Interning #5

After designing the output module in solidworks, I prepared the file for vacuum forming. With some advice from my solidworks tutor, I was able to duplicate the body, shell it, then subtract the shelled body from the original, leaving what would become the inside of the mould.

Using Autodesk’s 123D Make program, I separated the solidworks model into a stacked representation, which I could then translate into a layout for laser cutting. Fun fact – marine ply can’t be cut by laser; it just scorches the wood.

With the pieces cut, I stacked them in the correct order and glued them together. I then began plastering until it started to resemble the shape I was after.

I put it all together so that I could get the edges correctly aligned. Then I cut it into the two parts for vacuum forming. In hindsight, I never should have joined the two parts to begin with, because the plaster cracked away when I cut it anyway. In future, I’d just keep holding them up to one another to compare.

I got the interface elements laser cut and etched and was ready to vacuum form and assemble! The laser etcher can only go so deep, so to get my desired depth, I just kept running the program over and over until it was what I needed.

So far, the stacked mould was a much faster process than my input module moulds, which were carved from scratch.

It a came crashing down when I tried to vacuum form it.

First of all, I had chosen to use acrylic instead of PETG for this one because it came up cleaner after bead-blasting and was also a lot more scratch-resistant.

Secondly, my mould wasn’t one solid piece this time, it was layers of wood and fragile plaster.

The plastic and the mould both broke when the helpful workshop techs tried to bash it out.

I will say this, when they brake something, they certainly make up for it. They taped up the failed form and made a new plaster mould from it, so I had the option of repairing my old mould or sprucing up this new mould.

This gave me the opportunity to test some paint colours.

I ended up repairing the original mould using cornice cement, which is much stronger than pottery plaster. It survived this time!

My workshop tech helped me measure and plan the way I would mill out the square hole. I found the centre point, then measured half of the size of the desired hole, subtracted the diameter of the drill-bit, then followed the x and y coordinates until I reached the limits.

I realised that I hadn’t checked to make sure the piece wasn’t crooked before cutting it. It looks okay for now, but we’ll see how well the tech pack fits inside.


Speaking of which, the tech pack finally went into the input module!

I hadn’t accounted for all the extra bulk on the back of the PCB – I thought it was all going on the front, so it doesn’t fit into the enclosure as planned.

My boss hacked at the existing holes to make it fit, which is a little bit frustrating, but that’s not the main reason it looks ugly.


After seeing both modules side-by-side in real life, I was finally able to judge their aesthetic properties as a pair. I’d made so many tweaks from my original design, I had forgotten to make a foam model to represent the newest design.

I really like the look of the output module. I think the input module looks too bulky and square. It could be taller at the front to accommodate the PCB and flatter overall. The output module could lean back more to create a better sense of concinnity between the two.

My bosses are self-confessed design-illiterate, so I’ve asked my uni supervisor to discuss this problem with me. I’m not sure if I’ll have a chance to redesign and remake before they’re taken away for testing, as I know my bosses want to crank out prototypes for all of their imagined modules, pronto!


I also tried cutting down the button caps to see if that would help with the fit. This is not the most ideal scenario for mass production, but might help showcase our prototype in a better light.

I also realised that the buttons and switches aren’t all 100% straight. This could also have something to do with the ill-fit. I don’t know if there’s a way to rectify this with home-made PCBs.

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