Poll:2010 How many wheel drive are you using?

[billbo911]

Yes this is another poll. The one from last year was actually quite interesting.

The basic question is: "How many wheels are used in your drive train and why did you choose to use this approach?

[Alex Cormier]

We will have a 4.5wd.

6 Wheels will be powered, but only 4 on the ground constantly.

[billbo911]

In all fairness, I will start.
We are using 5 wheels. 4 sticky KOP wheels and a piston activated 5th wheel mounted perpendicular that drop down, lifting the back 2 wheels up. This will allow us to rotate onto target easier.

Edit: Wow, so much for being first.

[big1boom]

We are using 4, 4" plaction wheels. The real interesting part is that as it stands now, we are using 32 sprockets, on 12 loops of chain.

[Joe6391]

I want to see a 1 wheel bot, that would be awesome.

[billbo911]

Originally Posted by Joe6391

I want to see a 1 wheel bot, that would be awesome.

I couldn't agree more. That's why I requested pictures.

[spacegy4]

Treads all the way!

[Chris is me]

8 wheel drive is going to be common enough that I would highly recommend you add it to the poll. 2791 is doing 8 wheel.

[sdcantrell56]

1771 is going with 8wd

[Joe Johnson]

Team #2849, Ursa Major, (and I) are going with 12 Wheel Drive.

Why? It seemed like a good idea at the time ;-)

Honestly, because I am paranoid of getting stuck on those bumps and 12WD seemed like a good way to prevent that from happening.

Would 8WD been enough? Perhaps, but with each new crossing the bump video that gets uploaded to youtube, I grow more convinced that 12WD has its advantages...

Joe J.

[Matt382]

Originally Posted by Joe Johnson

Team #2849, Ursa Major, (and I) are going with 12 Wheel Drive.

Why? It seemed like a good idea at the time ;-)

Honestly, because I am paranoid of getting stuck on those bumps and 12WD seemed like a good way to prevent that from happening.

Would 8WD been enough? Perhaps, but with each new crossing the bump video that gets uploaded to youtube, I grow more convinced that 12WD has its advantages...

Joe J.

Yeah I think a lot of teams will be going with 8wd (we are). The reason 488's robot tipped like that (like many 6wd drive robots will) is because a lot of their weight is distributed in the back. If you can keep your weight balanced correctly, even with 8wd drive, you wouldn't flop like that. (We watched our robot cross the bump on CAD, but haven't gotten the chance to test it in real life yet).

[Chris is me]

Originally Posted by Matt382

Yeah I think a lot of teams will be going with 8wd (we are). The reason 488's robot tipped like that (like many 6wd drive robots will) is because a lot of their weight is distributed in the back. If you can keep your weight balanced correctly, even with 8wd drive, you wouldn't flop like that. (We watched our robot cross the bump on CAD, but haven't gotten the chance to test it in real life yet).

Be aware that with a centered CoG, you will still have a pretty spectacular fall over the bump due to momentum unless you take it somewhat slowly. But not too slowly that you get defended easily. Driving is hard...

8wd shouldn't be high centering diagonally too much. 488's video basically demonstrated you have to be completely sideways to high center.

[Andrew Schuetze]

The low clearance of a standard chassis with 8 wheels scares me now that I see it getting high centered on the hump sideways. That just seems to be another plus for the using the KOP stand-offs. The big negative is raising one's CG.

[Ken Leung]

Originally Posted by Joe Johnson

Team #2849, Ursa Major, (and I) are going with 12 Wheel Drive.

Why? It seemed like a good idea at the time ;-)

Honestly, because I am paranoid of getting stuck on those bumps and 12WD seemed like a good way to prevent that from happening.

Would 8WD been enough? Perhaps, but with each new crossing the bump video that gets uploaded to youtube, I grow more convinced that 12WD has its advantages...

Joe J.

I agree, except in this case I think less is more.

We are going with 4 wheels this year after a demonstration showing the dynamics is much more stable than 8 wheels could ever achieve.

Most 8 wheel drives are counting on very low center of gravity, except I don't think you can count on that if you want to do any sort of hanging, or if the CG is anywhere near 10-12 inches off the ground.

[Joe Johnson]

Originally Posted by Ken Leung

<snip>
We are going with 4 wheels this year after a demonstration showing the dynamics is much more stable than 8 wheels could ever achieve.

<snip>

Hey Ken,

Long time, no see (though more my fault than yours).

But... ...there you go again making blanket statements that may come back to haunt you.

Of course it is possible to make an 8WD or even a 12WD that is less stable than a 4WD robot going over the bump, I would just caution you about making statements that beg to be proven wrong.

"There are no black swans" only requires 1 observation to be wrong. "Black swans are rare" is a safer statement that is less likely to put egg on the face of the speaker.

Joe J.