Project:
Upgrading the electronics to a FTX Mauler
FTX Mauler is a Rock Racer type mix of Crawling car and the slightly
faster Rock Buggy. The plan is to upgrade the ESC, radio components
and the steering servo. As the ESC we chose the Hobbywing 80A Crawling controller, which has proved to be a versatile controller
with its many adjustment settings. Mauler is equipped with a standard
two-in-one type Receiver/ESC unit, which is why you have to upgrade
the radio components when you upgrade the ESC. As the radio component
we chose the most basic and reliable Etronix radio, which is enough for
basic driving. If you want to add a winch or programmable lights you
should choose a multichannel radio, for example Sanwa MT-44. As the
steering servo we chose an affordable Highest DT450 servo with a
plastic case. The servo offers a 15kg torque and has shown to be strong and reliable in faster cars.
We
started off by removing the tires and the body .
Handling the chassis
is much more convenient when you can
access all the components and the tires aren’t spreading dirt all
over the place. - You
can use a regular 7mm socket wrench to remove the tires.
You
need a cross head screwdriver (PH1)
and a 5.5 mm socket wrench or
a set wrench. We recommend removing the body from the hinge (circled
in the picture) so you can remove the whole thing.
When
you have disassembled the car, you can disassemble the electric parts
and installing the new components is easier.
First
you remove the 2in1 ESC /receiver unit. It’s good to note that the
receiver unit has a fixed extension wire for connecting the servo
(you need an extension wire when
installing a servo) and the driving lights have their own connection.
The
plan is to install a Hobbywing Quicrun Crawling ESC. The ESC comes
with a programming card and its equipped with a sturdy XT60 power connector. Note!
The power connector is
different from that in the stock
battery. If you want to use the stock
battery you need to change the connector.
The
radios are 2.4 GHz Etronix 1060 basic radio, which is enough for
normal use.
We
installed the ESC and receiver using double-sided tape on the surface
on top of the back axle. We ended up installing the receiver at the
front, so we could install the servo with a shorter extension wire.
We
made the extension wire using a wire
taken from an old servo, in which we
only had to add a female Futaba servo connector.
We
connected the ESC by soldering the motor wires. First, we cut the
motor wires from the base of the connector.
After peeling the cables, we soldered
together the ESC and motor cables. We used heat-shrink tubing to
protect the soldered spots. It’s good to note that we soldered the
cables “the wrong way”: yellow to black and red to blue) so that
we could get the motor running in the right direction. Note!
You can install most of the brushed motors
in either way, this only changes the
running direction of the motor. However, you should check the manual
if there are any restrictions.
After
this, we removed the original servo.
- To
remove a servo, you need a cross head screwdriver
(PH1)
After
installing the new Highest DT450 servo we first connected it to the
receiver for centering (channel CH1).
Next,
we turned the power on in the car to check the pairing of the radio
equipment (new radios are already paired),
we calibrated the ESC and centered the steering servo.
First,
we calibrated the ESC. Calibrating the Hobbywing Crawling ESC is easy
using the programming bottom next to the power button.
switch
on the transmitter (make sure the Trim of the throttle is at 0)
Turn
on the ESC by pressing the SET-button. The ESC starts making a
beeping sound.
Finger
off the throttle trigger -> press the SET button -> the ESC
beeps once
Pull
the throttle trigger -> press the SET button -> the ESC beeps
twice
Push
Brakes on -> press SET button -> the ESC beeps three times
Turn off the ESC and back on again, then make
sure throttle and brake work normally.
The ESC is now calibrated. Servo
is automaticly centered when Transmitter and Receiver is connected.
After
centering the steering servo, we installed a new aluminium servo arm (25T). After installing the steering link, we set the end points
with the Dual Rate setting.
The
light cables we connected to the Batt channel of the receiver (marked
with green color in the picture).
After
this, we tied Motor wires and the servo and light wires to the chassis with own zip
ties, so when maintaining the car in the future you don’t have to
take apart the whole bundle of wires.
Finally,
we tied the power cable on the other side of the chassis so that all
the wires don’t run along the same side. Neatly tied wires add to
the safe usage of the car when the wires don’t get caught in
branches when driving outside.
We
placed the power switch at the back which makes the power switching
easier as you don’t have to remove the body case to do it.
Now
the only thing left to do is charge the batteries and the Mauler is
ready for a test drive. During the test drive, we adjust the Trim and
if necessary, make changes to the ESC brake settings.