The Annual Drives Platform Poll [Archive]

dude__hi

17-01-2006, 13:20

We are using a four wheel drive with two onmi wheels in the front and 4 traction wheels in the back. Everything is being driven with 4 small cimms on 2 two-speed transmissions.

Nuttyman54

17-01-2006, 14:06

what's the Kiwi Drive?

Alex Cormier

17-01-2006, 14:10

what's the Kiwi Drive?
http://www.team229.org/site/photo/1076379180sphere_and_omni-wheel.jpg

Nuttyman54

17-01-2006, 14:17

Ahh so omni holonomic in 3 positions

artdutra04

17-01-2006, 14:23

Ahh so omni holonomic in 3 positionsBasically, yes. The omni-wheels are mounted at 120° angles ot the center of the robot. BTW, if you would like to see a video of one of these in action, here is a video of a kiwi drive robot from Team 857 in 2002.

http://stuweb.ee.mtu.edu/~alkrajew/FIRST/kiwi.mpg

Madison

17-01-2006, 14:25

So what's up with 10WD+?

I think we'll end up with 12 wheels, but only 6 will be powered.

Alex Cormier

17-01-2006, 14:29

Basically, yes. The omni-wheels are mounted at 120° angles ot the center of the robot. BTW, if you would like to see a video of one of these in action, here is a video of a kiwi drive robot from Team 857 in 2002.

http://stuweb.ee.mtu.edu/~alkrajew/FIRST/kiwi.mpg
looks similar to the robot that i posted a picture of, which was taken off of team229.org

Bcahn836

17-01-2006, 14:38

Meh who needs wheels, we are using legs. :D :D No not really, we will most likely use a 6wd system.

Alex Cormier

18-01-2006, 14:47

Very interesting, 2 say 10WD+, and one says Crab! i can't wait to see all these diffrent designs for this years game.

sanddrag

18-01-2006, 14:53

6 small wheels (all powered). Skid steering. 4 small CIMs. 2 speed shift on the fly.

Lil' Lavery

18-01-2006, 15:02

No swerve drive yet? I thought that would be a popular solution this year...

Kris Verdeyen

18-01-2006, 15:11

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

18-01-2006, 15:52

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/resources/galleries/drivetrains/drivetrains049.jpg
http://firstrobotics.uwaterloo.ca/resources/galleries/drivetrains/drivetrains058.jpg
http://firstrobotics.uwaterloo.ca/resources/galleries/drivetrains/drivetrains067.jpg

Omni:
http://firstrobotics.uwaterloo.ca/resources/galleries/drivetrains/drivetrains040.jpg
http://firstrobotics.uwaterloo.ca/resources/galleries/wheels/wheels07.jpg
http://firstrobotics.uwaterloo.ca/resources/galleries/wheels/wheels27.jpg

Just a few examples of each

BRosser314

18-01-2006, 15:52

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

25-01-2006, 08:39

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

BRosser314

25-01-2006, 15:42

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.

Chuck Glick

25-01-2006, 15:52

we're doin 6wd but how in the world would you do 8wd or even 10wd? that seems almost impossible

Greg Needel

25-01-2006, 16:00

we're doin 6wd but how in the world would you do 8wd or even 10wd? that seems almost impossible

nothing is impossible... ;)

Andrew Blair

25-01-2006, 16:06

Hmmm. It would seem that it would be quite easy with an omni drive...I'm thinking up to, say 60! If you count the rollers...

I'm just curious to see what this year will be like. The omnis are going to have trouble getting up the ramp, but they'll be unstoppable at center goal defense. We'll see...

devicenull

25-01-2006, 18:01

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.

Alex Cormier

25-01-2006, 18:04

we're doin 6wd but how in the world would you do 8wd or even 10wd? that seems almost impossible
very possible.

Chuck Glick

25-01-2006, 19:40

nothing is impossible... ;)

well i know that but ten wheels with all drive, either thats a lot of chain or something

Nuttyman54

25-01-2006, 20:07

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

Mr. Freeman

25-01-2006, 20:47

We're just working out the bugs in the anti-grav system.

Seriously though, we're (team 1552) is going with tank tracks.

greencactus3

25-01-2006, 22:38

well i know that but ten wheels with all drive, either thats a lot of chain or something
do duallys count as 2? or are you counting independant axles?
so if a robot had a 6wd platform but each driven axle had duallys on each, is that 12WD or 6WD?

hellish

26-01-2006, 17:34

Why's it called kiwi?

Alex Cormier

29-01-2006, 12:58

wow, im surprised to see the excesive amount of teams goign with 6WD.

ida_noeman

29-01-2006, 13:01

We (1719) are going with 4WD, that's because we're a rookie team and keepin' it simple.

David Guzman

29-01-2006, 13:13

There is no such a thing as impossible ;)

Pavan Dave

29-01-2006, 14:05

ida_noeman

29-01-2006, 14:12

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

29-01-2006, 14:25

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

29-01-2006, 14:56

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

29-01-2006, 15:44

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

03-02-2006, 08:25

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

bobotics319

03-02-2006, 08:57

are team is using a 6wd system and its all up and driving :D

kaszeta

03-02-2006, 10:01

Seeing that it's more than halfway through build season, I figure we can be a little more open with details now:

Our team's testing with our drive system has been very positive, so I think we're definitely going to use it on the final bot:

1. Four omni-wheels driven by 2 large CIMs and 2 small CIMs

2. Four IFI traction wheels on the corners (driven along with the omnis by the small CIMs).

So, we've got 8 powered wheels (with a max of 6 making contact), with holonomic ability.

This gives us holonomic drive (so we can align the whole bot with the target independent of translation) with ramp climbing capabilities. I'll try and post images when we get them.

aaeamdar

03-02-2006, 10:34

A very nice poll. Is there any way in the future to have it split into what newbies are going after and what veterans are going after? Like each bar would be split into two sections, showing rookies and veteran votes. It would be interesting to see if any rookies went for crab steering or kiwi for example.

And how does that thing go /forward/? I'm looking at the video, I'm just asking rhetorically.

Paul Dennis