No more "bolt and fastener"!!

[XXShadowXX]

we use wing nuts...

[smurfgirl]

We designed some awesome quick-release bumpers last season, forgetting that the reason we used the undesirable bolt-and-fastener method because it was required. (: I'm glad to see we can actually make use of this now!

[JesseK]

Well, sure we can design quick-release bumpers this year...but I'm pulling my hair out over the rule that says all regions of the bumper must be supported by the robot. E.g. no gaps for cantilevered wheels. Sure we'll all get over it but I think it unjustly complicates a simple design concept.

Can anyone think of a quick-release that can be mounted to foam? It's like a mix of lightweight foam and styrofoam. We could always use 2" bolts with wingnuts that go through the foam to the aluminum frame, but I wonder if there is a better solution...

[smurfgirl]

Originally Posted by JesseK

Well, sure we can design quick-release bumpers this year...but I'm pulling my hair out over the rule that says all regions of the bumper must be supported by the robot. E.g. no gaps for cantilevered wheels. Sure we'll all get over it but I think it unjustly complicates a simple design concept.

Can anyone think of a quick-release that can be mounted to foam? It's like a mix of lightweight foam and styrofoam. We could always use 2" bolts with wingnuts that go through the foam to the aluminum frame, but I wonder if there is a better solution...

I'm not sure exactly what you're describing, but I have a feeling that foam is not the best solution in this game, where there are going to be many collisions and lots of bumper-to-bumper contact. It doesn't sound like it will last...

If you're worried about trying to make sure your bumpers work with your wheels configuration, perhaps you could segment your bumpers? Or, if you could give a clearer view of the issue you're describing (I know you said that you have a really awesome drivetrain planned, but if you can do this without unveiling the whole secret), maybe we can suggest other solutions?

[JesseK]

The frame design is similar to a crab drive, and the wheels will be cantilevered. The KOP wheel dimensions and the strict bumper rules have really restricted the simplicity of this design, but we're not afraid to overcome it.

We will have an 'upper' frame and a 'lower' frame that will have hard connections to each other. Unfortunately, the upper frame will be above the top of the bumpers, and the lower frame will be at the very bottom of the bumper. Due to the cantilevered wheels, there will be a gap between the frame and the bumpers. The foam is meant to attach to the outer perimeter of both frames, and fill the gap to become the outer edge of our robot on the sides. This is so impacts will be spread between the upper and lower frames. There is no other simple solution to this, since moving the upper frame out further would overcomplicate the whole frame design.

The foam is used in an industrial application at Micron (one of our local sponsors) and their mentors said that as long as the force is spread out over a few square inches the foam will be ok since there will also be bumpers to absorb the impacts. So essentially the foam is like an inner bumper that is part of our robot and meant to also redirect some of the impact force to the upper frame.

Yet due to the design of the lower frame, and the unique feature of the drive train, the foam cannot extend into the corners like we were originally thinking...so we will have to derive a solution for that by the time the whole drive train is done. We'll sit on it until we find a simple solution that doesn't require intricate welding (which is what we've come up with so far).

[smurfgirl]

Yes, I can see how that is causing problems. Unfortunately, I'm not enough of an expert on drivetrains or bumpers to come up with an ideal solution to this problem. The foam sounds like it might work, but I'm guessing other people might stop by here and offer their insight.