To fit all of the things mentioned above into such a small body some subtractive manufacturing needed to happen. First the Hot Wheel needs to be separated into the shell and the bottom of the car with the rest of the stuff thrown away. To do this we drilled into both the bolts in the car and used pliers to separate them once they weren’t as attached to one another. For the bottom we need to sand and cut it down so that all the electronics would fit inside it. This was done through using sandpaper and wire cutters. Once that was done we had to thin the area in between the front two wheels so that the wheels in the front could turn and cut a bit of the back off entirely so that the back wheels could accelerate without any difficulties. 

On Friday Mr. Budzichowski recommended that we scale up the project since we weren’t able to solder on wires to the small DC motor. For the scaled up car body we made a sketch in Corel Draw similar to the cut up car. This got changed to Lego on Monday but the scaled up sketch was helpful for building up the scaled model In lego.

We wanted a larger module so that we could have a working module so everything was scaled up. To build a better scale for the car we used Lego for the frame. This allowed us to model the car in the exact way we wanted since it could be molded in any shape or form since it was additive manufacturing. To figure out how we wanted to design it we first scaled up the design of the cut up car on CorelDraw. With this new design it was a very easy process and the only issue we ran into was fitting the servo and dc motor into the Lego. For the dc motor so that it wouldn’t move around when in action. For the servo we just built a frame for it in Lego.

DC Motor:

The DC motor was very difficult to work with in this project. First it had to be removed from a 1.5 gram servo since the hotwheel needed such a small dc motor to fit in the body. Once that was done we had to take apart the dc motor so that we could get an axel to go all the way through the motor so that we could have two wheels moving. This was very difficult since the motors aren’t supposed to be taken apart normally and to do so is very tricky. This becomes more challenging when you realize the size of the motor we were taking apart. When we tried to solder onto the dc motor, the solder points would break so we couldn’t use such a small scale since we ran out of DC motors to use after lots of failed attempts

This led to scaling up the project. We changed the dc motor to a larger one so that the solder points were easier to access. It was very easy to change, the code wasn't impacted and we were still able to use the motor shield to control when the dc motor should move and in what direction. 

Steering Module:

To steer the car we couldn’t hook up the servo directly to the wheels so a steering module needed to be made to make the servo move the wheels. The first idea was to make the steering module a linkage one which would be very straight forward. The issue was that it was hard to figure out how it would connect to the wheels. The next idea was to take the design in the video and make it into a 3D print. The parts that would be printed are the two axle holders and the middle piece that would move the two axles together from the servo. To figure out the scale we spent a long time looking at his design and using the multimeter to measure parts of the front axle. 

When we scaled up the project we had to make a new steering module out of lego. We first started with a design where the control was on the top and the steering would go left to right from the top. This would work well for the 1.5 gram servo but once we realized that it wasn't strong enough we had to scrap the design. When we switched to the larger 9 gram servo we had to change the steering module to be controlled from the center with a wheel design where the steering is controlled by a clockwise and counterclockwise turning mechanism.

Battery:

To have the car be powered without being connected to the computer we had to use 2 lipo cell batteries. One for each ESP. The Lipo battery that was suggested in the video we couldn't find a charger for. Thankfully Mr. Dubik had similar Lipo cell batteries that he used for the planes. They could be charged but there wasn't a way for it to connect to the ESP. To solve this we took the part of the controller for the planes that connects the battery to the microcontroller and cut it off and stripped the wires so they could work for the car. These stripped wires were soldered to cut jumper wires so that there would be a strong connection from the battery to the ESP. The battery for the control ESP was put into the breadboard and then later into the protoboard. The battery for the camera ESP was soldered directly to the ESP.