Double Shooter for 2013 robot

[Boe]

Originally Posted by bEdhEd

Yeah I remember watching 1503 at championships and I was surprised that anyone actually tried that design, but we want to be able to do a 7 to 9 disk autonomous, and I'm not sure how simple a floor pickup and load for a multi-disk slingshot would be. We also want a below 30 inch robot, and a low slingshot would be quite unreliable, and at that angle, fitting four disks at the same time in the high goal would be difficult, if even possible.

We are pretty much locked in on wanting the side by side shooter at the moment. We have until September to start building, so there are definitely going to be some improvements or changes to the design. We're betting that the robot would have to be quite wide to accommodate the diameter of two shooter wheels, two disks, and the thickness of our metal stock all in a row across the width of the bot.

I can see it now a 1503 style shooter mounted to a four bar linkage with a pickup at the end

[Jonathan Norris]

I would highly recommend spending the time to just make a shooter twice as fast, its probably a more worthwhile exercise. Building a shooter that can shoot 4 discs in ~1.5sec is a challenging exercise that will stretch your iteration skills and programming talent. Every year the thing that separates the best teams from the rest is how quickly they can score, learning how to continuously iterate on your scoring mechanism to make it faster/more effective is a very important skill for any FRC Team.

Between Waterloo and Champs our mechanical and programming teams spent weeks iterating on a new shooter for champs. Using two mini CIMs instead of originally one, we iterated on everything from different speed control algorithms, to hopper designs to make sure the discs stack and fall properly into the shooter, new mechanism to pull the discs into the shooter wheel, and many iterations on the loading trey. This dramatically reduced our shooting time at the pyramid, and served us well at Champs...

[Kevin Leonard]

In theory, a side-by-side double shooter isn't difficult to build- what makes it difficult- especially if you also want floor pickup- is successfully indexing the discs. In addition- you're going to need to design with the number ofmotors available in mind - at least one CIM Per shooter, 4 on the drive train, any sort of drop-down intake will make use of another, etc.

I'm interested to see how your new robot comes out and performs.
Keep us posted on your progress!

[MichaelBick]

Originally Posted by Thunder910

In theory, a side-by-side double shooter isn't difficult to build- what makes it difficult- especially if you also want floor pickup- is successfully indexing the discs. In addition- you're going to need to design with the number ofmotors available in mind - at least one CIM Per shooter, 4 on the drive train, any sort of drop-down intake will make use of another, etc.

I'm interested to see how your new robot comes out and performs.
Keep us posted on your progress!

There is little reason to use a CIM for each shooter when you have 4 mini CIMs. They are lighter, spin a bit faster, and have sufficient torque. Also, you can spin the shooters off of the same motors, and while your spin up time might suffer, you the time it takes to get all your frisbees out is 1/3 of normal. 3 mini CIMs/2 CIMs powering both shooters will probably be fine.