Jim Spell

This came in from Jim Spell. He sent us a detailed description of how he built and set up our Sniper, hope it is helpful!

J K Aerotech's Original Sniper Combat Glider

If you are a traditionalist when it comes to building and flying airplanes, the Sniper Combat Glider will definitely change your mind. If you have entered the world of "foamies" but have been somewhat disappointed, the Sniper Combat Glider will bring you back into the fold. And if you just want to have a wonderful afternoon of worry-free flying...

The Original Sniper by J K Aerotech is the perfect glider if you have any interest at all in entering the exciting world of slope soaring. At twenty dollars it is a real bargain and the returns on investment are measured in sheer joy and excitement. It is well-designed and builds strong and resilient, providing a perfect platform from which to begin your entry into slope and combat soaring. With a little imagination it easily becomes a "looker" at the flying field, eventually becoming your favorite little zoomer when you just don't know what to "throw"

Building a foamie for the first time is an exhilarating if not a somewhat perplexing experience. Traditionally, a model put together this fast and easy and using techniques better suited to "Mail Boxes are Us", may be presumed to be unworthy of proper if not totally appropriate flight; but such is simply not the case. Yes, it takes some getting use to, this foam gouging and mailing tape covering process, but it is certainly not difficult and the rewards are great.

The instructions for the Original Sniper are, for the most part accurate. Follow them closely and with good intent. There are, however, a few things to remember and these come with an understanding of the building techniques employed and the aerodynamic intent of the model itself.

First and foremost remember that when you are cutting foam a dull X-Acto knife can mean hours of repair and reconstruction. Use a new blade for ALL cuts of ailerons and elevators. You can use the used blades for cutting and gouging the radio cavities, but leave it at that. A 10 cent blade will save you hours of work. When making the radio cavities, cut an accurate design and then gouge accordingly. Foam will break off horizontally very easily, but it needs to be cut in the vertical first or you risk loosing the shape of your cavity. Remember to leave enough foam around your cavities so as to utilize the natural strength and protection of the foam itself. "Forward but not flimsy" is a good rule of thumb.

When "covering " the various parts of the model it is best to spray 3-M 77 3M-45 spray glue first to allow for tape adhesion, but allow the spray to fully dry before beginning the taping process. An overnight wait seems to be the best course of action for complete satisfaction. Remember too, that mailing tape really doesn't stretch, (Editors note: we do recommend stretching the tape as it is installed on the wing only, as per our instructions. Doing so will strengthen the wing by placing the wing under tension. However if you do not balance the pull on the top and bottom, the wing will curve toward the tight side. Do not stretch the tape when applying it to the fuse unless you wish to change the wing/tail incidence.JKA)and attempting to lengthen it while applying can lead to disaster. UNTIL FOAM IS TAPED IT IS VERY BRITTLE. Tape firmly and evenly, but don't think that you have a rubber band in your hand. An even and firm tape application will be more than satisfactory.

As stated in the instructions, leftover tape at the ends of wings and tail sections can be carefully overlapped and will provide extra protection for those little accidents. Additionally, overlapping will ensure a "sealed foil" which will increase the strength dramatically, not to mention its water resistant capability.

A simple and economical glue for assembly is "Liquid Nails". It is strong yet does not shatter on impact. Just remember to cover, measure, and rehearse before attempting any gluing process. Don't paint anything. Although it may look better, it simply adds to weight and cover problems. Besides, there are great colored tapes available. If you are intent on "customizing" your Sniper you can add an old lightweight canopy up front to protect and cover the radio gear, or put some decals on the wings. As with all slopers, contrasting wings no matter how it is achieved, is a good idea; especially when its upside down and backwards.

To get the optimum performance envelope out of your Sniper it is important to understand the aerodynamic intent of the model and not try to defeat this either knowingly or unknowingly. The wing span of the Sniper is 42 in. and its over all length is 33 in. With a long and relatively thick chord length, a razor sharp leading edge, and a short "swing weight" (the distance between the CG and the tail sometimes referred to as "moment"), the CG, or Center of Gravity, becomes paramount. Its proper location marks the difference between a kite like floater and an efficient penetrating combat sloper and this difference can be less than 1/32nd of an inch. Its overall lightweight adds to this potentially lengthy "set up" of the Sniper. Calculating the distance from the leading edge to the CG is based on wing cord, its shape and thickness, and the subsequent aerodynamics that result. It is critical to overall satisfaction that the CG be placed at 3 and 6/32 inches from the leading edge and as stated, changes of a 32nd of an inch can have a profound effect on the penetrating ability of the glider. 3 and 6/32 inches is at least a beginning point that allows for the appropriate analysis of the Sniper's flight characteristics and the subsequent changes you may want to make. Again, it is the Snipers design that makes the CG placement tricky, yet of primary importance. Its razor sharp leading edge means that when the Sniper is in the air, the glider is either lifting, dragging, or penetrating efficiently with no turbulent room for error. A more rounded leading edge would allow a more forgiving CG point but would greatly sacrifice the model's precise control and exact maneuvering capabilities. Its light weight and short "swing weight" further exacerbates this process, but in the end the flying characteristics more than makes up for time lost to "trimming". To its credit, once this critical point has been achieved, the Sniper becomes a model that flies as if it were on "rails" in all types of wind. Finally, if you simply can't get the Sniper to penetrate to your satisfaction, simply add ballast at the approximate CG point, carefully drilling a hole into the bottom and adding weight. Make sure the weight cannot shift and then tape over the hole. This technique also serves well on "extreme" days when others are afraid to fly.(editors note: we adjusted blast at the slope site and 3 to 4 oz taped to the underside made the Sniper a rocket in 30+ mph winds.JKA)

Study the application of moveable surfaces on the Sniper. This technique, described in the instructions is invaluable and can serve you well on other gliders in your collection. One important note when it comes to control surfaces is in dealing with the installation of the control horns. Gluing them on as well as screwing them in will make for a stronger connection and the disturbing tendency of bent, crushed, and otherwise distorted control surfaces will be lessened.

Although the Sniper is relatively quick and easy to build, do not underestimate the flying capabilities of this superb model. Given the proper CG to allow for effective penetration, the glider becomes a very responsive and yet stable flyer. By "dialing in" the proper throw deflections for the ailerons and elevator and even adding a computer radio with micro servos for flaperons and precise adjustments, you can maneuver with the best of them. The sky, the wind, and your imagination are its only limits.

What makes the Sniper truly special however, is that when you fly it your learning curve jumps off the page. After a few flights you lose the fear of crashing that comes with building and flying a Sagitta 6OO or any other time intensive stick built model, and you just fly, free from worry and free from consequence. This, along with the incredible amount of time you can now spend perfecting that roll or hammerhead stall you have always been reluctant to try, makes the Sniper Combat Glider by J K Aerotech a truly indispensable addition to your airplane collection.

Jim Spell, Vail Fire Department, 42 W. Meadow Dr., Vail, CO. 81657