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Here is a pic of the "harvester" The roller has Pnuematic tubing sticking out of it to prick into the openings of the ball and feed it into a compression chamber with rollers to move the ball.
18-01-2009 04:11
HUNT397Looks good but you might want to look at <r08> because we were going to do the same thing and from this thread we have decided not to because it is not really legal. You need to have 6 in of bumper on the bumper peremeter on every exterior corner.
18-01-2009 04:26
keen101I'm pretty sure they can do it that way, but would need to wrap bumpers around the corners. But, if I'm wrong please someone correct me!!
our front design is drafted with corners like that too, and if it will be illegal i need to know asap. From what I've read i think it can be covered within the rules, but I'm not entirely sure...
18-01-2009 04:31
EricVicentiVery funny, when searching around for accumulator brush material on kickoff, we too discovered pneumatic tubing worked very well for this application. Our accumulator uses nearly the exact same system.
18-01-2009 05:56
sanddragQuestion: In a design such as this, is the bumper perimeter considered to go inward with the frame? If so, the roller would be outside the perimeter, and thus illegal.
18-01-2009 06:48
GaryVoshol
842 knows that their robot Carmen, as originally envisioned, does not meet the bumper rule: http://forums.usfirst.org/showthread.php?t=11170
Further discussion of their frame design can be found here: http://www.chiefdelphi.com/forums/sh...ad.php?t=71878 Note that this current pic has a portion of that frame removed; it looks like they're working on a fix to get legal bumpers.
Let's keep this thread on track discussing only the accumulator roller. It looks like a good design to me. The roller is inside the BUMPER PERIMETER and the soft pieces of tubing shouldn't harm the balls. My only question, have you done testing to see if that's enough little hooks to catch balls reliably?
Edit: I see from the video posting here http://www.chiefdelphi.com/forums/sh...925#post802925 it works pretty good. Nice!
18-01-2009 10:56
rogeryoungI was concerned about pressure feed as well for drawing in the ball. I am anxious to get to school today and try this out. How about attaching the tubes with a short 10-32 stud threaded into the roller? Are those white rings pvc pipe? Are they "grooves" for round tubing?
18-01-2009 11:00
Josh GoodmanWe prototyped with pneumatic tubing as well. It works very well and "sweeps" the balls in without touching the ground.
18-01-2009 12:00
Akash RastogiHehe, cool to see one of the ideas we came up with on the first day was used
We might switch back to this design.
18-01-2009 16:36
amariealbrechtwow this is a very cool and inventive idea...i like it!
have a good season,
Alicia Albrecht
Electrical subteam
The Robettes 2177
18-01-2009 17:52
smurfgirl
I like the design for the ball harvester. I saw the video of it, and it looks like it works really well. I think the little bits of tubing are a great idea!
18-01-2009 20:49
falconmaster
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Question: In a design such as this, is the bumper perimeter considered to go inward with the frame? If so, the roller would be outside the perimeter, and thus illegal.
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18-01-2009 22:28
Mr_IVery similar to our design, although we don't (yet) have the diagonal supports. The notion of 6" bumpers is frightening, to the point of show-stopping (or at least "massive redesign"). 842, what are your thoughts?
18-01-2009 22:40
falconmaster
Well we feel that we will be allowed with our bumper design. W willadd bumpers to the diagonal sections with 6 inch sections. If we are not allowed we will swap them out with a straight six inch sections. Our argument though will be that the corners will be protected, no bumper section will be less than 6 inches and the weight of the part not on the bumper perimeter will be counted against the robot weight. Even if you had a straight section instead of diagonals the corners would not be protected on the inside. Oh well we will see
18-01-2009 23:16
waialua359Its too bad that the bumpers are such a big issue.
The whole intent is to protect your own robot and other robots on the field, which should be the only things making contact with each other.
Instead, its turning into a wording or lack of wording issue.
I cant see how yours would be deemed illegal based on how you folks plan on putting them on.
18-01-2009 23:28
IndySam
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Well we feel that we will be allowed with our bumper design. W willadd bumpers to the diagonal sections with 6 inch sections. If we are not allowed we will swap them out with a straight six inch sections. Our argument though will be that the corners will be protected, no bumper section will be less than 6 inches and the weight of the part not on the bumper perimeter will be counted against the robot weight. Even if you had a straight section instead of diagonals the corners would not be protected on the inside. Oh well we will see
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18-01-2009 23:51
Bob SteeleI like your design but there is another rule that the bumpers must make first contact with the wall... I think your outside bumper corners should prevent your rollers from hitting the wall first... so that should be ok.
I would be careful though as another robot or trailer can hit the roller area... with the corner of their robot.. I can speak from experience in 2006 with a front roller that picked up the poof balls...
It was an issue then.. but of course ... in 2006 we didn't have mandated bumpers on the robot... just suggested...so we took many hits from unbumpered robots. We ended up having to use a titanium bar to protect our roller.
Good luck with your design... I hope it works great!!
19-01-2009 00:20
Greg Needel
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Well we feel that we will be allowed with our bumper design. W willadd bumpers to the diagonal sections with 6 inch sections. If we are not allowed we will swap them out with a straight six inch sections. Our argument though will be that the corners will be protected, no bumper section will be less than 6 inches and the weight of the part not on the bumper perimeter will be counted against the robot weight. Even if you had a straight section instead of diagonals the corners would not be protected on the inside. Oh well we will see
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19-01-2009 08:56
Wetzel
We've built several iterations of intake and lift prototypes, and the tubes work well. What are you using to secure them to the roller?
Wetzel
19-01-2009 09:58
Teched3Just another thought about your bumper design. Part of Team Update #3 is concerned with how far a trailer will enter your bumper perimeter. IMO, I don't think your design will pass inspection. As long as you have alternatives ready to modify, you won't be taking much of a chance. 
19-01-2009 10:45
keen101Well, were supposed to use a string to figure out our bumper perimeter. So, one interpretation would be that the angled bumpers would not be in the bumper perimeter, therefore you could still have them, but you'd have to consider them part of the robot and weigh them with the robot. But, that won't work either, because it clearly states that the trailer can only make contact with the bumpers, and if it made contact with the inside "bumpers", then that would technically be making contact with the robot. Even though it'd be a soft part of the robot.
So, i am concluding that it is illegal, and very risky to do it since we might have to change it later.
19-01-2009 12:29
falconmaster
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We've built several iterations of intake and lift prototypes, and the tubes work well. What are you using to secure them to the roller?
Wetzel |
19-01-2009 12:36
XXShadowXXHow fast does it propel the balls that pass under it?
19-01-2009 12:49
JVN|
Well we feel that we will be allowed with our bumper design. W willadd bumpers to the diagonal sections with 6 inch sections. If we are not allowed we will swap them out with a straight six inch sections. Our argument though will be that the corners will be protected, no bumper section will be less than 6 inches and the weight of the part not on the bumper perimeter will be counted against the robot weight. Even if you had a straight section instead of diagonals the corners would not be protected on the inside. Oh well we will see
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19-01-2009 12:53
falconmaster
19-01-2009 13:02
Vikesrock
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Well we feel that we will be allowed with our bumper design. W willadd bumpers to the diagonal sections with 6 inch sections. If we are not allowed we will swap them out with a straight six inch sections. Our argument though will be that the corners will be protected, no bumper section will be less than 6 inches and the weight of the part not on the bumper perimeter will be counted against the robot weight. Even if you had a straight section instead of diagonals the corners would not be protected on the inside. Oh well we will see
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19-01-2009 21:01
WhiteShadow1474how exactly did you get the pnumatic tubing to stay on there.
And; the bumper rules are so complex. I have no idea if this design is legal.
19-01-2009 21:10
EricH
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how exactly did you get the pnumatic tubing to stay on there.
And; the bumper rules are so complex. I have no idea if this design is legal. |
19-01-2009 22:23
Karthik
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And as for legality, 3/4 sides of the robot are legal. The remaining side needs work.
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Well we feel that we will be allowed with our bumper design. W willadd bumpers to the diagonal sections with 6 inch sections. If we are not allowed we will swap them out with a straight six inch sections. Our argument though will be that the corners will be protected, no bumper section will be less than 6 inches and the weight of the part not on the bumper perimeter will be counted against the robot weight. Even if you had a straight section instead of diagonals the corners would not be protected on the inside. Oh well we will see
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19-01-2009 23:05
falconmaster
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Well, were supposed to use a string to figure out our bumper perimeter. So, one interpretation would be that the angled bumpers would not be in the bumper perimeter, therefore you could still have them, but you'd have to consider them part of the robot and weigh them with the robot. But, that won't work either, because it clearly states that the trailer can only make contact with the bumpers, and if it made contact with the inside "bumpers", then that would technically be making contact with the robot. Even though it'd be a soft part of the robot.
So, i am concluding that it is illegal, and very risky to do it since we might have to change it later. |
19-01-2009 23:14
EricH
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Do the rules say the trailer contact part in rules that mention the trailer?
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19-01-2009 23:21
Andy LAm I the only one confused as to the dispute over the bumper legality? Didn't the GDC specifically say that the bumper configuration is illegal? And wouldn't you knowing this and still trying to dispute with your inspector be a little immoral?
19-01-2009 23:34
ChuckDickersonAngled bumper debate aside, wouldn't a design of this type be illegal IF the roller (or parts of it like the pneumatic tubes in this example) touched a trailer? It is my understanding that the ONLY thing the robot is allowed to touch on the trailer is the BUMPER and then ONLY with the BUMPERS of the robot. If an intake roller mounted near the front edge of a robot intake opening touches the trailer (BUMPER or not) isn't it illegal? Due to the height of the BUMPERS (7") and diameter of the balls (~8.5") doesn't this severly limit the placement and design of intake rollers placed near the edge of a robot?
19-01-2009 23:38
MrForbes
Yes, it sound like the intake rollers would need to be more than 7" high, at the lowest point. Pokey grippy thingys might be a problem, if they're too long.
20-01-2009 08:17
GaryVoshol
We're using <R32> "ROBOT to ROBOT Interaction" to describe ROBOT to Trailer interaction, but that seems to also be the way the GDC is doing it.
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Originally Posted by <R32>
B. Contact within the BUMPER ZONE is generally acceptable.
C. If a portion of the BUMPER PERIMETER polygon is unprotected by BUMPERS, any contact by another ROBOT within the unprotected region (including the vertical projection of the unprotected region) will be considered incidental contact and will not be penalized. |
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Originally Posted by 8.2 Definitions
BUMPER ZONE – the volume contained between two virtual horizontal planes, one inch above the floor and seven inches above the floor.
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20-01-2009 15:32
ChuckDickersonI have re-read the rules and agree that <G32> defines what is and isn't allowed concerning ROBOT-to-ROBOT and ROBOT-to-TRAILER interactions. For reference this is the whole rule:
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<G32> ROBOT to ROBOT Interaction - Strategies aimed solely at the destruction, damage, tipping over, or entanglement of ROBOTS or TRAILERS are not in the spirit of the FRC and are not allowed. In all cases involving ROBOT-to-ROBOT or ROBOT-to-TRAILER contact, the TEAM may receive a PENALTY and/or their ROBOT may be disqualified if the interaction is inappropriate or excessive. However, it is noted that Lunacy is a highly interactive game. Robust construction of ROBOTS will be very important in this high-speed competition. ROBOTS should be designed to withstand the contact that will occur during the MATCH. Appropriate contact is allowed under the following guidelines: A. High speed accidental collisions may occur during the MATCH, and are an expected part of the game. B. Contact within the BUMPER ZONE is generally acceptable. C. If a portion of the BUMPER PERIMETER polygon is unprotected by BUMPERS, any contact by another ROBOT within the unprotected region (including the vertical projection of the unprotected region) will be considered incidental contact and will not be penalized. D. Contact with a tilted or tipped ROBOT outside the BUMPER ZONE (particularly by the BUMPERS of the contacting ROBOT) will generally be considered incidental contact and will not be penalized. E. Contact outside of the BUMPER ZONE is not acceptable, and will result in a PENALTY. The offending ROBOT may be disqualified from the MATCH if the offense is particularly egregious or if it results in substantial damage to another ROBOT. F. A ROBOT may not attach to and/or climb onto a ROBOT or TRAILER. Doing so will be interpreted as an attempt to damage an opposing ROBOT, and will be penalized as such. G. Use of any sloped or angled feature of the ROBOT as a wedge to overturn an opposing ROBOT or TRAILER is explicitly prohibited, and will be assigned a PENALTY. |
20-01-2009 16:22
EricH
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Of course, this is just my interpretation of the rules. If others feel my logic is flawed in this interpretation please correct me.
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20-01-2009 23:35
falconmaster
OK, we have beaten to death. We will change our bot's front to have a six inch flat side on each side of our harvester's opening. It looks like it will not make too much of a difference , only ball's a ball width. We will just have to drive better! It was great watching all you debate the issue though, but if we stay with our design, we will loose the argument. We will bring our old angled side however in case we see the inspectors change their interpretation. Thanks all.
21-01-2009 00:48
ChuckDickersonEric, thanks for the great post in direct response to mine. Our two posts clearly show how two people can read the same words (rules) and come to two different conclusions. After reading your thoughtful and detailed response I can see how you arrived at your conclusions. However, not being able to read the minds of the GDC our team is opting to play it safe and is continuing to design and build our robot such that any contact between our robot and the trailer is bumper to bumper only (as long as the trailer is in it’s normal playing configuration). Does this limit our design possibilities? Probably, but we would rather be safe than sorry.
We think we have a pretty good plan though. 
21-01-2009 01:05
EricH
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Eric, thanks for the great post in direct response to mine. Our two posts clearly show how two people can read the same words (rules) and come to two different conclusions. After reading your thoughtful and detailed response I can see how you arrived at your conclusions. However, not being able to read the minds of the GDC our team is opting to play it safe and is continuing to design and build our robot such that any contact between our robot and the trailer is bumper to bumper only (as long as the trailer is in it’s normal playing configuration). Does this limit our design possibilities? Probably, but we would rather be safe than sorry.
We think we have a pretty good plan though. ![]() |
I also saw how you came to your conclusions. As it is written, both interpretations are valid without further clarification from above.
22-01-2009 02:19
tacopaco789Just seeing that frame tells me that this belongs to the falcons. Light weight and sturdy. Same style from when we where allied with you in Phoenix the 2005 regional. Love it. lol
Kyle
Team 624
2007 Pit captain
2008 Build Captain
2008 Driver
22-01-2009 09:54
ebarkerTo put Eric's comments into a nutshell -
a) a trailer is field equipment
b) thou shalt not damage field equipment
c) it has been so since the beginning of time.
I'd say that is the root cause of the GDC reasoning, rules and decisions on the matter.
22-01-2009 10:04
JesseKHere's a tidbit we've found:
We've found that while on a slick surface, about half the time the orbit balls run away when they're hit wrong by the harvester fingers ... so having the roller edge @ 9" off the floor with the fingers extending down to 7.5" is our best solution. The harvester roller edge is 8" from the opposite conveyor side though, so the ball is under slight compression while in the conveyor.
Are you guys integrating tubing/belting in between the fingers for the conveyor? If so, have you solved the issue of the belting getting caught on the harvester fingers? That's our next thing to tackle.
22-01-2009 13:12
falconmaster
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Here's a tidbit we've found:
We've found that while on a slick surface, about half the time the orbit balls run away when they're hit wrong by the harvester fingers ... so having the roller edge @ 9" off the floor with the fingers extending down to 7.5" is our best solution. The harvester roller edge is 8" from the opposite conveyor side though, so the ball is under slight compression while in the conveyor. Are you guys integrating tubing/belting in between the fingers for the conveyor? If so, have you solved the issue of the belting getting caught on the harvester fingers? That's our next thing to tackle. |
25-01-2009 15:33
Tristan Lall|
What I BELIEVE the GDC intent is to limit all contact with the trailer to the bumper only. I would even be willing to bet that at inspection there will be a legal TRAILER that will be pushed into and around your ROBOT and you better have designed it such that nothing but the BUMPERS of the trailer can touch your ROBOT inside and out. In other words, if you have an opening on the front of your robot such that the trailer can partially go inside your robot there is no such thing as "incidental contact" outside the bumper zone. The whole point of the drawings in Update #2 was to make sure we understood that the trailer bumper couldn't touch anything inside/under/etc. our robots, only the legal front minimum 6" bumpers. If you have an intake roller near the front of your robot with protrusions on it designed to grab the balls and pull them into your robot you better be careful that they can't touch the bumpers (or any other part) of the trailers.
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Originally Posted by FRC1120
(1) are two pictured configurations in Update 2 "legal"? They seem to meet all parts of <R08> and thus we are assuming they are legal. Correct assumption?
(2) Is it acceptable for the robot to extend over the bumper zone of the TRAILER (not of the robot), that is the "opponent's trailer", as shown? is this "incidental contact"? (3) If it IS ok to extend, any limits on reaching/touching the trailer posts? |
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Originally Posted by GDC
We believe that the two example illustrations in Team Update #2 are correct and satisfy the conditions defined in Rule <R08> as intended.
As shown in the illustrations, it is physically possible for a legal ROBOT configuration to partially enclose a TRAILER, including extending over the BUMPERS of the TRAILER. There are no rules that would prevent this, provided the TRAILER (including the BUMPERS, base, and vertical pipes) is not grasped, grappled, or attached to in a manner that would cause a violation of Rule <G29>). |