22 SERVO 04.2016
The frame can be made from any 3/4” stock. I used melamine coated particle board. Both plywood and plastic could also be used. I would not use metal as it
would make the machine too heavy and difficult to
The inside area of the frame is 16” x 16”, while the
footprint is 17. 5” x 18”. These dimensions were chosen to
accommodate 16” long 8 mm steel rods and flanged
supports for both the X and Y axis.
The frame consists of five components: two sides, a
front brace, a rear brace, and a top brace. Holes have also
been provided for mounting a 3/4” cleat. This cleat may be
desired if you want to mount a shelf inside the frame to
hold some of the electronic components.
It is important that the holes drilled into the frame
components be placed as accurately as possible. Having
dealt with various CNC builds in the past, I have found that
using templates is the best way to achieve that. I will be
offering a set of templates that can be placed over your
stock to allow you to easily mark the points to drill the
Let’s take a little closer look at each of these
There are two side components used on the frame.
They are identical with all the holes drilled through. Each
one is cut from a piece of stock that is 19” high by 18”
wide. A 12” x 12” section is cut out so that the side piece
forms an L shape as shown in Figure 1. You can fillet the
inside corner or make it a 90 degree angle.
The sides contain the holes used to mount the motors,
bearings, and rods for the X axis. The large holes on the
bottom are for optional fans or vents.
The front brace is positioned between the two sides.
In this installment, I
will show you how to
assemble the frame
components, so you
will need the means to
cut out the
components. This will
vary depending on the
materials used. In my
case, I used a table saw
to cut out the parts
and a jig saw to cut out
the larger holes. I used
a portable drill to make
all the holes.