Chief Delphi - pic: Bumper idea

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- - pic: Bumper idea - legal? (http://www.chiefdelphi.com/forums/showthread.php?t=82118)

Re: pic: Bumper idea - legal?

Well I guess that answers my question... now we just have to build them :ahh:

Better get to work, I'll be sure to post some pictures when we finish.

Anyone's welcome to use this design (or come up with other methods and post them!), but make sure you follow all the rules and build them robustly. On another note, it's pretty cool our idea made it into a team update...:cool:

Quote:

<R12> The color of the BUMPERS will be used to identify the ALLIANCE to which the ROBOT has been assigned, red or blue. Therefore, each ROBOT must be able to display red BUMPERS and blue BUMPERS. This may be done via either of two acceptable methods:
A. Each ROBOT may be built with two complete sets of interchangeable BUMPERS, one red and one blue. If this method is chosen, the BUMPERS must be identical except for the color of the covering fabric (see Rule <R07-F>).
B. Alternately, the ROBOT may use changeable BUMPER covers. The BUMPER covers
− may be removable, reversible, or fixed
− must completely enclose the BUMPERS
− must show only a single color such that when the BUMPER covers are in use, only fabric of the assigned ALLIANCE color may be visible.
− must be constructed solely of fabric and a fastening/restraining system to hold the cover in place. The fastening/restraining system must extend no further than one inch beyond the FRAME PERIMETER (i.e. no further than any other hard parts of the BUMPER - see Rule <R07-N>). Please note that the fastening/restraining system MUST be designed with robust performance in mind. The restraints must hold the
The BUMPERS may be constructed with a fabric covering of one color (see Rule <R07-F>), and then covered with a removable fabric shroud of the opposite color when appropriate. The removable cover must completely enclose the BUMPERS and conceal the contrasting fabric.
removable cover in place during
February 9, 2010
vigorous interactions with other ROBOTS and FIELD elements during the MATCH without allowing the cover to come off.

But this raises the question of if the stitching is allowed... would it count as "fabric?"

Quote:

must be constructed solely of fabric and a fastening/restraining system to hold the cover in place. The fastening/restraining system must extend no further than one inch beyond the FRAME PERIMETER (i.e. no further than any other hard parts of the BUMPER - see Rule <R07-N>).

Re: pic: Bumper idea - legal?

Quote:

Originally Posted by m^3 (Post 916691)

...But this raises the question of if the stitching is allowed... would it count as "fabric?"

Stitching is used to hem fabric all the time. As long as you use a good strong thread and not something weird like weld rod to stitch the fabric, I can not imagine an inspector who would not allow it.

JMHO,

Mike

Re: pic: Bumper idea - legal?

And the answer to the question...

B. Alternately, the ROBOT may use changeable BUMPER covers. The BUMPER covers
− may be removable, reversible, or fixed
− must completely enclose the BUMPERS
− must show only a single color such that when the BUMPER covers are in use, only fabric of the assigned ALLIANCE color may be visible.

We all win, nice job guys! Take a pat on the back out of petty cash!

Re: pic: Bumper idea - legal?

Quote:

Originally Posted by Chris is me (Post 916336)

Instead of velcro, perhaps a line of several snap fasteners would work better. Same repeatability, a bit more grip.

Caution re: snap fasteners. I think Velcro is a bit easier to work with. Snap fasteners:
--can be tricky to attach. You have to get it right on the first try.
--must be precisely aligned
--can sometimes be difficult to fasten
--often come unsnapped when under stress

There's a reason Velcro has outstripped snap fasteners in popularity. So be sure to experiment and test, test, test with extra fabric and bumper assemblies before committing to using snap fasteners on your competition bumpers.

Thread shouldn't be a problem; use of fabric implies use of thread, even more so than use of aluminum or steel implies use of welding. Thread is not generally regarded as a "fastener" the way buttons, snaps, and Velcro are.

Invisible thread would solve the problem of color matching. Sulky brand invisible thread is nicer to work with than some others, but I don't know if it's as strong. Sewing a second line of stitching over the first line of stitching is a good way to make a strong seam using any kind of thread.

Re: pic: Bumper idea - legal?

You might consider fusible interfacing between the red and blue to keep them laying flat and neat.

Re: pic: Bumper idea - legal?

Quote:

Originally Posted by GaryVoshol (Post 916966)

You might consider fusible interfacing between the red and blue to keep them laying flat and neat.

Stich witch?

Re: pic: Bumper idea - legal?

The other interesting change due to Update #9 is that apparently non-red/blue bumpers are allowed, as long as the covers are red and blue (or reversible red & blue).

Re: pic: Bumper idea - legal?

Quote:

Originally Posted by Tristan Lall (Post 917028)

The other interesting change due to Update #9 is that apparently non-red/blue bumpers are allowed, as long as the covers are red and blue (or reversible red & blue).

I agree. They struck out the wording "constructed with a fabric covering of one color" which was the basis for the base bumper cover having to be red or blue. My reasoning in this previous post http://www.chiefdelphi.com/forums/sh...9&postcount=22 is no longer valid.

Re: pic: Bumper idea - legal?

Quote:

Originally Posted by Tristan Lall (Post 917028)

The other interesting change due to Update #9 is that apparently non-red/blue bumpers are allowed, as long as the covers are red and blue (or reversible red & blue).

Rule <R07-F> has not been changed and is still in force.

.

Re: pic: Bumper idea - legal?

Quote:

Originally Posted by dlavery (Post 917220)

Rule <R07-F> has not been changed and is still in force..

For reference,

Quote:

<R07-F>. The fabric covering the BUMPERS must be solid red or solid blue in color. Visually, the red or blue must be as close to the corresponding color in the FIRST logo as reasonable (i.e. to a reasonably astute observer, they appear similar). The only markings permitted on the BUMPER fabric cover are the team number (see Rule <R15>).

I believe Tristan's comment meant that the bumpers themselves could be any color as long as the covers were the correct Red/Blue. This appears to be supported by the rules as well.

Now if the rule said: "The fabric the bumper is constructed of must be solid red or solid blue in color....." then it would be a different story.

Re: pic: Bumper idea - legal?

Quote:

Originally Posted by billbo911 (Post 917225)

Rule <R07> discusses the bumpers. Rule <R12-B> discusses removable/reversible covers. The changes to Rule <R12-B> in Update #9 do not affect the fact that Rule <R07> still requires that the BUMPERS be a single, solid red or blue color.

Re: pic: Bumper idea - legal?

I think to save everyone the hastle, just make a set of red and blue bumpers, case closed and worry about building the robot.
Seattle Fabrics doesnt have a shortage of those colors. :D

Re: pic: Bumper idea - legal?

Quote:

Originally Posted by dlavery (Post 917238)

OK, in light of BOTH rules <R07> and <R12-B>, I must concede you are correct again.
[Billbo bows in the presence of greatness....again]

(Man, my bald spot is starting to turn red from all the head slaps. Maybe I should read every rule on every detail before I stick my foot in my mouth again.) :o

Re: pic: Bumper idea - legal?

Quote:

Originally Posted by dlavery (Post 917238)

Dave,
Thank you for your thoughts on the matter.

This not being an official FIRST forum, I am asking your opinion, with the explicit understanding that your opinion (possibly expressed here) carries no weight at all as far as inspection, rules, or competitions are concerned. That is, your opinion is not an official communication from FIRST. Just some guy's opinion.

Is it legal to use the idea presented here?

Don
.

Re: pic: Bumper idea - legal?

Dave,
The proposed construction method above would present a single piece/color of fabric to the view of all. A good seamstress would of course use a different color when stitching the fabric so that the red side is stitched in red and the blue side in blue. Numbers would of course have to be present on both sides.