Wi! ;ql ;~,... TEe ONEYAII54...................................................................................... BY: Scott Barnhart I TALK UP TmSYAK Techone Hobby is a company schemes. The computer numeric accessories were individually established in 2007. They controlled (CNC) cut Depron Yak packaged. The packages were are quickly adding to their 54 is one of their newest models. neatly taped to the box to keep product line of high quality It exceeds past quality standards them from shifting during transit, models built of foam. Their put forth by Techone. which could otherwise damage airplanes range from expanded the parts inside. polypropylene (EPP) trainers Kit Upon opening the packages and 3D airplanes, to park flyer My Techone Yak 54 arrived in a few things got my attention jets, micro-planes, as well as top good condition, without shipping immediately. First, I discovered quality milled Depron airplanes. damage. The kit box was covered the high quality foam cutting was All the Techone airplanes display with numerous action shots of complimented by very nice mill excellent foam cut quality, the airplane. Inside the box I work and a sporty color scheme. hardware, and vibrant trim color found that all airframe parts and Also a well-made set of control
TECHONEYAK 54 and servo horns were included. There was also a very good instruction manual included, which was done in color to provide the builder with a stepby-step process for assembling the Yak 54. Of course the major airframe parts were provided: two wing halves, horizontal fuselage with the horizontal stabilizer, vertical fuselage, and simulated wheel pants. All the carbon fiber parts needed for a rigid structure were provided too, as well as nicely cut foam torque boxes. Various hardware packages, including G I 0 control horns and servo horns, heat shrink, pre-bent Z-bends, and pull-pull line were included. Note that this airplane is available as complete combo or airframe only. My model came with the items included in the complete combo. In the Air Prior to the maiden flight, I performed the usual confirmation of control throws, directions, and rate settings. A radio range check for indoor flying is usually not an issue, but must be done in the event that you fly the model outside. I connected the battery and set the model in place for its takeoff roll. The weather inside was about 65 degrees, 0 wind, and great lighting. This is what makes indoor flying so appealing. The Yak 54's takeoff required only quarter throttle, and the airplane practically leapt off the ground at that. Once in the air, the airplane $ This shows the very complete kit contents, also showing off the Techone Yak 54's crisp trim scheme. Techone laser cuts their kits. They now offer very clean CNC milling, to shave a few extra grams off their airframes. The RTF package available from Techone Hobby includes three Techone 5-gram servos, a C2404 brush less motor, a 10-amp ESC, a 350-mAh 25 LiPo battery, and a GWS 9x5HD propeller. Here you can see the slight modification to the carbon fiber trussing layout that I made to the model to reduce twist in the tail.
I used a plastic square to make certain that the fuselage was built square and true, which is important to having an airplane that flies well. The carbon fiber trussing allows for a strong lightweight structure, that will take almost any abuse you throw at it. 92 I RC SPORT FLYER - JUNE "0
ASSEMBLY Oue to the excellent cutting and prefabrication, including the pre-beveled and hinged surfaces, as well as tight fitting tab work, the assembly went very smooth. like a typical mono-wing foamy, the Yak 54 is built upside down, from the bottom up. I did rework the carbon trussing just a little different thanthe stock layout. The only reason for the alteration was to join the tail's carbon trussing to the wing trussing. Before the modification the tail trussing stopped about 3f4 in. behind where the wind trussing meets the lower portion of the vertical fuselage. The modification will reduce twisting of the tail caused by hard 30 flying. Building the model stock would probably be adequate, although with the modification the tail is less prone to : twi st. The installation of the electronics was a : breeze, as all the servo holes were cut perfectly, : so the servos dropped right in and required just afew "wicks" of glue on each side of their cases to fasten them in position. Also the kit's Gl0 control horns, extended length servo horns, and biased aileron servo horn are nice. I attached these extended arms to the stock servo arm with some think CA glue. Be sure to sand the Gl0 servo horns and the stock servo horns with some coarse sandpaper, so the glue has a rough surface to bond tightly to. The aileron linkage setup is done with Z-bends at the biased aileron servo horn and at the control surface horn. The manual instructs you to use just l -mm carbon for the aileron pushrods, which is what I used for my Yak. Although, I would suggest using maybe a 1.5-mm carbon rod instead, as it will provide the airplane with more precise aileron response. The motor installation was also altered slightly from the manual. This was for weight savings and rigidity. The Techone Hobby C2404 motor that I used has four mounting tabs with a small hole at the tip of each, intended for screws to mount into a l f32-in. plywood firewall. Instead of using the screws and the fire wall, I used four 1 lf2-in. pieces of Blenderm tape to mount the motor to the nose. (Refer to the picture.) Once you have the motor attached with the Blenderm tape, wick some thin foam safe CA on the back of the motor's mounting tabs where they meet the foam to bond in place. The last and most critical step of the build is to check the airplane's center of gravity. The CG with the battery mounted in the factory slot : is 225 mm from the firewall. The airplane flew great with the Techone 350-mAh 2-cell battery mounted in its slot. I suggest you not move the : airplane's CG more than five mm either forward : or aft of 225-mm location. Control Throws Aileron 45 mm UfO Expo 40% Elevator 45 mm UfO Expo 40% Rudder 45 mm UfO Expo 25% Recommended CG: 220-230 mm from the fire wall. The milled Yak 54 came in at 138 g, with very minimal weight saving techniques used. Just build light, use minimal glue where needed, and remove the servo cases. Knife-edge flight is very pleasant to do, and it has zero control coupling, so minimal rudder mixing is required. The Techone (2404 motor operates very smooth and has an abundance of torque to really give the Yak 54 plenty of power through the most demanding 3D maneuvers.
required no control trimming, it was flying straight as an arrow with my hands off the transmitter's controls. So I went directly to flying it into a rolling circle. It was like I had been flying the airplane for a while. I then stopped the rolling circle, and flew it into straight inverted flight. The airplane felt as it did on takeoff in upright flight, even though it was inverted. Since no trimming or center of gravity adjustments were required, I could go directly to exploring the airplane's performance by flying it through an array of maneuvers. The rudder and elevator are very responsive, which provide it with very good tail authority. Thanks to the biased aileron horns, rolls are very axial and almost effortless, requiring just slight inputs from the tail. Rolling loops are smooth like rolling circles, only the loops require a lot more control input from the tail. Point rolls and knifeedge flight are very predictable and there is only minimal coupling when the rudder gets too near its full deflection. Loops track very straight in both positive and negative attitudes. And waterfalls are very tight and track very straight as well. Flat spins, both upright and inverted, require full elevator and rudder control to enter the spin. Then once the spin is entered a slight amount of elevator input must be removed. Debrief The Techone Yak 54 is an excellent flying airplane, featuring a superb flight envelope, which will suit the intermediate to extremely advanced pilots. The excellent kit quality, as well as the excellent milled airframe parts, puts the performance vs. price right up there with some of the top foamy manufacturers in the world. This Yak is one to add to your hangar. D 'l'echone Yak 54 Techone Hobby No.388,Jlefang West Road Nanchang City, Jiangxl, P.R.Chlna 330029 Web site: techonehobby.com