Fasteners extending outside the FRAME PERIMETER

[engunneer]

To illustrate Kevin's (Vikesrock) workaround using Martin's drawing:
If the image Kevin posted shows an illegal configuration? Does this one?

http://picasaweb.google.com/lh/photo...eat=directlink


Also, would the frame perimeter now be defined as the red lines in my drawing, or is it the same as before, because of the bolt head into bumper provision?

[Al Skierkiewicz]

This does appear to be the gist of this discussion. Confusing isn't it?

[martin417]

Team update #6 really confuses the issue. The new wording:

Note: to permit a simplified definition of the FRAME PERIMETER and encourage a tight, robust connection between the BUMPERS and the FRAME PERIMETER, minor protrusions such as bolt heads, fastener ends, rivets, etc are excluded from the determination of the FRAME PERIMETER.

It sounds like the intent is to allow bolt heads, etc, but what it actually says is that they are not allowed. If they are excluded from the determination of FRAME PERIMETER, then, by definition, they extend beyond the FRAME PERIMETER, and are therefore illegal by

<R16> During normal operation no part of the ROBOT shall extend outside the vertical projection of the FRAME PERIMETER, except as permitted by Rule <G30>

(<G30> does not contain an exception to allow bolt heads to extend beyond the frame perimeter).

But <R07> D states that clearance pockets are allowed in the bumper backing for bolt heads etc. I believe the intent of the rule is to allow the bolt heads to extend past the perimeter, but the wording of the rule is very clear that it is illegal, even though clearance pockets for the illegal bolt heads are permitted.

Careful wording of any document that sets rules or guidelines is very important. It should never be open to interpretation. The language in the rules as written is concise, and not open to interpretation. I just believe that it says something different than what the writer intended.

[Al Skierkiewicz]

Martin,
Team Update 6 modifies the definition of the FRAME PERIMETER and as such modifies the rules that reference the definition including R16. My impression then is that fasteners as described in TU6 will not be considered to be outside the FRAME PERIMETER in the bumper zone or elsewhere. The drawings displayed this afternoon in this thread are therefore legal.

[Jones571]

Originally Posted by Al Skierkiewicz

Martin,
Team Update 6 modifies the definition of the FRAME PERIMETER and as such modifies the rules that reference the definition including R16. My impression then is that fasteners as described in TU6 will not be considered to be outside the FRAME PERIMETER in the bumper zone or elsewhere. The drawings displayed this afternoon in this thread are therefore legal.

So now a team can show up to a regional with a robot that wont fit in the box and can still be 100% legal i dont think i envy the inspectors this year

[mikelowry]

Originally Posted by Al Skierkiewicz

Martin,
Team Update 6 modifies the definition of the FRAME PERIMETER and as such modifies the rules that reference the definition including R16. My impression then is that fasteners as described in TU6 will not be considered to be outside the FRAME PERIMETER in the bumper zone or elsewhere. The drawings displayed this afternoon in this thread are therefore legal.

The update does not modify the definition of the FRAME PERIMETER, it simply says that fasteners are excluded from the determination of it. Which essentially means that even the workaround that was mentioned earlier (using identical dummy bolts in the bumper zone to enlarge the frame perimeter to allow bolt heads to protrude below the bumper zone) will not work because the dummy bolts will not define the FRAME PERIMETER. Thus with the current wording no bolts are allowed to protrude from the FRAME PERIMETER in any place.

However, I agree with Martin, that the update was misworded and the intent of the update is to allow fasteners to protrude, even though the update clearly states that no fasteners can protrude anywhere.

[Al Skierkiewicz]

Mike and Corey,
The team update modifies the definition of Frame Perimeter and uses these words...
"minor protrusions such as bolt heads, fastener ends, rivets, etc are excluded from the determination of the FRAME PERIMETER."
It does not modify the sizing rule <R90> nor does it modify the NORMAL CONFIGURATION as it is used in <R10>

<R10> During the MATCH, the ROBOT will assume one of two operating configurations. When in each configuration, the ROBOT shall fit within the limits shown below (note: these limits are defined in reference to the ROBOT, not the FIELD).

NORMAL CONFIGURATION
Max horizontal dimension Rectangular space no more than 28 inches (71.12cm) by 38 inches (96.52cm)
Max Height 60 inches (152.40cm)
Max Weight 120 pounds (54.43Kg)
FINALE CONFIGURATION
Max horizontal dimension 84 inch (213.4cm) diameter vertical right cylindrical volume
Max Height 90 inches (243.8cm)
Max Weight120 pounds (54.43Kg)

So if a robot fastener does not fit within the sizing box which is designed to test the max horizontal dimensions of 28" x 38", the team will need to make some modifications to do so.

[Tristan Lall]

Originally Posted by Al Skierkiewicz

Team Update 6 modifies the definition of the FRAME PERIMETER and as such modifies the rules that reference the definition including R16. My impression then is that fasteners as described in TU6 will not be considered to be outside the FRAME PERIMETER in the bumper zone or elsewhere. The drawings displayed this afternoon in this thread are therefore legal.

Sorry to disagree with you again, Al.... I'm with Martin on this one.

By definition, the frame perimeter is measured within the bumper zone. That hasn't been changed in Update #6. The update only modifies the method by which you identify the frame perimeter. It doesn't modify any of the consequences of exceeding the (newly-defined) frame perimeter. (Such as <R16>, <G30> and by extension, <S04>.)

Rather than allowing some uncertainty about whether a protruding fastener in a pocket was sufficiently protected by bumpers to satisfy <R07A> (it probably would have been), and whether the frame perimeter would have had to follow the contour of that protruding fastener irrespective of the pocketing (this could have been true if the pocketing was intended for use by bumper fasteners only, rather than fasteners in general), I think FIRST opted to simplify everything and give a straightforward method for employing the <R07D> pocketing allowance.

However, with regard to the robot size limit—you're absolutely right. That constrains the total size of the robot, irrespective its frame perimeter.

[martin417]

Originally Posted by Al Skierkiewicz

Martin,
Team Update 6 modifies the definition of the FRAME PERIMETER and as such modifies the rules that reference the definition including R16. My impression then is that fasteners as described in TU6 will not be considered to be outside the FRAME PERIMETER in the bumper zone or elsewhere. The drawings displayed this afternoon in this thread are therefore legal.

I agree that allowing the protrusions was probably the intent of the new wording, however, it was not the result of that wording. If you exclude the fasteners from the determination of the frame perimeter, then said perimeter is defined by the frame members. Anything outside the frame members is, by definition, outside the frame perimeter. There is no wiggle room. It can't be interpreted any other way. The frame perimeter is defined by the outermost vertices on the robot, exclusive of fasteners.

I'm not trying to be a pain, but words do have meanings, and in this case, I don't see any way to read those words except as stated above.

[Al Skierkiewicz]

Tristan,
Team Update 6 is excluding the fasteners from defining the FRAME PERIMETER which in turn defines the vertical plane defined by the same. This ruling makes the determination of G30 easier for the refs, easier for the robot inspectors to determine <R16> and it takes the worry away from teams trying to apply a fix to fasteners that hold the frame together. It is rather an elegant solution, don't you think?

[Tristan Lall]

Originally Posted by Al Skierkiewicz

Tristan,
Team Update 6 is excluding the fasteners from defining the FRAME PERIMETER which in turn defines the vertical plane defined by the same. This ruling makes the determination of G30 easier for the refs, easier for the robot inspectors to determine <R16> and it takes the worry away from teams trying to apply a fix to fasteners that hold the frame together. It is rather an elegant solution, don't you think?

I think Martin provided an excellent summary directly above. By excluding the protrusions within the bumper zone from the frame perimeter, you make the frame perimeter polygon smaller (than it would have been under the original rule). Therefore, if you were relying on a bolt (in the bumper zone) directly above or below another bolt (outside of the bumper zone) to extend your frame perimeter and make the 2^nd bolt legal, you have to make a design change (because the 1^st bolt no longer counts as part of the frame perimeter).

I agree that it makes determination of <R16> and <G30> easier, but only because there's no longer any need to take certain protrusions into account (which could have been hidden behind the bumper and thus especially difficult for referees to call).

I imagine that the hoped-for response would have excluded bolt heads (etc.) located outside of the bumper zone from scrutiny under <R16> and <G30>. That's not the change that the GDC chose to make.

So, with regard to the images posted earlier, Martin's is still illegal, and Branden's is now made illegal. (In both cases, the bolts in the lower frame violate the frame perimeter.)

[Scoutin' Master]

I have to agree, the rule does say that the frame perimeter is not determined by any bolts, fasteners, or rivets protruding from the frame at the bumper level. This would only prevent a team from extending their frame perimeter using dummy bolts, it mentions nothing about bolts outside of the bumper zone. I would have to assume that these would be illegal because of Rule G<30>.

I would try to keep any bolts, fasteners, or rivets that are outside of the bumper zone inside your frame perimeter, just to be safe!

Just my interpretation and $.02!

[MrForbes]

quote from a curious person about this issue:

"another solution is to just put a piece of quarter inch plywood around your frame in the bumper region"

[engunneer]

Originally Posted by Tristan Lall

So, with regard to the images posted earlier, Martin's is still illegal, and Branden's is now made illegal. (In both cases, the bolts in the lower frame violate the frame perimeter.)

I agree with this interpretation. Both drawings are illegal. The axle bolts are outside the frame perimeter.

[mikelowry]

Originally Posted by Al Skierkiewicz

Mike and Corey,
The team update modifies the definition of Frame Perimeter and uses these words...
"minor protrusions such as bolt heads, fastener ends, rivets, etc are excluded from the determination of the FRAME PERIMETER."
It does not modify the sizing rule <R90> nor does it modify the NORMAL CONFIGURATION as it is used in <R10>

<R10> During the MATCH, the ROBOT will assume one of two operating configurations. When in each configuration, the ROBOT shall fit within the limits shown below (note: these limits are defined in reference to the ROBOT, not the FIELD).

NORMAL CONFIGURATION
Max horizontal dimension Rectangular space no more than 28 inches (71.12cm) by 38 inches (96.52cm)
Max Height 60 inches (152.40cm)
Max Weight 120 pounds (54.43Kg)
FINALE CONFIGURATION
Max horizontal dimension 84 inch (213.4cm) diameter vertical right cylindrical volume
Max Height 90 inches (243.8cm)
Max Weight120 pounds (54.43Kg)

So if a robot fastener does not fit within the sizing box which is designed to test the max horizontal dimensions of 28" x 38", the team will need to make some modifications to do so.

We already established that this discussion has nothing to do with the NORMAL CONFIGURATION limitations. I understand that nothing whatsoever (except for the allowance made for a some type of kicker) can extend past the 28x38 footprint while in NORMAL CONFIGURATION. This discussion is about the FRAME PERIMETER. The problem still exists even if you have 12" by 12" robot. Then your FRAME PERIMETER would be decided by your frame members within the bumper zone. Any bolts that protrude from the FRAME PERIMETER, but NOT the NORMAL CONFIGURATION would be "excluded from determination" of the FRAME PERIMETER. Thus, they would extend past the FRAME PERIMETER and be illegal, and they would not allow for identical bolts below the FRAME PERIMETER either.