How does your robot hurdle?

[jimbot]

Our robot is using a spring/piston method to fire the ball over. It will sit 3 inches beind the ball on our composite arm and be raised by the window motor.

[dtengineering]

I'm not sure just what the difference between a 'catapult' and a 'shooter' is meant to be, but we are shooting the ball with a catapult-like mechanism powered by pneumatics.

We have managed to land the ball on the rack a few times during testing, although now that we have increased our shooter's power it would actually be quite a challenge to get the extra four points you get for putting it up on the overpass. We are more than willing to sacrifice four points (12 for leaving it on the rack - 8 for just shooting it over) for the speed and overall efficiency (fun!) of shooting.

As for knocking it off at the start of the match... a 2"x24" cylinder at 20 psi will only use as much air as a 2"x8" cylinder at 60 (about 5-10 seconds of compressor time). You can also set the cylinder up to be single-acting (note that this is different from using a single-acting cylinder, which is a no-no), so you don't need to waste air pushing the rod back down. It is still a lot of air, but not so much that we won't be able to recharge in time to shoot.

We figure that if the compressor recharge rate (approx one shot every 20 seconds) is the limiting factor to our ability to score points that we're probably having a fairly successful match.

That's the theory, anyways....

Jason

[roboticWanderor]

despite my madman ranting and crazy talk about a awesome shooter, we have built what is looking out to be a pretty functional lift arm claw ... thing...
we just have to get he chassis painted with racing stripes first...

[waialua359]

I am curious to see how dependent catapult/shooter robots will be where someone on their alliance needs to bring the balls down from the beginning of the match either during autonomous or tele-op play. If they cant do it and teammates cant, then what?
So far, a lot more lifting arm type mechanisms than anything else.

[=Martin=Taylor=]

We're using a dual roller system to shoot the ball.... and we can also use the rollers to pick it up again...

A catapult only accomplishes HALF of this year’s game. You have to catch your ball before you can throw it.

[rogerlsmith]

Team 904 is using the "smooth as silk" elevator/arm combo to execute a controlled hurdle and still have the ability to place the trackball on the overpass at the end.

[s_forbes]

Originally Posted by Hachiban VIII

We're using a dual roller system to shoot the ball.... and we can also use the rollers to pick it up again...

This I'd like to see... I was considering the idea but couldn't think of a good way to do it. Be sure to post a picture of your bot when it's done!

[=Martin=Taylor=]

Originally Posted by s_forbes

This I'd like to see... I was considering the idea but couldn't think of a good way to do it. Be sure to post a picture of your bot when it's done!

It probably doesn't work like you'd expect.

The rollers themselves turn very slowly and with great torque. The "shooting" ability comes from the mechanisms ability to squeeze the ball through a small opening. When the ball exists this opening it expands rapidly and is tossed a short distance.