Electric Car: AZ Racer

We made an electric car named AZ Racer.The two people who mainly worked on the car were Capree and Sarai.

Materials:

one small DC motor

one 1-hole conduit strap

one punched aluminum chassis

two battery holders

two AA batteries

four polyethylene wheels

one 16 tooth gear (pinion)

one 42/10 tooth gear

one 60 tooth gear

two 3 3/4" axles

one 2 3/4" axle

twenty-six washers

one 4-40 wing nut

one 4-40 1/2" machine screw

switch

screwdriver

pliers

electrical tape

Procedure:

1) First, we calculated gear ratios.We decided to use a 16 tooth gear, a 42/10 tooth gear, and a 60 tooth gear to give us a gear ratio of 0.43.

2) We put the axles into the holes in the chassis.

3) We put the 60 tooth gear on the 3 3/4" axle and the 42/10 gear on the 2 3/4" and made sure the two gears were touching.

4) We put on the tires on the 3 3/4" axles (with some washers in between).

5) The 16 tooth gear (pinion) was attached to the motor and was touching the 42/10 tooth gear.

6) We connected the batteries in series and placed them on the bottom of the chassis for convenience.

7) We took the positive wire of the motor and connected it to the positive end of the switch.

8) We took the positive wire of one battery and connected it to the negative end of the switch.

9) We took the negative wire of the other battery and connected it to the negative of the motor.

10) We made sure all the connections were tight by taping them with electrical tape.

11) We made a frame, using plastic from a soda bottle, pipe cleaners, poster board, crepe paper, felt, sequins and other materials.

11) We checked all the connections and gears and ran tests to make sure it was running and going up the incline pulling the load. We also had to make the hitch.

Obstacles:

We came across many problems while making the car, but we solved all of them. The hardest problem was finding the right gears. We needed a gear ratio that was less than one because the lower the gear ratio, the faster the car. We finally calculated a gear ratio of 0.43 by using several different formulas. Another problem we came across was the balance of the car. Putting the right amount of washers on each axle was a challenge. We had to put a broken gear on the end of the 2 3/4" axle because the axle was so short. Finding traction for the tires was yet another problem. We needed traction so that the wheels would not slip when when the car was going up the incline.

Line tracker

Our line tracker was made from a pre assembled kit. This robot follows a black line. Sharene and Kelsie were the ones who mainly worked on the line tracker.

Materials

parts supplied by the kit

pliers

screwdriver

hammer

wrench

Procedure:

1) Follow instructions in kit.

Obstacles:

We came across some problems while making the line tracker. Tighting the screws and nuts was always a problem. Sometimes we tightened them so tight that the wheels couldn't move, or we didn't tighten them good enough. Another problem we had was getting the gears into the right places. The 40 tooth gear with a pinion looked just like the 36 tooth gear and we got them confused a lot.