Funtana S .40 3D ARF

Model Airplane News, Jun 2004 by Thompson, Jet

HANGAR 9

Rewriting the 3D rules

An axiom in RC flying states that "bigger flies better." With the Funtana S .40 ARF, Hangar 9 has proven that a well-built and -engineered .40-size plane can be just as stable and responsive as a much larger model.

Hangar 9 has built a reputation for high-quality ARFs, and the Funtana is no exception. From the simple and attractive UltraCote covering to the included fiberglass wheel pants and cowl, Hangar 9 has yet another winner. There has been a lot of buzz on the Internet about this aircraft and its abilities, so let's take a closer look.

INSIDE THE BOX

First, inspect the components. The box has foam inserts to prevent the parts from shifting during shipment, and inside, everything is poly-bagged. The manual is well laid out and organized and includes many helpful diagrams and pictures. The Funtana is covered in UltraCote, and the fiberglass parts are painted to match the covering. The kit includes a full set of hardware, pushrods, wheels, a fuel tank and a tinted canopy. You'll need to supply the usual building tools and adhesives to put the Funtana together.

BUILDING NOTES

* Wing assembly. As with most ARFs on the market today, assembly starts with the wing. It comes in one piece, and this greatly speeds up assembly. First cpoxy the wing dowels into place, and then fit the wing in the fuselage. A single ¼-20 nylon bolt holds the wing in place1. Because I wanted to really wring this plane out in the air, I replaced the nylon bolt with a stronger metal bolt for extra security. This is one area where pilots who want to perform all-out aerobatics can never be too careful.

After I had secured the wing, I aligned and installed the horizontal stabilizer.

Before you do that, make sure that the wing is square to the fuselage. In my case, the right wingtip was ½ inch farther back than the left, which caused the plane to roll slightly to the right during hard pullups. I discovered this during the flighttesting. To fix the problem, I simply moved the holt's blind nut ¼ inch to the right to square the wing. To ensure that the strength of the wing-mounting block wasn't compromised, I epoxied a piece of lite-ply to it.

* Tail feathers. The horizontal stab slides into a slot in the fuselage, and carbon-fiber rods that brace the tail group provide a great deal of strength, which is critical for the punishment that 3D flying subjects the model to. I installed the stab, making sure that it was square and parallel with the wing. To install the carbon support rods, you are instructed to drill a hole 1 3/8 inches from the tip of the stabilizer and a corresponding hole in the fuselage. The rods in my kit were too short to allow them to fully seat in the holes, so I simply relocated the holes in the stab. I then glued the vertical fin into place and set the fuselage aside.

Now hinge the ailerons with the supplied CA hinges. I pushed a pin through the center of each of the hinges and slid them into the wing hinge slots, followed by the ailerons. There should be only a tiny gap between the wing and the leading edge of the aileron. The ailerons are truly huge and make up nearly a third of the wing. These large surfaces provide a lot of maneuverability and agility to the Funtana. When I was satisfied with their placement, I wicked plenty of thin CA into the hinges to secure them. When I do this, I have a rag with some CA debonder handy in case drip CA somewhere other than where it's needed. Let the CA cure naturally (without accelerator); the bond will be stronger.

I laid out the parts needed to install the elevators and rudder. Before I glued anything into place, I assembled the elevator halves with the joiner wire on my workbench. This is the perfect time to make any bends in the joiner wire so that the elevators lie flat and square. I hinged the elevators to the stab and let them cure, and I installed the tailwheel assembly. To make the slot for the tailwheel straight and square, I used my handy little Robart drill jig and then cut the slot in the rear of the fuselage. I coated the tail-wheel wire with petroleum jelly to prevent it from being glued to the bearing. I hinged the rudder into place and moved on to the engine installation.

* Engine installation. I elected to use the recommended Saito FA-72 4-stroke in this airplane. It has the quick throttle response and torque to perform the 3D maneuvers the Funtana S was designed for. The Saito is an excellent match for this plane, and with the proper propeller, it provides enough power to pull vertically out of a hover and do everything I want.

The Saito nestles nicely in the engine compartment, and the supplied mount fits it perfectly. The only quirk I encountered was that the throttle arm is a little too close to the firewall to allow a straight shot for the pushrod and clevis. I got around this by making the pushrod a little longer than called for and making a gentle 180-degree bend; this allowed the pushrod to be connected to the throttle arm from the front, clearing the firewall. I installed the provided fuel tank without a hitch.