3D Printed Breadboard (Work In Progress)

[LesterCHall]

I'm one of those types who just loves to share and I've discovered something really interesting and simple that accomplishes a somewhat significant objective. Thing is, I'm lazy this weekend and may not work on it til later so I'll share here. Here goes.

I figured out one way to make 3D printed breadboards. it's simple and easy to do. I ran a test shown in the pictures below and had very good results. All I really did was realize that the grippers in a standard breadboard could be replaced by a simple wedge! Then I designed a wedge in OpenSCAD and printed it - it worked!

Breadboard a la Proto-pasta - 1.jpg Breadboard a la Proto-pasta - 2.jpg

The first wedge I made was too big off the printer in all dimensions so I filed it down until it worked. Insertion of the leads was a bit rough on the leads, bending them if they were too long. I think this can be resolved with design of the nonconductive array, leaving small spaces for the wires to go.

When I measured the first wedge, each resistor had a 500 Ohm resistance to a central node. It was like the surface contact was 500 Ohms and the internal resistance was low by comparison. 500 Ohm connections are pretty large but I figured it would be OK for high impedance circuits so I forged ahead.

The second wedge I tried (not shown) was only too big on the ends so very little filing was required. The thing I did there was make the wedge surface, the angled part of the wedge that would be in contact with the leads be printed on the bottom side of the print. This left the stairstep details on the orthogonal lengths where the stairsteps would not matter, I reasoned.

Much to my surprise the second node had near zero resistance compared to the 100 Ohm resistors that I was using. I measured a few times and yep, sure enough - it was true. I figure that the reason for this is that during the print, which is on the hot side as recommended by the manufacturer (Proto-pasta) at 230C, the conductive material settles to the bottom of the print. So we have prints in layers in which each layer is a sandwich with many layers and each layer is conductive on the bottom mostly.

If this is true it's a useful discovery because it means that we can get lower resistance prints by using the bottom of the print for contacts.

Anyway, you can repeat my results as I will post them on Thingiverse and link them here in a moment. Oh, the print was done on a Printrbot Simple Metal using a 0.4mm nozzle, 100um layers, 230C temp, no heated bed, blue painter's tape on the bed, and solid infill.

Les

[LesterCHall]

The link to the Thingiverse entry with the files is here:

http://www.thingiverse.com/thing:921676

Les

[LesterCHall]

The link to the Thingiverse entry with the files is here:

http://www.thingiverse.com/thing:921676

Les