Re: How are you getting over the 4" bump?
 

Our frame's extruded aluminum (30x30 hand cut and welded). We toyed with a mechanized skid plate, treads, etc. In the end, one of the mentors and a student came up with the idea of putting angled braces on wither side of the front wheels.
Top view:
BBBBBBBRACE
Wheel
BBBBBBBRACE

Side view: (W=wheel)
Frame
WBrace
WBrace
WBrace
WBrace

The first wheel goes up, the skid braces hit and get you up then the rest of the 8 wheel drive takes over. Makes for a bumpy ride but in the end, it works. However you attach it, make sure they've got good welds/attachments and something like teflon on them to make things easier.

Re: How are you getting over the 4" bump?
 

Yeah, that's what we did. At least I think it is - I couldn't figure out how to describe it, and you've at least made a stab at it. But we have the "braces" (VAGUELY like fenders; our plywood prototypes looked like fenders, but the final ones are just tubes of aluminum defining the outline of the 'fender') just on the outside of each wheel. They are made of tubular aluminum and the "braces" actually hit the bump before the wheel, lifting the (8" mecanum) wheel up a little so it can just slide over the bump. The chassis is high enough that it doesn't touch the bump in the middle. So we go over 2 wheels at a time (budump, budump). It works.

Re: How are you getting over the 4" bump?
 

We went with a higher riding drive this year, so a good amount of speed should do it.

Most teams will probably go with the pneumatic wheels from mcmaster, and maybe have a guide-rail system under their chassis. No need for moving parts when you have a moving bot ;)

Re: How are you getting over the 4" bump?
 

Two words: Tank Treads.

Re: How are you getting over the 4" bump?
 

My team machined wheel mounts for our drive train that had skid plates on the front to get us over the bump. We are using just a basic 4 wheel mecanum drive train.

Re: How are you getting over the 4" bump?
 

(emphasis added)

Update: I believe I spoke too soon. At this point, it does NOT work. :( At least, it does not work with our plywood 'bump'. It worked great when tested on our 'chassis-only' bot, but with the extra weight of the actual bot, no dice. We're still thinking it might work with the steel bump, but if not, no big deal, we can just zip over the bridge. And we're going to be so busy scooping up balls and scoring that it probably won't matter that much. We hope.

Re: How are you getting over the 4" bump?
 

We're getting over the bump very easily and cleanly with a relatively simple system. It's an 8WD, with a specialized cutout in the center that prevents us from high centering on the top of the bump itself.

You can see us (125) crossing the bump a couple times in this video: http://youtu.be/HBwPsmAPN5M?t=53s

-Brando

Re: How are you getting over the 4" bump?
 

Wow, that's a great video. Really neat to see what other teams come up with.

Re: How are you getting over the 4" bump?
 

Two Words: We're not.

Re: How are you getting over the 4" bump?
 

On our robot we simply give our pneumatic wheels full throttle from stop and the front wheels come off the ground and the robot rockets over the bump. We're pretty excited about it.

Re: How are you getting over the 4" bump?
 

We're driving over one of the bridges to get over the barrier.

Re: How are you getting over the 4" bump?
 

this (once it finishes uploading) is how we are getting over the bump. Note that we are on a dead battery (running for about 30min) and only running on 3 out of 4 motors

http://www.youtube.com/watch?v=PZsMWhK-vNU

Re: How are you getting over the 4" bump?
 

Thanks, for the record I was very skeptical about this system. I'd seen a number of videos with just a stripped down chassis going over the bump and wasn't sure that a competition weight machine could make it over in the same manner. So I insisted on the test in that video before moving past the wooden prototype and cutting aluminum and poly carb.

Since it did pass that test we proceeded and I'm proud to present the production version (sans disquising). Doing the bump part 3

Re: How are you getting over the 4" bump?
 

I think this is the most efficient use of limited time. The bridge gets you over the field and scores points. The bump is clearly optional while the bridge is clearly mandatory.

But that's just me.

Re: How are you getting over the 4" bump?
 

Or you build something that manipulates the bridge and gets you over the bump too.