vertically and solder the whole lot. I was beginning to get
a feel for this new system (Figure 6).
Having made short work of the Robot Badge kit, I
decided to attempt an old Pocket Mini Computer (PMC)
kit which consisted of a 2” x 3” “shield” for the Parallax
QuickStart Board, with a 1” x 1” daughterboard on top.
These boards were mostly through-hole with some
surface-mount components, and component density was
high with a number of headers and connectors at the
PCB work I do, and I thought this kit would provide a
“real” test of the PCB Rax. In addition, I had built several
of these kits before using my tried-and-true method, which
I thought should provide a good baseline for a “before
and after” comparison of the system.
I started with the 2” x 3” shield board in the vertical
position, and had no trouble soldering the discrete
components and IC sockets. Some components needed
my little heatsink clamp to steady them while soldering,
but most didn’t, and things went smoothly.
This kit had several connectors on the board edges,
and I had to jockey the extension brackets a few times to
make room for the connectors being installed. Again,
things went pretty smoothly, except for my over-confidence-driven haste (hey, I’m starting to get the hang
of this!) that left a VGA connector slightly raised off the
board on one side (Figure 7).
The 1” x 1” daughterboard required some surface-mount work, which meant the PCB Rax had to be in the
horizontal position. To my mild surprise, the system held
this tiny board securely, using only two of the extension
brackets. It took some shifting around to get my iron
positioned comfortably above the PCB Rax in the
horizontal position (the feet stick up a couple of inches on
each corner), but with my heatsink clamp holding things
down, I was able to complete the necessary joints. I did
have to remove the board, rotate it 90 degrees in the
extension brackets, and re-tighten to get clear access to
some of the joints. All in all, construction of this Pocket
Mini Computer kit using the PCB Rax seemed easier and
quicker than the several I had built previously using my
old method (Figure 8).
My final PCB assembly test was a homebrew project
built on a 1-1/2” x 2-1/4” Parallax EDU circuit overlay
board which is a protoboard that can be used to create
“shields” for the Amigo computer kit sold in the Nuts &
Volts webstore. Unlike the three previous “kit” boards —
where component x goes in position y — effective layout
of the components on the protoboard is a big part of the
I found that my new skills with the PCB Rax allowed
me to quickly solder the male shield headers in place with
the system set vertically. Then, I switched to the horizontal
orientation with the component side of the board up, and
dropped the various components into the protoboard,
moving them around until I found a layout that I liked.
Gravity held everything in place, and the PCB Rax
elevation above my workspace allowed long component
leads to stick out below the board with no ill effects.
With the board still horizontal, I tacked down the
components I could, working easily from above and using
gravity as my helper. I then turned the system vertically
and soldered all the connections on the trace side of the
board, using my little heatsink clamp to hold components
I couldn’t tack from above. For me, the whole process was
surprisingly intuitive — I now had a good “feel” for this
new tool — and again my build seemed quicker and easier
FIGURE 8. My sloppy installation of a VGA
connector. I should have adjusted the
extension brackets on the PCB Rax to give me
FIGURE 7. The completed PMC shield and
daughterboard. The size, component density,
and component proximity to the board edges
are typical of many kits available today.
FIGURE 6. The PCB Rax extension brackets offer
good positioning flexibility and easily held the
small irregular-shaped Robot Badge PCB.
38 January 2017