Go to Post I think we must take seriously the importance of "infecting" the rest of the world with this passion. - Tstone [more]
Home
Go Back   Chief Delphi > FIRST > General Forum
CD-Media   CD-Spy  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

 
 
 
Thread Tools Rate Thread Display Modes
Prev Previous Post   Next Post Next
  #3   Spotlight this post!  
Unread 11-12-2015, 20:26
EricH's Avatar
EricH EricH is offline
New year, new team
FRC #1197 (Torbots)
Team Role: Engineer
 
Join Date: Jan 2005
Rookie Year: 2003
Location: SoCal
Posts: 19,823
EricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond repute
Re: FRC drive train

That depends a lot on the wheels. I would even go so far as to say that the tread choice would have more variation. But...

It also depends on the drivetrain. Confining ourselves to tank drivetrains, the single biggest factor is going to be the ratio of trackwidth (the distance between the left and right wheels) to wheelbase (distance between front and back wheels that are in contact with the floor). Bigger is better (unless your robot is falling over due to its own motion) for this ratio, as it relates to turning (but there are other design considerations as well, which I won't go into here as they're game-dependent).

A 6WD flat drivetrain will probably not turn as well as an 8WD flat drivetrain, but for different reasons than a 6WD drop vs. and 8WD drop. In this specific case, the 8WD has a slightly lower frictional force from the far corner wheels (less normal force on those wheels) with which to resist turning. A 4WD tank will be a nuisance to turn smoothly.

But when a dropped center wheel is introduced in a 6WD, the effective wheelbase is shortened. An 8WD has two dropped center wheels on each side, which will further shorten the wheelbase (and tends to remove the rocking motion of a 6WD). The shorter wheelbase improves turning, assuming the trackwidth stays the same.
__________________
Past teams:
2003-2007: FRC0330 BeachBots
2008: FRC1135 Shmoebotics
2012: FRC4046 Schroedinger's Dragons

"Rockets are tricky..."--Elon Musk

Reply With Quote
 


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 12:00.

The Chief Delphi Forums are sponsored by Innovation First International, Inc.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi