View Single Post
  #11   Spotlight this post!  
Unread 14-03-2012, 14:55
Dan_Karol Dan_Karol is offline
Mentor and Coach
AKA: Daniel Karol
FRC #0131 (CHAOS)
Team Role: Mentor
 
Join Date: Dec 2006
Rookie Year: 2004
Location: Southborough MA
Posts: 63
Dan_Karol has a spectacular aura aboutDan_Karol has a spectacular aura about
Send a message via AIM to Dan_Karol
Re: Flywheels and Shooter Wheels

Quote:
Originally Posted by Ether View Post
This wouldn't be very ideal (or safe) on a 19,000 rpm motor like the 550.


Ether,

You may be making several assumptions with this statement. This year 1100 is using a single wheel shooter that is mounted direct drive to a Fisher Price motor (9015 or 9013?) our shooter diameter is about 2.3" (although if I rebuilt it I would use 3" tubing instead) and as such we can get away with a very small flywheel.

We know the energy stored in a flywheel can be represented as:
E = (Moment_of_Inertia * Angular_Velocity^2)/2

So if you double the angular velocity you will effectively quadruple the Energy stored in the flywheel. On the same lines, if you have a target Energy you wish to store in the flywheel, then by connecting the flywheel to the motor and not to the shooter shaft you can use a smaller lighter flywheel (more ideal in FIRST applications where shooters tend to be high up in the robot and weight and balance are issues).

The other thing I would like to mention is that the safety of the system mostly depends on the configuration of how things are assembled. If properly done there is no more chance of something going wrong in one model of the system then in the other.

If you have concerns about the safety of direct drive applications of the flywheel/shooter in our robot please send me a PM.