I see 152.4 cm for max Starting Height but still see the discrepancy in Playing Config dimensions.
RQ
Threads merged.
What is wrong with me?
38 inch robot plus 22 inch extension fits in a 60 inch cylinder. 22 inches seems like enough to get halfway across a 30 inch base.
Surely I am missing something here.
Don,
Your analysis is correct if your robot is <<1in wide otherwise:
Draw a 30 x 38 rectangle. Then draw a 60" diameter circle. Make two points of the robot coincident to the circle … observe. Believe me, it is brutal.
Also remember that due to the bumper rule this year, any mechanism that tried to go all the way to the floor will have to do it around the bumper. You just lost another 3 inches.
Paul
…so maybe our minibots have to be deployed onto the base, find and attach to the tower themselves, and then climb/jump/shimmy…?
Yeah, this one looks a doozy!
You mean like this??
http://i.imgur.com/HVWEt.png
Generously drawn up & provided by Arthur Dutra IV from FRC 228.
So… what’s the issue?
The space in front of the robot is barely enough for an end effector… if you’re building in Inches. 
Maybe FIRST is trying to tell us that metric is the way to go. Really, I can’t blame them…
For reference in addition to the pic up above, it is 18.53" from the front of the bot to the edge of the circle in front of the bot (centrally located to the tangency of course).
Yay design constraints. Gotta love them! ::safety::
And that edge of the circle being 18.53 away is if your manipulator is ~≤1inch wide
Some figures
Width of manipulator measured parallel to the 28" edge of the robot and parallel to the ground
1" manipulator cut off .004"
2" cut of .017"
4" cut off .0667"
6" cut off .15"
8" cut off .268"
10" cut off .42"
12" cut off .606"
…
28" cut off 3.467 (the figure for the standard 28 x 38 bot)
Don’t forget there are at least two other degrees of freedom here… the end effector could extend over the wide dimension of the bot (i.e. wide drive profile), and the bot frame can be smaller than 28 by 38…
Could the original drawing be modified to contain a typical game piece? Beginning to look very dicey for pickup off the carpet. also for extension to get to a peg. They are 14" (?) so effector would not be able to slide anything very far onto one? Five feet never seemed so cramped until now.
Elgin,
There really is no issue. I just wanted people to be aware of this rule and its design implications. I understand the rule’s intent, but its side effect is a really brutal constraint that I want to make sure people understand.
The other point is the metric dimension does not agree with the English dimension. That needs to be fixed.
Paul
Exactly Paul,
The challenge is what it is and we will deal with it but the community needs to spread the word or there will be an inspection nightmare at regionals.
Inspection for compliance with the maximum playing configuration diameter should not be difficult – a tape line on the floor 60" (or 84"?) from a vertical wall should be an adequate gauge, to determine if a robot COULD exceed the limit.
However, as in previous games where such a limit was part of the rules, it will be up to referees to determine when a robot DOES exceed the limit. (See <G40>.)
It’s not that it will be difficult to inspect it’s the fact that teams won’t understand it and build a robot that won’t work in the 60" rule.
You are right.
I hope the clarification comes soon.
Especially those that follow the metric rule. :yikes:
There just went most arm designs! That is what the issue is. :rolleyes: Another year, another funny rule.
As was said, getting the word out about this is going to be important. I just sent an email to the mailing list of local teams, particularly because we have a few new teams and a number of existing teams with all new mentors. Whatever we can do to make sure people know the correct rule will be important.
As a side benefit, this nicely illustrates the need to carefully read the manual and to pay attention to FIRST email updates and the Q&A forum.
Paul, thanks for catching this! I never even paid attention to the metric dimensions (note to self, don’t make that mistake again), and spent hours this weekend wracking my brain for ways to avoid violating the 60" rule. I told a couple of kids their (very creative) arm design was not going to work. Hopefully I can tell them later this week it is back on the table.