Re: Bumper question
 

Joe,
The rule does not say that bumpers can only exist on the outside of the Frame Perimeter. It simply says they have to be attached Frame perimeter. If one were to assume that the above diagram had no mounting on the inside of cutout, I find nothing that makes it illegal but I am working on it.

Re: Bumper question
 

I believe the interior bumper is not ok as FIRST wants an 8" 'strike' zone to minimize damage to other machines. Otherwise below would be legal and leave a point that can cause damage to other machines. not to mention the whole 120 lb weight limit.
EDIT: It maybe good for a rule clarification about exterior angles that are less than 90* and thus protruding within the machine.

Re: Bumper question
 

Nate,
The 120 lbs does not apply to the bumpers. Bumpers can weigh up to 20 lbs. As of right now, there is no rule that prevents your drawing from being used. Please expect this to change momentarily.

Re: Bumper question
 

Just want to be really clear here. Since the maximum width of the bot is 28", andy ou need 8" of bumper on each side of that, your very maximum opening on the front is 12"? If you have no frame there, just a gap, does the 8" rule still apply? (Meaning you can't have say an 18" gap with 5" of bumpers on each side?

I would hate for this rule to be interpreted wrong and potentially use an opening 30% smaller than legal.

Re: Bumper question
 

Jared,
Current rules require a minimum of an 8" bumper section on both sides of the corner of the robot. Other parts of the bumper rule(s) cover slots, indents and gaps.

Re: Bumper question
 

<R01>Emphasis mine. In short, a bumper intruding into the Frame Perimeter, as Dr. Joe pointed out, would violate this rule.

Re: Bumper question
 

Samuel,
As I pointed out earlier, the rules specify that the bumper needs to be attached to the exterior of the frame perimeter. It does not say bumpers have to be outside the frame perimeter. I expect this to be clarified in the near future so watch for Team Updates. In 2011 the rule read as follows...

A. BUMPERS must provide complete protection of the entire FRAME PERIMETER of the ROBOT (i.e. BUMPERS must wrap entirely around the ROBOT). As part of the 100% coverage, BUMPERS must protect all exterior corners of the FRAME PERIMETER.

In 2012 the rule reads...

Robots are required to use Bumpers to protect all exterior vertices of the Frame Perimeter. For adequate protection, at least 8 in. of Bumper must be placed on each side of each exterior vertex (see Figure 4?1, Figure 4?2, and Figure 4?3).

Emphasis mine to show the difference. That difference, while slight in 2011 required bumpers around the entire Frame Perimeter, 2012 rules specify that as a minimum the bumpers must cover the exterior vertices. It does not say that interior surfaces cannot also be covered. I believe that the GDC had intended the rule to prevent bumpers on interior openings in the frame. That is why I expect it to be changed at a future date.

Re: Bumper question
 

OK, so per rules as they are stated in rev 00 and 01 this configuration would still be legal but would not meet the intent of having 8" strike zone so the bumper rules are likely to be revised to not allow for such frame?

Also, imagine starting off with a rectangular frame and chamfering two adjacent corners in such way that the chamfer diagonal length was at least 8". If the short wall in between the two chamfers was completely removed to make a ball intake would that satisfy all the rules? Figure 4.2 does not show such configuration. I assume it would also be against the spirit of the rule.

Wait: I think I got it. If the inlet is created by removing a section of straight wall as shown in fig 4.3 it does not create any new verticies for the frame perimeter. If the chamfers are added they will create two new verticies and those need 8" on each side of the vertex.

Re: Bumper question
 

Yes, I think you got it!

Re: Bumper question
 

As you told earlier, the bumpers have to be 2'' to 10'' from the floor. But until where? The bottom of the bumpers or till the higher part of it?

Re: Bumper question
 

"Robots are required to use Bumpers to protect all exterior vertices of the Frame Perimeter"

What if you have no exterior vertices...meaning your robot has a circular frame perimeter?

Re: Bumper question
 

The bumper zone (2-10" off the floor this year) typically is the zone that the bumpers have to be contained within - the top of the bumper can be no more than 10" from the floor, and the bottom no less than 2" from the floor.

Al - wouldn't a team with that design violate R35? I doubt anyone would consider those interior bumpers to be "approximately" 90 degrees from the other 3 sides of the robot!

Re: Bumper question
 

Eagle,
Are you referring to the indented design? If so, should one side of the indent have numerals and they were visible from that side and you circled the robot at 90 degree intervals (assuming the other sides join each other at 90 degrees) then it is conceivable that a robot could meet that rule with visible numerals on the other three sides. I don't know what the GDC had in mind for robot frame design.

As far as circular frame designs, one interpretation could be that the entire frame perimeter was a continuous vertex and therefore the entire frame perimeter needed to be protected by bumper. I would have to ask for GDC guidance for this case, considering the 8" segment length rule in addition to other considerations. You guys are always challenging us.

Re: Bumper question
 

I hate to bring up this discussion once again, but we are having a discrepency within our team. Some people believe that you will be able to split up the 8" of bumper on one side of the robot into two 4" pieces (backed by the frame that is). My interpretation of the rules is that each corner of the robot needs to have 8" of bumper on both sides of it, that is on a normal sized robot, the 28" side of one corner needs 8" minimum of bumper and the 38" side needs 8" also. Since this applies to each corner, the maximum ammount of opening on the short side is 12", correct?

Here is a restatement of the rule in question:

I also attached a diaghram. Please post which side you believe to be correct.

Re: Bumper question
 

Side A, hands down. 'at least 8" on each side of each exterior vertex' is what the rule says; that is what the inspectors are going to call legal.

No questions there.

And yes, the maximum opening (what I think you really meant to say) on the short side is 12" due to the 8". If you want more collection space, use a wide robot.