[FVC]: 3053's Robot

[sovierr]

Wow - this is very similar to our robot (FVC 3228). Our box/arm is only 1 tank tread wide though. How do you move the balls up and down the box? What do you use as a manipulator to pick up the balls? We were part of the winning alliance from the Florida Regional in December, so I look forward to seeing this machine in person in Atlanta.

[nonother]

Originally Posted by sovierr

Wow - this is very similar to our robot (FVC 3228). Our box/arm is only 1 tank tread wide though. How do you move the balls up and down the box? What do you use as a manipulator to pick up the balls? We were part of the winning alliance from the Florida Regional in December, so I look forward to seeing this machine in person in Atlanta.

The balls are moved up and down the "box" by the tank treads, this is also what is used to pick the balls up.

[Jared W]

As team leader of FVC #3228, I would like to add to our mentor's question.

For our robot, we had to put zipties on our single tank tread because the tank tread couldn't apply enough pressure to the balls to prevent them from slipping back down. If we lowered the height of the tank treads to add more pressure, then the balls couldnt get past the manipulator (front of the tank tread that had the wheel)..

Any secrets there? Or just extra tight tank treads?

Also, I was wondering about the bumper switch on the top of the tower, what is it's purpose?

[nonother]

Originally Posted by Jared W

As team leader of FVC #3228, I would like to add to our mentor's question.

For our robot, we had to put zipties on our single tank tread because the tank tread couldn't apply enough pressure to the balls to prevent them from slipping back down. If we lowered the height of the tank treads to add more pressure, then the balls couldnt get past the manipulator (front of the tank tread that had the wheel)..

Any secrets there? Or just extra tight tank treads?

Also, I was wondering about the bumper switch on the top of the tower, what is it's purpose?

No secret at all, if you look at the picture closely you will notice the tank treads do in fact have zip ties on them. So it works just like yours. A suggestion: our extensive experimenting with tank treads has taught us that super tight tank treads cause nothing but bent drive shafts...as in they don't work.

The bump switch is used to limit the motion of the arm, it is used in autonomous mode. The standoff beam slides over the bump switch, pressing it down, when it reaches a certain height.

[fredliu168]

What's the gear ratio on the arm?

[nonother]

Originally Posted by fredliu168

What's the gear ratio on the arm?

The gear ratio shown in that photograph is 1:5.

[macmaniac]

We just changed the gear ratio to 1:7. This allowed us to drop 2 of the four arm motors and move them to the drivetrain to increase maneuverability.

[sovierr]

Wow-I'm surprised that a 7:1 ratio can provide enough torque to lift that arm. I'm guessing it's aluminum - correct? Even still, I would have guessed twice that ratio.

[nonother]

Originally Posted by sovierr

Wow-I'm surprised that a 7:1 ratio can provide enough torque to lift that arm. I'm guessing it's aluminum - correct? Even still, I would have guessed twice that ratio.

The arm is made of aluminum and was designed to be as minimalist as possible to keep a low weight. The weight of the softballs is the more determing factor. Five softballs is approximately 1.9lbs.