ULTIMATEELECTRICS
TEXT & PHOTOS BY JOHN REID
High-Voltage Hardware
These latest innovations ensure longer, faster and safer electric flight
THIS MONTH, I WANT TO TALK about
some of the new products out there for our
electrified aircraft that have evolved from
new advances in material and technology.
Leading the pack has to be the new Storm
70mm ducted-fan unit from Hoffman Magnetics—one of the biggest innovations on
the market right now, at least for the electric
pilot. This bad boy makes the giant leap for
electric-ducted fans to become the new environmentally friendly turbine jet. The new
fan unit can use our current battery packs
and ESCs to produce outstanding thrust
without pushing the power system to the
limits. Other innovations include the new
30C battery packs, A123 batteries/chargers
and safety during charging.
THE LATEST IN DUCTED FANS
Recently, Hoffman Magnetics Inc. let us try
out their new Storm 70mm ducted-fan unit
and our first impression is, “Wow, this
thing is powerful!” It stands out from other
ducted-fan units in its class because of its
innovative design and construction. First of
all, the unit is constructed from composite
materials that keep the weight down. Even
though the material is lightweight, it is still
very rigid and retains its shape without flattening out during the entire speed range,
which is around 54,000rpm and above. The
ducted-fan unit is dynamically balanced,
which means that the blades are perfectly
balanced when they are spinning at their
operating rpm, making for a very smooth
operation.
What really separates this unit from all
others is that the motor is actually built in
and part of the DF unit. Other ducted fans
have the housing, blade and then a motor
is added or attached to the blades before
being installed into the housing. On the
Storm 70, the inside of the blades house the
Electric pilots will love Hoffman
Magnetics’ innovative new
Storm 70mm ducted-fan unit.
On the break-away below, you
can see that the motor is actually incorporated right into the
fan unit. This makes for a very
efficient operating fan.
magnets with the stator and winding
attached to the housing. Once assembled,
the ducted-fan unit itself becomes the
motor case. This eliminates the additional
weight of the motor housing and makes the
entire power transfer much more efficient.
One of the main obstacles to overcome
when putting the motor inside the blades
of the ducted fan is getting air flowing
through the motor and keeping it at a cool
operating temperature. This fan unit
accomplishes this by flushing cool air
through the motor with tiny air ducts in the
nose cone so the flow of air travels over the
