical off the shelf devices to create a vacuum, if they are powered by one of the motors supplied in the kit of parts?"

I KNOW these were not allowed last year, but this is not last year - the rules do change from year to year, just as the game itself changes. Our team has gotten burned before for 'living in the past' - not realizing an old rule had been done away with, and we missed opportunities.

[KenWittlief]

Im having trouble getting our password to the FIRST Q&A site - can someone please post this question to them?

____________________________________________
The word 'vacuum' does NOT appear in any section of the 2004 manual. Generating a vacuum is not really a pnuematics application.
Can we use commerical off the shelf devices to create a vacuum, if they are powered by one of the motors supplied in the kit of parts?
____________________________________________

[Al Skierkiewicz]

Im having trouble getting our password to the FIRST Q&A site - can someone please post this question to them?

____________________________________________
The word 'vacuum' does NOT appear in any section of the 2004 manual. Generating a vacuum is not really a pnuematics application.
Can we use commerical off the shelf devices to create a vacuum, if they are powered by one of the motors supplied in the kit of parts?
____________________________________________

If you follow the flow chart on page 10 of the section 5, "The Robot" and answer truthfully you will end up at the bottom box "No it may not be used." You will branch off at "pnuematics/ Hydraulics" or even further down under additional electronics "Is it a ...or pump?"

[Gabe Salas Jr.]

I have noticed that on the 2X balls that there are ridges on the surface. Wouldn't this make suction cupping and/or vacuuming the 2X balls very difficult? In 2000, our team attempted to do something similar and tested this out. We were not able to properly suction the cups onto the 30" inflated balls because the ridges prevented the suction cup to create a seal. So the air continuously escape. I am pretty sure that the balls this year are very similar to the ones used in 2000, and if your team is considering on sucking the 2X balls with a vacuum/suction cup mechanism, I highly suggest testing this out before considering purchasing all the parts needed to assemble or create this device.

[KenWittlief]

Al S. the restriction flowchart depends on whether you consider a vaccum mechanism to be pneumatics or not, and whether the 'pump' has a motor attached, or is strictly a mechanical device that you drive with one of the motors that FIRST has supplied.

Since we are allowed to build a vacuum pump with a cylinder and two flow restriction valves (they act as one way valves when closed all the way) - I cant see any reason why they wouldnt allow us to purchase a commercial device that does the same thing.

We got a couple suction cup devices from our sponsors factory floor, and when you hook them up to a commercial vacuum pump, it DOES hold the 2X ball very nicely - the ridges cause it to leak air a little - thats why you need a continuously running pump to make our little scheme work - we still have some more testing to do, but so far it looks like a viable option.

Our teams point of contact still hasnt found the Q&A password in the TIMS system yet - so if someone could still post my question (in my last post) I will buy you a cookie when I meet you at a regional :c)

[Gabe Salas Jr.]

We got a couple suction cup devices from our sponsors factory floor, and when you hook them up to a commercial vacuum pump, it DOES hold the 2X ball very nicely - the ridges cause it to leak air a little - thats why you need a continuously running pump to make our little scheme work - we still have some more testing to do, but so far it looks like a viable option.

Good job! :D

I am not sure if it is me, but it seems like there is a lot to manage with this suctioncup/vacuumed device on an arm (probably telescoping) for this robot if you guys plan on using it to cap a goal. This would be a pretty nice robot to build, but that seems like a lot of motors, and power used during a single match. You also have the weight limit and power management to consider. I am not saying to shoot down this idea, but there will be a lot of testing for this type of robot. Unless you guys has come up with a very effect way to integrate everything together. Then again, a "swiss-army-knife" type of robot never does very well during competition. If you really want the robot to be the best at capping goals with the 2X balls, then go right ahead. :)

Good luck to teams going for this design. :cool:

[Al Skierkiewicz]

Al S. the restriction flowchart depends on whether you consider a vaccum mechanism to be pneumatics or not, and whether the 'pump' has a motor attached, or is strictly a mechanical device that you drive with one of the motors that FIRST has supplied.

Ken,
I think you answered your own question here. If you go through the flowchart, following your lead that the vacuum is pnuematics, then you can't progress past the following question..."Is it an air cylinder ordered from the Custom Cylinder Order Form or any previous year’s pneumatic component except storage tanks, pressure switches or pressure regulators ?" Your answer is NO and that makes it an illegal part.
Sorry.