Week3 - Make through

the first thing you need to find an application that can handle designing schematic and board layout and can also create caming process files from milling

Autodesk Eagle can met all these requirement

you can download its educational version for free from the button below

this section

Download from here

How to install eagle

in this video you will find the steps to install eagle on your windows you can also find video on YouTube to install it over mac or lunix

Adding new Library

the first problem i faced that not all my required component is available in eagle library manger

so i have searched for this and i found many external library that i can add to eagle library manger most common component i need to use is available on (sparkfun library set and fab library)and you can download them from links below

and this video describe how you can add external library to Eagle

Sparkfun Lib

Fab Lib

Designing Schematic

and now i started to design my schematic

first adding all required component from the library to the sketch board

then adding nets to each pin i need to connect and define its name using the name tool in the right toolbox
and also draw border around each group like (Main Control , Power , io Pins) to make it easy to refine it in troubleshooting

Schematic File

Know Your Machine Limits

before start routing your board layout you need to know well your milling machine to get perfect traces you have to know minimum trace width and minimum tolerance for your machine in our case we are using Roland Miller we can produce trace at 0.4mm and minimum clearance between traces 0.4mm

DRC

Design Rules Check is a very important step before start routing you must assign your minimum trace width and clearance in our case its 0.4mm for each

Routing Board Layout

and now we can start routing traces from each and to each net

after arrenging the compnent in the right place to make the shortest path between pins

Board Layout

Preparing for Fabrication

and now we can start using the cam Proccess tool to generate .png files for top layer and profile and drill

Top Layer

Drills Layer

Profile Layer

and now the next step is to put all layer in one sketch to ensure that every thing is fitting and no layers are shifting we can using any grabber file application
we choose Gerbv for Windows

now we should export top layer file with profile to ensure the file get the right size we use profile layer as reference

and the we export drill file also with the profile layer in pdf format

and using any image editor application we need to invert top layer color as the milling machine goes around black line

Trail 1 (Failed)

first i have arrived to fablab to start fabrication

attached the blank pcb to milling machine using double face tapethen attaching the V-Bit 0.4MM to engraving motor and started to open fabmodule

set my setting to roland md-20x and used 1/32 inch endmill set speed 4mm/s and offsets number at 4

set my jog position and starting to calibrate Z axis bys clicking down button click by click till the v bit reach the surface of pcb ( you can fell the change of sound when endmill reach the surface )

now set jog Zero and start engraving

after engraving complete we just need to change the endmill with 0.8mm drilling bit and add drilling file to fabmodules change setting to met new drill bit and in the same way calibrate Z axis to zero and start
the last step is to add profile file and change setting to met 2.0mm endmill and slow speed to 1.0mm /s
then I started to soldering my component till i reach the ATTINY 44 soldering time and I got shoked
the problem is the legs of IC order didn't match the engraved legs order vcc is at ground and ground at vcc :'(

the board layout has been mirrored .....!!!!!!!!!!!!!!!!!

received_4533486466677883.mp4

Trail 2 ( Successful)

in this trail i have found the problem that i have made mistake by mirroring the top layer in 1 side pcb

so i started to fabricate the pcb again without mirror using another machine at my work (Ronos 3018) and i have got a perfect result

and start to re soldering component again

and start to uploading code using spi pin headers i have made and the uploading done :D

Arduino Code

and here is a video while testing every thing works fine

VID20210203233722.mp4

CONCLUSION

i have learnt this week how to..

Design Curicit Schematic
Make Board Layout and traces routing
fabricating pcb using milling machine
soldering smd component

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