Vex tank tread crab drive
 

this is a crab drive I made with vex then I decided to replace the wheels with four tank tread boxes. the front wheels and back wheels are controled speratley so I can drive it like a car as well as a tank and crab in any direction.
http://pic1.picturetrail.com/VOL1182.../195977180.jpg
http://pic1.picturetrail.com/VOL1182.../195977167.jpg
http://pic1.picturetrail.com/VOL1182.../195977148.jpg

Re: Vex tank tread crab drive
 

lol that looks pretty sweet, it looks very clean.. do you have any videos?

good job

Re: Vex tank tread crab drive
 

i've got some footage of it im editing into a video that will be out soon.

Re: Vex tank tread crab drive
 

That's pretty cool.

Re: Vex tank tread crab drive
 

Cool robot! Needs video. :D

Re: Vex tank tread crab drive
 

Great Looking robot. Any other plans for this drivetrain?

Re: Vex tank tread crab drive
 

Very cool...how well does it work...ie turn easy, quick, lots/little scrub.
Very nice design

Re: Vex tank tread crab drive
 

wow... I like. Nice work on it. So how well does it turn? I'd think the tread would add a bunch of scrub for turning...

Re: Vex tank tread crab drive
 

looks really clean. great job

Re: Vex tank tread crab drive
 

It reminds me of 461's 2001 robot. They had a similar setup as you do with the tracks on a crab drive, except when they wanted to crab, the back end of the tracks lifed off the ground so the robot was on the front end of the tracks making it easier to crab. I couldn't find a picture though. It looks really cool...I wish I could find a tank tread set at Radio Shack.
Eric

Re: Vex tank tread crab drive
 

You can get the tank treads from www.vexlabs.com. They cost $29.99.

Direct link to tracks

Re: Vex tank tread crab drive
 

Sweeeeeet :D

-Q

Re: Vex tank tread crab drive
 

the treads turn good because the vex tank treads dont have alot of tracion themselves, im planning on adding some kind of traction to them.
but because of the low tranction it turn as well as the wheels did.

Re: Vex tank tread crab drive
 

i having trouble seeing is each wheel independent or are the front and back independent?

Re: Vex tank tread crab drive
 

the front and back wheels spin with each other

Re: Vex tank tread crab drive
 

Why treads though. Yeah, the vex treads don't produce that much traction (in those lengths anyway), but they still produce more than the small wheels do. The treads produce additional scrub, are heavier (and therefore recquire more torque from the steering motors) and are more inefficient than wheels would be.
Especially if we think about using a similar design in FRC terms, if you wanted large amount of traction in a swerve drive, you would use traction wheels. While they add scrub, they are still lighter, simpler, smaller, and are more efficient than treads would be.
This drivetrain is really cool, but I don't think the treads are really a step in the right direction. While it might work, from an engineering perspective, wheels should be the right choice.

Re: Vex tank tread crab drive
 

basicaly I made it with wheels and got bored with that so i replaced them with treads just because it looks cooler. here is my original drivetrain:
http://pic1.picturetrail.com/VOL1182.../196607893.jpg
http://pic1.picturetrail.com/VOL1182.../196607883.jpg

Re: Vex tank tread crab drive
 

ive always been so interested in crab drive but ive never had a chance to learn how to build or use it on an frc bot. as soon as i get my hands on a vex kit ill build something like this.

Re: Vex tank tread crab drive
 

What's the structure above the RC?

Re: Vex tank tread crab drive
 

thats a rotating/pivioting arm for picking up tetras. heres a better picture: http://pic1.picturetrail.com/VOL1182.../196746562.jpg

Re: Vex tank tread crab drive
 

alright here is a video of it in action.
http://video.google.com/videoplay?do...58384631&hl=en