12. Mechanical Design¶
This week I worked on designing and building a machine with my group.
Weekly Objectives¶
Group assignment - design a machine that includes mechanism+actuation+automation+application - build the mechanical parts and operate it manually - document the group project and your individual contribution
Group Assignment¶
In this week group assignment, I did the wiring and designed and milled the PCB for our machine. You can find our full group documentation here.
Wiring¶
For the wiring part, I followed the circuit diagram that the tutorial provides.
Then I create a circuit on the breadboard with only one motor and one servo connected. I took off the switch because we thought it was unnecessary.
After this, Noah Smith (our coding genius) started to code the motor and the servo and made the motor spin like what we want and the servo spin constantly.
PCB¶
After Noah successfully made one motor and a servo work, I started to design the PCB board for our project.
This is the schematic diagram.
After Noah checked my wiring, we found out that the foot print may not be the right one for the motor driver. Then Irealized that it was just upside down so it was actually fine.
Then I made the traces in PCB editor.
Then I started milling. However, since it was my first time milling, the PCB was messed up on its back side.
After consulting our expert Cooper Cumbus I managed to mill a double sided PCB board.
Then I started to solder bunch of headers,a 5V regulator, and two capacitors onto the PCB board.
It took me two hours since the headers and the SMD components are really hard to solder on. But I managed to do it. I was also using multimeter to test if the current is flowing correctly everytime I soldered one component on.
Unfortunately, when you see the title, you know the fate of this board. It was not working correctly. It shorted the microcontroller XIAO esp32-c3.
After 1 hour of checking, we assumed that it was the design problem and we sadly gave up on the board.
Noah saw me being so miserable about making the board, so he took my heavy burden. He designed a more simplified PCB which got rid the unnecessary part like the capacitors and the regulators.
This is the board that Noah designed:
After I soldered all the header pins on, we nervously started to test the board.
Here’s the finished board with components on.
The board that Noah designed worked perfectly fine, and we can finally focus on the coding part.
Reflection of the Week¶
This week is particularly hard because we only had about one week to design and build our whole machine. We spent too much time on figuring out the distribution of work which later was considered inefficient. The night before the due date, we stayed up until 12 to finish up our machine. However, we only finished the mechanic part not the electronic part. Therefore, we did not get a reallygood feedback from Neil. However, we did not give up afterwards and still made our machine to work after spending more than a month to improve the code.
File Download¶
You can download my file here.