View Full Version : Bumper Rule
Compnerd
11-01-2008, 01:56
Do the bumpers have to surround the frame/base of the robot completly, or can there be a gap? My team has looked at the rules, and everyone interprets it slightly differently. Anyone know??
It has to cover 2/3, so you can have one side un-bumpered.
waialua359
11-01-2008, 02:10
this is a good question as we were wondering the same thing.
perhaps others can provide more insight.
Where is the 2/3 rule?
thanks
There was another thread on it that actually called out the exact rule, I'm going to bed pretty soon here so I won't look it up but I do remember reading it earlier today.
Eugene Fang
11-01-2008, 02:15
<R08>STANDARD BUMPERS must protect a minimum of 2/3 of the perimeter of the ROBOT withing the BUMPER ZONE... to provide flexibility in design options...
there u go!
waialua359
11-01-2008, 02:15
why so early? its only 9:15pm....
Hawaii time.:D :D
why so early? its only 9:15pm....
Hawaii time.:D :D
Because I'm in California. =p
So basically, to be safe, 3 sides of your robot... assuming its a rectangular robot. :rolleyes:
Sunshine
11-01-2008, 07:04
Another question and answer on bumpers just for clarification.
Rules say that bumpers need to 2 1/2 inches from floor and 5" tall. What if I do not want a chassis that is 7 1/2" tall from the chassis? I'm assuming that I can have the bumpers above the chassis walls/sides if I want. Is this correct?
I may have to go to Q&A on FIRST.
That would be correct. As long as the bumpers are in the bumper-zone space, you can put your chassis and effectors wherever you please.
I think the reasoning behind the super-defined bumper zone is to keep all contact at the same level and create a "safe zone" for the more fragile components such as manipulators.
65_Xero_Huskie
11-01-2008, 10:49
So basically, to be safe, 3 sides of your robot... assuming its a rectangular robot. :rolleyes:
This was the general rule last year. As long as you have 3 sides covered, you wont have any issues with the judges.
This was the general rule last year. As long as you have 3 sides covered, you wont have any issues with the judges.
There was no rule in place last year requiring teams to have bumpers.
Do the bumpers have to surround the frame/base of the robot completly, or can there be a gap? My team has looked at the rules, and everyone interprets it slightly differently. Anyone know??
To answer your original question - yes, there can be gaps as long as you cover 2/3 of the perimeter, and no bumper segment can be less than 6" long.
Elgin Clock
11-01-2008, 11:30
With a give maximum sized robot of 38" x 28" giving us:
((38*2) + (28*2)) = 132" perimeter
2/3 of 132" = 88"
Technically I guess you can only cover 88" worth of sides if you wanted to.
Some people tend to cover just 3 sides of their robots so using the 2 most basic configurations of robot design...
1) 38+38+28 = 104" of Bumper (38" Sides & 28" Rear)
or
2) 28+28+38 = 94" of Bumper (28" Sides & 38" Rear)
In configuration 1, you are good.
In configuration 2, you are good as well.
Specifically, the rule states that a STANDARD bumper as defined in Fig. 8-1 must be no shorter than 6 inches. Since they also do not want "hard" bumpers in the corners, you must place a vertical pool noodle to soften the corners of the side or front bumpers such that it covers the corner.
The extra vertical pool noodle that isn't part of the STANDARD bumper cannot count toward the minimum 6 inches. Though it is unfortunate, this is the only interpretation of this rule I can come up with.
With a give maximum sized robot of 38" x 28" giving us:
((38*2) + (28*2)) = 132" perimeter
2/3 of 132" = 88"
Technically I guess you can only cover 88" worth of sides if you wanted to.
Some people tend to cover just 3 sides of their robots so using the 2 most basic configurations of robot design...
1) 38+38+28 = 104" (38" Sides & 28" Rear)
or
2) 28+28+38 = 64" (28" Sides & 38" Rear)
In configuration 1, you are good.
In configuration 2, you are not.
If you design your robot to be a wide base (example 2), and your widest part of your robot is facing forward, and you leave that unbumpered, I guess you are breaking a rule.
That kinda sucks...
Hey Elgin, try doing that math again on #2.
Elgin Clock
11-01-2008, 11:40
Hey Elgin, try doing that math again on #2.
Oops.. bad typo! LOL Thanks, I'll go back and edit that.
Jon Stratis
11-01-2008, 11:45
Specifically, the rule states that a STANDARD bumper as defined in Fig. 8-1 must be no shorter than 6 inches. Since they also do not want "hard" bumpers in the corners, you must place a vertical pool noodle to soften the corners of the side or front bumpers such that it covers the corner.
The extra vertical pool noodle that isn't part of the STANDARD bumper cannot count toward the minimum 6 inches. Though it is unfortunate, this is the only interpretation of this rule I can come up with.
Can you quote the rule stating that you "must" use a vertical pool noodle on the corners? I've looked and can't seem to find it anywhere...
Elgin Clock
11-01-2008, 12:00
Can you quote the rule stating that you "must" use a vertical pool noodle on the corners? I've looked and can't seem to find it anywhere...
There is nothing requiring that a vertical pool noodle be used in the corner, but because the only thing that can be used in the corner is a pool noodle or cloth piece of bumper (and not wood, or other "hard" materials), most teams cut a pool noodle the height of a bumper and stand it up in the corner.
Figure 8-2 on page 10 of THE ROBOT shows exactly the scenario I am describing in the top left corner of the view of the robot on the left.
"If needed, a pool noodle corner can be wrapped into bumpers - but only pool noodles & cloth may penetrate corner space"
And lower left on the image....
"hard" bumper parts do not extend into the corners."
Basically what this is saying is that you can not "miter joint" the wood going around your robot behind your bumpers.
I'll try and get a good picture of what we have done and has been accepted in the past with these rules (which have not changed much, if any over the years of bumpers - other than the REQUIREMENT to have them this year as opposed to previous years.
GaryVoshol
11-01-2008, 12:07
... you may place a vertical pool noodle to soften the corners of the side or front bumpers such that it covers the corner.
The extra vertical pool noodle that isn't part of the STANDARD bumper cannot count toward the minimum 6 inches. Though it is unfortunate, this is the only interpretation of this rule I can come up with.
Fixed your post.
The note in Figure 8.2 says, "if needed, a pool noodle corner can be wrapped into bumpers - bou only pool noodle and cloth may penetrate the corner space"
Yea my bad. The point of the post was to clarify that the vertical pool noodle isn't part of a standard bumper by definition, therefore the vertical pool noodle should not be used in the 6" minimum dimension. I've thought about this several times due to the fact that our team this year is going with an open-front design and due to the nature of the bumper rules we unfortunately cannot have bumpers on the front, at all.
Brandon Holley
11-01-2008, 13:01
Heres a quick question:
What if one were to put bumpers on their robot in such a way that they fit all regulations and made contact within the bumper zone, but also extended below the 2.5" mark??
If it was below 2.5" it would not fit regulations.
The Lucas
11-01-2008, 16:11
Another question and answer on bumpers just for clarification.
Rules say that bumpers need to 2 1/2 inches from floor and 5" tall. What if I do not want a chassis that is 7 1/2" tall from the chassis? I'm assuming that I can have the bumpers above the chassis walls/sides if I want. Is this correct?
I may have to go to Q&A on FIRST.
Here is something to keep in mind for mounting bumpers in general, but especially on shorter bots:
Make sure that your standard bumpers can simply and securely attach to your chassis in the bumper zone with reasonably sized fasteners. Incorporate the bumpers into your design, don't wait till the last minute to to find a way to attach them.
As an inspector last year, I saw 1 or 2 teams that needed some sort of metal bracket to fit the bumpers in the right place vertically. The teams thought these brackets would be counted in the weight of the bumper, but the brackets are part of the chassis and counted against the weight (and size) of the robot. Many other teams simply mounted the bumpers several inches outside of the bumper zone (between 2.5" and 8.5") because that was where it fit easily on their chassis.
With bumper requirement this year many teams will be building them for the first time. Don't make bumpers an afterthought because unlike last year you can't just take them off if they don't meet requirements.
Our design calls for bumpers around the entire perimeter of a rectangular shaped robot and our design is such that the bumpers could be constructed (fastened together) as a single assembly with with either an overlap of the plywood in the corners and/or an angle bracket behind the plywood in the corners. If we did an overlap of the plywood in the corners would be be violating the no hard part of the bumpers may extend into the corners rule? If we rounded the outside corner of the plywood overlap so that no hard part of the bumper extends more than one inch beyond the robot frame would we be violating the rule? If we left the plywood completely out of the corners and fastened the segments together with an L bracket from behind would we be violating the rule?
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