Fast and Agile – Jak-52 Build Report by MACHflight

As with our first model (the Pitts S1S), we opted for an all-balsa construction for the Yak-52 as well. The same applies to the components. With a wingspan of 40 cm and a target total weight of 85 grams, we’re relying on e-flite’s proven AS3X technology. Armed with these key specifications, Chrigu got to work. What he designed in just a few days impressed me once again.

The fuselage is assembled using a pine strip, which is removed from the front of the fuselage only after the planking is complete. This ensures that the fuselage assembly is completely free of warping. (Figure 2)

The cowl is assembled separately and glued to the fuselage only after the planking is complete. It includes the battery compartment cover, which is held in place by small magnets. The battery compartment is located above the wing inside the fuselage. It is equipped with small feet that fit perfectly into two grooves in the fuselage floor.

To adjust the center of gravity, it can be slid forward or backward. It is permanently glued in place only once the center of gravity is correct. The tail unit is made of solid balsa. The control surfaces are attached with Scotch tape after covering.

The construction of the wing presented a particular challenge. We decided to design the lower planking to serve as a construction aid. In addition to the laser-cut outlines, the planking was provided with small cutouts into which the ribs and spars are inserted and glued. This eliminates the need for a tedious assembly process using pins on the construction plan and ensures that assembly errors are avoided. The rear spar is designed in two sections to ensure the ribs are properly aligned in the longitudinal direction. Before the lower planking is permanently attached, the “assisting” half is cut away. With this method, we have found a way to assemble even a very small wing with a very thin profile cleanly and without warping—and without having to contort your fingers.

To route the servo cables for the ailerons, we drilled a series of slotted holes in the lower skin. All control horns and the linkages for the elevator and rudder are made of 0.6 mm carbon rods and are connected solely with heat-shrink tubing. The heat-shrink tubing acts as a “joint” between the control rod and the control horn. The landing gear is a fixed-type design. The wheels and motor mount are 3D-printed parts. The canopy is thermoformed and made of PET.

For covering, we recommend Oralight by Oracover. This allows for a takeoff weight of less than 85 grams. Our latest version has a takeoff weight of 83 grams.

With the Yak-52, we’re launching our second model. It’s fast, agile, and boasts an incredible roll rate around the longitudinal axis. With generous control surface deflections, it’s perfect for flying “tricky” maneuvers. Thanks to the AS3X system, this “little one” can handle quite a bit of wind. However, flying our Yak-52 is most fun in calm conditions. This little plane is not suitable for beginners, though. Its relatively high speed requires the pilot to stay highly focused!

For more information and to purchase, visit www.machflight.ch