need help w/ bumper fastner designs

[chuckmerja]

Both one of my team members and I have tried to post to the FIRST forum re bumpers, as we are VERY concerned about what we are reading there and how it impacts our bumper attachment system.

The first bullet in R08 says "STANDARD BUMPERS must be designed as shown in figures 8-1 and 8-2. This is the only acceptable design for STANDARD BUMPERS." where the image shows a "T" nut attachment - and the rule says ONLY ACCEPTABLE.

Bullet 3 - "STANDARD BUMPERS must be attached to the ROBOT with a boltand-
fastener system to form a rigid, robust connection to the ROBOT structure (i.e. not attached with Velcro!)." does not say "THE nut and fastener system", which seems to leave open a little wiggle room for the attachment system.

Ours is definitely robust, quick, blind etc, but as we show in the pix we want have an aircraft quality pin as the attachment - of course we could use a bolt and nut here. However, a nit-picky inspector could cause us problems, so we are trying to get a ruling from the forum, but as I said earlyer, we can't post to that forum - could someone post this to the official FIRST forum for us - and of course discuss here.

Here's pic of our blind, easily detached, robust attachment (the bolt will go through holes in the aluminum backing plate, and the aluminum plate will be welded to the 1" square tube)
....

http://srvscience.org/FIRST/2008_bumper_attach.htm

[Jon Stratis]

From what i can see, your bumper will fulfill the definition of a standard bumper - You build the standard bumper, and attached it to that metal arm with a secure nut and bolt system. That arm, i believe, needs to also be securely attached to the rest of the robot with nuts and bolts - a pin probably wouldn't suffice. Another team posted a similar question to the GDC:

http://forums.usfirst.org/showthread.php?t=8551

Thank you for pointing out our ambiguous/erroneous language. We will amend the inspection check-list so that bolt and nut fasteners are accepted. In your case, we suggest that the "quick disconnect" pin be a bolt-nut combination. Please be sure that the Bumpers you use are compliant with the rest of Rule <R08>.