View Single Post
  #2   Spotlight this post!  
Unread 05-03-2012, 07:37
martin417's Avatar
martin417 martin417 is offline
Opinionated old goat
AKA: Martin Wilson
no team
Team Role: Mentor
 
Join Date: Feb 2008
Rookie Year: 2008
Location: Buford, GA
Posts: 719
martin417 has a reputation beyond reputemartin417 has a reputation beyond reputemartin417 has a reputation beyond reputemartin417 has a reputation beyond reputemartin417 has a reputation beyond reputemartin417 has a reputation beyond reputemartin417 has a reputation beyond reputemartin417 has a reputation beyond reputemartin417 has a reputation beyond reputemartin417 has a reputation beyond reputemartin417 has a reputation beyond repute
Re: shooter wheel tread types

Quote:
Originally Posted by wireties View Post
We have a shooter that uses 2 8" AM FIRST wheels with the standard urethane rubber treads on a rotating 55 degree LA turrent. We spin it up from 300 to 3K RPM using PID control of 2 FP 0673 (6:1) and 2 AM 9015 (4.64:1) motors. It works quite well but we keep tweaking the performance on a practice bot (typical engineers!).

I searched and did not find much discussion about using different wheel treads on an otherwise working shooter. Has anyone tried something like AM plaction wheels with wedge-top or rough-top tread? Does it help/hurt?

Opinions, suggestions?

TIA
Sounds like way more motor than necessary. We are using a custom 6" diameter polycarbonate wheel with 10" polycarbonate flanges on the sides. We are spinning it with a single FP 0673 using a BB Cimulator and further reducing through a belt drive for a final ratio of about 4.1:1. We spin the wheel anywhere from ~2200 RPM for close up shots to ~3300 RPM to shoot from the barrier. We have no problems spinning up quickly and maintaining speed, nor shooting rapidly.

By the way, A PID is over kill for this application. The system has enough inertia that speed changes slowly (in the computer sense of slowly) so there are better ways to control the speed than a PID.

As for tread, we covered the polycarb wheel with self adhesive rubber foam. It does wear away with use, but does not damage the ball.
__________________
Former Mentor Team 1771
Former mentor Team 4509