FlexRC Mini Owl Build Instructions

FlexRC Mini Owl - Extreme FPV Proximity Racing Drone - DIY Build Instructions

This guide will walk you through the detailed build steps using the FlexRC Mini Owl Extreme

FPV Racing Drone DIY Kit. The kit contains everything you need to build your Mini Owl except

the radio receiver, which is purchased as an add-on to the kit. In our example, we’ll be using
the Lemon Rx DSMX Satellite Receiver. The instructions also include the installation of an
optional Pololu voltage regulator.

The Mini Owl can be built as a pusher (motors “upside down”) or a standard (motors right side
up) quadcopter. We’re building ours as a standard quadcopter. There is very little difference in
the two builds other than motor directions and prop mounting.

The Kit:

● FlexRC Mini Owl frame with hardware

● Omnibus Mini F3 Flight Controller with OSD

● Tiny 10A 4 in 1 – Cicada – BusyBee2 BLHELI_S ESC

● 1pc of XT30 battery connector

● 1104 6500kv motors

● 2pcs of HQProp 1.9x3x3 Durable 3-Blade Propeller (2CW, 2CCW)

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● DIATONE 600TVL Miniature Camera

● Flexible Mini Camera Adjustable Mount

● Tiny FPV Kit

● 5V Mini Buzzer for FPV Micro Racing Drones

● Thin battery strap

Step 1: Install the motors and center stack screws

Locate the bottom plate and mount each motor using the included motor mount screws. It is
best to use all four screws to avoid having a motor pull out in a crash but, for now, it’s fine to just
install two screws. We’re just using them to hold the motors in place during the installation at
this point. Before flying, you should use Loc-Tite (blue) on all four screws.

Leave the motor leads full length for now; we’ll trim them when we solder them to the ESC.

Next, install the nylon screws by pushing them through the 20x20 holes from the bottom of the
frame. These will secure your center component stack. Place a nylon spacer on each screw.

Step 2: Prepare and install the 4-in-1 ESC.

The Cicada 4-in-1 comes with battery leads pre-soldered but we need to install an XT30 battery
connector to these leads. Slide the appropriate heat shrink over the bare wires but do not apply

heat yet. Solder the XT30 to the appropriate leads.

Note that it’s always a good idea to plug a spare XT30
connector (not a battery, just the plug!) into the one being
soldered. This will reduce the chance of warping or melting

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the XT30. Once the XT30 is installed and cool, slide the heat shrink over the copper
connections and shrink in place.

You can now place the 4-in-1 ESC over
the nylon screws. Place it face down so
that the plastic servo connector plug is on
the bottom. The nylon spacers on the
center bolts will provide enough clearance
so that the servo plug does not touch the
frame.

Now you can pre-tin the motor lead pads
on the 4-in-1 ESC. Be careful not to touch
the nylon center screws with your soldering iron as they easily melt.

Finally, locate the wiring harness that comes with the 4-in-1 ESC. The wiring harness consist of
six wires connected to a JST plug. We will only be using the ESC wires (orange, blue, yellow,
green) and will remove the positive and negative (red and black) wires. To remove the red and
black wires, use the tip of a sharp knife to lift the small plastic tab above the connector of the
corresponding wire. With the tab lifted, the entire wire and crimped end should slide out of the
connector.

Plug the 4-wire harness into the ESC.

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Step 3: Solder the motors and FC power leads

Carefully route the motor wires under the ESC so they wrap around the center screws and
around the bottom of the ESC. This routing method will keep the motor wires nice and neat and
will help avoid being snagged by a prop.. Confirm your measurements and trim each motor
wire.

Strip ~2mm of insulation off each motor wire and pre-tin them. Take care not to pre-tin any
wires directly over the ESC, as tiny drops of solder can land on the ESC and damage or short
the mounted components.

Once all the wires are pre-tinned, solder each wire to the appropriate pads on the ESC. Note
that the motor layout and ESC pad orientation aren’t consistently named! Specifically, motor 3
will be soldered to pads A4, B4, and C4. Motor 4 will be soldered to pads A3, B3, and C3.
Motors 1 and 2 solder to the properly numbered pads. Don’t worry about which individual
motor wire goes to which pad in the group of three, as we will set motor spin directions in the
BLHeli Suite software.

We will now attach power leads for the flight controller. Trim two pieces of 20-24 awg wire to
about 30cm and strip and tin the ends. Solder one to the positive battery lead joint and one to
the negative battery lead joint as shown in the photo. The orange wire is the positive and the
black wire is ground. Leave the other ends loose for now.

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