|
Re: 4607 Butterslide Drivetrain
"Butterslide" is a cool name. This drive has existed in various iterations before (The "nonadrive" / "decadrive" 148 sometimes uses that the butterfly drive emerged from is a different version of this), but this is still cool. The design has some neat tricks in it and is a great start
The first challenge you'll encounter with this style of drive is that in Omni mode, you'll have six wheels touching the ground at the same time. These probably won't end up coplanar, and you may encounter weird variations in strafing ability based on CG, chassis rigidity, etc. Lots of teams spring-load at least the sideways Omni wheels (or sometimes, all of the Omni wheels!) in order to deal with variation in chassis rigidity, etc. With good code, you may be able to compensate for unexpected chassis maneuvers though. Not sure how it'll work out.
The second challenge is going to be how the traction wheels are loaded. You are essentially cantilevering a wheel off of another cantilevered shaft, and this multiplies the forces and torques at play to an extent. Minimizing the length of that second lever arm (which it seems you've done) is a great first step to mitigating this issue, but only testing will show if this setup is robust enough. I would look into how the Vex Drop Drive handles this issue - these modules actually transmit some of the forces through the 2x1 tube with physical constraints in a really clever way.
Some teams (148 most notably) have found the easiest way to make a robust setup is to have the TRACTION wheel permanently mounted to the chassis, and make the OMNI wheel pivot. Since the Omni wheel obviously deals with less side load than the traction wheel, this setup is more robust. However this does present a challenge since generally the traction wheel runs at a lower gear ratio than the Omni (which is a good choice by the way) and thus it's hard to gear it right without also putting the CIM on the pivot. Other teams (3928, the Drop Drive) deal with this issue differently.
Great start! Keep doing stuff like this. Make sure you have enough clearance to actually insert your gears into the tubing / whatever as well.
__________________
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)
|