View Single Post
  #6   Spotlight this post!  
Unread 20-09-2015, 11:21
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: 7,601
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: 2015 robot offseason redesign

Quote:
Originally Posted by Bob Z View Post
Do you know why 4 wheel intake is so efficient?
Quote:
Originally Posted by asid61 View Post
I'm not 100% sure, having not built one myself (no time, even in the offseason) but it appears to be that the totes keeps constant contact with the wheels, even when intaking a tote diagonally (such as 1114's landfill mining thins year).

I agree that you need some kind of container flipper capable of (imo) flipping in 5 seconds or less, for maximum efficiency.
asid is pretty much right here - a four wheel intake is much, much faster at dealing with totes collected at odd angles than a two wheel intake. With the right geometry you can drive into a tote oriented horizontally relative to the robot and the robot will just spin the tote into the proper orientation without a second thought.

You can use either some kind of suspension / compliance in order to allow the pairs of wheels to articulate, or if you get the geometry right you can place the outer wheels slightly farther apart than the inner wheels, or both of these things - each of these ways seems to work.

You also need to get the right kind of traction material - a soft polyurethane is best. Colsons, kit wheels, etc. are too firm. Nitrile (white "marshmallow" wheels) are not tacky enough. Polyurethane drive rollers from McMaster work well, or you can buy polyurethane (surgical) tubing of the right OD and ID and attach them to custom wheels.
__________________
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