Re: Yale and ERA Tardis Key Research (Info for the 2005-present keys)
Thanks for the tips... Sorry if it had already been covered.
No, no trouble at all.
OK, thanks to Birdie we got these great pics from the 2009 Art of Doctor Who exhibit where the three chipped keys were displayed:
Using the pictures we could get a rough approximation of the wiring of the keys though unfortunately due to the resolution we don't get all the details we need. This is my rough guess as to the layout:
I wasn't entirely sure about the blue resistor keys wiring. It LOOKS like the black and red wire meet so that's why there's a question mark. Also between the two keys the pin #1 location appears to get reversed from one to another as well as several other wire position changes. Dunno why though. The key I decided to try out is apparently Maratha's key as seen by this screen capture of when she held up the key to show someone:
You can make out the position of the red wire and the tan resistor. Originally I used an ERA key though I know that is incorrect now but here's the rest of the build anyway.
My rough layout to approximate the position of the main parts:
TO do the chip I basically cut off the thinnest part of the chips pins and then sanded the rest down till it was flat with the underside of the chip then softened their edges a bit. You need to do this to keep the chip sitting as flush against the key as possible. One thing to note is that I used an actual SIM card pad that I removed and trimmed down and sanded the edges smooth and also sanded the pad thin on the back as well. I would hazard to guess that they might have used thin sheet brass, cut it and maybe etched the SIM card separation lines into it rather than use an actual SIM card but I did this anyway because hey, I can say I used actual SIM cards XD Here's my first assembly completed:
I really was pleased with the finish on this:
That's the underside where the SIM cards chip is very visible now and one thing I want to point out is that to keep everything in place while soldering, I just glued the corner of the chip the the very edge of the SIM card. You can see a small dab of it there just where the two parts meet. I also tried to line up the one leg of the chip on the corner of the SIM card pad enough so I could solder the leg to the pad directly. That way nothing would shift during assembly. One that was done I soldered the resistor to the chip and the other end of the resistor to the SIM card pad. Then the red wire and THEN the black wire last. When it was entirely assembled it sits pretty flat against the key. This is mainly due to how thin I sanded the SIM card pad and this is important:
That SIM card pad is literally paper thin. Still strong due to there being some micro-thin fiberglass under it but thin. I could probably cut myself on that. Positioned on the key:
I basically tried to get the same layout as the real key and used the positioning of the resistor to line everything up properly. There's still a few minor variances but it's really close. Finally permanently glued to the key and with a three-ply jute cord that matches the picture above:
Like I said, I used an ERA key but the next keys I make will be on JMA's and if possible I'll transplant these parts onto the new key, failing that I may just sell it and start from scratch XD I started to make the blue resistor Key but I accidentally screwed up the SIM card and need to start over. XP Oh well.
Anyway I hope that helps.
