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What are You Sinking About?

A project log for PewPew Standalone

A Python-based micro game console, optimized for game development workshops.

ꝺeshipuꝺeshipu 08/10/2018 at 16:317 Comments

Today is the PCB day. A purple envelope arrived, filled with goods. But before I assemble and test the prototype #8 of the device, with all row and column pins capable of PWN, I want to finish an experiment that I described in the first log here. The business card.

In an attempt to make the device as thin as possible, I decided to try and make most of the component "sunken". What does it mean? It means that the PCB has leaks. I mean holes. And the SMD components that would normally sit on top of the PCB instead go inside those holes, from the bottom, and are soldered to pads adjacent to those holes. Here's a view from the back with the switches soldered:

And here's the almost-finished device:

I still need to test the charlieplexing before I solder the rest of the LEDs, but you get the idea.

Of course this is not practical. The holes have to be manually corrected with a dremel (see the first image), because the CNC tool is a bit too big to make good corners (and because I got some sizes wrong). Then the parts need to be fit into the holes just right, and held in place while you solder them. It actually took me several tries to get a working USB socket — you can even see I stripped one of the pads, fortunately that one is unused.

So in conclusion, yes, it is possible to do, no, I wouldn't do it for more than a single unit. It's not practical.

Discussions

megazoid wrote 08/11/2018 at 10:21 point

Unsoldered it looks like one of those credit card multi tools. hehe.

I love it. It's got my mind ticking...

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ꝺeshipu wrote 08/11/2018 at 22:11 point

We should definitely have more business card shaped devices out there! Hmm... maybe a contest...

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Jan wrote 08/11/2018 at 10:02 point

Nobody mentioned the nice pun in the title yet? Haha. 

Cool PCB as well! 

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Jarrett wrote 08/10/2018 at 23:00 point

For the corners, you should be able to use dog-bones ( http://fablab.ruc.dk/more-elegant-cnc-dogbones/ )

The corners themselves aren't particularly structural.


Still not practical for mass production because of soldering, but neat technique.

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ꝺeshipu wrote 08/10/2018 at 23:13 point

Yes, thanks, it was also suggested by someone on Mastodon. But that would require me to actually go and find out what tool size they use, which at the time was too much work. A quick dremel was faster, especially since I got some of those cutouts too tight anyways.

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davedarko wrote 08/10/2018 at 21:22 point

that's a neat design :)

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ꝺeshipu wrote 08/10/2018 at 21:25 point

Thanks! I'm thinking about something similar, but less experimental (no sunken parts and normal batteries)

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