robot design question

so, we’re trying to figure out if it’s legal to design the bot so part of the trailer would be within the robot’s dimensions, kind of like something between a fork. Can’t find anything in the rules. Help?

<R18> To attach the TRAILER to the ROBOT, TEAMS must use a Trailer Hitch constructed from
materials provided in the 2009 Kit Of Parts. Details on the construction of the Trailer Hitch
are provided in Drawing “GE-09040.”

There it is, so if your design includes that then I don’t think it’s a violation.

what we had thought up was something like a shape, with the trailer hitch in the middle of the vertical section in between the ‘prongs’.

Just found this too:

D. The Trailer Hitch must be located on an outer edge of the ROBOT structure such that it may
easily connect with the tongue of the TRAILER (attached to the TRAILER).
E. The Trailer Hitch must be placed such that, as the TRAILER swings from side to side, the
first contact between the TRAILER and ROBOT is BUMPER-to-BUMPER and not TRAILER-
tongue-to-BUMPER (to prevent placing excessive stress upon, and possibly damaging, the
TRAILER tongue). See Figure 8-6.

This is all under <R18> so look at that once more, if there are no violations in your design I say it’s all good.

<r18> section D says outer edge, technically the inside of a bracket would be inside edge, thus illegal.

oh well.

Well if it’s up vertically and attached, will that allow it to swing side to side, because it has to do that.

Oh w8 look at this:

B. The Trailer Hitch must be rigidly attached to a fixed location on the ROBOT, **with the long
dimension of the Trailer Hitch horizontal **and the opening of the C-channel facing away from
the ROBOT. The horizontal center line of the Trailer Hitch must be 2-13/16 inches above
the floor.

If you are planning a vertical fork it won’t work

i’ll try and get a 3d image of what i’m talking about.

The dimensions of the trailer with bumpers range from approximately 34" (distance between midpoints of opposite sides) to 39" (distance between opposite corners). This would make it near-impossible to fit within a U-shape, as each side of the U could only be 2 inches wide.

Also note that the trailer tongue protrudes about 10" from the trailer, so you would not be able to achieve a tight fit.

B. The Trailer Hitch must be rigidly attached to a fixed location on the ROBOT, with the long
dimension of the Trailer Hitch horizontal and the opening of the C-channel facing away from
the ROBOT. The horizontal center line of the Trailer Hitch must be 2-13/16 inches above
the floor.

Also note that you may not move the hitch mount after the match has started.

http://img296.imageshack.us/img296/1382/imagexw6.png

image is top view, and not to scale completely, but you get the general idea.

The question is “Is this legal?”. In so far as what constitutes an “outside” edge. The rule’s not completely unambiguious about this. Can parts of the robot “wrap around” the trailer so to speak? Would we be allowed to make a design that limits the lateral movement, through the placement of the hitch alone and no other modifications, of the trailer, assuming that trailer to robot contact is still going to be bumper-to-bumper?

EDIT: also, this design won’t ever see field time, I kinda wanna keep the real one hidden, so just imagine that the trailer isn’t as engulfed as it is here. The same questions apply, though.

I’ve been doodling that all day with a scale and dimentions, and with the size restrictions, its possible, but hard. If you do, as you sketched, you’re in the clear, but there is a rule about the trailed bumper and your robot 's contact, its clearly stated in <R18>.

So long as the trailer only contacts the robot bumper to bumper, it’s legal, then.

Alright.

I think what you are talking about is this. (16"x36" contact base)

http://img301.imageshack.us/img301/8693/firstblocking3tp5.jpg
http://img301.imageshack.us/img301/8874/firstblocking2og9.jpg
http://img301.imageshack.us/img301/7093/firstblocking4ha6.jpg
http://img301.imageshack.us/img301/1378/firstblockingsi4.jpg

The red areas are the “blocking spaces where balls can’t be thrown. All measurements are ballpark (within 1-2” accurate, Proof of Concept)

The robot fits in the “box” and hugs at least half of the trailer. Weight issues might be a problem, but if you make the shroud light enough and place the batteries and heavy stuff in front you might be OK.

A neat design, nice drafting in the short time since kickoff.

My $0.02 is that with such a design, and the way it effectively eats your entire size envelope, you cant hopper up the balls to bring them to your human players more effectively, and you can’t really fit a launcher in there either, meaning two key ways of scoring are severely hindered… not sure if its a net gain or not.

EDIT: also, the CoG being off center like that could make you easily tippable/have problems with moving on this already difficult to move on surface.

Furthermore, strategies like this will just make the human players go for your teammates goals, since they’re wide open they’re more likely to score there, rendering the protection they give more or less redundant.

Are those short segments adjacent to the trailer proper 6" minimum lengths? (You count the plywood, not the foam.)

Is 2/3 of the BUMPER PERIMETER enclosed by bumpers? I think so, if the short pieces are at least 6".

BUMPER PERIMETER is defined by the outermost corners of the robot. The “outer” location for the trailer hitch is not defined.

I see one problem with this design concept with the way I am reading R11.
The width is defined as a max of 28 at the start and during the match. The way I am reading this rule, you can’t construct a ‘wide-body’ robot. Does anyone else see this the same way I do?

“<R11>At the start of, and during, the MATCH the ROBOT shall fit within the dimensions listed below:
Width Maximum 28 inches (71.12cm)
Depth Maximum 38 inches (96.52cm)
Height Maximum 60 inches (152.40cm)
Weight Maximum 120 pounds (54.43Kg)”

Is width and depth defined in any particular direction relative to the robot travel?

Rule <R80> defines width and depth in the opposite directions for the driver station, 60" wide by 12" deep.

That’s the magic question in my book…
I was comparing to the language from the 2008 manual, where R11 reads:
“Prior to the beginning of the MATCH, the ROBOT shall be placed in a STARTING CONFIGURATION that fits within the dimensions listed below: (with the exact same chart as this year)”

It seems to me the language in that opening sentence this year may be more restrictive to what length and depth are, not just restricting the overall size of the robot during the match. Perhaps it’s a good question for Q&A.

I haven’t seen anything that prevents your robot from having “sideways” wheels so that it travels “left” and “right” instead of “forward” and “backward”, and the trailer hitch isn’t required to be mounted on the “back” of the robot.

So even if the front of the robot is defined as the narrow side, the rules don’t seem to make you put that front facing away from the trailer.

I’m inclined to start leaning your way Alan. Mind you the ONLY info I have right now is from the 2008 Q&A, but last year’s manual had the same sizing chart and the wide body orientation was allowed in the Q&A in 2008. Should prob still be asked this year, but carry on with the wide design ideas…