Below are the required steps for building FrugalBot. Note that many of these steps involve using dangerous equipment, such as sharp knives and soldering irons. Use caution with all of these steps, and get appropriate help if you aren’t sure how to safely use these tools.
Draw the parts you want to use in your robot on a piece of paper and cut out the shapes with an Exacto knife or a pair of scissors.
Trace the outlines of the paper shapes you cut out onto the foam core board. Try to group your shapes as closely together as possible in order to save material.
A compass works very well for making neat circles. It is also convenient because the hole made by the point on the compass lets you know exactly where the center of the circle is.
Use an Exacto knife to cut out the shapes.
Draw a small square on the large wheel that will fit over the motor hub. Cut this square out with the Exacto knife.
You should now have the following pieces cut out.
Run a small screw driver around the edge off the wheel. This will partially crush the foam core and will make a convenient groove to hold a rubber band.
Stretch a rubber band into the groove made into the step above. This will help your robot get more traction.
Put the top and the bottom pieces of the body together. These should fit together snugly so that they don’t easily fall apart.
Place a small amount of hot-melt glue on the bottom of the frame.
Use a small amount of hot-melt glue to attach the wheel to the motor axle. Be careful not to use too much glue, or you may glue the wheel directly to the body of the motor. I also placed a size 2-56 machine screw with several washers into the hole in the motor axle to help secure the wheels (screw not shown in the picture).
If you have not done so already, solder two different color wires onto the terminals of the motors. It is helpful to solder the same color wire onto the matching terminals in each motor. Place the motors into the body of the robot facing in opposite directions as shown below. Place two rubber bands on the body of the robot as shown.
Place a small amount of glue on the side of the motor to hold it in place.
Attach the front wheels to the robot. I used size 2-56 machine screws, but any small rod like a toothpick or a paper clip will also work.
Follow the separate instructions to build the controller board. Note that yours may look different from mine, but it should still function the same.
Place the battery box and the controller board under the rubber band. Connect the motors and the battery box. Pay careful attention to correctly connect the power and the ground wires, otherwise you could damage your controller board if you reverse the polarity of the wires.
That’s it. You’re ready to program your robot. Connect the USB to Serial converter as shown below and attach the USB cable to your computer.