Ramp Angle Survey

[KTorak]

Originally Posted by Assassin Shadow

Forgive me if I'm wrong, but does it really matter whether the robot is up past the ramp. It doesn't have to be past the corner at the top of the ramp to earn points, it just has to be at least 4 inches up the ramp. So in a worst case scenario, just make it so that your robot can make it that far up a ramp and then turn a little sideways so that they don't roll back down. Viola!

However, as seen last year, your robot must be able to sustain its final position for up to 30 seconds or more while scoring takes place. Therefore, if you are not over the apex of the ramp, you will fall off and you most likely will not receive the points. But, this is probably Q&A material.

[DonRotolo]

Originally Posted by Assassin Shadow

Forgive me if I'm wrong, but does it really matter whether the robot is up past the ramp. It doesn't have to be past the corner at the top of the ramp to earn points, it just has to be at least 4 inches up the ramp. So in a worst case scenario, just make it so that your robot can make it that far up a ramp and then turn a little sideways so that they don't roll back down. Viola!

4" up the ramp is NOT the same as 4" from the floor.
Many robots will roll when powered down. You'd have to turn sideways to be sure you don't roll. Do you want another robot turning atop yours? I don't


We are thinking of an 8" tall robot with a 36" long ramp, Sin (8/36) = ~13 degrees.

Don

[WeldedHarlequin]

Originally Posted by DjAlamose

Nope, one solid piece. Of corse this is still in design and we aren't even sure this is the route we want to take.

Oh, and by the way, a sheet of aluminum diamond plate 24x48x(1/16) weighs only 7.056 lbs (yeah thats alot of weight, but holes can be drilled....Lots of holes....)

Do you know how many quarter-inch holes you would have to drill in a sheet of diamond-plate to significantly reduce the weight?

Lots and Lots.

Keep in mind that all those holes will reduce the structural strength as well. I'm sure nobody wants to see their robot fall through a ramp...

[Bongle]

Originally Posted by Don Rotolo

Do you want another robot turning atop yours? I don't

That's really a moot point. From driving previous robots, I've noticed that motor stall and joystick sensitivity at low speeds is a BIG issue. Since I imagine you don't want robots climbing at high speeds, then you're going to be dealing with robots turning on your robot no matter what.

I think it a plausible sequence would be like this:
-Team is driving very slowly up skinny ramp
-Team stops to make sure orientation is good
-Team attempts to continue at low speeds, but one side un-stalls first, causing the robot to rotate. They now either have to deliberately rotate, drive off and try again, or just give up and hope they reached 4".

Which makes me realize that painted-on markings for vertical displacement of 4" and 12" on any given ramp would be a very good idea. Also, having your ramp removeable between matches would be good. Who wants a 4ft ramp above their heads if they know before their match that they'll be climbing an partner's ramp?

Keep in mind that all those holes will reduce the structural strength as well. I'm sure nobody wants to see their robot fall through a ramp...

Your ramp certainly doesn't have to be a flat piece of metal. You could probably get away with a honeycomb-like bit of metal supported by some posts, with thin carpet on top.

[Jeremiah H]

I like the info posted here, it will be very helpful to us, as we are designing a rampable bot, hopefully capable of holding two others.
Here's an idea for you all to consider- what if, instead of a flat ramp, you had a curved (or maybe even parabolic-less trouble with that leading bumper edge) ramp. l believe that this could potentially allow a shorter (in length) ramp to accommodate a longer/less ground clearance wheelbase, especially if said ramp was parabolic rather than a perfect circular curve.
Just a thought. Let me know what you think.

[Setsanto]

Originally Posted by SkiMasterATV

I am a member of a rookie team, and we are just curious about the approach angle of the ramps that are being built out there. Supposedly 60% of the teams polled in a recent survey said that they would be allowing both alliance partners to get on to them for 30 points apiece.

The poll is found here

If so many people are focusing on ramp construction, and if you will have one, we are just curious as to what your floor-ramp angle will be, and what set of points are you going for...

The hope is that an average approach angle can be achieved and be used in the planning of our design.

Any help would be greatly appreciated. Thanks in advance.

-Bryan/2046

I personally a of the belief that not everyone that answers such polls is quite telling the truth. Creating a ramp, or other lifting device, that can succesfully lift robots between 100-120 lbs., that have different wheelbases, could have extensions, and different driving mechanisms is an extremely difficuly feat.

-Nick/1334

[Assassin Shadow]

Originally Posted by Setsanto

I personally a of the belief that not everyone that answers such polls is quite telling the truth. Creating a ramp, or other lifting device, that can succesfully lift robots between 100-120 lbs., that have different wheelbases, could have extensions, and different driving mechanisms is an extremely difficuly feat.

-Nick/1334

difficult maybe, but not impossible...

[TJ4nier]

We have about a 19 degree angle. We're a shorthanded rookie team, so we thought it would have been easiest. The robot itself is only going to be about 13" tall, I believe, so we fit the 12" high bonus.

[Donut]

We're hoping to be having a ramp on the front of our robot, folding out to the sides. It will be 28" wide (so it will leave 10" of our overall length), will have a ramp fall of one side, then a platform with a 90 degree support fall off to the other. Then, we're going to try to mount an arm in the 6" we have left at the end of our robot for scoring tubes, with the arm being on the opposite side of the robot at the end of the match so our partners won't hit it.

Because of the design, we've decided what we're actually building is an aircraft carrier. Right now we're considering adding side rails to help guide partners, and possible runway lines or a bullseye for artistic value.

[Assassin Shadow]

Originally Posted by Donut

Because of the design, we've decided what we're actually building is an aircraft carrier. Right now we're considering adding side rails to help guide partners, and possible runway lines or a bullseye for artistic value.

I like the artistic value, that's some brilliantly creative decoration...especially if you actually managed to make it look like an aircraft carrier or something...

[Raul]

Originally Posted by DjAlamose

If you have a robot with 4wd tank steering and a 30" wheel base, the maximum ramp angle you can achieve before you bottom out (with 2" ground clearance) is only a 7 degree ramp! (This is looking at when the robot gets to the top of the ramp and is going over that corner).

This is obviously a round about number and i didn't do any special calculations for it, but still it gets the point across.

So, you would need a ground clearance of about 4.3" if the ramp was 16 degrees (the angle I have been looking at for a ramp design). Again this is 30' wheel base and 4wd.

To make getting up a ramp easy, just make your robot 6wd and you should have no problems.

By the way, does anyone know the angle of the ramp 111 (wildstang) used in their 2001 robot?
...

In 2001, our robot had a multi-faceted ramp - it had two different angles. the first angle was 12 deg which transitioned to 5.8 deg which then transitioned to flat. By breaking up the ramp into facets, less than 1 inch of clearance was required to make it over those very gradual humps.
Check out this post to use a spreadsheet I created a while ago to figure out ground clearances:
http://www.chiefdelphi.com/forums/sh...ound+clearance

You will see that with a 30" wheel base you can actually tolerate a 15 deg hump transistion if you have 2" of ground clearance.

[SSMike]

Hopefully 10- 15 degrees. This is half the angle that last year's ramp was so it might be easier to get up