Hello,
So far, our team has been able to construct a mechanism to push the bridge down. We were planning on going over the bump as well, we have the mechanism in mind for it as well and we have the parts for it. What are your ideas on getting over the bump? And is it, or is it better to just stick with the bridge?
I hate to burst your bubble, but I think this is a decision that should have been made weeks ago.
However, I think lots of teams are using pneumatic tires, or having wheel spacing geometry that lets them float over it.
-Nick
We are using tank treads, but there are still some question marks that make us unsure that we will succeed.
Three words. Eight-wheel-Drive!
Pneumatic tires
As mentioned above, if you haven’t already built this into your design, you are probably not going to be able to do so this late into the design and build season.
My suggestion is to use what you have, instead of going over the center barrier, use your ability to cross the bridge instead. Make sure that works flawlessly, so you can cross from one side of the field to the other, as needed, plus have the ability to balance on the bridge at the end.
Pretty much, the chassis and bumpers should be high enough so the robot doesn’t get completely stuck. Your wheels should be large enough in diameter as well (8" + is good)and/or you can add a skid plate or casters to lift up and push the front over. Your CG should be low to avoid tipping over while crossing.
We are using a 4 tires system in which the 2 far tires are bigger than the either 2. We have 8 tires in all. Hope this helps
Tanx 3003
I hate to burst the Bubble Burster’s bubble, but it is most certainly not too late to tackle this challenge. Not that i recommend waiting until now, but hey, SHIFT happens, and sometimes it becomes a week 4-5 matter.
Now to solve the real problem.
Here’s some solutions:
- Pneumatic Tires/Wheels
- *Other Pneumatic like tires, such as Bead-LOK wheels from Skyway
- Use a relatively sturdy
wheel with a diameter that is > 8 in. - Use some kind of delrin angle like, passive device to maneuver the bump more easily - Deal with going over the bump once per match, and become a feeder bot. This really isn’t too bad of a strategy if executed properly.
I hope this helps!
Good Luck this season!
-Duke
*Someone please use these someday, it’d be soooo cool 
Well-designed suspension systems could raise up your 'bot to, as formerly put, “float over it”. Shocks would be difficult, but in the past, we’ve used six wheels, on a swiveling mechanism that approximates that effect.
With our Mult-tool
http://tahomarobotics.org/2012/02/02/doing-the-bump-part-two/
Yes, but it is never too late to redesign, especially something that isn’t working just quite right. If you can move, focus on scoring. But if you can score, then now is a good time to look for other areas to improve such as better movement capabilities.
2 too few!
We have a mechanism that works for both. It pushes the bridge down, as well as our robot up when we cross the bump. And a little bit of linkage magic to minimize the work required by the robot (it just drives).
My team opted for an arm of sorts (picture 2 arms connected so it’s “one appendage” per the rules). This manipulator can lower the ramp, raise it for an alliance partner on the other side (or for an opponent for the final shared balance), and actually lift our front end to get our frame over the barrier, where the 6 wheel drive takes it. The arm has roller wheels (3" diam) to allow us to roll on the arm with it touching the ground. We also have a type of skid plate to prevent the bot from bottoming out on the barrier.
We’re going with two pneumatic wheels and an angled chassis to launch over the bump. It’s going to be super cool to watch and hopefully very effective!
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.
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.
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 
Two words: Tank Treads.
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.