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-   -   pic: Team 870 Suction Cups (http://www.chiefdelphi.com/forums/showthread.php?t=18634)

pras870 27-02-2003 15:29

The red tread on the tire is simply the timing belt given out by FIRST. As for the cups, a small scratch in the HDPE should not really matter. We even tested this on a surface of our HDPE which was scratched, and it did not effect it at all. The way the cups are designed, the pressure which is generated is spread out evenly over the base of the cup, for more surface area. We locked them down, created a vacuum, and had half our team try to push it horizontally from side to side and front to back, and it would not budge.

evulish 27-02-2003 15:49

What about dirt on the HDPE...I think that was our teams concern with suction cups (and the pneumatic resources it would use)...the only time I have seen FIRST take care of the field is when the carpet gets unwound. I really doubt they'll be shining the HDPE after every matching.

Rob Colatutto 27-02-2003 15:52

i;d like to know how dirt is going to get on the hdpe..... i'd imagine they make the feild reseters clean thier shoes before going out because that could cause a lot to the rug too

Rook 27-02-2003 16:24

Quote:

Originally posted by Nataku
i;d like to know how dirt is going to get on the hdpe..... i'd imagine they make the feild reseters clean thier shoes before going out because that could cause a lot to the rug too
Ground metal and rubber, dust, grease from chains, just to name a few things that can get on the HDPE. The top of our practice ramp has some hefty gauges in it, not just fine scratching. In testing our bot, we put it through some rigorous drills and hit some of the old bots we had sitting on top pretty hard. The colisions often resulted in the old bots getting knocked around and the ramp took a licking. We maybe wrong that the HDPE may look just fine after each match. Maybe FIRST will even break out a Zamboni and polish it, but it was just too risky for us to take that chance.

pras870 27-02-2003 16:30

a little zamboni driven by a midget would be funny to watch, and serve a great purpose :)

UlTiMaTeP 27-02-2003 17:32

I have no doubt that suction cups will hold great. BUT when a bot hits you its not gonna try and pull you up like a potato its gonna try and push you from the side which a suction cup grips straight down.... for example take any suction cup and take somthing flat, stick it on and feel how much force is needed to pull it straight off, then stick it back on and try and slide it, if the surface is flat and smooth the suction will stay intact but you will be able to move it where ever you would like. Which is exactly what is going to happen at KOH

Rook 27-02-2003 18:15

Quote:

Originally posted by UlTiMaTeP
I have no doubt that suction cups will hold great. BUT when a bot hits you its not gonna try and pull you up like a potato its gonna try and push you from the side which a suction cup grips straight down.... for example take any suction cup and take somthing flat, stick it on and feel how much force is needed to pull it straight off, then stick it back on and try and slide it, if the surface is flat and smooth the suction will stay intact but you will be able to move it where ever you would like. Which is exactly what is going to happen at KOH
This picture

Moving Glass

Should put away any debate on suction cups. The full weight of the glass pane is being held by the suction cups and its on it's side. I don't think the worker would stand where he is, if those cups weren't safe.

Matt Reiland 27-02-2003 18:16

I have no doubt that there are suction cups that can support huge side loads on them. My Mitsubishi Big Screen was carried into the house with 2 suction cups vertically on each side and they didn't slip. The key here is that it was on a 'prefectly' smooth surface (Glossed Burlwood). People out there that are talking about how glass panels are lifted like this are right, BUT.......... once there are small scratches in the plastic where air can leak past the rubber, your suction is gone it is not the same as glass after the first few pushing matches up there.

Rook 27-02-2003 18:27

Quote:

Originally posted by Matt Reiland
I have no doubt that there are suction cups that can support huge side loads on them. My Mitsubishi Big Screen was carried into the house with 2 suction cups vertically on each side and they didn't slip. The key here is that it was on a 'prefectly' smooth surface (Glossed Burlwood). People out there that are talking about how glass panels are lifted like this are right, BUT.......... once there are small scratches in the plastic where air can leak past the rubber, your suction is gone it is not the same as glass after the first few pushing matches up there.
I agree

Katie Reynolds 27-02-2003 18:41

Quote:

Originally posted by Matt Reiland
I have no doubt that there are suction cups that can support huge side loads on them. My Mitsubishi Big Screen was carried into the house with 2 suction cups vertically on each side and they didn't slip. The key here is that it was on a 'prefectly' smooth surface (Glossed Burlwood). People out there that are talking about how glass panels are lifted like this are right, BUT.......... once there are small scratches in the plastic where air can leak past the rubber, your suction is gone it is not the same as glass after the first few pushing matches up there.
My sentiments, exactly.

- Katie

OneAngryDaisy 27-02-2003 18:47

Quote:

Originally posted by Cory
wow...those things are humongous.

Cory

If you think those are humongous, you should catch the cup on team 1218 from nearby here in Chesnut Hill- those guys have one enormous cup mounted right in the center of their robot.. seemed to work pretty well too..

WakeZero 27-02-2003 18:47

Relax people, only a few more weeks and will we find out for sure :yikes:

soezgg 27-02-2003 19:02

well, there are basically 2 ways to use a suction cup.

1: Put it on the ground and suck all the air out of it so it attatches

2: Push down on it and have all the air go out of it creating suction.


the first way is reverseable

the second way is pretty good if you do it right.


admittedly, it is a good strategy for a koth bot, whether it works or not.


good luck.

Clark Gilbert 27-02-2003 19:12

Hmmm
 
There is another way...

Force it down, and then pull it up.

I've done some research on the internet and there are a ton of suction cups out there, (even rectange shaped). It should be really interesting what teams use this year and how they use them.

:)

evulish 27-02-2003 20:12

The suction cup we had prototyped was made out of a circlular peice of aluminum with a groove in the bottom where a latex O-ring fit. It worked pretty well...untill we stratched up the surface a bit. Still, it wasn't very much for the resources it would use (like 2 of our cylinders) If anyone can make it hold and stay...that's where my money is going. Ohh...and that suction cup sticks to faces...not stomachs. Not that I know this personally or anything.


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