Re: FRC 2012: Update #3
 

I regret asking for a simple game manual when it causes this much confusion.

The fact that the GDC didn't include how long the "end of the bumper" is means they probably didn't think about everyone requesting a specific measurable distance. Your robot bumpers need two attachment methods on the left and right side of the wood surface. One single attachment is not going to cut it and you need to spread them out as to get the most support possible.

Re: FRC 2012: Update #3
 

Agreed.

Re: FRC 2012: Update #3
 

This rule about fastening the bumpers was the result of the LRI training. It was noticed that a bumper and backing could extend 7 " into open air and still be legal. The rule as stated means that both sides of the gap must be fastened and no bumper backing can hang free over the gap. I hope that this clears things up.

Re: FRC 2012: Update #3
 

I'm still a bit confused on this. Does this mean that the bumpers need the 2 connecting brackets to be on the very farthest ends of it, or will it be ok as long as the bumper connectors are near the ends of the base, but not exactly at them?

Thanks!

Re: FRC 2012: Update #3
 

There could not be a vaguer update. Looks like we have to put off the fabrication of our chassis until an update defining what the "end" of the bumpers are.

Re: FRC 2012: Update #3
 

More Vague is the expression i believe you were going for, but this is not the english teacher board, nor am I an english teacher ;)

We are using a Kitbot chassis (KISS, especially with a 2nd year team with not a whole lot of practice time), and we already determined that we will need to modify our bumper connection some. All this does is delay our timeline on that (honestly I wasn't going to attack it until our shooter is done, and we need to get it over the front bumper).

Re: FRC 2012: Update #3
 

I would assume the words are interchangeable since "vaguer" is indeed a word according to the Merriam-Webster Dictionary. But you do have a point, "more vague" sounds better.

Nevertheless, this update is VAGUE and is confusing people more than before it was released.... Something an update should NOT do.

Re: FRC 2012: Update #3
 

As long as you don't say "more vaguer" your good. I thought we wanted a concise and precise manual, not a "simple" and nebulous one.

Re: FRC 2012: Update #3
 

Steve (just asking for your interpretation, not an official ruling)-

Is the intention that the bumpers simply be backed their entire length?

The way I first read the rule update I had the corner shaped bumper in mind. So when I read each "end" I read that each side of the corner must be attached. Meaning- you could not attach an angled bumper to a robot just on one side. was this the intention of the update?

-Brando

Re: FRC 2012: Update #3
 

Before this update, it would be very easy to construct a bumper that would pass inspection, but break off completely during the match. Some examples:

You have an open-ended robot. Essentially, it's a big "C". Across the missing side, you have 2 8" bumper segments that are only supported by the corners (since you have have up to 8" of bumper unsupported). When those bumpers take a hit, they'll bend inwards and break off.

You actually have support material behind the entire length of your 8" bumper, but you only have it attached at the corner. Your bumper is at the maximum height (5-10"). Another robot has its bumpers rigidly attached as low as possible (2-7"). When the two robots collide, there's going to be significant upwards force on your bumper due to the height difference in bumpers (in fact, I've heard some talk from some very experienced individuals about the increased possibility of tipping because of this height difference). Now your bumper either swivels up and is sitting at a diagonal outside of the bumper zone, or it breaks off completely.


The point behind attaching both ends to the frame perimeter is to ensure that the bumpers are attached to the robot in a way that will keep them from breaking off or otherwise not working as intended. Yes, I agree with others here that the rule change probably could have been worded better in order to get a similar end affect... but none of us are on the GDC.


PS. When trying to "Save as PDF" on any of the sections, is anyone else getting similar errors to this: "TCPDF ERROR: [Image] Unable to get image: http://frc-manual.usfirst.org/upload/Section1.jpg" I've been seeing that ever since update 2... I've tried on Both Mac and Windows, using IE, Firefox, Chrome, and Safari. While I can still manage to get them to print off in a PDF format using other tools, it then doesn't include the links and navigational aids I want.

Re: FRC 2012: Update #3
 

In case you didn't see it yet, today's Bill's Blog says the save as pdf problem is a known issue and they're working on it.

Re: FRC 2012: Update #3
 

My interpretation is that the bumper backing must be fastened to the robot frame so that minimal (less than an inch) backing goes unsupported and fastened. For example, if you have a gap in your frame that is 20" wide and you robot is 28" wide then to meet the minimum bumper rule, the bumpers must be 8 inches from each of the vertices. That would mean that there would be 4" of each bumper unsupported by the frame. There was no rule to cover this so FIRST says that the bumpers must be supported on each end.

I hope that this was of help but should be checked with Q&A and further team updates.

Re: FRC 2012: Update #3
 

This was covered in rule R28(B):

I think the intent is more along the lines of what Brandon said, to prevent teams from having loose end bumpers. Did any teams in the last couple of years, who built corner or "c" bumpers that weren't supported on all the sides, have them break at the wood joint? If so, this rule makes sense to prevent those bumpers from hanging just by the cloth if they break.

Re: FRC 2012: Update #3
 

That rule only applied to bumpers that were hanging off the end of the robot, not ones that were hanging in the middle of a gap in the frame. The general rule of thumb is "wrap a string around your robot within the bumper zone. That string is your frame perimeter." So any gaps in your frame do not change what the frame perimeter is, and prior to this update you could have up to 8 inches of unsupported bumper that was on the frame perimeter hanging off the edge of a gap. Now you have to make sure the other side is supported as well.

Re: FRC 2012: Update #3
 

This is correct!