Welcome to the site! There is a build on here called Magnus and he built tracks for it - very impressive. Look under "robots" Here is a link to how to build tracks you might find useful:
RC Tank Tracks

Tymtravler , my.best recommendation is buy a premade set unless you have a good amount of fabrication skills. Lynxmotion sells just the tracks and sprockets cheap , 25 bucks per 23" of track at 2" width , that's what I'm going with I believe. Lynxmotion.com don't buy the kit its overpriced unless you need motors and all...

@Tymtravler I was looking to build a robot exactly what you have in mind, only my frame is going to be out of L shape aluminum you can find for very cheap at home depot. They carry other size and shape of aluminum as well.

@jstarne1 I was thinking of using Lynxmotion track for their quality but do you know exactly what parts we need to buy to make a complete set track/sprockets? and what kind of motors to use and how to make it run from EZ-B? how to attach motors to the sprockets? I want a tri-track based system but didn't want to buy their overpriced kit. I read their assembly instruction but still not clear what all that needs. Is it possible to run low KV brushless motor instead of brushed geared motor? Any help would be appreciated.

Hey thanks to all for the great suggestions, I checked out Lynx and the tracks are not big and mostly strong enough for what I am building. My robot well look similar to the HK Tank so they need to be around 3" wide and be able to support around 100lb. I found this great site thanks to bret.tallent that shows several types of DIY tracks and the one I found that will work is the plastic conveyor.

http://www.rctankcombat.com/articles/track-systems/42PlasticPerformance.jpg

Here is the belts I will use. http://www.intralox.com/hLaunch_nd-nag-eu3.aspx?id=2014&terms=900

The company has a robot customer service team to help you with creating your track system. They can be contacted at

first.robotics@intralox.com

@Tymtravler Hi...and welcome to the forum! It's so good to see just how many people are getting into robot building. The intralox plastic conveyor is what I am using on my robot Magnus. If I remember correctly the tracks and sprockets were around $150. I bought two wheelchair motors (24V) off of EBay for around $65 and I purchased two Victor 883 for speed control from robotmarketplace.com ($150 each). Also had to purchase some square aluminum bar that fit the intrlox sprockets, some steel rod for axles, two large steel sprockets, two small steel sprockets and flange mount bearings from Mcmaster Carr. I can get the cat. numbers for you if you want. I already had the #25 chain for the steel chain sprockets. The size of the steel chain sprockets will depend on your application requirements for speed and torque. I had someone drill out the square bar to accept the round steel axle rods.

Robot Market Place

Hey thanks for the information, I enjoy this forum for if I need something, someone has a source.