Love my printer. 3D printed project box building is an essential part of my projects, and to be honest, almost as much fun as the electronics!
A few months ago, I bought some Barebones Distill AM Bandstop Filters. As previously described, these cheap notch filters do a great job of reducing really strong signals from local medium wave stations. This is especially important when using wideband loop antennas with wideband SDR receivers.
So, I decided to package two of these filters into a little box for use with my two wideband loop antennas and various two-channel SDR radios like the RSPduo from SDRplay. I also wanted the option for connecting with either SMA or BNC cables.
My design is a small plastic box, less than 2″ square, with holes for connections. Since the Distill filters are fully shielded, I could just use a plastic box without any EMI shielding paint. The final product is shown above left and cost around $3 in plastic filament.
You need to start out with careful measurements, typically using a digital caliper. My $20 digital calipers are very accurate down to around 0.1 mm which is all I need. While most modules provide measurements on spec sheets, I always do the measuring myself just to make sure.
Next, I opened my CAD program to design the box in two parts – base and lid. Usually, you do your 3D printed project box building in several pieces that fit together. As you can see above right above, the holes for my input and output connectors were an important part of the design, as well as some ledges for firmly mounting the filter modules.
3D Printed Project Box Building – Getting it Right
Careful measurements and CAD visualization really help in getting 3D printed project box building right the first time. But the plastic is so cheap, that even if you have to make some changes and do it again, you normally don’t lose much.
My filter holds together firmly with nuts and lock washers on the SMA connectors, as well as properly placed mounts on the bottom of the box. I can use threaded inserts to attach the top lid, or just simply glue it down with some superglue or silicone caulk.