DIY: Shruti-1 Synthesizer by glitched

Note: This article was initially hosted on the wonderful, but now defunct, sharing site.  I’m putting it on my site, for posterity’s sake.  Scroll to the end to view the picture gallery.

This case was used by several people, including the Shruti-1′s developer, Oliver: It also inspired similar case designs for the successor to the Shruti-1, the ShruTHi-1:

By the way, you can still download the design for this case, on ponoko, here: You won’t be able to put any of the Shruti-1 guts into it because the kits are no longer available, but it’s perdy to look at.

So, it’s finally finished.  After a solid week of planning and designing and another three weeks of waiting for Ponoko, the enclosure is finished.  I call it, “Whiteout”, for obvious reasons.

It’s simple and elegant, if a bit generic, but the point was to make a compact case for under $30 (the price of just a faceplate at some places).

More so, it was important for me to go through the entire DIY process without any (or much) help.

Prior to this project, I had done an x0xb0x and a MIdibox SID with customized cases, but nothing completely from scratch.  There was always an idea that came from this guy, a template from that guy…this time, I needed to do everything myself.

So, the first thing I had to do was get the dimensions of the components and their locations on the control board.  Seems simple enough, but I had never done this before.  Taking a look at the PCB .dxf files gave me the coordinates I needed.

I then plotted these in FrontPanel Designer.  Why?  It was the only app I had at that time that would allow me to do the job quickly and accurately.

Checking the data sheets for the sizes of the components was the next thing to do; this was no problem because Oliver had already made a thread which collected all of this information in one place.

Ok, now the faceplate is done, but what about the rest of the case?  I didn’t want to go with the traditional Hammond/Pactec/OKW case route and I wasn’t sure how to create something in Inkscape, from scratch.

I believe it was smrl who introduced me to Google Sketchup.  After opening the program and fooling around, it seemed daunting; I had never messed around in 3d before and making a simple cube was beyond my capabilities.

After a few hours and tutorials, I figured that Sketchup, in tandem with Inkscape, would be the perfect team of applications in which to model my case.

On to the design phase…

How big should this thing be?  Tiny.  The final dimensions of my case are: 160 x 108 x 60mm.  In other words, it takes up less space than a small USPS Flat Rate box, but is slightly larger than a standard stomp box.

Crap, what about all that work I did on the frontpanel in FPD?

Thankfully, I didn’t have to start completely from scratch.  The new version of Front Panel Designer (4.01) exports .dxf files and Google Sketchup (version 7 only–version 8 doesn’t allow this) imports them, if you can find the plugin.

One minor change I made near the end was turning groups of LEDs into rectangles.  (The Shruti-1 has buttons, which cycle through a group of functions when pressed.  The LED’s correspond to these functional groups.)  This also cut down on cost a Ponoko (circles cost more than squares).

From there, it was more a matter of figuring out to work the program than figuring out how I wanted the case to look.

The real final challenge was modeling the backplate.

I opened the PCB dxf files again and got the coordinates for the components, as I did for the faceplate.  The additional things I had to take into account were: 1) the height of the spacers,  2) the thickness of the material, 3) the thickness of the pcb, and 4) the space between the pcb and the component (if any).  In other words, in my case, the ports on the back panel should start no lower than 11.82mm from the bottom of the case.

Figuring this stuff out was a combination of looking at data sheets and real-world physical measuring, using a ruler.  All that hard work paid off because when I started to assemble the case, the fit was per-fect.  Perfect.

When the design was complete, I added the “teeth” for an interlocking design.  This was a painstaking procedure, but it proved to be worthwhile, ultimately.

I exported the whole thing to Inkscape, using a special plugin (check one of smrl’s threads or google it).  It took a while to get the settings right, but when I got it, the results were good; a real time-saver.

Why go from Sketchup to Inkscape and not just design in Inkscape?  Well, having never worked with either app, I thought that learning just enough about both was a better idea.

The journey wasn’t over, however; lots of tweaking had to be done in Inkscape to prepare it for Ponoko.  Plus, if I wanted to have an interlocking design, I had to create “nodes” on each one of the teeth of each panel.

After wasting a couple hours at 1200% zoom, I decided to leave the nodes out.  If the panels don’t fit together tightly, I’ll just glue ‘em.

Also, ponoko recommends placing your pieces together, like a jigsaw puzzle, to save money and laser time.  This was a complete waste of time, as the cost of an “optimized” design was more than one where the pieces were laid out separately.

Blah, blah, blah…3 weeks later and it’s finally here.  It took some time to figure out how to put the pieces together.  Laugh at me if you want, but I got so paranoid that I messed up on the design that I clipped off a tiny nub, in order to make it fit.  Turns out dumb-dumb had the piece the wrong way.  Oh well.  I consider it to be an accent.

Anyway, the pieces fit together perfectly, but there was no friction to hold them together.  A little superglue solved the problem.  The top panel is not glued, but it doesn’t have to be because it’s not going anywhere.

Attaching the panels and LCD to the case was pretty simple: spacers screwed into the PCBs and glued to the case with epoxy.  No screw holes to worry about.

Overall, my first Ponoko experience was very positive.  Their workmanship is top tier and their prices are fair.  My only gripe is the time it took to make the thing, but Ponoko is always expanding and I’m sure that picking up more lasers is at the top of their capital procurement list.

Feel free to post questions or comments here or in this thread: