Building the gear system and back wheels

4. Now that the large gear is in place, it is time to add the small gear system to allow the wheels to spin faster:

5. To begin this part of the build, you will build a sub-model of the gear axle. Follow these steps to do that:
   1. Start with a yellow 7L axle and add a black 12-tooth double bevel gear into the middle of the axle.
   2. Add two gray bushings on either side of the gear:

Figure 6.6 – Building out the small gear axle

6. This sub-model should fit between the azure 13L beams and line up with the larger gear. At this point, nothing is going to hold it into place, but you will take care of that in the next step:

   Figure 6.7 – The location of the small gear axle

7. You are going to build another sub-model for the wheels. Follow these steps:
   1. Connect two wheels together using a yellow 7L axle.
   2. Add a gray bushing on the side where the yellow 7L axle is most exposed.
   3. On the other side, add a white tooth onto the yellow...