Place the connectors towards the front of the robot
(actuators 1 and 4); make sure you leave enough room
to mount a barrier strip and USB2Dynamixel controller as
shown in Figure 13. There are many ways to hold the
battery in place. I used some right angle connectors I had
on hand, but some hook and loop straps would work
just as well (choose the heavy duty kind available at most
home centers). Attach the straps to the base on either side
of the battery with wood and finishing washers.
The battery comes
with an output power
connector and you are
free to use this one.
Cut off about 3" of
cable and attach it to
a two-position barrier
strip as shown in
FIGURE 11 Figure 9. Since I own
several laptops, I
wanted to keep the output cable intact, so I cut the plug
off of an old AC adapter for my installation. As a last
resort, you can take the battery down to your local
RadioShack and they will help you find a connector.
Attach the barrier strip to the base with #4 wood
screws as shown in Figure 9.
Now, take two pieces of red 18 gauge wire ( 12" each)
and connect them together with solder. Attach the soldered
end to the positive terminal on the barrier strip. Connect
each of the other ends to the positive lead on the four-position barrier strip that is on each wheel assembly as
shown in Figure 10. Repeat this using the two black wires.
It's important that you use at least 18 gauge wires or you
may not supply enough power for your actuators. Notice
how I have attached everything close to the base with
Connect the Data Leads
Run a yellow and white wire from the barrier strips on
the wheel assemblies to each other as shown in Figure 11.
Make sure you route the leads through the existing cable
clamps and add a couple near the rear of the battery.
Mount the USB2Dynamixel
Add a couple pieces of double-stick foam tape to the
bottom (flat side) of the USB2Dynamixel. Make sure the
USB2Dynamixel is close enough to connect to actuator 4
as shown in Figure 12. Also make sure you have room to
connect a USB extension cable to the controller. Try dry
fitting the controller before attaching it.
The bottom of the base is now complete. It should be
laid out like Figure 13. I have included the IDs for each of
Before we move to the top of the base, I want to say
something about using two Ryobi batteries. First, I
recommend mounting the batteries on the underside of
the base. However, this can be problematic if the Megabot
will be used on rough and rocky terrain. Connect each
battery to the power leads on each wheel assembly. When
connecting the data leads from wheel assembly to wheel
assembly, you will also need to connect the negative
terminal, as well.
36 SERVO 02.2009