Issue 111 – February 2013
Hopefully you find this additional information helpful… check out the full article, written by Jon Barnes, in the February 2013 issue of Fly RC Magazine.
EPP foam is somewhat unique for the way that it breaks cleanly when the inevitable crash occurs. As such, repairs are usually quick, painless and nearly invisible. This factor alone makes the Hacker Sea Fury Furias a great model to expand one’s aerobatics abilities. The Hacker Models 1200mm wingspan Reno- style warbird racers are somewhat larger than most EPP foamies, which translates into being able to fly them higher and farther out than smaller models. These foamy aircraft are modeled after several of the more famous Reno war birds that have raced in Nevada over the years and the graphic schemes of each are painted on at the factory. The SuperTigre .10 brushless motor and 30 amp ESC are a perfect pair for this airplane and will not break the bank. Though economical in price, their quality and performance is more than respectable.
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Before you start assembling the Hacker Furias, make sure you have a fresh bottle of thin Cyanocrylate adhesive and a dozen or so new hobby knife blades. Thin or medium CA works best when gluing EPP foam. CA accelerator is used on many of the steps, to expedite the cure time. Fresh knife blades are a must. Trying to use a blade for too many slices will result in fracturing the foam instead of cleanly parting it. Assembly of the model requires more than few long cuts along the length of the fuselage and wing, to embed the carbon stiffening rods and servo leads. Hacker cuts convenient channels into the fuselage which are used to route servo leads and the the radio connection lead from the speed controller up to the cockpit. I was not able to locate the supposedly provided channel to route the rudder and elevator servo leads forward to the cockpit but routing them was as easy as cutting shallow channels in the fuselage and then carefully embedding them down into these grooves using a butter knife. This is one of the reasons that I like working with EPP foam; it is quite easy to hide any and all wiring by simply embedding it down into the foam. The fuselage and wing of the Furias are thick and capable of hiding quite a bit of wiring! Once all of the servo and ESC leads are routed up into the cockpit area, they can be attached to the receiver. The receiver is then buried down into the foam so that it is not visible in flight. I fashioned a cover plate out of a sheet of white plastic that I had lying around, to cover the receiver more completely. Had I been able to locate a proper pilot figure in my parts boxes, I would have installed him atop the buried receiver. The canopy is constructed of a clear Lexan type of material. Curved tip scissors work best when removing the excess edges of the canopy. I used white acrylic paint to create the framing on the inside of the canopy and then secured it in place using a few pieces of 3M Blenderm tape. Using CA as the instructions suggest could make getting to the receiver for rebinding or removal a daunting task.
When cutting the pocket for the speed controller in the forward section of the fuselage, I failed to pay close enough attention to the assembly illustrations and accidentally cut the recess into the top of the fuselage instead of the bottom. However, I justified my little mistake with the reasoning that the top is ultimately a better location. The speed controller generates heat and heat always rises. Locating it atop of the fuselage allows any heat that it creates to vent to atmosphere instead of trying to rise up into the foam of the fuselage. In the end, either location is probably perfectly fine. One step of the instructions that must be adhered to closely involves the assembly of the light ply motor mount box assembly. It is keyed so that it will create a bit of down and right thrust, typically necessary in flying models, to compensate for motor torque. Getting this part wrong will almost assuredly result in a poorly performing model in flight. I used five minute epoxy to assemble and install this motor mount. I followed up the initial installation of it into the fuselage with a second batch of epoxy, creating fillets of epoxy along the wood-to-foam joints for added adhesion and insurance. Once you have determined where in the fuselage that the battery must be placed in order to get the center of gravity right, a fairly large hole must be cut into the foam. I find that the cleanest way to accomplish this is to use a fine hacksaw blade. An initial slice must be made all the way through the fuselage for each of the four sides of the rectangular battery box. It is important to cut the hole a little smaller than the batteries that you intend to use, so that they fit snugly into the hole. Once I had all of the power system components in place, I thought the appearance of the motor leads downright untidy and distracting. I used small dabs of hot glue to neatly arrange and lock them into place on the side of the fuselage.
Some of the hardware included with this model is on the microscopic size, namely the small snap washers that secure the quick link style connectors to the servo arms. I do not know if my kit was just missing a few of them or if the carpet monster sucked them off of my workbench and ate them. In any event, I could not locate the requisite four required to finish the kit and had to search my parts bins for alternate connectors. I recommend carefully pouring all of the hardware into a bowel at the outset of the build and inventorying it to be sure none of the small parts get misplaced.
The Sea Fury went together very squarely right out of the box. There was no need to sand either the wing saddle or the horizontal stabilizer saddle in order to achieve the right geometry; all of the components were correctly cut right out of the box. The one area where it is still possible to get it wrong though involves making sure that the wing and horizontal stabilizer/elevator are parallel, when viewed from the top or bottom of the aircraft. I recommend attaching the wing and then dry fitting the stabilizer, making alignment marks when it is perfectly positioned in place. Another recommendation involves the choice of adhesive when installing the servos into the foam. The assembly instructions suggest wrapping the servos in tape and then using thin CA to secure them into place. The super runny viscosity of thin CA allows it to freely flow into places that you would often prefer it not to flow. Getting even a drop of CA into the internals of a servo is almost sure to render it a dead player. I opted to use hot glue as a slightly safer means of securing the servos. It is much thicker in viscosity and should you ever need to remove or replace a servo, I find that it is usually easier to convince hot glue to give up its grip than CA.