A Main Hobbies Frenzy V2-2011/12

Author: Roth Heyes

Edition: Model Aviation - 2011/12
Page Numbers: 60,61,62,63,64,65,66

A Main Hobbies Frenzy V2

A glow-powered sport helicopter that's easy to own and grow into

Roth Heyes

With a little—okay, a lot—of practice, hovering low and inverted is no more challenging than flying upright, especially with a helicopter as stable and smooth as the Frenzy 50.

There are many ways to hop-up the Frenzy. The lightweight fiberglass canopy shown is a Canomod product, specially made for A Main Hobbies as one of three available color options.

Not long ago, I wasn't what you'd call a "helicopter person." For most of the last 20 years, my car was filled with fixed-wing glow- and electric-powered models on a normal flying day. But since the small electric coaxial helicopters came out, my curiosity about the air-beaters has grown steadily. After getting my first one, I kept at it and honestly, I think that little heli helped with my ability to fly airplanes—lots of left-thumb practice.

Then bravery got the better of me and I invested in an electric 450-class helicopter. That required a large leap in my ability. Collective-pitch helicopters are more sensitive to pilot input but can be flown outdoors and can perform forward flight. Once I became good at hovering in the backyard, that machine found its way into the car between the fuselage and wings.

Although it crashed a few times, the helicopter could be put back together as good as new, as long as I was careful and didn't skimp on cheap parts. Helicopters can be flown much like airplanes, and doing so at the club field kept my airplane pals happy because I'd follow the same pattern as the other aircraft. My left thumb got much practice mixing tail-rotor control into the turns and managing the collective (that's the throttle stick on airplanes).

Helicopters need plenty of maintenance, and I think that taking good care of my helicopters made me want to take better care of my airplanes. It got me thinking that maybe a bigger helicopter would increase my abilities as an RC pilot.

Roughly a year ago, I bought the JS Models TZ V2 .50 Frenzy helicopter from A Main Hobbies. My business with A Main Hobbies has been satisfying. Ordering online is a breeze; I always have a wish list going. A Main Hobbies has many products in stock and ships fast. The Frenzy is a lot of helicopter for the money, and everything I needed to get the helicopter flying was available in one order from A Main Hobbies. All of the stock parts are available for the helicopter, and there are even some replacement parts made from metal instead of plastic that harden the heli and improve its looks and performance.

The Frenzy 50 is a glow-powered machine that requires a .50-class helicopter engine, muffler, 600mm main blades, gyro, and above-standard-grade servos to work the cyclic controls, throttle, and tail rotor. Although the Frenzy is available at a great price—hundreds less than many other kits available—that's not an excuse to skimp on accessory equipment. I've learned through my 450-size machine that lousy radio and power systems make even the best helicopter fly poorly.

My experience with O.S. engines in airplanes made my engine choice for a helicopter easy. I went with the O.S. 50SX-H engine instead of the newer 55-size helicopter engine that O.S. now offers because the advertised weight of the Frenzy and my flying style didn't dictate an ultimate power requirement—or expense. To get every bit of power out of the reliable 50-size engine, I selected a muffler from Hatori USA (available from A Main Hobbies).

The Futaba 10C FASST radio system that I've used for aircraft works well for helicopters. This choice kept me from having to learn a different radio system, and bringing only one transmitter to the field for airplanes and helicopters makes sense. I like to keep things simple (and yes, I understand the irony of being attracted to complex machines such as helicopters).

Keeping things simple is a challenge with a helicopter, but I tried anyway in the interest of weight savings and reduced failure points by making a list of needs. I wanted to go with a lithium battery for receiver power (I don't use nickel-chemistry batteries anymore), but I didn't want to carry a separate voltage regulator. I needed a great gyro and considered adding a throttle governor down the road. There are many gadgets and add-ons you can add; some are worthwhile, others not so much depending on your needs and skill level.

Hobbico’s LifeSource batteries have a nominal voltage of 6.6 volts, and they’re supplied with three output leads for redundancy and multiple supply options. Here was one battery that provided multiple needs. Excellent!

The Futaba GY701 is a multitasking accessory as well. Not only is it a state-of-the-art gyro, but it can also be used as a throttle governor with the add-on of a hall sensor. One accessory, two tasks—now we’re cooking. Bonus: the GY701 also can operate on the voltage straight from the LiFe pack.

Hitec offers a wide range of servos that work well in my airplanes. I’m fond of the durability and precision of Karbonite gears. I compared the specifications of the highest-rated helicopter servos and matched them with what I could find from Hitec. I quickly found matching—or better—servos under the Hitec label; nearly all of the Hitec servos can operate at 6.0 volts or higher. The Futaba eight-channel FASST receiver can operate at 6.6 volts, too.

So there I was, keeping things simple, but still finding everything I needed to fully trick out the Frenzy—time to open the kit and get building.

The Frenzy is a modern helicopter with mechanics that are similar to more expensive machines. Its design is comparable—albeit larger—to the 450-size machine on which I learned, so none of that practice was wasted! The head and tail mechanics are nearly identical in look and function, plus the swash mixing was cyclic/collective pitch mixing (CCPM), as with every popular helicopter. To me, the Frenzy didn’t look like a complicated project at all.

The helicopter is shipped mostly assembled. The composite frame is complete with its combination of plastic and metal bearing blocks installed and the efficient accessory tray hanging out the front. The metal/plastic hybrid head mechanics are completely assembled with the main mast, and the tail rotor is fully assembled with the drive belt installed and triple ball-bearing blade grips attached.

The instructions include full assembly procedures and exploded views as if building the machine from a totally disassembled kit—really detailed. The English translations are rough in some areas, but the steps and data turned out to be accurate.

Although the major assemblies appeared tight, inspection of random hardware proved that thread-lock compound wasn’t always present, but the torque needed to remove the metric socket-head hardware was significant.

Instead of the servos directly linking to the swashplate as on my 450-class helicopter, indirect ball-bearing-supported bellcranks interconnect between the mechanics and the servo for extra support and reduced load to the servos themselves. The push-pull linkage of the cyclic controls is ideal for precision and load-bearing assurance.

Geometry is important with helicopter mechanics. It’s why the Frenzy has multiple linkage connection options on the head mechanics; a pilot can tune the mechanics to suit a certain flying style. I didn’t like that the push-pull bellcranks on the Frenzy have 27.5 mm ball-link spacing because it doesn’t match the standard 25 mm or 30 mm spaced ball-link mounting hole choices of the Hitec servo wheel. As it turned out, using the mismatched spacing didn’t produce any significant binding or interference; however, on professional-grade machines, the spacing is matched.

The Frenzy is quick to build, even taking the time to inspect the hardware for tightness. In two evenings the helicopter was framed with the engine installed. I’m impressed with the frame engineering. A large bottom plate made of 2.5 mm G10 composite (the same material as the frame) bolted to the bottom of the frame adds an enormous amount of twist resistance. Both the landing gear and engine block tie into this part, making the stressors and support components work in unison.

The four landing-gear posts are flexible; replaceable points are easily serviced if a hard landing occurs (or you practice autorotations as hard as I do). A lot of high-end helicopter designs require expensive and extensive component replacement when an issue as simple as a hard landing occurs. The Frenzy only needs a $5 bag of landing-gear brackets.

The servos should be installed starting from the bottom; otherwise getting the 2.5 mm stop-nuts to thread on is difficult. The power switch should be installed in the factory-made opening in that sequence as well, and mounted with rubber grommets to isolate the switch from vibration. Pay careful attention to the direction of the servos to ensure that the factory-assembled pushrods will fit; follow the manual and you'll be fine. The servos are located so that the wire leads are easily within reach of the forward accessory tray.

Every pushrod is supplied finished, which is great because there are many, but they're bundled and labeled for easy reference and quick installation. The links are an accurate fit on the balls and require a firm press to attach.

Routing and bundling the wires was simple; there are lots of strapping points on the accessory tray. I treated myself to a PushGlo from the company that makes the SwitchGlo onboard glow plug igniter. It operates from a spare lead off the LiFe pack, or from a spare receiver port. Push the button and glow heat is applied for 5 seconds—plenty of time to start the great-running O.S. engine.

The Futaba GY701 gyro and governor turned out to be a great investment. Simple to program, it has options for multiple flying styles, and advanced features to fine-tune the operation. The data screen is easy to read, even in direct sunlight. The Quick Start Guide instructions had me flying in no time and the detailed booklet is even more enlightening.

In fact, my confidence in the gyro operation had me quickly back to the A Main Hobbies website to order the governor option. Because the gyro and governor work through the same unit, throttle response to tail-rotor demand is almost predictive.

My Frenzy weighs slightly less than specified. Had I opted for separate accessories—bigger engine, heavier muffler, and adding a regulator—the machine would have been heavier.

The included fiberglass canopy dressed up brightly with the included V2 graphics, although I wish the adhesive on the graphics was a little more aggressive—I doubt that they'll stay looking good for long because engine exhaust quickly settled in the seams.

First flights with the Frenzy were spent with the engine running rich. I run Rapicon fuel, which is very reasonably priced and popular where I fly. I tended to the tail-rotor trim and gain response during the initial flights.

To this day, I'm happy with the GY701's hold on the tail; however, I can't say that I like how the tail bounces at the stops. Gain adjustments could not eliminate the bounce and I explored every option within the GY701's parameters.

I understand that there is a firmware update for the GY701 that can be accessed with the use and purchase of the Futaba CIU-2 PC Interface (FUTM0951). Maybe I'll invest in a programmer and chase the problem down.

I chased the tail enough to get response and achieve pirouette rates better than I needed in order to fly. Cyclic and pitch response required little adjustment, which pleased me. The CG is spot-on over the main shaft. This means that I should expect neutral flip and roll response—maybe it will even be axial. A forward CG would offer more stability for forward flight, and an aft CG would make the helicopter more pitch sensitive—hey, that's just like an airplane!

A CG on the main mast means that the swashplate stays perpendicular to the main mast. A tilted or trimmed swashplate will inhibit the helicopter from performing square maneuvers and cause a variable-change rate across the pitch range. In other words, the helicopter won't ever feel in trim, and loops, rolls, or any combination thereof will look "funny."

My Frenzy flips and rolls smoothly with little need for correction—or only needs correction because of my sloppy input! It's difficult to describe what a pleasure it is to fly the Frenzy. My experience was with smaller machines; the Frenzy is a Giant Scale experience by comparison!

As is true with airplanes, bigger helicopters fly better. They seem to react more smoothly and respond instantly to my every command, although doing so over a larger area. The perception gives me the time I need to think and appreciate my input along with the helicopter's flight path. I'm able to correct my mistakes rather than recover from them. Flying the Frenzy allows me to breathe during the flight; before I held my breath.

I can actually practice autorotations with the Frenzy—a skill that was not long ago merely a dream to ponder. I've bent the flybar with a few hard landings, but haven't broken the gear or struck the boom.

There was a shake in the tail that required chasing. I replaced the tail blades with KBDD Tony Whiteside Extreme Edition blades. They helped and their green color helps visually with the machine, but the shake still persisted. That led me to balance the tail-rotor assembly and look again at the balance of the head.

The shake crumpled away slowly, but still wasn't totally gone. There is a boom support brace available that might help. It will tie together the boom supports at midspan, dampening the frame vibration traveling down the boom. Another thought is to relocate the frame mounting points of the boom supports from the fuel tank stays to a point lower and forward on the frame, perhaps on the rear gear strut hard point.

I've had lots of fun flying the Frenzy. The O.S. 50 and Hatori combination offers plenty of power. Aside from my tinkering, it has been a trouble-free helicopter to fly. I explored different mixing, both with that already provided in the head mechanics and with accessories available separately such as the 140° swashplate mixing.

The 140° mixing improved the helicopter the most. Besides the longer swashplate arms, you will want to purchase the new servo pushrod kit specifically for 140° mixing; the stock arms are too long. At the stops, I noticed that it's possible for the 110 in-oz torque Hitec servos to slightly leverage a bend in the plastic swashplate. I'll be ordering the all-metal swashplate from A Main Hobbies soon because my aerobatics skills are getting daring and I don't want the swashplate to fail.

The KBDD Tony Whiteside paddles and blades smoothed and improved the Frenzy's capabilities. Unfortunately, the included dampeners in the KBDD kit won't fit the aircraft—they're too small and the Frenzy's spindle is only 5 mm.

I've changed the look of my Frenzy with a painted canopy from A Main Hobbies. Did that ever make the helicopter pop!

Even old airplane pilots can get a kick out of flashy helicopters. As I mentioned before, my helicopter experience has made me a better airplane pilot, and the challenge has helped me not only appreciate the hobby more, but also have more fun.

—Roth Heyes [email protected]