How much pressure to lower ramp?

[Jon Stratis]

First, a correction. According to section 2.2.5 of the Game Manual ("The Arena chapter), the bridges, when level, are 12 inches off the ground, not 10.5.

As for force, check out the video FIRST posted about the bridges here: http://www.youtube.com/watch?v=-AMaq...eature=related

The use standard FRC batteries in a great demonstration of the tipping point, and you should be able to use that to figure out how much you need to push on it with your manipulator to get it to go down.

[JakeD]

900 inch pounds of torque is a reasonably close number and easy to remember.

2 * 15 lbs (batteries * 30 inches* off center = 900 inch lbs.

Some more quick math revels that 900/44 inches from center of bridge is about 20.5 lbs straight down on the bridge. Just remember to round up to be safe.

[372 lives on]

Originally Posted by JakeD

900 inch pounds of torque is a reasonably close number and easy to remember.

2 * 15 lbs (batteries * 30 inches* off center = 900 inch lbs.

Some more quick math revels that 900/44 inches from center of bridge is about 20.5 lbs straight down on the bridge. Just remember to round up to be safe.

are you referring to the batteries as 15 lbs? because that is a little heavy :/

[JakeD]

Easy to remember numbers and safe assumptions.

EDIT: im aware that the batteries are lighter, as well as their center of mass is closer to the 27.5 inch mark on the bridge.

[372 lives on]

I prefer accurate > easy

[Alan Anderson]

Originally Posted by JakeD

900 inch pounds of torque is a reasonably close number and easy to remember.

2 * 15 lbs (batteries * 30 inches* off center = 900 inch lbs.

If you want a more accurate number, start with a better estimate of the batteries' weight and location of their center of mass, and remember that the pivot point of the bridge is about 3.5 inches closer to its downward than the actual center.