Go to Post To the people in purple - I am so proud of what you have accomplished as individuals and as a team! - Ken Patton [more]
Home
Go Back   Chief Delphi > Technical > Technical Discussion
CD-Media   CD-Spy  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

 
Closed Thread
Thread Tools Rate Thread Display Modes
  #1   Spotlight this post!  
Unread 07-01-2008, 20:51
GGCO's Avatar
GGCO GGCO is offline
Registered User
AKA: Grant
FRC #3357
Team Role: Alumni
 
Join Date: Jan 2008
Rookie Year: 2004
Location: Michigan
Posts: 406
GGCO is a splendid one to beholdGGCO is a splendid one to beholdGGCO is a splendid one to beholdGGCO is a splendid one to beholdGGCO is a splendid one to beholdGGCO is a splendid one to beholdGGCO is a splendid one to beholdGGCO is a splendid one to behold
Send a message via AIM to GGCO
Crab Drive HELP!!***

Ok, this is a huge issue on my FRC team. Many of the other team mates (including myself) want our robot to have a crab drive system on it, but some of the other members are opposed to this idea because it is well....new and they have no clue as to how they are going to build something like this.

Can someone please help me out and point me in the right direction as to where I can find some drawings or parts? Thanks in advance.
  #2   Spotlight this post!  
Unread 07-01-2008, 21:00
DonRotolo's Avatar
DonRotolo DonRotolo is offline
Back to humble
FRC #0832
Team Role: Mentor
 
Join Date: Jan 2005
Rookie Year: 2005
Location: Atlanta GA
Posts: 7,007
DonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond repute
Re: Crab Drive HELP!!***

Search the white papers here, also google Crab Drive, especially Wildstang's site.

Crab sounds like a great idea, but if you've never implemented one before, be advised it's not as easy as it looks. Most teams successful with it built a prototype between the end of the last season and the beginning of the next season - 8 months? - and learned how to make it work while there was no time pressure. Your team might consider this approach.

One point: NASCAR doesn't use crab drive, why does your team think it needs to? Examine that question, and the answers might surprise you.

Don
__________________

I am N2IRZ - What's your callsign?
  #3   Spotlight this post!  
Unread 07-01-2008, 21:03
tanmaker
 
Posts: n/a
Re: Crab Drive HELP!!***

Do a little research here at ChiefDelphi. I know there are tons of people willing to help, and they have had some of the same problems as you. I would also recommend doing a search on google, or similar search engine. I would personally suggest a mecanum are omni wheel drive, as they are easier, more reliable, and you should be able to find more info on those drive trains.
  #4   Spotlight this post!  
Unread 07-01-2008, 21:38
lukevanoort lukevanoort is offline
in between teams
AKA: Luke Van Oort
no team
 
Join Date: Oct 2005
Rookie Year: 2005
Location: Waterloo, ON, Canada
Posts: 1,873
lukevanoort has a reputation beyond reputelukevanoort has a reputation beyond reputelukevanoort has a reputation beyond reputelukevanoort has a reputation beyond reputelukevanoort has a reputation beyond reputelukevanoort has a reputation beyond reputelukevanoort has a reputation beyond reputelukevanoort has a reputation beyond reputelukevanoort has a reputation beyond reputelukevanoort has a reputation beyond reputelukevanoort has a reputation beyond repute
Send a message via AIM to lukevanoort
Re: Crab Drive HELP!!***

I agree with Don; if you haven't already built a crab/swerve or have a really solid idea of how to do it, don't. Crab/swerve is probably the most mechanically complex drive system you could try, and the software is even worse. I also agree with Tyler, mecanum is probably the simplest way to a omni system, but it still will require significant amounts of research. The bottom line is, do you want to spend six weeks on a drive system that you've never tried before and risk completely failing, or do you want something tried and true that can be complete by week two (or even before, depending on shipping times)? If you;re adamant on using an omnidirectional system, the PowerPoint on them at the FIRST Robotics Canada Resources Site would be a good start.
__________________
Team 1219: 2009 - Mentor
Team 587: 2005 - Animator, 2006-2008 - Team Captain
  #5   Spotlight this post!  
Unread 07-01-2008, 21:39
Pavan Dave's Avatar
Pavan Dave Pavan Dave is offline
Busy in College
AKA: I am John Gault.
FRC #1745 (P-51 Mustangs) FRC #118 (Robonauts)
Team Role: Mentor
 
Join Date: Jan 2006
Rookie Year: 2006
Location: Richardson, Texas
Posts: 1,387
Pavan Dave has a reputation beyond reputePavan Dave has a reputation beyond reputePavan Dave has a reputation beyond reputePavan Dave has a reputation beyond reputePavan Dave has a reputation beyond reputePavan Dave has a reputation beyond reputePavan Dave has a reputation beyond reputePavan Dave has a reputation beyond reputePavan Dave has a reputation beyond reputePavan Dave has a reputation beyond reputePavan Dave has a reputation beyond repute
Send a message via AIM to Pavan Dave
Re: Crab Drive HELP!!***

I would also recommend looking at the Chief Delphi Media pages. There are very detailed designs of crabs that you may want to incorporate.

Here's the link:
http://www.chiefdelphi.com/media/photos/tags/crabdrive
__________________
Times change. People change. Teams change.
---
2008-Present: FRC1745, P51-Mustangs - Mentor
2005-2008: FRC118, Robonauts - Alumni
National Director of Philanthropy - Delta Epsilon Psi Fraternity, Inc.
1745 - 118 - ΔΕΨ

Last edited by Pavan Dave : 07-01-2008 at 21:44.
  #6   Spotlight this post!  
Unread 07-01-2008, 22:09
IndySam's Avatar
IndySam IndySam is offline
Registered User
FRC #0829 (Digital Goats)
Team Role: Mentor
 
Join Date: Nov 2005
Rookie Year: 2004
Location: Indy
Posts: 3,360
IndySam has a reputation beyond reputeIndySam has a reputation beyond reputeIndySam has a reputation beyond reputeIndySam has a reputation beyond reputeIndySam has a reputation beyond reputeIndySam has a reputation beyond reputeIndySam has a reputation beyond reputeIndySam has a reputation beyond reputeIndySam has a reputation beyond reputeIndySam has a reputation beyond reputeIndySam has a reputation beyond repute
Re: Crab Drive HELP!!***

Quote:
Originally Posted by lukevanoort View Post
I agree with Don; if you haven't already built a crab/swerve or have a really solid idea of how to do it, don't. Crab/swerve is probably the most mechanically complex drive system you could try, and the software is even worse. I also agree with Tyler, mecanum is probably the simplest way to a omni system, but it still will require significant amounts of research. The bottom line is, do you want to spend six weeks on a drive system that you've never tried before and risk completely failing, or do you want something tried and true that can be complete by week two (or even before, depending on shipping times)? If you;re adamant on using an omnidirectional system, the PowerPoint on them at the FIRST Robotics Canada Resources Site would be a good start.
Good advice but the good thing about a mecanum drive is if you can't get it to work you can always put on regular wheels and drive.
__________________
"Champions are champions not because they do anything extraordinary but because they do the ordinary things better than anyone else." —Chuck Knoll


2015 Indianapolis District Winner
2014 Boilermaker Regional Industrial Design Award
2013 Smoky Mountain Regional Industrial Design Award
2012 Boilermaker Engineering Excellence Award
2010 Boilermaker Rockwell Innovation in Control Award.
2009 Buckeye J&J Gracious Professionalism Award
2009 Boilermaker J&J Gracious Professionalism Award
2008 Boilermaker J&J Gracious Professionalism Award
2007 St Louis Regional Winners
  #7   Spotlight this post!  
Unread 07-01-2008, 23:04
ToolGuy91 ToolGuy91 is offline
tool guy
FRC #0384
Team Role: Mascot
 
Join Date: Jan 2008
Rookie Year: 2006
Location: richmond va
Posts: 1
ToolGuy91 is an unknown quantity at this point
Re: Crab Drive HELP!!***

the crab drive is a useful thing to have and as far as pictures go look at either 1086 or 384 robot from last year
  #8   Spotlight this post!  
Unread 07-01-2008, 23:15
CraigHickman
 
Posts: n/a
Re: Crab Drive HELP!!***

Quote:
Originally Posted by Don Rotolo View Post

One point: NASCAR doesn't use crab drive, why does your team think it needs to? Examine that question, and the answers might surprise you.

Don
Because of the hundreds of rules that don't allow drive systems not sold on production cars? Maybe?

Anyway, if you haven't built a crab before, or spent months designing one, you're way behind. Good luck building one, if you can.
  #9   Spotlight this post!  
Unread 07-01-2008, 23:21
abeD's Avatar
abeD abeD is offline
Registered User
FRC #4707 (Mentor FRC#4707 Alumni FRC#710)
Team Role: Mentor
 
Join Date: Sep 2003
Rookie Year: 2001
Location: Ft Lauderdale, FL
Posts: 305
abeD is a splendid one to beholdabeD is a splendid one to beholdabeD is a splendid one to beholdabeD is a splendid one to beholdabeD is a splendid one to beholdabeD is a splendid one to beholdabeD is a splendid one to behold
Re: Crab Drive HELP!!***

Yea I have to agree you are behind, but that shouldn't stop you from trying you can always go to a standard tank drive or even only a two wheel crab with omnis in the back (teams have used this effectively before) if things don't go your way.
__________________
Penn Class 08
  #10   Spotlight this post!  
Unread 07-01-2008, 23:33
Steve_Alaniz Steve_Alaniz is offline
Registered User
FRC #2848 (All Sparks)
Team Role: Mentor
 
Join Date: Mar 2007
Rookie Year: 1997
Location: Dallas
Posts: 211
Steve_Alaniz has a reputation beyond reputeSteve_Alaniz has a reputation beyond reputeSteve_Alaniz has a reputation beyond reputeSteve_Alaniz has a reputation beyond reputeSteve_Alaniz has a reputation beyond reputeSteve_Alaniz has a reputation beyond reputeSteve_Alaniz has a reputation beyond reputeSteve_Alaniz has a reputation beyond reputeSteve_Alaniz has a reputation beyond reputeSteve_Alaniz has a reputation beyond reputeSteve_Alaniz has a reputation beyond repute
Re: Crab Drive HELP!!***

Check out Team 118
http://www.robonauts.org/
They are a Great Bunch of guys and would be happy to advise you. They have been using a crab drive for several years and have developed a fairly complex system. They may tell you you're in over your head but at least if they do, you'll know it's true.

Good luck!
Steve
  #11   Spotlight this post!  
Unread 07-01-2008, 23:42
Ryan Dognaux's Avatar
Ryan Dognaux Ryan Dognaux is offline
Back Home in Indiana
FRC #4329 (Lutheran Roboteers)
Team Role: Mentor
 
Join Date: Apr 2002
Rookie Year: 2001
Location: Indianapolis, IN
Posts: 2,674
Ryan Dognaux has a reputation beyond reputeRyan Dognaux has a reputation beyond reputeRyan Dognaux has a reputation beyond reputeRyan Dognaux has a reputation beyond reputeRyan Dognaux has a reputation beyond reputeRyan Dognaux has a reputation beyond reputeRyan Dognaux has a reputation beyond reputeRyan Dognaux has a reputation beyond reputeRyan Dognaux has a reputation beyond reputeRyan Dognaux has a reputation beyond reputeRyan Dognaux has a reputation beyond repute
Send a message via AIM to Ryan Dognaux
Re: Crab Drive HELP!!***

I will echo what everyone else has pretty much said, check out the mecanum drive as it's probably your best bet for what you're looking to achieve in a short amount of time. It's no easy task, but it's easier than other omni-directional drives. My opinion of this year's game is that if you can create a very slick, very well practiced and smoothly operating mecanum drive, you'll have a significant advantage. Be prepared to put in a lot of time though.
__________________
Ryan Dognaux :: Last Name Pronounced 'Doane Yo'
Team 234 Alum: 2002 - 2005 :: Purdue FIRST Member: 2006 - 2009
Team 1646 Mentor: 2007 - 2009 :: Team 357 Mentor: 2009 - 2012
Team 4329 Mentor: Current
STL Off-Season Event: www.gatewayroboticschallenge.com
  #12   Spotlight this post!  
Unread 07-01-2008, 23:52
Elgin Clock's Avatar
Elgin Clock Elgin Clock is offline
updates this status less than FB!
AKA: the one who "will break into your thoughts..."
FRC #0237 (Black Magic)
Team Role: Mentor
 
Join Date: May 2001
Rookie Year: 2001
Location: H20-Town, Connecticut
Posts: 7,773
Elgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond repute
Send a message via AIM to Elgin Clock
Re: Crab Drive HELP!!***

Can't this team just use the Andymark Mecanum drive that is available as a COTS item?
Fabrication time of the drive wheels themselves would essentially be nothing at that point, (minus some obvious separate assembly time) and then it's just a matter of waiting for it to be shipped to you, mounting it on the robot, and then having drivers practice with them.

Am I missing something here with my suggestion?
__________________
The influence of many leads to the individuality of one. - E.C.C. (That's me!!)

  #13   Spotlight this post!  
Unread 08-01-2008, 00:44
Cory's Avatar
Cory Cory is offline
Registered User
AKA: Cory McBride
FRC #0254 (The Cheesy Poofs)
Team Role: Engineer
 
Join Date: May 2002
Rookie Year: 2001
Location: Redwood City, CA
Posts: 6,812
Cory has a reputation beyond reputeCory has a reputation beyond reputeCory has a reputation beyond reputeCory has a reputation beyond reputeCory has a reputation beyond reputeCory has a reputation beyond reputeCory has a reputation beyond reputeCory has a reputation beyond reputeCory has a reputation beyond reputeCory has a reputation beyond reputeCory has a reputation beyond repute
Send a message via AIM to Cory
Re: Crab Drive HELP!!***

Quote:
Originally Posted by ToolGuy91 View Post
the crab drive is a useful thing to have and as far as pictures go look at either 1086 or 384 robot from last year
As I remember it, both teams used mechanum drive, which is totally different than swerve.
__________________
2001-2004: Team 100
2006-Present: Team 254
  #14   Spotlight this post!  
Unread 08-01-2008, 01:04
=Martin=Taylor= =Martin=Taylor= is offline
run the trap!!!
FRC #0100 (The Wild Hat Society)
Team Role: Human Player
 
Join Date: Feb 2006
Rookie Year: 2005
Location: Bezerkeley, California
Posts: 1,255
=Martin=Taylor= has a reputation beyond repute=Martin=Taylor= has a reputation beyond repute=Martin=Taylor= has a reputation beyond repute=Martin=Taylor= has a reputation beyond repute=Martin=Taylor= has a reputation beyond repute=Martin=Taylor= has a reputation beyond repute=Martin=Taylor= has a reputation beyond repute=Martin=Taylor= has a reputation beyond repute=Martin=Taylor= has a reputation beyond repute=Martin=Taylor= has a reputation beyond repute=Martin=Taylor= has a reputation beyond repute
Re: Crab Drive HELP!!***

Quote:
Originally Posted by GGCO View Post
Ok, this is a huge issue on my FRC team. Many of the other team mates (including myself) want our robot to have a crab drive system on it, but some of the other members are opposed to this idea because it is well....new and they have no clue as to how they are going to build something like this.

Can someone please help me out and point me in the right direction as to where I can find some drawings or parts? Thanks in advance.
If you are planning to build a swerve AND a hurdling mechanism... Good Luck... I certainly wouldn't undertake it...

But if you just want to focus on herding the balls and quickly moving around the track why not? If your drive train is the only thing your building this season why not do something sophisticated like a swerve?
__________________
"Cooperation; because life is a team sport"
-Philip J. Fry
  #15   Spotlight this post!  
Unread 08-01-2008, 01:35
AdamHeard's Avatar
AdamHeard AdamHeard is offline
Lead Mentor
FRC #0973 (Greybots)
Team Role: Mentor
 
Join Date: Oct 2004
Rookie Year: 2004
Location: Atascadero
Posts: 5,508
AdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond reputeAdamHeard has a reputation beyond repute
Send a message via AIM to AdamHeard
Re: Crab Drive HELP!!***

If you do decide to undertake a swerve/crab design make sure to spend a little extra time in the design process to build in a back up plan; Make you can switch the crab/swerve into just a normal 4WD in case it doesn't work out. This way you at least have a driving base in case of failure and won't be stuck with a completely disappointing season.

I'd say go for it if you have you have a reasonable amount of resources; you miss 100% of the shots you don't take.
Closed Thread


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

Similar Threads
Thread Thread Starter Forum Replies Last Post
Crab Drive nukelear1991 Programming 13 21-12-2007 18:02
HELP?!? with Omnidirectional/Crab Drive KMAC42 Technical Discussion 8 09-01-2007 21:34
Crab Drive Joe_Widen Technical Discussion 9 21-04-2006 21:50
Crab drive question Tazlikesrobots Technical Discussion 13 31-07-2005 20:51
Crab Drive Collin Fultz Technical Discussion 3 04-09-2002 16:35


All times are GMT -5. The time now is 02:11.

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