Best Way to Launch unusual items?

[Dominick Ferone]

We were talking and whats the best way to launch unusual items, such as lunacy balls, breakaway balls, frisbees, footballs and other random object you could also find around the shop?

[Kludgy]

A specially designed hammer?

[MaGiC_PiKaChU]

Originally Posted by Kludgy

A specially designed hammer?

i've seen 3996 use a hammer to kick basketballs back in 2012

[JosephC]

Catapult/Slingshot, unless you know a way to make a wheeled shooter account for every shape change

[Richard Wallace]

Do you want to launch these objects more than 30 ft?

[carpedav000]

Wheeled shooter with suspension to account for various ball sizes.

[JDGallagher]

Originally Posted by carpedav000

Wheeled shooter with suspension to account for various ball sizes.

This or use a large foam wheel, similar to 118 in 2013.

[AdamHeard]

This faux TED talk covers some of the parameters of odd items being launched.

[Chris is me]

When you're shooting a variety of various shaped items long distances, wheeled shooters aren't going to perform as well. Wheeled shooters as we know them in FRC work best with objects that can roll / spin - balls, frisbees, etc. We are abe to design such precise and repeatable wheeled shooters because we are shooting such an incredibly narrow range of items - a single game piece, with manufacturing tolerances being the only varying factor. Wheeled shooters also shoot multiple game pieces in quick succession really well, which doesn't seem like is needed here. Wheeled shooters are solving the wrong problem.

A catapult cares much less about the geometry of what is inside it - it brings itself and its object up to speed and stops at the angle producing the desired trajectory. Obviously this will have varying results with each game piece as well, but I think it's a better solution for the constraints at hand.

Take a look at what 16 did in 2012 as a starting point.

[GeeTwo]

Originally Posted by Dominick Ferone

We were talking and whats the best way to launch unusual items, such as lunacy balls, breakaway balls, frisbees, footballs and other random object you could also find around the shop?

Most FRC grippers are made specifically to hold a certain size/shape/weight piece, so most of the usual tricks won't work. Some sort of speed-controlled catapult/ballista (I'm thinking motors and encoders) could be used to get everything up to an appropriate/consistent speed. To hold the pieces, I'd try a gripper that can accommodate many shapes, probably by having multiple pneumatic arms that curl in on the "game piece". You can use the thing on the other side of your wrist as a rough template.

[Dominick Ferone]

The argument was started while going over the design of our hockey puck shooter on whether we should go:

air powered(paintball gun like)
inline wheel shooter(ultimate ascent)
top wheel shooter with roller bottom(baseball shooter)
Spring loaded plate(pinball)
Slingshot

or is there something else more efficient to shoot the put accurately at really high speeds for our challenge.

[Scott Kozutsky]

This is an amazing opportunity to make plywood ghetto prototypes and do some good ol' fashioned testing. The three main things that peoples are suggesting are catapults, slingshots, hammers (all easy to prototype) and wheeled shooters (more difficult but doable).

Things like air power can probably be crossed off the list because getting a seal on a lunacy ball would be... lunacy (sorry, I had to) as well as accommodating the different shapes and sizes of the other pieces.

I think that a catapult would work best in this application but have no real experience (and neither does anyone else as far as I'm aware). Unless someone here can point to an off-season project they've done shooting multiple different gamepieces I would take everything with a large grain of salt. Implementation is an entirely new can of worms. If you do go for a catapult there are multiple options; lots of motor, stored energy and release (surgical tubing/spring), pneumatic, something else I've inevitably forgotten. Each option has advantages and disadvantages.

[Dominick Ferone]

Originally Posted by Scott Kozutsky

This is an amazing opportunity to make plywood ghetto prototypes and do some good ol' fashioned testing. The three main things that peoples are suggesting are catapults, slingshots, hammers (all easy to prototype) and wheeled shooters (more difficult but doable).

I think that a catapult would work best in this application but have no real experience (and neither does anyone else as far as I'm aware). Unless someone here can point to an off-season project they've done I would take everything with a large grain of salt.

I did a catapult a few years back for rebound, with our initial prototype we saw potential because it did give the arch but it isn't what would be needed for this project which is more speed.

and as for a slingshot i know people (my team included) made kickers that were a piece of lexan held back and then released to exert a force to kick the soccer balls.

[Scott Kozutsky]

Originally Posted by Dominick Ferone

I did a catapult a few years back for rebound, with our initial prototype we saw potential because it did give the arch but it isn't what would be needed for this project which is more speed.

and as for a slingshot i know people (my team included) made kickers that were a piece of lexan held back and then released to exert a force to kick the soccer balls.

Have you tried more power? You can relatively easily get catapults to launch really far and really fast. You can flatten the exit angle for it to go faster but not farther.

33 using a catapult to full court shoot in 2014
https://www.youtube.com/watch?v=1-oWAS9_Rl4

[GeeTwo]

Originally Posted by Dominick Ferone

The argument was started while going over the design of our hockey puck shooter on whether we should go:

air powered(paintball gun like)
inline wheel shooter(ultimate ascent)
top wheel shooter with roller bottom(baseball shooter)
Spring loaded plate(pinball)
Slingshot

or is there something else more efficient to shoot the put accurately at really high speeds for our challenge.

For hockey pucks, I would constrain the puck to be flat with some sort of chute and use a dual-wheel (left/right) shooter. If you want them to fly rather than slide along the ground, you could make one of the wheels rotate a bit faster than the other to give some gyroscopic stabilization.

Also, I recall a linear accelerator that I rough-designed for Aerial Assist that used a motor and gearbox, two linkage arms, and an angled glide with a basket that the ball sat in. The point of the two-armed linkage was to match impedance between a motor/gearbox running at a constant speed and a load which was accelerating. If you aren't interested in picking up strange pieces (or will do this separately), this would be a useful design. We didn't build it (used a hammer for AA), but I am pretty sure we could have gotten the yoga ball high enough and far enough to make clear truss and high goal within the required frame perimeter. By making the travel longer and gearing the motor lower, any reasonable speed should be feasible. I'll look for the drawings and spreadsheet this evening.