Grade Slope for Robot Ramp [Archive]

digitalgoldfish

29-09-2012, 19:36

Hello All,
Forgive me for any errors as this is my first post on Chief Delphi, but anyway;
We, the Vashon Pirate Team 5961, are considering building a ramp on our robot for our alliance members to drive up, and we were wondering what grade of slope can your robots drive pp?

Madison

29-09-2012, 19:42

I moved this to the FTC forum.

This isn't a thing that people test for since there isn't an on-field ramp. If we were pursuing this sort of design, I'd recommend to my team that they build something that's no steeper than 15* or so because teams are usually really, really terrible at driving straight up an incline.

RRLedford

29-09-2012, 20:14

I moved this to the FTC forum.

This isn't a thing that people test for since there isn't an on-field ramp. If we were pursuing this sort of design, I'd recommend to my team that they build something that's no steeper than 15* or so because teams are usually really, really terrible at driving straight up an incline.

I agree with this and also suggest that the ramp be coated with high friction material for good traction, but I am not sure what is actually legal. Double stick tape perhaps.

The second thing to consider is to have a lop at the sides so that it is less easy for wheels to drive off the sides.

-Dick Ledford

Sasha

01-10-2012, 11:59

just FYI: last year, the slope of the ramp was 18 degrees: http://www.usfirst.org/sites/default/files/uploadedFiles/Robotics_Programs/FTC/Game_Info/2011/FTC12FIELDCONSTRUCTIONSEPT6.pdf. Given that we can increase traction by using materials other than plain plywood, I think that 20 deg would be OK.

IKE

01-10-2012, 13:27

In FRC we did a couple platforms that were basically a 1 foot rise with a 3 foot long ramp. This gets you right aroun 30-35 degrees. This was similar to the ramp in the 2006 FRC game. This was very difficult for a lot of teams to climb, but not impossible. Look back over the 2007 FRC game and see what some of the folks did there.

Sasha

01-10-2012, 16:37

1 foot rise with a 3 foot long ramp. This gets you right aroun 30-35 degrees.
arcsin(1 / 3) = 19.4712206 deg

IKE

02-10-2012, 13:42

arcsin(1 / 3) = 19.4712206 deg

Good catch.

MisterStig

22-10-2012, 16:57

just FYI: last year, the slope of the ramp was 18 degrees: http://www.usfirst.org/sites/default/files/uploadedFiles/Robotics_Programs/FTC/Game_Info/2011/FTC12FIELDCONSTRUCTIONSEPT6.pdf. Given that we can increase traction by using materials other than plain plywood, I think that 20 deg would be OK.

I would agree that 20 degrees is safe and maybe also 25. I also suggest adding non-slip material, such as the stuff used on stairs.

If you have the time, you can test your ramp by building some simple robots. Try using different will sizes/types and also make the robot different weights.

MisterStig

22-10-2012, 18:25

I agree that 20 degrees is safe and maybe even 25. Also, I suggest adding non-slip material such as the stuff used on stairs.

If you have the time, you can test your ramp by building a simple test robot. Try using different wheel types/sizes and try increasing/decreasing the weight of the robot.

MisterStig

23-10-2012, 15:16

Having delt with several ramp before, I would say 20-25 degrees would be safe. Also, I suggest adding non-slip material such as the stuff used on stairs.

If you have the time, build a seperate (simple) robot so that you can test your ramp. When testing, try using differnt wheel types/sizes and be sure to change the weight of the robot also.

Telthien

31-10-2012, 20:02

Two years ago? Probably around 55 degrees.

Last year? 25.

This year, I really don't know, but I don't imagine it being more than 15 or 20.

It varies from robot to robot, and is not a stable measurement. Best idea is to go as low as possible so the largest number of robots can drive up.