the offset of the servo drive shaft. While there is
technically no “front” or “rear” of the ArdBot, for
the purposes of assembly, the top of the
illustration in Figure 5 is the front and the
bottom is the rear.
Insert a servo into a servo mount by sliding it
back-end first through the mount. The fit may be
tight, depending on the make and model of the
servo. (As necessary, enlarge the rectangle for the
servo using a file or coarse sandpaper.) Do not
force the servo into the mount or the mount may
Secure the servo to the mount with 4-40 x
1/2” screws and hex nuts (Figure 6). You can use
four screws for each servo, or only two. When
using two screws position them on opposite
corners of the servo mounting flange, as shown.
Repeat for the opposite servo and mount. Be sure to
construct the second servo and mount in a mirror image to
the first! Refer to Figure 9 in Step 3 to see how the motors
should be inserted into the mounts. For reference, also see
Figure 12 for an aerial view of the ArdBot and its
completed bottom deck.
FIGURE 4. Layout pattern for cutting and drilling the servo mount. You’ll
need two of these. If cutting the inside rectangle proves difficult, you can
instead make the mounts by cutting through at the dotted line.
The mount will be a little more fragile, so handle it carefully.
Use all four screws to secure the servo in the mount, rather than just two.
Insert the machine screws through the L bracket, then
through the servo mount. Secure on the other end with a
nut. Before tightening, be sure the bottom of the L bracket
is flush with the bottom edge of the servo mount.
Using 4-40 x 1/2” machine screws and nuts, attach
two plastic L brackets to each of the servo mounts (Figure
7). You’ll be make a “left” and a “right” mount assembly.
For the left mount assembly, the motor shaft should
face to the left and toward the “top” of the deck (as
referenced in Figure 5). Attach the L brackets to the right
side of the mount. For the right mount assembly, the motor
shaft should face to the right, also toward the top of the
deck. Attach the L brackets to the left side of the mount.
Attach the left mount assembly to the bottom deck
using two 4-40 x 1/2” screws and standoffs. The screws
should come up from the underside of the deck, through
FIGURE 6. Servo motor secured into one of the servo mounts.
You need two of these.
FIGURE 5. Only four holes are critical for the bottom deck: the two
sets marked Holes for servo mounting, and the front and rear Skid.
The rest are optional for sensors and other
accessories you may want to add later.
SERVO 12.2010 55