Shipping from China is rather confusing.
The things that were meant to arrive last (SNES cases) actually arrived first. The things that were meant to arrive first (the RCA/USB to TRRS cables) are on a very slow airplane. The tracking information on the TRRS cables said that they were put on a plane on the 4th of December, and as of yet have not “Arrived in destination country”.
This post is meant to be about progress though, not about waiting. So onto some photos of the said progress.
About three weeks ago an unexpected box arrived. Inside it were 100 SNES controllers. Over a week early.
I counted them out to make sure there was 100 of them. Then proceeded to pull them apart. This was an unsurprisingly tedious process.
If anyone has any use for 100 SNES controller cords, you are more than welcome to them.
Next step in the process was cutting away parts of the plastic to fit the new larger PCB, the uSD socket and TRRS plug. When I did the first batch of five prototypes, the controller was just held to the CNC table with double sided tape. This was a bit scary. So for the 100 units I decided to cast a snugly fitting plastic holder.
Out with the old lego to make a box to pour in the PU plastic. It was blutaked down and then sprayed with mold release.
I calculated how much plastic I needed and mixed it up. And that is when the problems started.
The large batch was so exothermic that it started to go opaque and harden in about one min. I quickly grabbed the box and started pouring in the rapidly setting plastic, but a few 10’s of seconds later it was mostly set. It looked and felt like some weird large tongue hanging out of the mixing cup when it was partially set and still rubbery.
So I tried it again, but this time aimed to have the liquids mixed and poured in well under a minute. The photos below show that it didn’t turn out great, but it made a serviceable holder.
The lesson I can take away from this – stick to small batches. So far all my castings have been very small batches of say 20 grams or less. This >100 gram batch was extremely hot, impossibly fast to work with, and made lots of bubbles.
When I did the pour for the back part of the case, I made it as two smaller batches of about 60g each. This was also a bit hot and fast, but a lot more manageable.
The plastic holder was then mounted to the base of the Roland MDX 20. The grey plastic SNES controller pushed into the snug fitting new holder. The the NC-code was sent to the CNC machine.
There is a very boring 3 min long video of it being cut on the you tubes here https://www.youtube.com/watch?v=NRADneg2RA0.
How the NC code for cutting gets created is interesting in itself and will be the topic of a future blog. For now though, I can leave you with some shots of the final cut front and back shells.
All 100 cases are cut and ready for reassembly with the new PCBs