The Annual Drives Platform Poll

[Kris Verdeyen]

Someone please describe the difference between Crab and Swerve. And while you're at it, tell us what omni means. I'm lost. I thought Omni, crab, and swerve meant essentially the same thing.

[Greg Perkins]

Originally Posted by Kris Verdeyen

Someone please describe the difference between Crab and Swerve. And while you're at it, tell us what omni means. I'm lost. I thought Omni, crab, and swerve meant essentially the same thing.

Crab and Swerve are the same thing, Both have "modules" which turn in relation to another. As omni's do not require the drive to move, just the wheel..

Crab/Swerve:
http://firstrobotics.uwaterloo.ca/re...etrains049.jpg
http://firstrobotics.uwaterloo.ca/re...etrains058.jpg
http://firstrobotics.uwaterloo.ca/re...etrains067.jpg

Omni:
http://firstrobotics.uwaterloo.ca/re...etrains040.jpg
http://firstrobotics.uwaterloo.ca/re...s/wheels07.jpg
http://firstrobotics.uwaterloo.ca/re...s/wheels27.jpg

Just a few examples of each

[Pavan Dave]

We are using the Crab Drive meathod on our robot. Also I was wondering the efficiency of the Kiwi Drive system. See the video I believe it would be easy to trap or "Pin" this robot on the sides not even needing a corner. Could someone that is using it explain maybe?

-Pavan

[ida_noeman]

Originally Posted by Pavan

We are using the Crab Drive meathod on our robot. Also I was wondering the efficiency of the Kiwi Drive system. See the video I believe it would be easy to trap or "Pin" this robot on the sides not even needing a corner.
-Pavan

According to 4.3.4.4 <G24>, you can only pin another robot for 10 seconds before you have to back up 3 feet (then try again). Perhaps it's not that much of a disadvantage to be weak against pinning.

[Andrew Blair]

The idea of a holonomic drive is that, on a flat field, you don't need to worry too much about being pinned because with a good driver, the bot is so fast and maneuverable that you can't get it.

[Gdeaver]

I hope that all teams that are going up the ramp have looked at the dynamic of their drive choice and the CG issues. Teams that don't could be great tippers.

[Gene F]

Metal in Motion, team 343 will be on tracks again this year for the forth year in a row. We're getting quite comfortable with them. We talked about a 6 wheel base but felt there wasn't enough of an advantage to change from what we are familiar with. Look for the 6 wheel base next year!

[Alex Cormier]

interesting. slowly 4WD is creeping up to 6WD, who will have the most be the end of build season??

[BRosser314]

Originally Posted by Kris Verdeyen

Someone please describe the difference between Crab and Swerve. And while you're at it, tell us what omni means. I'm lost. I thought Omni, crab, and swerve meant essentially the same thing.

essentially crab and swerve are similiar, but few differences. i believe that a swerve drive has one wheel that turns like a turret and having only 3 wheels in total which are all driven. so in crab all four wheels are able to spin like a turret and be driven. in omni the wheels are stationary and turn in similar direction to the way there paermanently mounted too. there are little wheels that make up the circumfrence of the wlarger wheel, say someone is pushing you from the side omni wheels allow the robot pushing you to move you a lot easier.

[Alex Cormier]

interesting still no 2WD or 8WD, lots of 6WD. wahoo

[BRosser314]

Originally Posted by Alex Cormier

interesting still no 2WD or 8WD, lots of 6WD. wahoo

I think there might be people not reading the poll properly and thinking that two wheels might mean driven only. I know there is a spot for that but there must be some confusion. I know of some teams that are going with two wheels with some rolling casters like skid plates.

[devicenull]

Originally Posted by BRosser314

essentially crab and swerve are similiar, but few differences. i believe that a swerve drive has one wheel that turns like a turret and having only 3 wheels in total which are all driven. so in crab all four wheels are able to spin like a turret and be driven. in omni the wheels are stationary and turn in similar direction to the way there paermanently mounted too. there are little wheels that make up the circumfrence of the wlarger wheel, say someone is pushing you from the side omni wheels allow the robot pushing you to move you a lot easier.

Omni wheels aren't all bad, you can do lots of quick turns with them. Among other things I can spin our entire robot around one of the back wheels quite easily. I can't see how 4WD without them would be efficient without them.

[Nuttyman54]

Originally Posted by devicenull

Omni wheels aren't all bad, you can do lots of quick turns with them. Among other things I can spin our entire robot around one of the back wheels quite easily. I can't see how 4WD without them would be efficient without them.

been there done that...it's not efficient at all. You either have to have low traction on one pair of wheels (front or back), or hop...a lot. it's NOT fun, especially when you're holding a tetra 7 feet in the air