How are you getting over the 4" bump?
 

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?

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

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

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

We are using tank treads, but there are still some question marks that make us unsure that we will succeed.

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

Three words. Eight-wheel-Drive!

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

Pneumatic tires

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

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.

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

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.

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

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

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

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 :D

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

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.

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

With our Mult-tool

http://tahomarobotics.org/2012/02/02...bump-part-two/

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

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.

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

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).

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

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.

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

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!

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.

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

Our robot's a bit top heavy. So there's no way we can get over the bump. We designed our robot to have rollers that would enable the robot just to 'glide' over the 4" bump but not in practice it seems unlikely since the bump acts like a brick wall. But we are successful in getting over the bridge and balancing! So the bump's one less thing to worry about!

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

Thanks for the suggestions and good luck at your regionals!

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