Re: [FTC]: Unlimited raw materials. Welding. Wow!
 

From what I know of the "special LEGO tires" JesseK is referring to, it fits snugly onto the 3'' TETRIX wheels. I personally saw them on 1885 (one of JesseK's teams) back in HotShot! and I track them down to utilize them the following year.

There's also another kind of LEGO tire when stretched and replaced the rubber tire on the 4'' wheels that fits perfectly also.

Re: [FTC]: Unlimited raw materials. Welding. Wow!
 

Can you tell me how such a heavy robot will turn?

We (3785) had a mostly tetrix robot last year (other than our scissor lift) that weighed 50 lbs. We had to use omniwheels for our back wheels so that the robot could turn.

Re: [FTC]: Unlimited raw materials. Welding. Wow!
 

This can not be given an overall answer. It entirely depends on how much motor power/ratio you have on your drivetrain. Yes there are a few other factors involved, wheel spacing, wheel drop, material on the wheels etc. To turn an FTC bot that wieghs 50 lbs is certainly possible, but with new material allowances why would you even want/even get close to 50 lbs?

Re: [FTC]: Unlimited raw materials. Welding. Wow!
 

Last year our robot was a little over 50 lb. We had 2 motors on each side of the drive train, we have four wheels on each side, two small omni wheels in front and two normal wheels on the back. It was geared 1 to 1, it turned and drove fine and we had no problems with it. It's a good idea to use double sided support, so the wheels don't fall off.

Re: [FTC]: Unlimited raw materials. Welding. Wow!
 

Thanks for your response. This might be a great year to play with those treads since the rules seem to allow some tough defense at the scoring racks.