3-D Printing/Softrock Enclosure
While helping KI6ZHD build his Softrock Lite II SDR (from KB9YIG), I ended up breaking the leads on my Softrock and we both talked about needing an enclosure for the receiver. We also talked about 3-D printing, which is something that sounds really cool. So this exercise is about designing an enclosure for the Softrock Lite II SDR that can be printed on a 3-D printer.
I spent some time surfing web sites and reading tutorials where I learned that 3-D printing commonly starts with a solid model. There are a number of solid modeling programs and as long as they can produce STL files they will work with 3-D printing systems. I chose OpenSCAD which is available for Linux, Mac, and MS-Windows. While OpenSCAD isn't GUI based, the language is easy to learn and it was easy for me to enter values I measured from the parts that would be enclosed.
As for dimensions for the Softrock Lite II, I would have measured my board, but it is on loan. So a query to the softrock40 Yahoo Group got me a response from the designer, Tony, KB9YIG. He provided the critical dimensions and I estimated the rest (like crystal height and location).
The requirements are pretty simple. The enclosure will
house the Softrock Lite II RX PCB with all components mounted using the mounting holes designed into the PCB.
with mounting holes for:
a dual-pole PowerPole power connector.
a 3.5mm stereo jack.
a panel mounted BNC jack.
I installed OpenSCAD which I configured for 'Automatic Load and Compile' so that I could use an external editor (Vim with OpenSCAD highlighting extension.).I set up a Git repository to track my work and practiced with some of the exercises from the OpenSCAD Tutorial Series.
I then built up the model a bit at a time. Sub-models for the Softrock PCB, connectors, and stand-offs are in separate files. The final model is shown at the top of this page. This cut-away shows the PCB and connector models and how they fit in the enclosure:
The enclosure model was cut in half to make a top and a bottom which were arranged side-by-side so that they can be printed at the same time:
The final step was to export the file (softrockEnc.scad) to STL. I don't have a 3-D printer (yet?) so I uploaded the STL file to i.materialize.com to see if it could be printed. There were no errors and I can print this enclosure in polymide for about $20.
The tools for 3-D printing, at least from a service, are ready for use; even on Linux. Once I discovered OpenSCAD this turned into a pretty easy exercise. It only took a few hours even though I had a lot to learn.
While researching 3-D printing for this exercise I found a number of web sites that were of particular interest or potential future use:
Thingiverse - A Makerbot Industries web site for sharing 3-D designs.
Shapeways - A well known 3-D printing service.
Ponoko - Another printing service provides laser cutting and printed 3-D ceramics.
If you want to contact me about this exercise, look for me on Google+ (Jerry Dunmire) or use my call sign (KA6HLD) to send me mail @arrl.net.