Ramp bot angle

We are thinking of some possible designs for a ramp robot and wondering what the maximum angle peoples robots will be able to drive up (assume the surface has grip tape). We are especially interested in taller robots.

The taller the robot, the less steep of an angle. If the robot’s CG is in the front, the ramp can be steep(assuming that the robot’s drivetrain is strong enough).

The easiest thing to do here is if you have a KOP chassis, weigh it down to full weight and build a ramp out of wood. Then try driving up it. If it makes it, you’re probably good, if not, there’s your answer.

I disagree, since I think most of the concern is going to be top-heavy robots tipping over than being able to physically drive up the ramp. I think a lot of elevator/arm robots will have far too much weight (motors, gearing, actuators, etc, all adds up) too far up on the robot to be able to drive up.

our team calculated the max angle a drivetrain with bumpers could climb was 28 degrees.

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i guess my question is meant to not only address the actual strength of the robot but also balancing issues, btw our ramp is at a 22 degree incline

Depends somewhat on the drivetrain and how high the bumpers are. Specifically, how close to the Frame Perimeter the wheels get. (Or… outriggers with powered wheels on them. Not unheard-of at least in speculation/theory though I can’t say for sure anybody’s used 'em in a match.) I would posit that a robot that had lots of small highly-exposed wheels near the ends of the robot could handle a bit of a steeper angle. Using an outrigger or two would also work.

Also consider getting off of said ramp onto platform–you’ll need to watch for high-centering. But there are ways to get around that too.

For reference you could watch some game video from 2006. The ramp was 12" high at a 30 degree angle. Climbing it was a distinct challenge… but teams could do it.

Keep in mind, however, that many teams would need the assistance of a push from a partner, while others were custom designed to climb a ramp ALMOST as high as the center platform. And the robots would have had lots of practice climbing that nice, wide ramp. 30 degree ramps are within reach of a robot that can shoot a ball in a high goal.

Jason

I’m dumb. I forgot to suggest ‘07 robots for viewing. Some of those ramps were pretty steep despite teams’ best efforts to make them shallow. I don’t think any were 30 degrees (expansion rules were quite relaxed that year in that particular area), but 12" high proved to be a challenge for many teams.

We’ve done some testing and have gotten a drive base up to ~33 degrees. But that’s really pushing it.

If you build a ramp bot, you are probably gonna have a bad time. I would suggest looking at other methods of getting to level 3 and being capable of getting on top of it on your own. There are plenty of other things you could also focus your time to make a really good robot that elite teams will want to pick.

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That’s pretty close (28 deg )to what we are seeing in practice

We found that 28 degrees is the maximum angle for a ramp to work, but if you plan on making one you may want to make it less steep in case the robot going over it has a high center of gravity. You’ll have to do your own calculations if you plan on allowing tall bots onto the ramp.

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