Realistic high goal scoring rate

[Kevin Sevcik]

Originally Posted by Chris is me

This isn't 2016 - volume and accuracy are tradeoffs where the right answer very well may be on the side of volume. Turreted shooter in 2009 could be more accurate than dumpers, but dumpers certainly were the more dominant design in general that year. This year's game has five times as many game pieces as 2009!

I am in complete agreement with this, actually. The important shooter metric is balls scored per second, not accuracy or balls fired per second. Erring on the side of volume is almost certainly preferred because it's probably easier to increase accuracy for a high volume system than to increase volume for a high accuracy system. I think it IS interesting that if you're pursuing a single stream shooter*, at some point you have to start backing away from the goal to increase your rate of fire without running balls into each other.

*How long do you think until the first joke about crossing the streams?

Originally Posted by Chris is me

I don't think that's how it works. The motor is only at max power spinning half its free speed at full voltage, IE if the load the motor is under is slowing it down that much. If you're just spinning the motor at half its free speed with speed control, you're just applying a bit more than 6 volts to the motor (a bit more to account for friction losses etc). You definitely do want to be spinning a flywheel at less than 100% speed so it has some headroom to recover with, but I don't think it's exactly half voltage or half free speed either.

Like I said, I need to revisit my spreadsheet to better account for this. But two things are true about my statement:
1. If your wheel slows down by x% per ball, the fastest way to spin it back up to target speed is at at the peak mechanical power point. (Physics, that) And the peak power is at 12V and 50% free speed.
2. Peak power is the MOST power you'll ever get out of the motor. That's 337W for a single CIM. If it takes 33J to fire a ball, the most balls you can fire without slowing down is 10 balls per second. And that's going to be with the motor running at 1/2 free speed. If the motor's running any faster, it won't put enough energy back into the system and the wheel will slow until energy out = energy in.

[notmattlythgoe]

Originally Posted by Kevin Sevcik

I am in complete agreement with this, actually. The important shooter metric is balls scored per second, not accuracy or balls fired per second. Erring on the side of volume is almost certainly preferred because it's probably easier to increase accuracy for a high volume system than to increase volume for a high accuracy system. I think it IS interesting that if you're pursuing a single stream shooter*, at some point you have to start backing away from the goal to increase your rate of fire without running balls into each other.

*How long do you think until the first joke about crossing the streams?

[Eric Scheuing]

Originally Posted by Kevin Sevcik

*How long do you think until the first joke about crossing the streams?

Originally Posted by notmattlythgoe

Ghostbusters!

14:06-14:13, so ~7 minutes

Longer than I expected actually.

[Kevin Sevcik]

Originally Posted by Eric Scheuing

14:06-14:13, so ~7 minutes

Longer than I expected actually.

He has to have some kind of intelligent filter that notifies him of joke opportunities, I swear.

[Andrew Schreiber]

Originally Posted by Kevin Sevcik

He has to have some kind of intelligent filter that notifies him of joke opportunities, I swear.

That's the first time I've ever heard him referred to as "intelligent"

[D_Price]

We are looking at about 12 balls per second at the moment with our protoype with consistency.

[Andrew_L]

97.1 balls per second.

[MaGiC_PiKaChU]

Originally Posted by Andrew_L

97.1 balls per second.

next thing you know 254 does better than that

[rick.oliver]

So, check my math, but assuming a single Fuel leaving the shooter wheel which is located at the top of a tall robot parked in the key against the boiler wall. My trajectory model calculates about 86 degree launch angle at about 5.7 m/s muzzle velocity. At a 5" pitch, that is 40 to 45 Fuels per second.

So that would be the max; of course, there would be a gap as you wouldn't be feeding the shooter as fast, so something less than that.

Am I missing something?

[Daniel_LaFleur]

Originally Posted by rick.oliver

So, check my math, but assuming a single Fuel leaving the shooter wheel which is located at the top of a tall robot parked in the key against the boiler wall. My trajectory model calculates about 86 degree launch angle at about 5.7 m/s muzzle velocity. At a 5" pitch, that is 40 to 45 Fuels per second.

So that would be the max; of course, there would be a gap as you wouldn't be feeding the shooter as fast, so something less than that.

Am I missing something?

Does that include drag on the wiffleball?

[s-neff]

Originally Posted by rick.oliver

So, check my math, but assuming a single Fuel leaving the shooter wheel which is located at the top of a tall robot parked in the key against the boiler wall. My trajectory model calculates about 86 degree launch angle at about 5.7 m/s muzzle velocity. At a 5" pitch, that is 40 to 45 Fuels per second.

So that would be the max; of course, there would be a gap as you wouldn't be feeding the shooter as fast, so something less than that.

Without checking your math, that seems like a solid upper limit "in flight". The feed process into the shooter will definitely be the limiting factor for top teams.

Am I missing something?

[Lil' Lavery]

Peak rate or sustained rate? I could see some team with peak rates well above 30 balls/second.
Flywheel shooters are the only way to launch a ball

[Kevin Sevcik]

Originally Posted by rick.oliver

Am I missing something?

How fast is the ball traveling at the apex of your trajectory? The slowest speed on your trajectory is what you should use with pitch to calculate balls per second.

[Andrew_L]

Originally Posted by MaGiC_PiKaChU

next thing you know 254 does better than that

I can't hear you over my ACTUAL TRANSFORMER ROBOT*



*Whose design I didn't contribute to in the slightest

[Kevin Sevcik]

Originally Posted by Andrew_L

97.1 balls per second.

At 25 ft/s, that's about 12 lbs of thrust. I don't think you'll be going to space today with that engine.