bumpers for interior perimeter

[cbeavers6790]

we were planning to have a cut out in the front of our frame to allow for our grasping mechanism ot be dropped to the ground. Will we need bumpers inside the cutout? now i dont thinks we do but i just want to make sure

[tim-tim]

As stated in <R07> you will need bumpers to cover the entire bumper perimeter. Please look at how bumper perimeter is defined in section 1.6.

BUMPER PERIMETER – the polygon defined by the outer-most set of exterior vertices of the BUMPERS when they are attached to the HOSTBOT. (To identify the BUMPER PERIMETER, wrap a string around the BUMPERS at the level of the BUMPER ZONE - the string describes the polygon.)

This being said, you can have a cut out if you would like, but the bumpers will still be in the way.

[GaryVoshol]

Originally Posted by cbeavers6790

we were planning to have a cut out in the front of our frame to allow for our grasping mechanism ot be dropped to the ground. Will we need bumpers inside the cutout? now i dont thinks we do but i just want to make sure

No, you will not need BUMPERS inside the cutout. But you will need a BUMPER spanning the cutout, and the cutout cannot be more than 8 inches wide. See <R07> A and K, including Figure 4-3.

[Sunshine]

"and the cutout cannot be more than 8 inches wide. See <R07> A and K, including Figure 4-3."

I believe that your interpretation is incorrect. <R07> and the corresponding pictures is describing the backing needed for the bumpers.

[GaryVoshol]

Originally Posted by Sunshine

"and the cutout cannot be more than 8 inches wide. See <R07> A and K, including Figure 4-3."

I believe that your interpretation is incorrect. <R07> and the corresponding pictures is describing the backing needed for the bumpers.

Can you explain how I misinterpreted this?

Originally Posted by <R07-K>

The BUMPER backing must be supported by the structure/frame of the ROBOT (i.e. the gap between the backing material and the frame must not be greater than 1/4” and no section of BUMPER greater than 8” may be unsupported).

[Sunshine]

Here are the sound bites you should be thinking about that pertain to the discussion.

BUMPER PERIMETER – the polygon defined by the outer-most set of exterior vertices of the BUMPERS when they are attached to the HOSTBOT. (To identify the BUMPER PERIMETER, wrap a string around the BUMPERS at the level of the BUMPER ZONE - the string describes the polygon.)

If implemented as intended, a ROBOT that is pushed against a vertical wall in any STARTING CONFIGURATION will always have the BUMPER be the first thing to contact the wall

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. For adequate protection,

BUMPERS segments must have a minimum length of six inches

BUMPER – an assembly designed to attach to the exterior of the HOSTBOT and constructed as specified in Section 3.4.2, Bumper Rules.

[EricH]

Gary, Figure 4-3 clearly shows that a gap of 1/4" or less can go longer than 8" long, and a gap of less than 8" can go deeper than 1/4". Two separate parts are marked OK that are either longer than 8" or deeper than 1/4".

So either the rule is not written clearly or the pictures are wrong. Assuming the Figure 4-3 is right, the rule should really read something like, "Any gap that is deeper than 1/4" && wider than 8" will be considered unsupported." If the figure is wrong, all three marked areas are illegal.

[GaryVoshol]

The cutout as described by the OP is an unsupported section of the BUMPER. Thus it is limited to 8".

I can see the disconnect between the written rule and the picture, and why my post might be misunderstood. I believe the GDC considers a bumper with 1/4" or less gap to be a supported bumper, not unsupported.

[dodar]

So if i have a gap in between my drivetrain side plates that is about 4.75 inches across and 4 inches deep but still have an entire front bumper that goes all the way across, that is legal?

[GaryVoshol]

Originally Posted by dodar

So if i have a gap in between my drivetrain side plates that is about 4.75 inches across and 4 inches deep but still have an entire front bumper that goes all the way across, that is legal?

According to figure 4-3, Yes. According to the text, ???

[EricH]

Yep, unsupported needs to be that short--and spanned by bumpers is going to make life very interesting for those that were around in 2007.

dodar, the answer would be Yes, legal, assuming I'm reading the rule correctly. It's less than 8" across, even though it's more than 1/4" deep.

[cbeavers6790]

so lets say i have a gap that is less than 8 inches long but more than 1/4 inch deep. there will be bumpers on each side of the cutout but i cannot put bumpers in front of the cutout beucase that is where the grasping mechanism must go to fit inside the dimensions of the starting robot is this illegal or not?

[EricH]

Originally Posted by cbeavers6790

so lets say i have a gap that is less than 8 inches long but more than 1/4 inch deep. there will be bumpers on each side of the cutout but i cannot put bumpers in front of the cutout beucase that is where the grasping mechanism must go to fit inside the dimensions of the starting robot is this illegal or not?

Your frame perimeter is not 100% protected. Therefore, you are in violation of <R07-A> and will not be allowed to compete until there is 100% protection of the frame perimeter.

[Sunshine]

I guess we'll just have to agree to disagree until Q&A starts up and answers this question. I believe that they can have the cut out. An open space would not make contact with a vertical wall LOL

I'd have to go back to the archives but I do not see the rule being much different than 2 years ago when when cut outs were permitted.

I believe that a few teams that plan on using forklift type mechanisms are planning on having a cutout so they can pick up parts from the floor. Only a guess.

[GaryVoshol]

Originally Posted by Sunshine

I guess we'll just have to agree to disagree until Q&A starts up and answers this question. I believe that they can have the cut out. An open space would not make contact with a vertical wall LOL

I'd have to go back to the archives but I do not see the rule being much different than 2 years ago when when cut outs were permitted.

The rules changed significantly.

Originally Posted by 2008 Rule <R08>

STANDARD BUMPERS must protect a minimum of 2/3 of the perimeter of the ROBOT within the BUMPER ZONE.

Originally Posted by 2011 Rule <R07-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.

See the difference?