Grace Schwan Silva
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    Week1:Principles and Practices, Project Management Week2:Computer Aided Design Week3:Computer Controlled cutting Week4:Electronics Production Week5:3D Scanning and Printing Week6:Embedded Programming Week7:Computer Controlled Machining Week8:Electronics Design Week9:Output Devices Week10:Mechanical Design, Machine Design Week11:Input Devices Week12:Molding and Casting Week13:Networking and Communications Week14:Interfaces and Applications Programming Week15:Wildcard Week Week16:Applications and Implications Week17:Invention, Intellectual property, and Income Week18:Project Development Final Project

WEEK 4

ELECTRONICS PRODUCTION

Assignment :

Group assignment:

- characterize the design rules for your in-house PCB production process send a PCB design out to a board house

Individual assignment:

- make and test a microcontroller development board that you designed extra credit: make it with another process

* Extra-credit : personnalize the board

* Extra credit: make it with another process

Group assignment:

This week, we focused on electronic fabrication using a CNC milling machine. As a first step as a team, we worked on testing and adjusting the machine's parameters. After completing this phase, we proceeded with the necessary tests. Once the board was ready, we soldered the electronic components and finally programmed the XIAO RP2040.

TWe started using the machine they have at the Scientific University of the South,MILLING MONOFAB SRM-20 thanks to our friends and Academy colleagues: Marjory, Hans and José Alberto and the directors and deans we were able to carry out our group task.

DESCRIPTION MILLING MONOFAB SRM-20

PSRM-20 Specifications
Acceptable material Resins such as chemical wood and modeling wax (does not accept metal), substrates for machining
Operating path of X, Y and Z axes 203.2(X) x 152.4(Y) x 60.5(Z)mm
Collar tip to table distance Maximum 130.75mm
table size 232.2(X) x 152.4(Y) x 60.5(Z) mm
Maximum acceptable weight on equipment 2kg
E, Y and Z axes driving system stepper motor
Operating speed From 6 to 1800mm/min
Software resolution 0.01 mm/step (RML-1), 0.001 mm/step (NC Code) 0.00039 inch/step (RML-1), 0.000039 inch/step (NC Code)
Mechanical resolution 0.000998594 mm/step
rotor motor 380 type DC motor
Maximum rotor rotation 7000rpm
Mandrel cutting tool Necklace method
Interface USB
Instruction commands RML-1, CN code
Power requirements Equipment: DC 24V, 2.5 A, Dedicated AC Adapter: AC 100V ± 10%, 50/60 Hz
Electrical consumption About 55W
Noise level Operating: 65 dB(A) or lower (uncut), during standby: maximum 45 dB(A)
Dimensions / Weight 451.0 (W) x 426.6 (D) x 426.2 (H) mm / 19.6 kg
Around Temperature from 5 to 40°C, relative humidity from 35 to 80% (non-condensing)
Accessories included anAC Adapter, Power Cable, USB Cable, Cutting Tool, Necklace, Screw Set, Wrenches (7.10mm), Hex Wrench (2.3mm size), Positioning Pins, Double-sided Tape, Startup Information Card, Read First (Brochure)

INVENTORY:

The first thing we did was make sure that we had all the electronic components necessary to be able to carry out the task.

Milling cutters used in the manufacturing process (1/64 and 1/32)

We used 1/64 and 1/32 milling bits, which were crucial in the manufacturing process. Here, I share an image of each one. It’s essential to be cautious when calibrating because these tools are fragile and can break easily. During calibration, it's important to leave a small gap between the bit and the base; you can initially use a piece of paper to measure the distance. Afterward, remove the paper and lower the bit by about 100 microns. Another option is to insert the bit slightly deeper and then release it in the small gap you've left between the base and the bit’s tip. Finally, make sure to adjust the height to approximately half an inch.

The calibration process of a milling machine like the Roland monoFab SRM-20 is essential to ensure precise and high-quality milling.

Design rule characterization

For this first step, we need to download the image and import it into the IMODELA CREATOR program, which we use beforehand to set the configuration and define the material characteristics we’ll be working with.

MODS CE (Community Edition)

MODS CE (Community Edition) is an extension of the CBA mods research project. This modular, cross-platform tool is designed for fablabs and is made up of independent but interconnected modules. MODS has potential applications in CAD (computer-aided design), CAM (computer-aided manufacturing), machine control, automation, creating user interfaces, reading input devices, responding to physical models, and more. The applications are almost endless. The Community Edition aims to provide documentation and support, promote community participation in the project, and stimulate development and collaboration in the creation of new modules.

MILLING TEST FILE

Here I give you a step-by-step process on how to enter MODS, download an image in PNG format and take it to the milling machine:

Step 1: Access MODS

1.- Open a web browser and go to the official MODS page "modsproject.org".

2.- You must use the Google Chrome browser for the mods project to work well.

Step 2: Set MODS to Process PNG Image

1.- In the MODS interface, right click to bring up the menu and select “Programs”. .

2.- Within the programs menu, choose the “Open Program” option and select the milling machine you will use, in this case I will use this: Roland -> SRM-20 Mill and select "2D PCB milling".

This is what the interface looks like when you enter with what you have selected, don't worry, it is not as complicated as it seems.

Step 3: Upload the PNG Image

1.- In the module, you will see several options to upload files, look for the option to upload an image in PNG format..

2.- The screen will appear where your downloads are, select the PNG image you want to process from your computer. Make sure the image is the correct size and details for the milling. MODS will generate the tool path based on the image.

Step 4: Configure the Tool and Parameters

1.- Here I changed it to 1 offset number times 1 to make it finer.

2.- Verify that the configuration options are correctly set for the material you are going to mill and calculate it.

Step 5: Generate the file

1.- Once you have calculated a preview will appear.

2.- Save the generated file to your computer.

MODS FILE

Step 6: Activate file download mode.

1.- We deactivate the “webUSB” option.

2.- We activate the “save file” option.

We carried out the first tests, but the results were not what we expected. We decided to try again by adjusting the parameters, did another test and finally identified the problem. So, with a little patience, we move forward.

Here you can notice the difference compared to previous tests. This time we managed to achieve the requested objective for group work. We understood the processes and configurations better, and finally got our test board...mission accomplished!!!

MODS FILE

Individual Assignment

Electronic Components List

Item Description Price (PEN)
1 SEED XIAO RP2040 36 PEN
2 SMD HEADER CONNECTOR 10POS 1.27MM (2x2 Male Connector) 2 PEN
3 SMD HEADER CONNECTOR R/A 6POS 2.54MM 2 PEN
4 SPST-NO Tactile Switch Surface Mount Top Actuated 1 PEN
5 BLUE, GREEN, BLANCO LED 1206 SMD 3 PEN
TOTAL 44 PEN

Programming

We reviewed the documentation provided by Adrian Torres and carefully examined all the indications and the microcontroller used on the board. We copy the links following the instructions, verifying that they are correctly located as indicated.

Manufacturing my first electronic board

The first thing to do is calibrate the CNC milling machine. It is advisable to place double contact tape so that the Bakelite has greater stability.

Quentorres file download.

The first thing we will do is download the Quentorre file from our dear friend Adrian Torres and we will take it to MODS.

We download the png files of the Quentorres PCB. You can consult all the PCB Quentorres documentation on its website.

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License

WE CONTINUE
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