58 February 2017
The Maximite software also has a built-in editor
for writing and editing programs. There are third-party
applications for loading programs into the Maximite
through the USB connector, so you have that option as
I wanted more than a bare board sitting on my desk
when I use this retro computer, so I decided to 3D print a
custom case for it. The case is made of ABS plastic and has
slots in the back for the connectors, and a slot in the front
for the SD card. It also has slots on top for the Arduino
connectors to poke through. The back has the keyboard,
VGA, power, USB, speaker, and expansion connector slots.
I designed the case in Tinkercad (as usual) which is the
free easy-to-use CAD program that is in the cloud. I like
it because I can create a design by just placing different
shaped objects together to form the final design; it’s similar
to building with LEGO Blocks. I designed the case into
two pieces: a bottom box and a top cover that just sets on
top, with a groove cut in the bottom side that fits over the
bottom box walls to hold it in place.
The bottom box has a lower base or lip that matches
the top cover shape. In fact, I created the top and then
copied it and placed the copy on the bottom of the base.
The base has holes cut out for the various connectors and
a slot in front for the SD card. To finish it off, I recessed
the name MAXIMITE into the front surface. I later added
slots in the top cover for the Arduino connectors to pop
through. Figures 3A and 3B were captured before that was
I also considered making the top screw down in place,
so I extended the mounting holes in the base up through
the cover; I didn’t like that design, however. The top
actually sits tightly on the base because the
groove cut in the bottom of it (that you can’t
see in the graphic) is just barely larger than the
base, so I get a friction fit.
I 3D printed the case in the position
shown in Figure 3, though I printed the cover
separately. Round holes tend to print fine
because they gradually change shape, but the rectangular
holes have the long flat tops which will result in the plastic
material sagging. Figure 4 shows an example of printing
without any support underneath. This can be corrected
with support material in the slicing software.
The Tinkercad design is exported as an .STL file
and then sliced by (you guessed it) a slicing software
to create the GCode the 3D printer will run. I prefer to
use Simplify3D software for this. One advantage to this
software is I can manually place where to put support
material that is designed to break away easily.
The red colored blocks are the supports I added to
the design before slicing. These will print with the same
material as the case; I used a light blue ABS plastic for the
final design. The software makes these supports thin so
they can easily break away. They are printed in a zig zag
fashion despite the block look in Figure 5.
Figure 6 shows my first attempt at making the box
with supports. I used a white plastic for this. I printed it in
a 0.3 layer height to make it print quicker, and used a far
lower 10% fill. This makes the design rougher but produces
a great first prototype when finished. The final design will
be done at a 0.2 layer height and a more solid fill of 50%,
which comes out smoother.
Figure 7 shows the zig zag look of the support. This
first attempt showed that I needed to adjust the separation
settings in the slicing software to make the supports break
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n FIGURE 3A and 3B. Case design in Tinkercad.
n FIGURE 4. No support for holes. n FIGURE 5. Simplify3D support structure.