Figure 27. Layer 0 and Layer 1 in the jig,
showing the placement of the extended
Figure 28. Layer 0 and Layer 1 in the jig;
the red circles show the common
cathode solder joints.
Figure 29. Layers 0, 1, and 2 in the jig.
Soldering Layers to
Form the Cube
Insert four bolts into the four corner 1/4”
holes. Secure each bolt to the jig using a 1/4-20
nut. Place LED Layer 0 in the jig holes. Pay
attention to which side has the extended anode
lead. Go to each bolt. On top of the existing nut,
place a spacer, then on top of the spacer place an
LED holder. Then, on top of the LED holders, put
another 1/4-20 nut to secure everything down.
Fasten Layer 1 into the LED holders. Keep the
extended anode leads on the same side (Figure
27). The bent cathode leads of the LEDs layers
should overlap. If the cathode leads don’t touch
each other, use narrow tweezers to bend them so
they are in contact with the previous LED layers.
Solder the overlapping cathode leads; there are a
total of 16 cathode solder joints per layer as
shown in Figure 28. The red circles highlight the vertical cathode solder joints for Layers 0 and l. Place Layer 2 with the
four corner LEDs into the four corner hole’s LED holders (Figure 29). Solder the vertical cathode leads as before. Do the
same thing for Layer 3. Notice how the extended anode leads are positioned on one side of the 3D LED matrix. The four
extended common anode layer leads (one for each layer) end up in a staircase pattern (note the arrows). This is important
for when we solder the matrix to the printed circuit board (PCB). You can test the LEDs before mounting the 3D LED
matrix to the PCB. Unscrew all the nuts and remove the spacers and LED holders so you can get the LED matrix cube out
of the jig. Your 3D matrix should look like Figure 30.
Layers 0, 1, 2,
and 3 in the
Transparent Case Mounting
There is an optional transparent case available for the LED
cube (Figure A). The case itself may be purchased assembled or
in a kit (also at
www.nutsvolts.com). The instructions for assembly
are provided with the cube, so we will not repeat them here. The
holes in the transparent case line up with the holes for the L
brackets and the DC jack on the lower end.
When it’s time, you’ll slide the case over the cube (with the
PCB) with the correct orientation so that holes for the L brackets
and DC jack match with those on the PCB. Insert the plastic push
rivets from outside of the case into the holes on the case that
match with the L bracket long arm hole.
Figure A. Transparent
case, assembled and
August 2011 49