56 February 2016
to create more surface area so the plastic stays flat and
doesn’t warp while cooling. These are then broken off
after printing. I decided to leave them on the base to
allow it to be clamped or screwed down to a board if I
wanted in the future.
When I printed this on my da Vinci 1.0, one of the
sidecar’s surface areas seemed large enough to hold it
down, but the edge lifted a little during the print. The
sidecar still works but I’ll probably reprint it at some point.
All the design pieces fit on my larger da Vinci 1.0 3D
printer (200 mm x 200 mm), but just about any printer
can produce these because you can print them
individually on even the smallest machine.
A 4” x 4” bed size (100 mm x 100 mm) can accept
any of the parts individually. The base has five triangular
holes in the sides and slots that run horizontally. This
design was for a medium sized breadboard, however,
there is also a design available for a larger size
breadboard. The sidecars are offset so the one on the
right uses two of the five triangular holes, while the one
on the left uses two more. This leaves a center groove for
the rubber band to run through. I gathered up all the
pieces (Figure 4) I needed to assemble it, including the
medium sized breadboard, rubber band, base, and two
sidecars. Then, with a little help from a tiny screwdriver, I
fed the rubber band into the center slot (Figure 5). The
sidecars have cone shaped posts on the bottom to accept
the rubber band loop.
The rubber band pulls the sidecars into the base at
the same time from the same rubber band. The base has a
V-groove on the side to accept a circuit board edge; the
sidecar also has the same groove (Figure 6). This allows
just about any circuit board two inches wide or less to be
held in place. Then, you can use jumper wires to the
board from the main breadboard. I installed a stepper
motor board that I will control from a microcontroller. The
stepper motor board is an ETT-Mini board I found at
www.futurlec.com/Mini_SMCC.shtml. They have lots of
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■ FIGURE 4. Pieces to assemble.
■ FIGURE 5. Rubber band inserted.
■ FIGURE 6. Sidecar grooves hold the board.