View Single Post
  #6   Spotlight this post!  
Unread 12-01-2011, 03:14
Chris is me's Avatar
Chris is me Chris is me is offline
no bag, vex only, final destination
AKA: Pinecone
FRC #0228 (GUS Robotics); FRC #2170 (Titanium Tomahawks)
Team Role: Mentor
 
Join Date: Dec 2008
Rookie Year: 2006
Location: Glastonbury, CT
Posts: 7,705
Chris is me has a reputation beyond reputeChris is me has a reputation beyond reputeChris is me has a reputation beyond reputeChris is me has a reputation beyond reputeChris is me has a reputation beyond reputeChris is me has a reputation beyond reputeChris is me has a reputation beyond reputeChris is me has a reputation beyond reputeChris is me has a reputation beyond reputeChris is me has a reputation beyond reputeChris is me has a reputation beyond repute
Send a message via AIM to Chris is me
Re: pic: 2791's Chassis

Quote:
Originally Posted by Matt H. View Post
Why did you choose to use six motors in your drive train?

4 CIMs at a 7.4:1 ratio gives a maximum of 634 in-lbs of torque at the wheels. With 4 inch wheels, that becomes ~315 lbs of force to accelerate the robot. However, with a generous coefficient of friction of 1.5 your robot will spin its wheels at 180 lbs of accelerating force.
We're assuming about 1.3 for traction.

Essentially, pushing power. 4 CIMs geared at 12 FPS draws a LOT of current. 4 CIMs and 2 BB isn't quite traction limited (60some amps last time I checked) but at least we won't stall out pushing mecanum bots and kitbots around a bit, and we'll have great acceleration.
__________________
Mentor / Drive Coach: 228 (2016-?)
...2016 Waterbury SFs (with 3314, 3719), RIDE #2 Seed / Winners (with 1058, 6153), Carver QFs (with 503, 359, 4607)
Mentor / Consultant Person: 2170 (2017-?)
---
College Mentor: 2791 (2010-2015)
...2015 TVR Motorola Quality, FLR GM Industrial Design
...2014 FLR Motorola Quality / SFs (with 341, 4930)
...2013 BAE Motorola Quality, WPI Regional #1 Seed / Delphi Excellence in Engineering / Finalists (with 20, 3182)
...2012 BAE Imagery / Finalists (with 1519, 885), CT Xerox Creativity / SFs (with 2168, 118)
Student: 1714 (2009) - 2009 Minnesota 10,000 Lakes Regional Winners (with 2826, 2470)
2791 Build Season Photo Gallery - Look here for mechanism photos My Robotics Blog (Updated April 11 2014)
Reply With Quote