Al's 2016 Inspection Thread

[Jimmy Nichols]

Originally Posted by frcguy

We ripped ours too just practicing, no robot-robot contact, although we are using the standard RoboPromo stuff that came in the KOP.

Checking the interweb:

The Robopromo super slick material is a 70 Denier Nylon

The AM Slick is a 200 Denier Nylon

[BrendanB]

Originally Posted by Wayne Doenges

I'm a little disappointed in the AM bumper material. Just in practice we have managed to rip the fabric

We ripped our bumpers up on Saturday at the Week Zero event using the AM slick bumper material. The fabric cut right along the edge of the plywood. The small lexan walls on the batter were what caused the rips since it is so easy to drive up on top of them.

We are going to remake them using the tougher cordura and put thin aluminum angle along the bottom edge to protect the fabric in accordance with the rules. I would highly recommend teams consider doing this before you end up with a serious tear like ours.

[Al Skierkiewicz]

Nate,
Think from the other side of the discussion...
"If I can't cover 8" from the corner than I don't have to use bumpers on that side."
That is one thing the GDC does not want. In the past this dimension has often been 6". This year due to the game, the dimension was changed to 8". In my opinion it is pretty obvious that was decided to give a greater challenge to designers.

[orangemoore]

Originally Posted by Al Skierkiewicz

Nate,
Think from the other side of the discussion...
"If I can't cover 8" from the corner than I don't have to use bumpers on that side."
That is one thing the GDC does not want. In the past this dimension has often been 6". This year due to the game, the dimension was changed to 8". In my opinion it is pretty obvious that was decided to give a greater challenge to designers.

Al,

I just checked the manuals from 2012 until now and they had the minimum set for 8". Maybe I'm missing what you are saying but it would appear this rule has been set like this for awhile.

[engunneer]

It's been 8" for a long time.

The other point trying to be made is that there is no configuration of a 16" or shorter side that doesn't require the entire side to be covered. It is the logical consequence of 8"from each corner needing covering. Another way to say it is that all frame sides greater than 16" require at least 16" of total bumper on that side in addition to the 8" from each corner.

The wording of the rule for "sides less than 8"" could also be written "sides less than 16"" without changing any actual bumper requirements.

[Al Skierkiewicz]

"Long time" is a relative term when you have been around since 1996. The rule was 6" in 2011.

[GeeTwo]

My understanding is that the "shorter than 8 inch" rule was placed there to explicitly allow sides shorter than 8 inches (and require that they have bumpers). Without this rule, you couldn't have a (for example) four-inch long side because you could not then put 8 inches of bumper extending from each corner without violating other bumper rules limiting extension of hard and soft parts away from the frame perimeter.

[bkahl]

Originally Posted by JohnBoucher

Thanks Al.

Bumpers are bumpers, it's shouldn't be this hard!

With 2 years of rookie teams(~700 IIRC) that have never made bumpers, for some people it IS challenging.

[rich2202]

I usually run the pointy end of a nail across the fabric and see if it rips - jk.

It can be hard to tell. There are some really light weight durable fabrics out there. Expensive, but that is their choice. I usually let the LRI know.

The issue usually resolves itself rather quickly. If it rips during bumper to bumper contact, it isn't durable enough. At some point, you won't be let back on the field until the bumper is fully repaired (not just patched with fabric tape).

[JohnBoucher]

Originally Posted by bkahl

With 2 years of rookie teams(~700 IIRC) that have never made bumpers, for some people it IS challenging.

You are correct. I am from the old school, no bumpers generation.

No bumpers 2004 Youtube

[Daniel_LaFleur]

Originally Posted by Al Skierkiewicz

2. If your FRAME side is less than 8" long, then the entire side must be covered by bumper.
.

Al,

Just out of curiosity, wouldn't it be less than 16" (8" from EACH of the vertices)?

[ratdude747]

Originally Posted by Daniel_LaFleur

Al,

Just out of curiosity, wouldn't it be less than 16" (8" from EACH of the vertices)?

Technically although Al was just quoting the manual there.

[BBray_T1296]

In 2013 our robot hit a defensive robot pretty hard (not by 2014 standards though) and not one, not two, but all four bumpers fell off at the same time. Don't be that robot.

[gpetilli]

Originally Posted by ratdude747

Technically although Al was just quoting the manual there.

I disagree the minimum side is 16". I propose that a side that is 8" long, completely protected by bumpers has bumpers 8" from each vertex. The minimum side is essentially 8" not 16". Of course the other side of each of those vertexes also need a minimum 8" of bumper.

The <8" being completely covered wording was intended to address the "infinite vertexes" case of a circular robot.

I suspect the confusion arises from FRAME PERIMETER sides with concave segments. I agree that a side with a concave segment (aka intake throat) needs a minimum of 16" of fully supported bumpers.

I would also suggest that the term FRAME perimeter is confusing and should be changed to CONVEX PERIMETER or string perimeter. Wheels sticking out past the FRAME are still part of the CONVEX perimeter.

[Jon Stratis]

Originally Posted by gpetilli

I disagree the minimum side is 16". I propose that a side that is 8" long, completely protected by bumpers has bumpers 8" from each vertex. The minimum side is essentially 8" not 16". Of course the other side of each of those vertexes also need at minimum 8" of bumper.

The completely covered wording was intended to address the "infinite vertexes" case of a circular robot.

It also covers cases where a robots side is less than 8". I've seen teams cut the corners off their ROBOT to help with frame perimeter issues, leaving a side of 1-3". Fully cover that side, plus 8" on the other sides of each of those corners along the longer sides.