23-03-2012 17:00

=Martin=Taylor=

Re: pic: 2949 PWNAGE: 2012 Robot

Wow!

That looks really well designed! The quality of your CAD is phenomenal.

What was the motivation behind using belts instead of wheels to shoot the balls? My old team tried something similar for reasons that IMO did not make sense. The end result was a horribly inefficient system that (despite using two CIMs) could only fire a miserable 15'. It looks like your system is far better designed and probably vastly more efficient but still, 4 motors for the shooter is a lot.

23-03-2012 18:55

DampRobot

Re: pic: 2949 PWNAGE: 2012 Robot

Quote:

Originally Posted by =Martin=Taylor= Wow! That looks really well designed! The quality of your CAD is phenomenal. What was the motivation behind using belts instead of wheels to shoot the balls? My old team tried something similar for reasons that IMO did not make sense. The end result was a horribly inefficient system that (despite using two CIMs) could only fire a miserable 15'. It looks like your system is far better designed and probably vastly more efficient but still, 4 motors for the shooter is a lot.

24-03-2012 00:00

=Martin=Taylor=

Re: pic: 2949 PWNAGE: 2012 Robot

Quote:

Originally Posted by DampRobot Same. My team is using belts too, which have been a really bad decision. I keep trying to get us to switch to a hooded shooter, but no. The claim on my team is is improves accuracy, the theory being that the belts are essentially a very consistent feeder. Apparently, tests revealed that belts were more accurate. Whatever. It doesn't look like most teams are shooting farther than the key anyway...

24-03-2012 00:25

theawesome1730

Re: pic: 2949 PWNAGE: 2012 Robot

Really great robot! Thanks for helping us at GKC in quarterfinals!

24-03-2012 01:38

pwnageNick

Re: pic: 2949 PWNAGE: 2012 Robot

We went with the belt shooter for a couple of reasons. First, because the belts have a shooting length of 14in, it gives the ball more contact time to be able to build up to the full speed that the belts are running at. We found that with the wheel shooters, you tend to have less contact time with the wheel, which means you had to compress the ball more to be able to shoot it far enough. After doing some prototyping, we found that compressing the ball too much made the ball deform a lot in mid-air, and we wanted to avoid this. So because the ball can get to the full velocity of the RPM of the belts, we don't have to compress the ball nearly as much. Also, we are able to more precisely change the amount of backspin we put on the ball. Each side has an encoder on it, so we can adjust the distance the balls travel using a PID controller.

With everything in FIRST though, there are many different effective ways to score the balls in this years game. Personally for us this was the best and most accurate way that we found.

Hope that explained it well.