Go to Post Thinking about this game within the confines of previous years will limit you. - Gregor [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 26-04-2004, 13:40
George1902's Avatar
George1902 George1902 is offline
It's a SPAM thing...
AKA: George1083; George180
FRC #0180 (SPAM)
Team Role: Mentor
 
Join Date: Dec 2001
Rookie Year: 1998
Location: Stuart, FL
Posts: 785
George1902 has a reputation beyond reputeGeorge1902 has a reputation beyond reputeGeorge1902 has a reputation beyond reputeGeorge1902 has a reputation beyond reputeGeorge1902 has a reputation beyond reputeGeorge1902 has a reputation beyond reputeGeorge1902 has a reputation beyond reputeGeorge1902 has a reputation beyond reputeGeorge1902 has a reputation beyond reputeGeorge1902 has a reputation beyond reputeGeorge1902 has a reputation beyond repute
Re: Omni Wheels Survey

If the mecanum wheels produced 100% power in the forward or reverse direction, it would be impossible to strafe. We know that this setup can strafe, so the power must be in the direction that the rollers are facing.

Another proof is to watch a video of a holonomic platform with mecanum wheels. Watch what happens when 2 wheels on a diagonal are powered. The robot moves in the direction that the rollers are facing.
__________________
George

"Darkness cannot drive out darkness; only light can do that. Hate cannot drive out hate; only love can do that."
-- Martin Luther King, Jr.
  #2   Spotlight this post!  
Unread 26-04-2004, 13:58
Max Lobovsky's Avatar
Max Lobovsky Max Lobovsky is offline
Fold em oval!
FRC #1257 (Parallel Universe)
Team Role: College Student
 
Join Date: Jan 2004
Rookie Year: 2004
Location: Scotch Plains, NJ
Posts: 1,026
Max Lobovsky has a brilliant futureMax Lobovsky has a brilliant futureMax Lobovsky has a brilliant futureMax Lobovsky has a brilliant futureMax Lobovsky has a brilliant futureMax Lobovsky has a brilliant futureMax Lobovsky has a brilliant futureMax Lobovsky has a brilliant futureMax Lobovsky has a brilliant futureMax Lobovsky has a brilliant futureMax Lobovsky has a brilliant future
Send a message via AIM to Max Lobovsky
Re: Omni Wheels Survey

George, i know 1083 wants to try to build its own omniwheels next year and i was wondering if you were planning to make them bigger than those 4.72" ones from omniwheel.com. I can't actually think of a valid reason why wheels that small are bad, but very few teams seem to use wheels that small, so there is probably a reason. Maybe a larger wheel gives you the potential for better traction. (yes, i know in theory traction is only dependent on the weight of the robot and the materials contacting each other, but in practice, it isnt that simple) Your grooved omniwheels seemed to have better traction than any others, bought or built.
__________________
Learn, edit, inspire: The FIRSTwiki.
Team 1257


2005 NYC Regional - 2nd seed, Xerox Creativity Award, Autodesk Visualization Award
2005 Chesapeake Regional - Engineering Inspiration Award
2004 Chesapeake Regional - Rookie Inspiration award
2004 NJ Regional - Team Spirit Award
  #3   Spotlight this post!  
Unread 26-04-2004, 23:10
George1902's Avatar
George1902 George1902 is offline
It's a SPAM thing...
AKA: George1083; George180
FRC #0180 (SPAM)
Team Role: Mentor
 
Join Date: Dec 2001
Rookie Year: 1998
Location: Stuart, FL
Posts: 785
George1902 has a reputation beyond reputeGeorge1902 has a reputation beyond reputeGeorge1902 has a reputation beyond reputeGeorge1902 has a reputation beyond reputeGeorge1902 has a reputation beyond reputeGeorge1902 has a reputation beyond reputeGeorge1902 has a reputation beyond reputeGeorge1902 has a reputation beyond reputeGeorge1902 has a reputation beyond reputeGeorge1902 has a reputation beyond reputeGeorge1902 has a reputation beyond repute
Re: Omni Wheels Survey

Quote:
Originally Posted by maxlobovsky
George, i know 1083 wants to try to build its own omniwheels next year and i was wondering if you were planning to make them bigger than those 4.72" ones from omniwheel.com.
If we do build our own, they'll prolly be bigger. I think bigger ones are easier to make, although I'm not totally sure about that. 6" would be a good size, I think.
Quote:
Originally Posted by maxlobovsky
I can't actually think of a valid reason why wheels that small are bad, but very few teams seem to use wheels that small, so there is probably a reason.
The main problem we had with the smaller wheels was clearance. I think our robot ended up with < .5" of ground clearance.
Quote:
Originally Posted by maxlobovsky
Your grooved omniwheels seemed to have better traction than any others, bought or built.
Thank you very much. =-]
That's probably the best argument for us using them again in the future.
__________________
George

"Darkness cannot drive out darkness; only light can do that. Hate cannot drive out hate; only love can do that."
-- Martin Luther King, Jr.
  #4   Spotlight this post!  
Unread 26-04-2004, 19:45
RogerR's Avatar
RogerR RogerR is offline
its spelled *ya'll*, not *y'all*
AKA: Roger Riquelme
FRC #3844 (Wildbots)
Team Role: Teacher
 
Join Date: Feb 2003
Rookie Year: 2001
Location: Somerset, KY
Posts: 913
RogerR has a reputation beyond reputeRogerR has a reputation beyond reputeRogerR has a reputation beyond reputeRogerR has a reputation beyond reputeRogerR has a reputation beyond reputeRogerR has a reputation beyond reputeRogerR has a reputation beyond reputeRogerR has a reputation beyond reputeRogerR has a reputation beyond reputeRogerR has a reputation beyond reputeRogerR has a reputation beyond repute
Send a message via AIM to RogerR Send a message via MSN to RogerR
Re: Omni Wheels Survey

sorry i took so long replying...
Quote:
Originally Posted by George1083
If the mecanum wheels produced 100% power in the forward or reverse direction, it would be impossible to strafe. We know that this setup can strafe, so the power must be in the direction that the rollers are facing....
thats the thing though; the only time that the mecanum wheels are acting like 'traditional' omni wheels are when the bot is moving at any angle between forward/back and side to side. when moving forward/back, they act like treads. when strafing, they act like propeller blades.

<hare-brained idea> on that note (prop. blades) i'd also like to throw out an idea that i got from watching the bots strafe back and forth. what if you were able to change the angle of the rollers? decreasing the angle would move you less distance per each "wheel" rotation, but would give you more pushing force.the angle of the rollers could be changed by a mechanism similar to the ones used to change the blade pitch on prop. aircraft. </hare-brained idea>
__________________
"But to say that the race is a metaphor for life is to miss the point. The race is everything. It obliterates whatever isn't racing. Life is a metaphor for the race." -- Donald Antrim
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: omni wheels CD47-Bot Robot Showcase 15 03-03-2004 20:10
pic: #1018's omni wheels CD47-Bot Robot Showcase 22 19-02-2004 15:04
We need Omni Wheels!! archiver 2001 0 24-06-2002 01:02
Lots of Wheels and F = u x N archiver 2001 17 23-06-2002 23:37
"Motors and Drive train edition" of Fresh From the Forum Ken Leung CD Forum Support 6 29-01-2002 12:32


All times are GMT -5. The time now is 04:59.

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