Page 42 - TPM Issue3

LEGO TECHNIC BUILD

Above:
The arm assembly showing some of the gearing.

which are also installed at this stage. left:
Stage 3 involves building the boom Various components to
and arm, using the remaining 3 add realism to the model.
medium motors to control the arm,
bucket curl and shovel actuators with
a clever arrangement of gearing and
drive shafts. Once the arm is
connected to the body, it is time for
another test of the system. This time
testing the arm functions.

Stage 4 adds the various structures
on the top of the body, including
hinged doors that open to access the
button on the hub, the cooling array your shovelling technique and that’s it,
which is achieved with clear parts the build is complete. Now time to get
and stickers to allow the fan units to to grips with the Control+ app.
be seen beneath. The twin exhaust
stacks are added along with the air Functionality
filters and a line of fire suppressant The only way to operate the model
cannisters for authenticity which is a once built is through the control+ app,
nice touch. and the first operation is to calibrate
the different actuators so that it knows
Stage 5 constructs the cabin, the model position and the limits of
walkways, access ladder and the each movement. The tracks can be
safety railings that run around the top controlled individually and there is
of the body. On the boom, different some proportional control so you have
lengths of flexible tubing are added fine control over the movements.
to simulate the hydraulic hoses to the The clutches in the track frames do
actuators and this really adds to occasionally click when attempting to
the realism. turn on a carpet but there is enough
torque to allow the model to climb
Stage 6 finishes off the model by gradients and over objects. The slew
fixing the lower shovel part into place, control is a good speed and while the
this alone is an interesting single piece actuators are a little slow in achieving
casting which incorporates the tooth the full range of movement, they do
detailing convincingly. A number of authentically capture the operation
blocks are included for you to practice of the full-sized machine. The two

42 TPMMW Magazine - Spring 2020