For our drive base we decided to scrap the rack and pinion idea and go for mini four bar, the reasons for this decision is because the rack and pinion was,int able to place in the 10 point zone and also was'int super reliable. Here is a picture of the original rack and pinion design.
our drive base is very basic, we used c-1x3x35's for the main peices, we decided to change the internal gearing in our motors to hight speed and we found it is alot better than normal torque settings. We also set up a gear ratio for our mobile goal and it looked like this. (Sorry mr ma only picture i could find)
This is the origional gear ratio its a 3:1 but after doing some testing we decided we needed more torque so we swiched to a 5:1 ratio, and it looks like this.
Now we have completed our drive base and we are vety happy with the way it turned out and we hope it will preform well in competitions.