group assignment:

characterize the design rules for your PCB production process

individual assignment:

make an in-circuit programmer by milling and stuffing the PCB, test it, then optionally try other PCB processes

1.Electronics Production

Group assignment

Machines-Roland modela MDX-20

Our fablab has Roland mdx-20

The Roland Modela MDX-20 is a small milling machine and a 2 1/2D precision scanner. This machine is mostly used for milling circuit boards, though it can also mill in other soft materials like machinable wax. For milling circuit boards you should export you design into a black&white monocroome png. For milling out 3 dimensional molds you should export your design as .stl The second use of this machine is scanning. It uses a thin needle to gently touch the object and calculates from this a 2 and a half dimensional model. Though slow at processing, it can create high detailed model. Work area: 203 x 152 x 60 mm (directly picked from wikipidia)

2.milling bits

We have two different bits to work with our PCBs. 1/64” - Used for milling the trails on the board 1/32” - Used for drilling holes and cutting the board

3.Softwares

Our instructors recommended us to test the machines generating files from two different softwares: MODS and Fab Modules. The one that i preferred most is the fab modules which wasnt straigh forwared but i got the gist of it.

the following is how is set up my mods for cutting using the via modela

4.Process description

the process of milling showed up to being defficult on setting up the modela and time was running out

having been familiar with the fabmodules i went ahead and generated the following for my programmer

still configuring modela roland MDX-20

After the failure to configure modela my only other option was to use chemical method which i tried as much as i could to avoid

This is the chemicals bought for the process:

sulphiric acid

hydrogen peroxide

the etchants were mixed in the ratio of 2:1 repspectively

after downloading the files i continued to etching

the final etched board looked as follows

>

You might be wondering how i transffered the traces to the board, i used the iron boxto transfer them

5.Electronic Componenets

Obtain the components:

1x ATtiny45 or ATtiny85

2x 1kΩ resistors

2x 499Ω resistors

2x 49Ω resistors

2x 3.3v zener diodes

1x red LED

1x green LED

1x 100nF capacitor

1x 2x3 pin header

I decided to end the production here and since there was production of the same in week six and try to use modela to do the milling of the pcd

6.Programming

The last bit was to program the ISP to be ISP itself. I used Avrdude to do this following tutorials provided. i decicided to push this to week 6 since of the problem experincing below

for this week i decided to download and keep the files ready following closely how my fellow students managed to do it

this is by downloading the software for ATtiny45

and setting it up

i decided to push to week six and set up the modela

7.Problem experiencing

Configuring modela is turning out to be a deficult thing to do One of itbeing the modela software/drivers are not installing correctly on my laptop. trying to use terninal to operate the same but the results are still the same nothing is working on the modela i am using. turning out am using alot of time on it and its a repetitive process cant be able to figure out whats the problem.

Without knowing the concentration racial of the chemicals you can end up etching the whole copper

corrosive chemicals can be dengourous if you dont use appropreate gear

you can get the files here

Design File

Problem facing

missing modela installation file thus it was very hard for me as individual to use the modela to mill the my pcb

Fumes produced by the etching chemicals could be dengarous and if not handled with care could be degerous for health

missing Vpannel software

proceed to week six

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