A prototyping breadboard is expensive for what it is. It’s just 3,000 or so breadboard tie-points mounted to a board with banana plug terminals. The popular Elenco 9440 model is currently selling for $34.95 on Amazon, and my local Fry’s is asking $39.99 for the Elenco 9438. Meanwhile, 2 feet away, a breadboard with 1020 tie-points costs just $6.99! By my calculations, if three of the inexpensive standalone breadboards can be had for $21, Elenco/Fry’s is essentially valuing that flat board and 4 terminals at $19. Challenge accepted!!
Spending next to no time bargain-hunting for terminals, I purchased the first seemingly good deal I came across. A 10-piece binding post set for $9. I obviously didn’t need that many, but the extra 9 will come in handy when I finally get around to building some speakers.
As soon as I had the terminal posts in hand, I deconstructed them to make sure I’d be able to adapt them for my purposes. Each set of posts comes with more hardware than I was expecting!
Modeling the Terminals
Next, I loaded up SolidWorks and started shaping up a part that would securely house the posts’ conductive elements. Next, I used my calipers to make some careful measurements of the posts themselves. When I was done, I had the model shown below. The idea being that the large body replaces the black plastic piece that shipped with the posts. Both end caps would then prevent any conductive material from bridging the contacts and creating a short.
With the model in hand, I fired up Simplify3D and got to printing. At a layer height of 0.20 mm with 20% infill, these parts took 57 minutes to print. They used 14 grams of toxic-green colored plastic (that includes rafting). All that was left to do was assembly everything!
To construct the final board, I grabbed some extra masonite I had lying around and cut a 7″x9″ rectangle. I then used the interlocking notches built into the breadboards to connect them together. Lastly, I used the double-sided adhesive on the back of the breadboards to affix them to the masonite. The same sort of double sided sticky tape was used to adhere the terminals. I hooked my power supply up to my Frankenstein DIY Prototyping Breadboard, and a go figure – it worked just fine!
If you’re thinking about duplicating this project, you can find the 3D stl files on Thingiverse.