Go to Post There's more to the game then winning. - Gabriel [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 05-12-2006, 17:18
Andy Baker's Avatar Woodie Flowers Award
Andy Baker Andy Baker is offline
President, AndyMark, Inc.
FRC #3940 (CyberTooth)
Team Role: Engineer
 
Join Date: May 2001
Rookie Year: 1998
Location: Kokomo, Indiana
Posts: 3,422
Andy Baker has a reputation beyond reputeAndy Baker has a reputation beyond reputeAndy Baker has a reputation beyond reputeAndy Baker has a reputation beyond reputeAndy Baker has a reputation beyond reputeAndy Baker has a reputation beyond reputeAndy Baker has a reputation beyond reputeAndy Baker has a reputation beyond reputeAndy Baker has a reputation beyond reputeAndy Baker has a reputation beyond reputeAndy Baker has a reputation beyond repute
Send a message via AIM to Andy Baker
Friction coefficients for Omni wheels and Mecanum wheels from AndyMark

Mark and I did some work last night that has been overdue. We performed a test of friction coefficients on our wheels from AndyMark, Inc.. We got some interesting results.

Each wheel was tested in 4 ways:

Radial Static Friction
Radial Dynamic Friction
Transverse Static Friction
Transverse Dynamic Friction

Radial friction could also be considered driving friction, as it is the friction involved when the wheel is being driven forward and reverse. Or, it can be applied when the wheel is stationary and it is resisting a force from the front or back.

Transverse Friction is the ability of the wheel to move sideways, or scrub. This is also the friction involved when the wheel is stationary and a force from the side is applied to it.

Static friction is involved when the wheel just begins to move from a stationary position. Dynamic friction is involved when the wheel is already moving.

6 wheels were involved in the testing:

8" and 6" Plastic Omni Wheels
8" and 6" Aluminum Omni Wheels (not on website yet, but VERY soon)
8" Coolie Dualie Wheel (not on website yet, but VERY soon)
8" Mecanum Wheel

Here are results:

8" Plastic Omni Wheel
  • Radial Static: 1.07
  • Radial Dynamic: 0.9
  • Transverse Static: 0.20
  • Transverse Dynamic: 0.16
6" Plastic Omni Wheel
  • Radial Static: 0.9
  • Radial Dynamic: 0.8
  • Transverse Static: 0.27
  • Transverse Dynamic: 0.20
8" Aluminum Omni Wheel
  • Radial Static: 1.15
  • Radial Dynamic: 0.9
  • Transverse Static: 0.31
  • Transverse Dynamic: 0.20
6" Aluminum Omni Wheel
  • Radial Static: 0.9
  • Radial Dynamic: 0.8
  • Transverse Static: 0.26
  • Transverse Dynamic: 0.20
8" Coolie Dualie Wheel
  • Radial Static: 1.05
  • Radial Dynamic: 1.0
  • Transverse Static: 0.29
  • Transverse Dynamic: 0.20
8" Mecanum Wheel
  • Radial Static: 0.7
  • Radial Dynamic: 0.6
  • Transverse Static: 0.7
  • Transverse Dynamic: 0.6
The new Aluminum Omni-Wheels have the same roller geometry and setup as the Plastic Omni-Wheels.

<edit...

These tests were made on FRC-type carpet, with 30 lbs. of downforce on each wheel. The omni wheels were tested individually, while the Mecanums were tested in a right and left pair, with 60 lbs. of downforce.

(thanks for the question, Andrew Blair)

... end edit>

Andy Baker

Last edited by Andy Baker : 05-12-2006 at 20:27.
  #2   Spotlight this post!  
Unread 05-12-2006, 18:16
efoote868 efoote868 is offline
foote stepped in
AKA: E. Foote
FRC #0868
Team Role: Mentor
 
Join Date: Mar 2006
Rookie Year: 2005
Location: Noblesville, IN
Posts: 1,421
efoote868 has a reputation beyond reputeefoote868 has a reputation beyond reputeefoote868 has a reputation beyond reputeefoote868 has a reputation beyond reputeefoote868 has a reputation beyond reputeefoote868 has a reputation beyond reputeefoote868 has a reputation beyond reputeefoote868 has a reputation beyond reputeefoote868 has a reputation beyond reputeefoote868 has a reputation beyond reputeefoote868 has a reputation beyond repute
Re: Friction coefficients for Omni wheels and Mecanum wheels from AndyMark

Correct me if i'm wrong, but doesn't the mecanum wheel have a theoretical value of .707? (cos45)... Which means you're doing fairly well.
__________________

Be Healthy. Never Stop Learning. Say It Like It Is. Own It. Like our values? Flexware Innovation is hiring!. We're looking for Senior Automation, Software, and System Engineers. Check us out!
  #3   Spotlight this post!  
Unread 05-12-2006, 18:43
Tristan Lall's Avatar
Tristan Lall Tristan Lall is offline
Registered User
FRC #0188 (Woburn Robotics)
 
Join Date: Aug 2001
Rookie Year: 1999
Location: Toronto, ON
Posts: 2,484
Tristan Lall has a reputation beyond reputeTristan Lall has a reputation beyond reputeTristan Lall has a reputation beyond reputeTristan Lall has a reputation beyond reputeTristan Lall has a reputation beyond reputeTristan Lall has a reputation beyond reputeTristan Lall has a reputation beyond reputeTristan Lall has a reputation beyond reputeTristan Lall has a reputation beyond reputeTristan Lall has a reputation beyond reputeTristan Lall has a reputation beyond repute
Re: Friction coefficients for Omni wheels and Mecanum wheels from AndyMark

Quote:
Originally Posted by efoote868
Correct me if i'm wrong, but doesn't the mecanum wheel have a theoretical value of .707? (cos45)... Which means you're doing fairly well.
You seem to be thinking of efficiency. The coefficient of friction is independent of this.
  #4   Spotlight this post!  
Unread 05-12-2006, 19:16
Michael Hill's Avatar
Michael Hill Michael Hill is offline
Registered User
FRC #3138 (Innovators Robotics)
Team Role: Mentor
 
Join Date: Jul 2004
Rookie Year: 2003
Location: Dayton, OH
Posts: 1,580
Michael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond repute
Re: Friction coefficients for Omni wheels and Mecanum wheels from AndyMark

I don't think you can have a theoretical coefficient of friction. My engineering professor said that it has to be measured.
  #5   Spotlight this post!  
Unread 05-12-2006, 19:30
Andrew Blair's Avatar
Andrew Blair Andrew Blair is offline
SAE Formula is FIRST with Gasoline.
FRC #0306 (CRT)
Team Role: Alumni
 
Join Date: Feb 2005
Rookie Year: 2004
Location: Corry
Posts: 1,193
Andrew Blair has a reputation beyond reputeAndrew Blair has a reputation beyond reputeAndrew Blair has a reputation beyond reputeAndrew Blair has a reputation beyond reputeAndrew Blair has a reputation beyond reputeAndrew Blair has a reputation beyond reputeAndrew Blair has a reputation beyond reputeAndrew Blair has a reputation beyond reputeAndrew Blair has a reputation beyond reputeAndrew Blair has a reputation beyond reputeAndrew Blair has a reputation beyond repute
Send a message via AIM to Andrew Blair Send a message via Yahoo to Andrew Blair
Re: Friction coefficients for Omni wheels and Mecanum wheels from AndyMark

Andy, what surface were these tested on? Game carpet probably?
__________________
Reading makes a full man, conference a ready man, and writing an exact man.
-Sir Francis Bacon

"Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius -- and a lot of courage -- to move in the opposite direction."
-Albert Einstein
  #6   Spotlight this post!  
Unread 05-12-2006, 20:28
Andy Baker's Avatar Woodie Flowers Award
Andy Baker Andy Baker is offline
President, AndyMark, Inc.
FRC #3940 (CyberTooth)
Team Role: Engineer
 
Join Date: May 2001
Rookie Year: 1998
Location: Kokomo, Indiana
Posts: 3,422
Andy Baker has a reputation beyond reputeAndy Baker has a reputation beyond reputeAndy Baker has a reputation beyond reputeAndy Baker has a reputation beyond reputeAndy Baker has a reputation beyond reputeAndy Baker has a reputation beyond reputeAndy Baker has a reputation beyond reputeAndy Baker has a reputation beyond reputeAndy Baker has a reputation beyond reputeAndy Baker has a reputation beyond reputeAndy Baker has a reputation beyond repute
Send a message via AIM to Andy Baker
Re: Friction coefficients for Omni wheels and Mecanum wheels from AndyMark

Quote:
Originally Posted by Andrew Blair
Andy, what surface were these tested on? Game carpet probably?
Yes, thanks. I edited my original note above with this info and also downforce info.

Andy
  #7   Spotlight this post!  
Unread 05-12-2006, 20:37
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: Friction coefficients for Omni wheels and Mecanum wheels from AndyMark

Is there a chance of future testing using other relatively common FIRST field materials like HDPE?
__________________
Team 1219: 2009 - Mentor
Team 587: 2005 - Animator, 2006-2008 - Team Captain
  #8   Spotlight this post!  
Unread 16-12-2006, 19:01
Scott358 Scott358 is offline
Engineer/Mentor
AKA: Scott5736
FRC #5736 (Kingsmen)
Team Role: Mentor
 
Join Date: Jan 2002
Rookie Year: 1999
Location: Kings Park, Long Island, NY
Posts: 152
Scott358 is just really niceScott358 is just really niceScott358 is just really niceScott358 is just really niceScott358 is just really nice
Re: Friction coefficients for Omni wheels and Mecanum wheels from AndyMark

Thanks Andy.. great info.

As we're prototyping with the 4" traction wheels from AM, and we're looking for more traction, does anyone have any thoughts for materials with a higher cof than the rough top?

Any thoughts would be appreciated.
__________________
Scott5736 (formerly Scott3137(formerly Scott358))
  #9   Spotlight this post!  
Unread 16-12-2006, 19:15
Joel J's Avatar
Joel J Joel J is offline
do you..
no team
 
Join Date: May 2001
Rookie Year: 2000
Location: San Jose, CA
Posts: 1,445
Joel J has a reputation beyond reputeJoel J has a reputation beyond reputeJoel J has a reputation beyond reputeJoel J has a reputation beyond reputeJoel J has a reputation beyond reputeJoel J has a reputation beyond reputeJoel J has a reputation beyond reputeJoel J has a reputation beyond reputeJoel J has a reputation beyond reputeJoel J has a reputation beyond reputeJoel J has a reputation beyond repute
Re: Friction coefficients for Omni wheels and Mecanum wheels from AndyMark

Quote:
Originally Posted by Scott358 View Post
Thanks Andy.. great info.

As we're prototyping with the 4" traction wheels from AM, and we're looking for more traction, does anyone have any thoughts for materials with a higher cof than the rough top?

Any thoughts would be appreciated.
the brecoflex stuff.. Supergrip green, is it? 1.5-1.7 vs. 1.2-1.3, I think.
__________________
Joel Johnson

Division By Zero (229) Alumni, 2003-2007
RAGE (173) Alumni, 1999-2003
  #10   Spotlight this post!  
Unread 16-12-2006, 19:23
chris31 chris31 is offline
Team 2021 Captain
AKA: Chris Davidson
FRC #2021 (FA Robotics)
Team Role: Mentor
 
Join Date: Nov 2005
Rookie Year: 2006
Location: Atlanta, GA/ Fredericksburg,VA
Posts: 949
chris31 has a reputation beyond reputechris31 has a reputation beyond reputechris31 has a reputation beyond reputechris31 has a reputation beyond reputechris31 has a reputation beyond reputechris31 has a reputation beyond reputechris31 has a reputation beyond reputechris31 has a reputation beyond reputechris31 has a reputation beyond reputechris31 has a reputation beyond reputechris31 has a reputation beyond repute
Send a message via AIM to chris31
Re: Friction coefficients for Omni wheels and Mecanum wheels from AndyMark

Quote:
Originally Posted by Joel J. View Post
the brecoflex stuff.. Supergrip green, is it? 1.5-1.7 vs. 1.2-1.3, I think.
This is what I see on there site. http://brecoflex.com/images.php?IMGID=82&TBL=submenu2

However, like you said, I thought they had something more grippy.
  #11   Spotlight this post!  
Unread 16-12-2006, 19:32
Joel J's Avatar
Joel J Joel J is offline
do you..
no team
 
Join Date: May 2001
Rookie Year: 2000
Location: San Jose, CA
Posts: 1,445
Joel J has a reputation beyond reputeJoel J has a reputation beyond reputeJoel J has a reputation beyond reputeJoel J has a reputation beyond reputeJoel J has a reputation beyond reputeJoel J has a reputation beyond reputeJoel J has a reputation beyond reputeJoel J has a reputation beyond reputeJoel J has a reputation beyond reputeJoel J has a reputation beyond reputeJoel J has a reputation beyond repute
Re: Friction coefficients for Omni wheels and Mecanum wheels from AndyMark

Ignore that. They sent out a message to all teams at the start of the 2006 season, and they reported the findings of their tests of several of their backing material on the carpet, diamond plate, and ramp.. Its in the white paper's section somewhere. That message aside, I don't think I have ever seen anything grip better than the green brecoflex treads.

edit: http://www.chiefdelphi.com/media/papers/1772
__________________
Joel Johnson

Division By Zero (229) Alumni, 2003-2007
RAGE (173) Alumni, 1999-2003
  #12   Spotlight this post!  
Unread 16-12-2006, 19:40
Scott358 Scott358 is offline
Engineer/Mentor
AKA: Scott5736
FRC #5736 (Kingsmen)
Team Role: Mentor
 
Join Date: Jan 2002
Rookie Year: 1999
Location: Kings Park, Long Island, NY
Posts: 152
Scott358 is just really niceScott358 is just really niceScott358 is just really niceScott358 is just really niceScott358 is just really nice
Re: Friction coefficients for Omni wheels and Mecanum wheels from AndyMark

Hey Joel...

Thanks for the info... I had searched the white papers and somehow missed this. I'll give them a call.

On a side note, is your footer up-to-date? If so, I'll see you in Hartford and on LI.

Regards,
__________________
Scott5736 (formerly Scott3137(formerly Scott358))
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
pic: AndyMark Mecanum Wheels Madison Technical Discussion 13 09-10-2006 00:29
Looking for Mecanum Wheels Armando Gonzalez General Forum 30 24-05-2006 12:54
AndyMark Omni Wheels Wayne Doenges Technical Discussion 11 25-01-2006 23:54
omni wheel instead of mecanum wheels Leav Technical Discussion 4 15-01-2006 18:53


All times are GMT -5. The time now is 02:20.

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