Thundet Tiger: Tiger Sport 40L

Model Airplane News, Mar 1999 by Trachten, Craig

"It's Grrrrrrrreat" to quote Tony. The Thunder Tiger* Tiger Sport 40L has to be one of the best low-wing trainers I have come across. Do not stop reading because the term "trainer" was employed; it's much more than a trainer and will be enjoyed by the most proficient flyer. It is as docile as any trainer on the market but as agile as most sport planes and will be enjoyable to fly by everyone.

Step one of any kit is to open the box, look through it and theN read the instruction manual. The documentation is typical Thunder Tiger-excellent! The first few pages show each parts bag and what's in it and which tools and supplies are required to complete the kit. There is even a section with pre-assembly notes. Construction instructions do not begin until page 6. Take your time, read the directions arid look at the excellent construction photos, and you will have absolutely no problem completing this aircraft.

* Wing assembly. Start by epoxying the three dihedral/wing-joiner brace pieces together. Pictured are three butterfly paper clips being used as clamps while the epoxy is drying. This is also where my wife loses her clothespins, as anything that will hold the pieces together while drying will do.

Measure and cut out the opening; for the aileron servo on each wing half. Laminate the four cecter rib pieces together to form two, 1/4-inch plates. By now, the wing brace will be try, so you can test-fit it into the wing halves. Make sure it goes in all the way without binding. I sand this type of brace to where it is almost too loose; I do this so that when it is epoxied into place, not all the epoxy is squeezed out. All this means is that I have to make sure the wing halves are braced while they're drying so there isn't any shifting. Epoxy the center brace into one half of the wing and then into the center rib. The center rib should match the lines of the wing; if it is slightly over or under, position the center rib so that it is flush with the bottom of the wing. When the glue has dried, epoxy the two wing halves together, making sure they are taped and braced so they will not shift while drying. Before you tape and brace the wing halves, clean off any epoxy "ooze"; rubbing alcohol works well for this. Builder's tip: I use two-hour epoxy to join the wings. I am never in a rush, and two-hour epoxy has its advantages: it affords me plenty of work time, and it is thinner than 30-minute epoxy, so it flows down more easily into the brace slot; and, as with all adhesives, the longer the cure time, the stronger the bond.

Back to the building. Assemble the aileron servo tray; I used Zap* CA Gel for this. Apply the white trim tape (supplied) to give the wing a nice finished look. CA-gel the plastic wing protector into place, and you're then ready for the final wing construction: aileron installation. First, I took my hobby knife and trimmed off any covering material that was in the way of the hinge hole, then I applied a light oil to the hinge area.

With all the prep work out of the way, I mixed up a batch of two-hour epoxy. Using a toothpick, I placed a drop of it into each hole, then I went back to hole one and started over. After my third epoxy pass, each hole was about half full of epoxy. Perfect! There was enough goo in there to firmly secure each hinge, but not so much that it oozed all over the place. While the epoxy was still wet, I attached the aileron and wing. Every few minutes, I moved the aileron up and down. This served two purposes: it made sure the hinge moved freely, and it helped align each hinge point so I would not experience any binding caused by hinge-point misalignment. When the epoxy had dried, I repeated this process for the other side.

Remove the covering material over the factory-installed landing-gear blocks, and insert the two landing-gear wires. Pilot-drill the holes for the landing-gear straps (two each side), then fasten the straps into place. Put the wheel on the wire, tighten down the wheel collar and you've finished!

Wing mounting. Start by putting a center mark on the fuselage just behind the wing opening. Next, the instructions ask you to mark the center of the wing mounting plate. Builder's tip: I measured in from each aileron opening to find the mounting plate center point. This ensures you mark the exact center of the wing. Put the wing into place, lining up both center marks. Drill a 5/32-inch hole through the wing and the wing-mounting block inside the fuse. The hole you drill should be perpendicular to the wing-mounting block inside the fuse, not perpendicular to the bottom of the wing. Remove the wing, open the hole in the block with a 3A6-inch bit and insert the blind nut. Put a washer onto the wing bolt, insert the bolt through the wing, and then place an O-ring over the bolt. The O-ring will help you avoid losing the wing bolt; I do this on all my aircraft.

Engine and cowl. Mounting the engine is no different from mounting the engine in any other kit on the market that uses a two-piece adjustable mount; the cowl, however, is a different story. The cowl I received with this kit had a problem: it did not fit. I spoke to the products manager at Thunder Tiger and found he was already aware of it; he assured me that the problem would be fixed by the time this review is published. If you happen to have one of the bad cowls, call Thunder Tiger, and the folks there will be more than happy to send out a replacement.