FRC488 Pneumatic Catapult

Originally Posted by militaryrobot

Great idea ! How do you guys plan on keeping the ball stationary when an opponent hits you?

I think they could implement a feeding solution that holds the three balls until they are absolutely ready to be fired, so they aren't in the catapult yet if they get hit. When they want to fire it loads the ball into the catapult. I imagine they'd ideally be shooting from the key, where they won't be in danger of being hit without the other team taking a penalty.

As far as exactly what this would look like, imagine the ball return at a bowling alley. Put this on the back of the robot facing sideways toward the ball holder on the catapult. Balls roll up and drop out into the catapult.

Another option would be to turn the upper surface of the catapult arm into a trough/tube for balls to roll down and into the launcher, where a large enough lip would prevent roll-back. The ball holder/feeder would dump balls into this trough/tube at the fulcrum (or really anywhere on the arm above the launcher) when the arm is in the down and "reloading" position.

I hope those explanations make sense . I can clarify if anyone is confused.

[Lil' Lavery]

Originally Posted by SenorZ

Cool. Looks like it takes up a lot of space though.

The travel of the arm also allows for balls to be loaded at a lower position on the robot and still have a high release point. This means that you could potentially allocate a lot less space for loading mechanisms.

[penguinfrk]

One of the best videos yet...... "Pie" is in the URL.


OT: Did you find that the orientation of the ball mattered for the shots?

We came to similar conclusions about the inconsistency of using wheels as far as the compression and spin of the ball upon release goes, and made a sort of catapult. We were using the same ball over and over for testing, and we found that we were most consistent with the FIRST logo facing up (as opposed to the side) because there was a dent in the ball immediately underneath it.