SoXos/Heli-Professional Strike 7 Kit

High-performance 3D machine

High-performance 3D machine

Originally formed in Germany, the Heli-Professional brand was purchased in 2010 by Alex Kung, who moved it to his home in Switzerland. In 2014 Alex launched his new SoXoS designs, including the 600, 700 and larger 800-sized machines. More recently Heli-Professional has been focusing on its current SoXoS 550, 600 and the all-new 700-size Strike 7 model.

UNIQUE FEATURES

The Strike 7 is a very simple design and features a low parts count. The airframe can be fully assembled in around 8 hours. The quality and fit of the parts is outstanding, just like a Swiss watch. The manual is super easy to follow and is written in both English and German, it’s very detailed with drawings for each step of the build. It is worth spending some time looking over each step before starting the build as there are lots of notes that will aid the assembly process.

At the top of the Strike 7 is a full alloy black anodized rotor head. It is relatively large at 7.28 inches between the blade bolt holes. A large pair of ball races hold the spindle shaft support firmly in the head block. Each blade grip has a pair of bearing, thrust race bearing and a rubber damper. Alloy pitch control arms are screwed directly into the blade grips. A through bolt and secondary clamp bolt firmly hold the head onto the 12mm (0.47 in.) main shaft. An anti-rotation mount is incorporated into

the head block with a single ball link connecting to the swashplate.

A matching black alloy 120-degree CCPM swashplate sits below the rotor head and has been optimized for the best servo geometry. This helps gain as much mechanical advantage with the minimum of input required by the flight controller. It is important to note that when connecting any ball links to the ball stud ends make sure you have the molded-in number facing the ball stub.

MAIN FRAME

One of the many unusual features of the Strike 7 is its one-piece alloy main frame. The frame is very light but incredibly stiff and has also been anodized in black. Intergraded into the upper part of the frame are the three cyclic servos. They have been positioned for the best possible performance, allowing the linkages to run straight up to the swashplate to minimize resolution loss.

Below the servos is the drive train. The 81-tooth helical cut plastic main gear

has the alloy 56-tooth belt tail drive pulley attached directly below it. HeliProfessional has included some shims to be used if needed to remove any end float in the main shaft, however I didn’t need to use these as the tolerance was just right.

Moving forward from the main shaft is a secondary gear reduction. The lower gear of this set also holds the one-way auto-rotation bearing and hub.

The drive motor sits vertically in an adjustable mount which features fins to aid motor cooling. The 16-tooth metal pinion is held both above and below in ball races to stop any gear spread when under extreme loads. With the included kit 16-tooth pinion installed the final drive ratio is 9.43 to 1.

At the rear of the frame is the boom clamp, this holds the 24mm (0.94 in.) diameter alloy tail boom with a double clamp arrangement. The top of this clamping area is flat and serves as the mounting area for either the flight controller or receiver

depending on how you wish to layout your electronics. There is also a carbon fiber plate that bridges the alloy frame that can also be used to mount electronics.

SIDE FRAMES

A more conventional pair of 2mm carbon fiber side frames attach to the upper alloy frame with eight screws. At the front of these is a sub-assembly of two carbon fiber plates used to mount the electronic speed controller and separate BEC if your speed control doesn’t

have an internal one. Both the carbon plates have slots to help secure your chosen electronics firmly in place.

Right on the nose of the airframe is the spring-loaded battery release lever. Simply pull this upward to release the battery tray. The tray itself is plastic and slides easily in between the side frames. Included Velcro straps hold a pair of 6s flight packs firmly in place.

At the bottom of the side frames are a pair of alloy landing skid holders. The wide and low undercarriage

The Strike 7 is the latest addition to the Heli-Professional series of 3D capable helicopters.

From the very first flight, the Strike 7 proved itself a stable and capable hovering machine.

Just forward of the motor, the speed control is attached to the frame and is easy to get to.

On top of the main frame, the Scorpion motor is vertically attached.

Here the carbon fiber side frames and landing gear have been assembled and are ready to be attached to the main frame.

Here is the intricate main frame made of alloy and anodized with a black finish.

Here is the tail rotor pitch servo with its unique drive attachment.

Here the helical gears have been installed in the upper frame.