pic: Team 675 2011 Robot CAD

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This year’s Robot CAD as of ship day. There are still polycarb sides that we have to attach as well as our minibot deployment which our CAD-ers haven’t haven’t gotten around to adding yet!

How do you mount bumpers to this?

Very carefully lol

The bumpers have C-channel on the bottom so we just slide them on and slip in a pin.

I think the question was more directed at the large gap in the front of the frame, in terms of complying with <R07> K: “No section of the BUMPER greater than 8” may be unsupported".

It appears that the cutout in the front of the robot is wider than 8", so that section cannot legally meet all the bumper rules. You will need to put a frame member to support a bumper there. Per rule <R07> A, you need bumper coverage around your entire FRAME PERIMETER, which does include that gap.

I believe the C channel would count as the support

The frame perimeter is when you wrap a string around the robot and whatever the string touches is now defined as area for needed bumper coverage. Thus if we have a gap that is not touched by the string, we don’t need to cover that area with bumpers. Thus, looking at all rules from 2008-2009, the bumper definitions are exactly the same, we would argue that having this open area in the bumpers is in fact legal. In previous year’s robot we have indeed had these gaps in the frame and it was legal to not cover that area with bumpers. 2010 was the same way, except the bumper zone was higher than most people’s kickers, thus most teams had bumpers around their whole robot, however there were a few that did not and it was still legal.

I hate to tell you but this is very simply wrong…

You better bring more plywood, pool noodles, and fabric to your first regional, because you’re going to need to make a new front bumper.

The key part there is the 100% coverage part.

The whole “wrap a string around the robot” thing is IMHO a poorly worded way of FIRST trying to communicate that the frame perimeter that the bumpers mount to must be a convex polygon.

Can you show me a picture of a team that did not have full bumper coverage? At every event I went to, and every match video I watched, I did not see a single legal robot without full bumper coverage.

For the record, The last year where full bumper coverage was not required was 2009.

That arm looks like it might need to be rebuilt or at least tweaked to be able to function with a front bumper in place. You (OP) might want to pack some parts for that too.

We’ve built it in mind with having to place bumpers on the front of the robot, we were just curios as if we needed to or not. The arm does work with the bumpers there, but thanks for the heads up!

If the C-Channel is attached to the bumpers, it would not count as support, backing, or coverage. There has to be actual robot frame to connect to on the front of your robot.

We’re aware, but a removable bracket bolted to the robot frame that the bumpers pin to does not count as part of the bumpers, thus it will count.

This design looks familiar :slight_smile:

Fixing your bumper problem should be simple if the claw will still work with the bumper there.

Just bolt another tube across the front to provide “frame backing” and you’ll be good.

What is the claw made out of? We made ours out of plywood, fiberglass, and chopped carbon fiber in '07; it was somewhat of a tour de force for our team at the time…

GL in Sactown!

I don’t know what you’re talking about :wink:

We made it by epoxying two pieces of hexel together. It’s quite light!

That’s where we got some of our inspiration from :wink:

Like Kevin said, we epoxied two pieces of 1/4" plywood together and epoxied the outer rim to stabilize it. There are parts where we glued c-channel to the outside to prevent damage, but overall we expect it to be strong enough :wink:
We had a second damaged one without the siding or extra epoxying and one of the claw “jaws” held 50 lbs of downward force by itself before it gave way :smiley:

In reply to your bumper fix, I guess great minds think alike :smiley: That’s what we did today once we realized that we had skipped over a crucial rule, seems to have worked well enough on our practice robot!

See you at Sac!!!

Hexcell***

Not plywood sorry!! xD

I’m curious for your claw this year, we saw the CAD but are still baffled :wink:

What kind of wheels are those? I know you’ve used mecanums in the past, but the render makes it hard to tell.

Also, anyone know how much it weighed? Looks light.