Great Planes Twinstar EP ARF

Written by Tom Sullivan A nice-performing twin-powered sport model Abridged product review Photos by the author Read the full product review in the May 2016 issue of Model Aviation.

Specifications

Model type: Sport ARF Skill level: Intermediate Wingspan: 47.5 inches Wing area: 392 square inches Airfoil: Semisymmetrical Length: 42.5 inches Weight: 4 to 4.25 pounds recommended Power system: Two RimFire .10 brushless motors; two 25-amp brushless ESCs; 3S 3,800 mAh LiPo battery Radio: Minimum four-channel transmitter and receiver; four micro servos Street price: $139.98

Test-model Details

Radio system: Tactic TTX850 transmitter; Tactic TR625 receiver; four S3115 Futaba servos; two Futaba Y harnesses; and two 12-inch servo extensions Power system used: Two RimFire .10 brushless motors; two 25-amp brushless ESCs; 3S 3,800 mAh LiPo battery Flying weight: 3.75 pounds Flight duration: 6 to 10 minutes

Pluses

• Laser-cut balsa and plywood used for construction. • Includes all control hardware, wheels, and fiberglass wheel pants and cowl. • Airframe comes precovered with MonoKote iron-on film. • Vacuum-formed nose is painted to match the covering. • Firewalls are predrilled for the RimFire motors and include preinstalled T-nuts. • The front “cockpit” area is a removable hatch held in place with magnets, allowing quick access to swap out battery packs. • It can go from the box to ready-to-fly in roughly 5 hours.

Minus

• The design limits the physical size of batteries that can be used. I’ve outlined a quick, easy modification that forgoes this limit.

Abridged Product Review

I think all of us need that go-to airplane—something that is small enough to throw in a car and doesn’t require much support equipment, yet is big enough to have fun with. I’m reviewing a model that might fill that spot for many of us. It is of one the newest offerings from Great Planes: the Twinstar EP. This aircraft is a smaller, electric-powered design with tricycle gear and twin motors mounted outboard on each wing. If I’ve caught your attention so far, trust me; it gets better as we go. Let’s dive in. My reviews start by opening and inspecting all of the parts as I arrange them for pictures. A few things caught my eye. With the exception of the two nacelles and the nose cone, the entire airframe is assembled from laser-cut balsa and plywood, making it lightweight, but strong. All of the airframe pieces are precovered with MonoKote in a blue and white color scheme, with red and black trim.

The Twinstar EP ARF is built up from balsa and plywood construction. It comes with a complete hardware set, including wheels, control hardware, and three plastic spinners.

The nacelles and the nose cone are vacuum-formed plastic. The nose cone’s walls felt thin, so I made a note to be careful not to dent it during assembly. A 24-page printed manual is included, along with a couple of addendums. These addendums cover the nose gear steering pushrod and the application of the windscreen stickers. A large sheet of self-adhesive stickers is included, giving the Twinstar the look of cockpit windows, and some fake N-numbers for a realistic appearance. Rounding out the parts count is a complete hardware kit, including the wheels, pushrods, clevises, hook-and-loop straps, and two red plastic spinners. One thing I didn’t expect was the inclusion of a Y harness for the power system.

To access the battery compartment, the front cabin area doubles as a hatch. It’s securely held with four magnets.

This shot of the underside of the wing shows the aileron servo installation as well as the main gear installed. All of the hardware you see is included in the box and installs in minutes.

Each of the Twinstar’s motors mount to premade motor boxes. There’s plenty of room for a variety of motors and speed controls and everything is cleaned up with the included nacelle covers.

Flying

If you’ve read any of my previous reviews about electric-powered models, I’m all about using arming switches to protect my fingers! There are no provisions for an arming switch in the Twinstar; however, if you use the power setup I used in this review model (specifically the ElectriFly ESCs), these speed controls have an electric arming sequence. Before the propellers will move at all, the throttle stick must be moved to low then advanced to high throttle, and then returned to low. After a few beeps, only then is the power system armed. In trying to categorize how the Twinstar flies and where it fits in, I think it is best described as an all-around sportster. It’s not great at any one thing, and by that I mean it’s not an aerobatics aircraft, it’s not a Scale model, it’s not a high-speed racer, nor is it a trainer. It is simply a good, all-around model that you’ll have fun with. There’s plenty of power for eye-catching high-speed passes, fairly powerful climbouts, and eating up a lot of sky. But there’s also a good amount of control for a nice variety of loops, rolls, spins, snaps, and more. Granted, you wouldn’t catch any full-scale twin such as this on a low-level inverted pass, but the Twinstar does it with ease and doesn’t need full power to do it.

Conclusion

The Twinstar is a fun little design that offers a scalelike look without the fuss. Its twin powerplants make it unique and give it a great sound in the air. Depending on your use of the throttle stick, you can get a good, 6- to 8-minute, highly aerobatic flight, or a longer 8- to 10-minute flight just cruising around the sky. It goes together quickly and has proven itself to be the perfect size to throw in the trunk of my car so I’ll have it with me for a quick flight on my way home from work. —Tom Sullivan [email protected]

Bonus video

Manufacturer/Distributor

Hobbico (800) 637-7660 www.greatplanes.com

Sources

Twinstar manual http://manuals.hobbico.com/gpm/gpma1609-manual-v1_1.pdf FlightPower (800) 637-7660 www.flightpowerbatteries.com ElectriFly (800) 637-7660 www.electrifly.com