Appendage Rules

[jeremy5561]

I'm not sure about the rules on arms for robots competing the the 2012 FRC competition. I know robots are allowed to extend one arm at a time, up to 14 in beyond frame perimeter. My team's robot is near its maximum length. Can we extend appendages beyond our maximum length?

[nitneylion452]

Yes. The 14" is beyond the end of your frame perimeter. Your frame perimeter may be up to 28x38 and you can extend an appendage up to 14" beyond that.

For more discussion of this rule, look at this thread:

http://www.chiefdelphi.com/forums/showthread.php?t=100696

[wilhitern1]

14 inch from the nearest point on your frame is a vertical plane (or more accurately envelope). If you are within the envelope, you are legal. Otherwise not. As far as length goes. So if you start extending at on corner of your frame, diagonally towards the opposite corner of the envelope. You can extend a fairly long distance. Much longer than 14 inches. But if you penetrate the envelope, you become illegal. You'll have to indicate to the inspectors how you intend to avoid that.

[PAR_WIG1350]

14 inch from the nearest point on your frame is a vertical plane (or more accurately envelope). If you are within the envelope, you are legal. Otherwise not. As far as length goes. So if you start extending at on corner of your frame, diagonally towards the opposite corner of the envelope. You can extend a fairly long distance. Much longer than 14 inches. But if you penetrate the envelope, you become illegal. You'll have to indicate to the inspectors how you intend to avoid that.

Rule# or Q&A please.

The rules could also be interpreted to say that the envelope has 14" radius arcs in the corners, or that you can't extend into corners and that you have to stay within perpendicular boundaries extending from each side.

[wilhitern1]

Rule# or Q&A please.

The rules could also be interpreted to say that the envelope has 14" radius arcs in the corners, or that you can't extend into corners and that you have to stay within perpendicular boundaries extending from each side.

The rule numbers have been clearly listed in the thread below, so I won't waste the time on that.

The radius arcs I believe to be completely Valid. Not extending into those arcs I believe to be completely hokey.

However, if you want anything other than an opinion, you must post your own Q&A.

[EricH]

The rule numbers have been clearly listed in the thread below, so I won't waste the time on that.

The radius arcs I believe to be completely Valid. Not extending into those arcs I believe to be completely hokey.

However, if you want anything other than an opinion, you must post your own Q&A.
I don't see any rule numbers in this thread. The linked thread has to do with defining an appendage and making it so it's legal all the time. Please do post the rule numbers.

If you go into the corner, you are at risk of crossing 2 edges of the frame perimeter at the same time. See [G21] for the penalty this situation. This would bar any devices in the corners unless they go out one side and twist/extend into place.

[wilhitern1]

I don't see any rule numbers in this thread. The linked thread has to do with defining an appendage and making it so it's legal all the time. Please do post the rule numbers.

If you go into the corner, you are at risk of crossing 2 edges of the frame perimeter at the same time. See [G21] for the penalty this situation. This would bar any devices in the corners unless they go out one side and twist/extend into place.

Sorry to have taken so long Eric,

[G21]

Robots may extend one appendage up to 14 in. beyond a single edge of their frame perimeter at any time.

There is no specification of any direction that should be measured from nor any point on the frame. Therefore, I choose the one most
advantageous to my self. Without specifications, that is the most appropriate and also tends to be how inspectors do it [IMO, but I do understand that my O is not necessarily all that good]...

So far, I can find no update that references G21. I could be wrong, but I don't think so.

Additionally the following question and answer seem to me to bear this out:

Q. What is the width limit of an appendage? Can an appendage cross the line drawn as an extension of a perimeter edge that
is perpendicular to the base edge that the appendage is crossing? FRC0053 2012-01-15
A. There is no explicit width limit for a Robot appendage. Per Rule [R21], "Robots may extend one appendage up to 14 in. beyond
a single edge of their Frame Perimeter at any time."

[PAR_WIG1350]

Additionally the following question and answer seem to me to bear this out:

Q. What is the width limit of an appendage? Can an appendage cross the line drawn as an extension of a perimeter edge that
is perpendicular to the base edge that the appendage is crossing? FRC0053 2012-01-15
A. There is no explicit width limit for a Robot appendage. Per Rule [R21], "Robots may extend one appendage up to 14 in. beyond
a single edge of their Frame Perimeter at any time."

Actually, it appears to be saying that the corners are entirely off limits. the question asks if an appendage can cross the fame at one edge then cross the imaginary extension of another. The Answer seems to be hinting (why can't they just tell us instead of giving vague hints?) that this would be illegal. Further clarification might be necessary.

[wilhitern1]

Actually, it appears to be saying that the corners are entirely off limits. the question asks if an appendage can cross the fame at one edge then cross the imaginary extension of another. The Answer seems to be hinting (why can't they just tell us instead of giving vague hints?) that this would be illegal. Further clarification might be necessary.

That is definitely not how I read it. Feel free to put a question in Q&A however...

[nitneylion452]

Sorry to have taken so long Eric,

[G21]

Robots may extend one appendage up to 14 in. beyond a single edge of their frame perimeter at any time.

There is no specification of any direction that should be measured from nor any point on the frame. Therefore, I choose the one most
advantageous to my self. Without specifications, that is the most appropriate and also tends to be how inspectors do it [IMO, but I do understand that my O is not necessarily all that good]...

So far, I can find no update that references G21. I could be wrong, but I don't think so.

Additionally the following question and answer seem to me to bear this out:

Q. What is the width limit of an appendage? Can an appendage cross the line drawn as an extension of a perimeter edge that
is perpendicular to the base edge that the appendage is crossing? FRC0053 2012-01-15
A. There is no explicit width limit for a Robot appendage. Per Rule [R21], "Robots may extend one appendage up to 14 in. beyond
a single edge of their Frame Perimeter at any time."

The intent of this question seems to be to ask if it is okay for the outer most extension of an appendage can cross the horizontal projection of the frame perimeter. Meaning that the appendage doesn't cross 2 physical edges of the frame perimeter, but it passes the plane of the frame perimeter. Can anyone from team 53 confirm/deny this?

A corner is an intersection of 2 edges and crossing over the corner would most likely constitute crossing 2 edges simultaneously, which is a penalty under [G21].

[wilhitern1]

The intent of this question seems to be to ask if it is okay for the outer most extension of an appendage can cross the horizontal projection of the frame perimeter. Meaning that the appendage doesn't cross 2 physical edges of the frame perimeter, but it passes the plane of the frame perimeter. Can anyone from team 53 confirm/deny this?

A corner is an intersection of 2 edges and crossing over the corner would most likely constitute crossing 2 edges simultaneously, which is a penalty under [G21].

Please feel free to ask the question on Q&A. I personally am satisfied that it is not intended that way and that it will not be judged that way.

[EricH]

Please feel free to ask the question on Q&A. I personally am satisfied that it is not intended that way and that it will not be judged that way.
If you personally are satisfied, but the refs and inspectors are not, then you will need to redesign if you can't show the Q&A ruling.

So why don't you ask the question on Q&A? You have a team account. If there are several people saying that you could easily be wrong, and some of them are inspectors/refs, or have long experience reading and interpreting the rules, then maybe you need to think about your design a bit.

[LinuxArchitect]

The intent of this question seems to be to ask if it is okay for the outer most extension of an appendage can cross the horizontal projection of the frame perimeter. Meaning that the appendage doesn't cross 2 physical edges of the frame perimeter, but it passes the plane of the frame perimeter. Can anyone from team 53 confirm/deny this?

A corner is an intersection of 2 edges and crossing over the corner would most likely constitute crossing 2 edges simultaneously, which is a penalty under [G21].

Yes, I was trying to ask if there was a width limit for an appendage. I now believe there is a limit based on answers to questions in [R-02]; you can't cross a second projected edge of your robot's frame perimeter (my words). If you have a rectangular frame, the width limit is thus the width of the side you cross. I don't know what they would rule for a round robot.

It would have been much cleaner if they had simply defined a horizontal envelope as they have in past years, e.g. 56x66 or 28x38 + 14 in any one direction at a time. IMHO, the "can't cross a second perimeter edge" language is confusing when they define the perimeter as the path made by a piece of string stretched around the frame. Obviously, I'm only crossing that string on one side. But whatever. Since we'll have a rectangular frame, I'm confident I know the limits of the appendages.

[wilhitern1]

Yes, I was trying to ask if there was a width limit for an appendage. I now believe there is a limit based on answers to questions in [R-02]; you can't cross a second projected edge of your robot's frame perimeter (my words). If you have a rectangular frame, the width limit is thus the width of the side you cross. I don't know what they would rule for a round robot.

It would have been much cleaner if they had simply defined a horizontal envelope as they have in past years, e.g. 56x66 or 28x38 + 14 in any one direction at a time. IMHO, the "can't cross a second perimeter edge" language is confusing when they define the perimeter as the path made by a piece of string stretched around the frame. Obviously, I'm only crossing that string on one side. But whatever. Since we'll have a rectangular frame, I'm confident I know the limits of the appendages.

Which would indicate that you can't cross any edge if you have a circular robot...

[wilhitern1]

If you personally are satisfied, but the refs and inspectors are not, then you will need to redesign if you can't show the Q&A ruling.

So why don't you ask the question on Q&A? You have a team account. If there are several people saying that you could easily be wrong, and some of them are inspectors/refs, or have long experience reading and interpreting the rules, then maybe you need to think about your design a bit.

I'd sure like to just to make this go away, but our account doesn't work and no one (at least no one in charge) is interested enough to fix it.

Secondly, our robot doesn't even do that, so it has no bearing on us...

[wilhitern1]

And yes, GDC should have put a picture in the rules. They did it for bumpers. Why not this...