Fun Tiger Extra Building Info

Thunder Tiger Fun Tiger Extra
Page 2 - Final Assembly
First page - assembly notes.

	The horizontal stabilizer was allowed to set overnight. The Vertical stabilizer was set to 90 degrees from the horizontal stabilizer and glued in place using 90 minute epoxy. Note the use of the small wood blocks used to "extend" the square. A similar square and wood spacer is used on the other side of the vertical stabilizer as well. Masking tape was used to hold the parts in place as the epoxy cured.
	After the vertical stabilizer epoxy had set, the main wing components were rechecked for fit, then a liberal amount of epoxy was used to glue the dihedral brace into the wing and the wing to the fuselage. Excess epoxy was cleaned off using alcohol and a rag prior to the glue setting.
	The main wing halves were glued and the alignment verified as the 30 minute epoxy set. The alignment of the horizontal stabilizer to the main wing was checked several times as the epoxy cured to make sure everything stayed aligned. Next we will mount the engine, install the radio components, and balance the model. Preliminary balancing shows that the model is tail heavy, so everything that can be, will be moved toward the nose as we proceed.
	We mounted the engine and the landing gear. The model is looking pretty good. The side mounted engine will require some weight on the other side for balance. Since the engine is offset to the right side of the model and side mounted, the prop can't be used as a holding point for checking lateral balance. We used the bottom of the fuselage instead. This should be checked as building progresses so that part placement helps to balance the model. Doing this avoids having to add lead later.
	A JR PCM 10S radio with a 6.0 volt lithium receiver battery will be used for this model - the nineth model on this radio. We started the radio component installation by adding the two aileron servos first. We used the Hitec HS-77 servos (76 oz in torque, 0.14 sec/60 at 1.23 ounces weight). The servos were selected by checking the centering and range of several servos and using the two that most closely matched. The receiver, switch and battery were connected to the servos during the install to keep them centered.
	The radio receiver is on other other side, held in place with a balsa strap. You can see the Hitec HS-615 servo (left) used for the elevator (130 oz in torque, 0.14 sec at 2.12 ounces weight). A HS-615 was also used for the rudder (on the other side). The right side servo bay holds the battery and power switch. Stuff is tight, but fits with just a little modification to the servo rails. A Futaba S-148 servo (center) was used for throttle control. A hole was drilled through the wing leading edge into the servo bay for the throttle. Welding wire in a nylon sleeve was used as a push rod.
	We took the completed model outside to run the engine and do some ground handling. The engine idle needed some adjustment and we installed a new OS type F glow plug. The engine ran reliably with a solid low idle and lots of power using the Morgan Fuels Cool Power 4-cycle. Ground handling was solid.
	Ye Haw! We're off. Yep, we went to the flying field. The sun was out, temperature was 82 degrees with no wind. We did quick check of the radio range and control surface deflection with the engine stopped and running. No problems... Now for the maiden voyage. The model hugged the ground as it picked up speed and the with a little up elevator it still stayed on the ground. We added more up to the elevator input and suddently the model shot vertically up into the air! We were airborne!
	As built with this engine, the model had a CG at 5-1/4 inches. Per the addendum that stated the CG from 4-3/4 to 5-3/4 inches, this was in the range. Luckily, we set the three rate positions for the elevator, ailerons and rudder to be at 100% full range, 75% and 50% for the three positions with at least 25% exponential for each of the positions. This model was fast and a bear to control initially. Most of the first flight was spent selecting rates (lowest!!!) and trimming. The landing and low speed handling was great and the model acted like it was on rails.

On the second flight, we added 230 grams to the nose (rubber banded a Swiss army knife on the front) and flew it again. This time, the model was noticeably tamer. The plane flew at all speeds really well and landed almost by itself. We later checked the new CG and found it to be at 5-inches from the leading edge of the wing at the fuselage.
At the shop, we moved the engine 1-inch forward and replaced the kit 2-1/2 inch wheels with the slightly heavier Sullivan Skylite 3-inch wheels. This allowed the CG to be at 5-inches without adding any lead (or army knives) to the model.
We recommend that you save mounting the engine until near the end of the building sequence to help balance the model, rather than follow the instructions (mount the engine so the spinner is 1/16-inch from the end of the fuselage).
The model specs are as follows:

Fuel 6 oz - flying time ~ 9 minutes (depending on speed setting)
Weight: 5.6 lbs
Wingspan: 48 1/2 inches
Wing Area: 788 SQ in
Wing Loading: 16.4 oz/sq ft
Length: 45 inches from tail to spinner
CG set to 5" from wing leading edge at the fuselage

This kit will most likely be one of our favorites to take to the field. It is quick to set up, the fuel tank is visible and the plane flies great. If you're in the market for a Fun Fly type of plane, this would be a good choice.

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Last Updated 7/13/02

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