THSS REVIEWFrank Cavasos Model Craft "BOOMERANG"
Specifications:
Wingspan: 48"
Weight: 16 oz.
Wingloading: 4.8 oz./sq. ft.
Airfoil: Who knows
Radio: Micro Receiver and Servos for competitive weight
Skill level: Intermediate
Why the Boomerang. I picked the Boomerang because almost everyone said that was the best combat wing out there. The purchase was prompted by a crash which irrepairably damaged the last wing I had.
Building the Boomerang. I've built three boomerangs so far, and I think I've come up with a few good tricks. Construction, like most EPP flying wings, comes in five main parts, joining the wing, installation of the radio equipment, taping, covering, and attaching the elevons.
No neat tricks in joining the wing. Just make sure the spar is glued in nicely and there aren't gaps of glue between the wing halves.
The radio equipment installation is probably the most time consuming. I used Hitec HS-225MG's in my last two Boomers because they're nice and tough with their metal gears, have good torque and speed, and they were easy to come by. You can get smaller and lighter servos, but I still haven't built a Boomerang that didn't need nose weight, so the extra weight and strength of the larger servos are more useful than the extra lead you would need for smaller servos. Whatever you do, don't use really small weak servos (e.g. HS-80's), since they'll probably strip. I used a micro Hitec 555 receiver, but a larger one would work fine (less nose weight with a bigger receiver, I figure. Total weight would probably be higher with a bigger receiver, but not by very much at all). Batteries are the short Sanyo 600AE's. I think the shape of these, when compared to the standard 600 mah cells, helps reduce the amount of nose weight you need by allowing you to put stuff closer to the front. I used four cells and had to put a bit of nose weight in my latest Boomerang, so five of them would have probably worked to eliminate any nose weight. However, I like to fly all day sometimes, so the longer run-time of the four cell pack is a plus for me. One important thing that I do when I install the radio equipment is to bury the servos as far down as possible and to enclose the pushrods. I use the round control arm for the servo for strength and so they don't stick out so much, dig a tunnel from the servo to about 2.5 inches from the TE of the wing (not including the elevons) and instal semi-flexible blue and yellow Goldenrods for the pushrod. This helps in two ways. It helps in aerodynamics, but mainly it will eliminate the weakest point of a standard set-up which is the servo arm breaking off or the servo gears stripping after a hard hit or landing. That happened to me much too many times when I had it set up the normal way (with the control rods exposed on top of the wing).
Taping is done almost according to the plans except I don't do the cross-wing tape on the bottom (the one that runs from the center trailing edge to the LE diagonally accross the wing) and I add tape which runs parallel to the wing joint about two inches away on both sides, both top and bottom. My theory for this is that it'll help keep the shape of the wing at the center instead of warping up or down (the noses on the last two Boomers I had warped downwards, and I've seen them warp upwards).
For covering, I like to use two big pieces of ultracoat. One for the top, one for the bottom. This helps by making it easier to re-iron when it gets all wrinkled and by eliminating weak points for the covering to unstick.
I attach the elevons according to plans but I sand them down to a sharp trailing edge to help a bit with the aerodynamics. All up weight should be around 16-17 oz or less, or you did something wrong.
Flying the Boomerang. This is why I've already bought three Boomerangs. I absolutely love the way they fly. I set mine up to be very twitchy with huge throws on the elevons, which makes for great low speed handling. It's simply the most maneuverable thing on the slope, hands down. At the same time, however, it is inherently stable and will go where you point it. With moderated control throws, its a great wing to use as a second aileron ship (or first, if you think you can handle it).
Inverted performance is very good, but I've seen better. It's not the fastest wing, but it's not supposed to be. It does one thing better than anything else out there, recover from hits. It really takes most hits and just shrugs it off after a few feet of recovery. Its light weight helps a lot here. If you build it light, it can get down to less that 15 oz., which really helps in combat. Despite what some people may think, a lighter plane is a better plane for combat. The extra momentum of a heavier plane only helps in certain situations. Besides all out combat, I just love to fly the Boomerang. It will fly in very light winds and very strong winds without any problems. For testing out the lift at a slope, you couldn't pick a better plane.
Once you get used to flying a Boomerang, you can pull tricks with it which you wouldn't even imagine being able to do with other planes. I enjoy flying it four or five feet in front of me, rolling and looping and flying it like it was a puppet controlled by strings.
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