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(4.9 cc - 6.6 cc 2 - stroke) .50 to .70 4 - stroke (6.6 cc - 8.2 4 - stroke) |
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For the first year of World War II, the Junkers Ju87 dive-bomber enjoyed a fearsome reputation. The crank-winged silhouette of approaching Ju87s and the banshee wail of their rampaging dives struck panic in even the most disciplined troops. In conjunction with the Panzers, it formed the core of the Blitzkrieg. The 'terror weapon' of the invasion of Poland, the assault on Scandinavia and the Blitzkrieg through Western Europe, the Ju 87 Stuka had its reputation dented during the Battle of Britain. And from mid-1942 onwards the Stuka proved to be little more than cannon fodder for allied fighters. However, it will always be remembered as one of the most effective dive-bombers of all time. The Heritage R/C Stuka retains most of the original lines and provides a very stable and fun to fly sport kit. Anxiety started as soon as UPS delivered the kit. The box contained a clear plastic canopy, very thick ABS plastic parts for the wheel pants and cowl, well marked plywood parts, balsa ribs and a very high quality stack of balsa. The balsa was very light, clean and undamaged. All part bags and wood parts were well labeled and all items were there when inventory was completed, which is always a relief when getting a new kit. Plans are drawn on two sheets; one for the fuselage, which is not to scale, and the other has the wing and horizontal stabilizer. Note that these plans are originals that are printed in color. Also, the instructions include many real pictures to describe the building process. Many errors wer found in the instructions and the pictures and plans were a real lifesaver. Heritage was informed of the errors in the instructions and they have since been corrected. Time was spent studying the plans and instructions before actual construction was started. The ribs, formers, firewall and landing gear blocks for the wings are all perfectly cut. As a note, the landing gear wire is more than thick enough for this plane. The wing is a conventional built up balsa design and is built in one piece, which greatly speeds up the process. However, the technique for building the wing is unique. This to be expected with the cranked-wing of the Stuka. Construction starts at the middle and progresses to the tips. Using this method makes the building process very simple and straightforward. If flaps are to be used, this must be taken into account before the wing is started. The flaps are strongly recommended. They do not require a lot of additional work and they really make landing the plane a breeze. None of the sheeting was done until the entire wing was completed, which is not in line with the instructions. This helps to keep from getting any dings in the sheeting as the wing is moved around. The wing is built up with spruce spars and balsa stringers. Bell cranks are used for both the ailerons and flaps. Only one servo is used for the flaps and one for the ailerons. The hardest part about building the wing is the extensive sanding required to round out the wingtips and sanding the sheeting to get is nice and smooth for the covering process. Pushrods and tubing must be fitted since the lengths stated in the instructions are incorrect. The Stuka has off-set flaps and ailerons and the method used to create these is very ingenious and extremely easy to accomplish. The instructions were very good and it was really a very simple process. The aileron and flaps are made up of two halves, a top and bottom with a steel rod that is sandwiched in between them when they are glued together. Prior to gluing, this rod is threaded through the specially designed plastic hinges that are epoxied to the ribs in the wing through slots that are cut though the sheeting. When installing workable flaps, an extra rod is soldered off of the installed rod for the flaps. The method for doing this is well described and is very effective in producing a strong joint. A small amount of sanding is required to finish the control surfaces. The tail-feathers were very straightforward and are built flat over the plans. The stabilizer and fin are built up and then sheeted with 1/16" balsa. This results in surfaces that are very strong. The leading edges are sanded to shape and the rudder and elevator halves sanded to a taper. A great deal of filler must be added to create a smooth transition from the vertical stabilizer and the fuselage. The instructions regarding how to glue the horizontal stabilizer onto the fuselage and then attach the elevator are lacking. The decision was made to first connect the elevator to the stabilizer and then glue the stabilizer to the fuselage. The vertical stabilizer was then epoxied to the horizontal stabilizer and finally the rudder was attached. Both the elevator and rudder were attached with CA hinges. The wood tips were glued onto the horizontal stabilizer and elevator after covering making the process much easier. The fuselage was a breeze to build. Using a standard balsa stringer method, a skeleton is created for the top of the fuselage first and once complete, the entire area is sheeted. The top fuselage half is flipped over and a skeleton is built to create the bottom of the fuselage, which is also sheeted. Time taken during the sheeting process will save a lot of sanding later. Prior to the firewall being installed in the fuselage, the blind nuts and fuel tank must be installed, neither of which are mentioned in the instructions. Since .60 size engine was to be used, the firewall was installed with metal pins passing through the sidewalls into the firewall for added strength. The engine box is made up of several side pieces that must be glued in at one time. The firewall should be dry-fitted prior to being epoxied in place to assure the best fit possible. The cowl and wheel pants are high quality ABS plastic and their installation was straightforward. The engine was on its side with a Pitts style muffler. This required that a majority of the right side of the cowl be cut out to fit the engine but this was to be expected. The cutouts were completed on the right half of the cowl prior to the halves being glued together. This method is very effective in making the most accurate opening. The engine head and muffler had to be removed to get the cowl to fit over the engine. These were reattached after the cowl was in place. The kit comes with a hard steel wire that installs into the rudder for the tail wheel. The wheel pants are made up of two pieces, one of which is connected to the wire and the other is glued to the connected side. A method of making the pants removable is described this was not done on this model. An Airtronics RD6000 was chosen to control the Stuka. The receiver was mounted in foam at the trailing edge of the wing in the fuselage and the 1800 Mah battery pack was located in the back compartment of the cockpit. This setup balanced the plane right on the CG. Standard servos were used for the flaps, ailerons, rudder and the throttle and high torque servo was used for the elevator. When setting up the neutral location of the flaps and aileron it is necessary to used the incident gauges. No mention of control throws is provided. Heritage indicated that they did not like to imply limits. The control throws were set to 1/4" up and down for low rates and 1/2" up and down for high rates on the ailerons, 1/4" down for the flaps, 3/8" up and down for low rates and 1/2" for high rates for the elevator and 1/2" left and right for the rudder. The low rates created very scale like flight characteristics while the high rates were very sport-like. More flaps could be used to create a very slow flight. After final sanding was completed, the model was covered with the new warbird colored Monocote with matching Topflight paint on the cowl and wheel pants. The color scheme was picked from StG1 used in operation Marita. Many color options can be obtained from pictures out of the Osprey Combat Aircraft Series. A vinyl decal set was purchased from CuttingEdge Vinyl Graphics since the supplied decals were paper and not fuel proof. A plastic gun from wing was obtained from Wing Manufacturing for the back seat gun. The engine used was an OS 60-FP and is more than enough engine for this plane. With a 12x8 prop, it has more power than this plane will ever need. The exhaust is routed through a Pitts style muffler exiting the bottom of the cowl. The muffler was easy to install and fits mostly within the cowl. The first flight of the Stuka was on a Friday when the winds were blowing gently. After a couple of seconds with the chicken stick, the engine was running. After a 1/8 turn leaner on the low end and a 1/4 turn richer on the high end the engine was ready to go. The plane tracked perfect down the runway and took off at 1/4 throttle. Two clicks of right and a click of down and it was flying straight and level. The plane flew great at 1/2 throttle and 3/4 throttle was needed only for vertical maneuvers. The plane looped great, rolls were very smooth, inverted flight was effortless. The most amazing thing about this plane is the landing. It was lined up and landed as smooth as glass without any bounce. The flaps wee not used on the first landing but when used on the next landing, the plane slowed down very nicely. The plane nosed up a bit when the flaps were first dropped but after attitude correction, it was very solid on landing. All takeoffs were smooth and this plane can really fly and looks great in the air. The Heritage R/C 1/9 scale Stuka is very satisfying in it performance. It is a great sport scale kit and is a great value. The kit now comes with a fiberglass cowl and with the corrections made to the instructions. This warbird is highly recommended over the highly popular Top-Flite Gold edition kits that require an extremely large time commitment to build and are not the best flyers. |
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