Category: making things

Are any of you interested in having a MIDI-fied Casio SK-1? It doesn’t add full control, but it does allow one to trigger all keys remotely via MIDI.

I had tried to etch my own PCB for it before, but because of a crappy design and the difficulties of fine pitch doing double-sided boards at home, I stopped.

I’m wanting to get this project finished, so I’m going to lay out a new PCB and have it manufactured. Should be about $15/board once done. Plus parts, of course. But you’ll have to source those yourself.

Anyway, anyone want one?

(My boards are based on the info here.)

MIDIbox SID-NUXX Front Panel PCB

PCBs all milled and trimmed. I’m going to pick up the first front panel in something like two hours.

If everything goes as planned, there will be a complete MIDIbox SID-NUXX sitting on my workbench tonight.

< glee! >

Then I’ll just have to place one more (rather pricey) order and all five MIDIbox SID-NUXX’s will be ready to go. The three I’m building, and the two which are being sent to and . I’m really excited.

(Photo of the rear of the PCB showing how close the traces are to the edge of the board.)

UPDATE: I’ve just discovered that I seriously screwed up something on these PCBs. Basically, the switches are eternally pressed. I think I can fix it with some simple trace cutting, but I need to take a long look at it to be sure. Guh. I feel like an idiot. I must have somehow drawn the part wrong in EAGLE and then used it…

< sigh >

I would swear that I checked it at least three times, too.

This really bothers me. I think I’ll go eat a meal, pick up the front panel from ‘s house, then decide what needs to be done.

Well, it turns out that there is a slight error in the layout of the display for the MIDIbox SID-NUXX. Everything on it is sized *perfectly* for the LCD display. As it turns out, the ‘active area’ of the OLED is a bit smaller than that of the LCD, and thusly the buttons on the front panel are slightly misaligned (by a max of 1.2mm I believe) when using an OLED instead of an LCD.

Oops.

In reality, it likely won’t be noticable, especially with the display being set back a few mm from the inside of the metal panel anway. So, it’s nothing to worry about…

Oh, the PCBs I received yesterday? Look / work great, and I’ve had no problems whatsoever with cutting the center out of the first one. I used the combination of Dremel / used dental bit mill and a hand file with a vise. Worked great. Only problem was the epoxy / fiberglass dust, so I may do the remaining ones in the garage.

But that won’t be until next week. For now I’m out here on vacation. Woo!

Whoops. Someone from Front Panel Express just called to tell me that my design for the MIDIbox SID-NUXX rear panel I had drawn the slots in a manner which caused some problems with the milling. One of their engineers fixed the drawing and re-cut a new end panel, but they wanted to tell me that in the future the drawing should be done a bit differently.

(The problem was that I drew the angled slots by taking a milled hole, slanting the sides 45°, and making the corner radius that of the tool. In the future I should draw a line and rotate it 45° instead.)

I just wrote up a quick article on how I remove flux from PCBs after assembling them.

If you’d like to read it and see some sample photos of a PCB before and after cleaning, take a look at the article here: http://www.nuxx.net/wiki/Flux_Removal

There we go, the three MIDIbox SID-NUXXs which I’m assembling.

The top one is ‘s, and is fully setup and working using one of the SIDs which was nice enough to send me. I just have to drop ‘s SID into it and it’ll be ready to go. Oh, and maaaaybe change the resistors, depending on how the LEDs look with those. (The LEDs will generally be brightness matched to the LCD.)

The other two are mine, with the top one being a 12V version for a 6581 SID, and the bottom being 9V for an 8580. Neither of these have been fitted with their socketed ICs, and I also left out the resistors which control LED brightness. Of course, this means that neither of mine have been tested, but they should work.

With any luck I’ll have a pair of OLEDs to play with sometime within the next few days. Provided these work as expected, they are what I’ll be using to display things on my MIDIbox SID-NUXXs. ‘s will get the CFAH2002A-RMI-JP which can be seen here, not set right, and very overexposed.

< smile > This is finally all coming together.

Yay! Leave it up to me to screw up yet something else on this synth project…

1) The black screws from McMaster-Carr are a bit larger than I’d figured, so they won’t sit quite right in the holes on the front panel. And since I want them to match on both panels… Well… I need to try and cancel the orders tomorrow, then resubmit them.

2) I ordered a $9 bag of 4-40 bolts with captive lock washers. Not bad… Except I needed 6-32. I must have clicked the wrong fscking thing. :\

Ah well…

I have just ordered the last of the parts needed for building the first MIDIbox SID-NUXX. Provided everything goes as planned I will simply have to wait for the parts to arrive, then assemble the synth. If that goes as planned, I can build one for Bryan, a second one for myself, then determine what will be done with the other two PCB sets. :D

Oh, I had to pull a weird hack to order the front panel PCBs. It will require me to cut out the center of each board, but that shouldn’t be too difficult.

Now I’m going home. :D

Paper models of the front and rear panels and associated PCB for the MIDIbox SID-NUXX.

Making paper models of the mechanical parts for things is really handy. For example, the bottom two ones up above there helped me identify a problem with the alignment of the LCD and pushbuttons. Takes about 20 minutes to make, works out really well. Those bottom two are the front panel itself, and the PCB which is sandwhiched between the LCD and the front panel, in order to hold the LEDs, rotary encoder, and pushbuttons.

Oh, and yes, this project is starting to wrap up. As soon as I finalize the design for the front panel and order the parts, it’s all a matter of waiting. Then provided the parts all fit together, it’s all then a matter of final assembly and documentation and the MIDIbox SID-NUXX will be complete.