How is 54" size limit being inspected?

[dtengineering]

What we can be sure of is that if any two points on the robot are more than 54" apart then they violate the rule.

There are also many machines that clearly are not in violation of the rule.

That leaves some "borderline" machines, but likely not many. It might be easiest to tape off a 54" circle, tangent to a wall, extend the appendage to touch the wall, and then place the robot inside the circle.

Just so long as we don't have that silly hoop back again. What year was it that we had the big hula hoop?

Jason

[Tristan Lall]

Originally Posted by dtengineering

What we can be sure of is that if any two points on the robot are more than 54" apart then they violate the rule.

Unless they're not in a plane perpendicular to the axis of the cylinder....

[tickspe15]

In Portland there was a circle taped on the ground to set the robot in. Then a vertical board was run around the circle to make sure that no part of the robot extended out of the circle. I think they will use the same technique in ellensburg.

[Jon Stratis]

At Lake Superior, there were only a couple robots that warranted measuring - the others were all clearly within the limit. All but one of those measured didn't need any further looking, they clearly had more than an inch to spare with just some quick "napkin math". The other however was close enough that I felt the need to go further... I did a quick (less than 10 mins) CAD mockup with all the inportant critical dimensions to check it out.

[Gregor]

Originally Posted by Jon Stratis

At Lake Superior, there were only a couple robots that warranted measuring - the others were all clearly within the limit. All but one of those measured didn't need any further looking, they clearly had more than an inch to spare with just some quick "napkin math". The other however was close enough that I felt the need to go further... I did a quick (less than 10 mins) CAD mockup with all the inportant critical dimensions to check it out.

I'm just trying to get in an inspector's head, but if a team provided you with a CAD printout, would you have done your quick CAD anyway?

[Jon Stratis]

Originally Posted by Gregor

I'm just trying to get in an inspector's head, but if a team provided you with a CAD printout, would you have done your quick CAD anyway?

If the critical dimensions (length/width of each part, measurements of diagonals) were included on the printout by the CAD software and it was clear that everything fit within the cylinder on the printout, then no, I wouldn't have done my own CAD. I would have verified those critical measurements, however, to ensure that the CAD model was a valid representation of the robot in its maximum playing configuration... often what we design on the computer doesn't exactly match what's built!

[LH Machinist]

At our district event the inspectors used a 54" ID polycarbonate circle. The circle was halved and could be oriented in any direction, I assumed FIRST supplied it.

They used it and even told an inside climbing team they would be penalized if they started outside the pyramid (their climbing mechanism deflected when they went under). They played the elimination matches never leaving the inside of a pyramid.

[rsisk]

Does the 54" cylinder include bumpers?

I was trying to determine this by reading the rules. G23 says the ROBOT must fit within the 54" cylinder.

The definition of ROBOT does not mention bumpers.

The definition of BUMPERS says they attach to the ROBOT.

That would make me think that BUMPERS are separate from the ROBOT and not included in the 54" cylinder for inspection.

[tickspe15]

Yes the 54" rule does include bumpers

[rsisk]

Originally Posted by tickspe15

Yes the 54" rule does include bumpers

Can you tell me how you reach that conclusion?

[Jon Stratis]

Originally Posted by rsisk

Can you tell me how you reach that conclusion?

https://frc-qa.usfirst.org/Question/44/questionlink

Q. Does the 54" diameter cylinder include the bumpers or not. R05 ambiguous.
A. Yes, BUMPERS are considered part of the ROBOT for [G23]. This will be addressed in Team UPDATE - 2013-01-11.

[rsisk]

Yet when weighing the ROBOT, the BUMPERS are excluded from the weight for R05. And all through the rules ROBOT and BUMPERS are mentioned separately.

So only for G23 and G23-1 are BUMPERS considered part of the ROBOT.

OK, that clears things up

[fb39ca4]

Originally Posted by Tristan Lall

Unless they're not in a plane perpendicular to the axis of the cylinder....

Ok, two points projected onto the ground plane then.