Week 08. Electronics Production
Machining PCB's and soldering tiny components to make things work...
Assignment
group assignment:
- characterise the design rules for your in-house PCB production process
- submit a PCB design to a board house
individual assignment:
- make and test a microcontroller development board that you designed
- extra credit: make it with another process
Making a microcontroller development board
The plan was to produce the PCB board I designed in week 6.
However, I had some design changes that needed to be made to accommodate the components I had to hand. So it was back to Fusion and electronics design workspace to make the changes. I copied the original design into a new folder for week 8 in my Fusion Academy project in the Fusion Hub. Here is a screenshot of the original design and the one with the changes I made.
It was now time to setup for CNC milling. I inserted the design into a new file in Fusion - this seemed easier than working in the 3D PCB workspace as I wanted to customise the outer profile to allow for a Board Flip - I wasn't able to make a single-sided PCB. This new file would allow me to create a Board flip that would hold the board in place when machining the back. I copy and pasted the F as a body in the document and flipped it. I then created a new sketch and offset it by 2mm (the diameter of the cutting tool I would be using to machine the profile of the board). This would allow the F board to be held in position when machining the back. I also adjusted a portion of the F so it would grip the back of the board when machining.
When this is done, save the document and update/push to the other files. For example, when I made the change to the PCB because it is derived from another document, this will need to be updated. See screenshot below.
Now into the Manufacturing Workspace
\sent the files to the CNC and cut the holes and the lect slot to how the CNC would preform /br the slot dodnt reach the bottom so i adjusted the setup for the slot changed to 0.75mm below the coutour for the bottom height (it was 0.5mm) i also switched off multipl depths - lets try again.
I had to create a new milling tool in the Roland MDX 540. This was a bit of a challenge as I had to create a new tool path for the mill.
Once I had the necessary design changes made, I prepared the board to be milled using the Roland MDX 540 as this was the mill I had available at South West College.
Here is a screenshot of the board in the milling machine.
When I had the cutting tool paths produced using the manufacture workspace, I was able to output the NC code and run it on the Roland MDX 540. This code was imported into the VPanel. See screenshots below.
Once the milling was complete I was able to remove the board from the milling machine and clean the surface of the board.
Here is a screenshot of the board after milling.
At this point, I was able to flip the board and machine the back side. This is where the additional parts that were machined came in handy.
Here is a screenshot of the board after milling the back side.
I ran out of time at this point so no soldering yet --- I'm blaming Paddy's Day... it's our national holiday and I was out celebrating. But I know there should be no excuses....
Issues I've encountered
AGHHHHH
What went wrong - I ran out of time this week - I had hoped to have the board milled and then solder the components on but time escaped me.
This seems to be a recurring theme for me during this course. It really does require the full 30+ hours effort every week - with a full-time job, family and everything else it is a challenge.
The mill bits that I brought back from Creative Spark Fab Lab did not fit the collet or the adaptor I had at South West College.
So down to the mill to create a new adaptor.
I used some 6mm bar, faced it off on the mill, used a centre drill and then used a 4mm drill to drill it out.
Then I cut down the length to make a slot which would allow the collet to be tightened around the tool.
Here is a photo of the adaptor on the milling tool and in the milling machine.
Then the bed was too low so I had to raise it up to allow the board to be milled.
Here is a photo of the board in the milling machine.
and a photo of the board after being raised - this required additional MDF to be added and then leveled to ensure the board was flat.
I wasn't able to push to the repo on the college network - I expect it is to do with the college firewall and IT restrictions within the college. I had to hotspot from my mobile phone to get content pushed to the website.
Bringing in components from internet downloads - I haven't nailed this yet.
I would like to be able to create my own library - however, each import into Fusion seems to be its own library.
I need to find a tutorial that will help me understand how to do this properly.
What went wrong.
Learning Outcomes
So far - I've a better grasp of Fusion Electronics and how it works - still frustrating though - especially having to push from 2D PCB to 3D PCB - but I'm getting there.
The Manufacture Workspace in Fusion to produce the cutting tool paths for the Roland MDX 540 - I did try Mods however it didn't have output for the MDX-540 so I reverted back to Fusion.
I have a good grounding in the Arduino IDE and have a good understanding of the code structure and how the types of flow required.