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-   -   Non-sagging Bumpers Q&A Response (http://www.chiefdelphi.com/forums/showthread.php?t=125384)

AllenGregoryIV 28-01-2014 15:24

Non-sagging Bumpers Q&A Response
 
In previous years I have been on teams and seen teams that have secured their pool noodles to their bumper wood before wrapping them in the outside cover.

I have always thought that it was fine even though it was never mentioned in the rules. It makes construction much easier and it makes the bumpers look nicer.

However when I posted in the Q&A about it this year, the GDC came back with a simple answer, No it's not legal.

Quote:

Q. Is it legal for teams to use tape, shrink wrap, or other soft material to secure the pool noodles to the wood underneath the bumper fabric? In previous years teams have had issues with pool noodles that would sag below the wood.
2014-01-24 by FRC3847
A. No.
This practice has been pretty common on a lot of teams to avoid having sagging bumpers. Will this change how your team makes their bumpers?

Jon Stratis 28-01-2014 15:39

Re: Non-sagging Bumpers Q&A Response
 
The GDC is correct - Tape (most often of the duct variety), shrink wrap, etc are not part of the official cross-section for bumpers - wood, pool noodles, cloth covering, optional angle on the top and bottom, and mounting hardware. I wonder how the GDC would respond to the same question regarding gaffers tape, though? Gaffers tape is classified as cloth, and I know I've borrowed a little from the field in the past to help teams do quick bumper repairs when needed (since the field usually has some red and blue available).

But now that that question is out of the way, I'd like to see the GDC address sagging bumper covers and get consistent ruling on those on the field. It's one of my personal pet peeves when it comes to robots.

Phyrxes 28-01-2014 15:41

Re: Non-sagging Bumpers Q&A Response
 
Makes me glad we planned to have smaller bumper sections this year. Guess its time to shift them up in the bumper zone to account for sag.

AllenGregoryIV 28-01-2014 15:43

Re: Non-sagging Bumpers Q&A Response
 
Quote:

Originally Posted by Jon Stratis (Post 1333759)
The GDC is correct - Tape (most often of the duct variety), shrink wrap, etc are not part of the official cross-section for bumpers - wood, pool noodles, cloth covering, optional angle on the top and bottom, and mounting hardware. I wonder how the GDC would respond to the same question regarding gaffers tape, though? Gaffers tape is classified as cloth, and I know I've borrowed a little from the field in the past to help teams do quick bumper repairs when needed (since the field usually has some red and blue available).

But now that that question is out of the way, I'd like to see the GDC address sagging bumper covers and get consistent ruling on those on the field. It's one of my personal pet peeves when it comes to robots.

I've already asked the follow up question about Gaffers Tape. If they say no to that too then I'll be very confused. What about strips of fabric that are stapled on to the wood and around the noodles before the cover is placed on.

There should be some way to do this without requiring 6 students to try to tug on the fabric while a seventh staples it.

Christopher149 28-01-2014 15:49

Re: Non-sagging Bumpers Q&A Response
 
We've used two strips of tape for several years, and I'm pretty sure that's how our bumpers have already been made. ::rtm::

Hmmm...

Dan.Tyler 28-01-2014 15:52

I've never made a bumper without tape. Might have to disassemble ours tonight...

Nate Laverdure 28-01-2014 15:59

Re: Non-sagging Bumpers Q&A Response
 
Goes to show: don't ask the question if you're unprepared for a disappointing answer.

Michael Hill 28-01-2014 16:04

Re: Non-sagging Bumpers Q&A Response
 
The rigidity of the GDC really bothers me sometimes...

Steven Donow 28-01-2014 16:42

Re: Non-sagging Bumpers Q&A Response
 
I don't know if I've ever seen bumpers made without tape underneath...


Hopefully this answer was just an oversight/quick misinterpretation by the GDC and will be overturned soon...it arguably is a "pointless restriction", ie. you really get no significant competitive advantage by taping down your pool noodles.

Dan.Tyler 28-01-2014 17:03

You can definitely get a competitive advantage if your bumpers are more rigid than others'.

You gain a higher ability to control movement while in pushing matches. If you were to fully laminate your pool noodles with tape or other binding (we've only ever used enough to hold the noodles up, per the spirit of FIRST), you would be able to interact with other bots on a whole new level. Similar, but reduced, results can be found when wrapping heavyweight cloth more tightly vs loose, light cloth.

dellagd 28-01-2014 17:43

Re: Non-sagging Bumpers Q&A Response
 
We've taped out pool noodles to the wood for years now, and sagging has never been an issue. There's no need to over-engineer bumpers :P

Nuttyman54 28-01-2014 17:46

Re: Non-sagging Bumpers Q&A Response
 
Quote:

Originally Posted by dellagd (Post 1333809)
We've taped out pool noodles to the wood for years now, and sagging has never been an issue. There's no need to over-engineer bumpers :P

Yes, except the GDC has just ruled via Q&A that taping the bumpers to the wood is illegal.

Nick Lawrence 28-01-2014 17:46

Re: Non-sagging Bumpers Q&A Response
 
You could also clamp the fabric with some angle or flatbar across the top to aid in keeping it tight.

-Nick

Nuttyman54 28-01-2014 17:50

Re: Non-sagging Bumpers Q&A Response
 
One thing that 971 has been doing for the past few years to keep the fabric tight is using a custom clamp-compression tool:

https://picasaweb.google.com/1177698...07224523241618

https://picasaweb.google.com/1177698...07277222737666

The bumper fabric is stapled while the noodles are compressed, and everything tightens up when the noodles are allowed to expand again.

MrBasse 28-01-2014 18:06

Re: Non-sagging Bumpers Q&A Response
 
We used a loop of fabric this year and it works amazingly better than tape or zip ties ever did in the past. We used two four inch stops on the short side of our robot and three on the long side.


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