Plane Talk: Great Planes Revolver .61 ARF
WILLIAM RAMSEY
The chat around our flying field is that the 40-size Revolver from Great Planes is excellent. Its wide-bodied look adds full-scale appeal to an otherwise tricked-out sport design. I think it would make a great full-scale home-built.
Does that tail moment look short to you? I asked my dad that question, and he got a surprised look on his face. I guess he didn't think I knew any aircraft-design lingo.
I don't, really, but I hear him talking about moments while explaining models, so it seemed like a smart question to ask. Sure enough, he started a speech and I learned a few things.
That short tail adds a lot of character to the Revolver. The way I understand it, people are frightened of short tails because they can make an airplane difficult to handle. Dad's no engineer, but he explained to me that the short tail is tamed in this case with a generous amount of wing area and an oversized horizontal stabilizer.
The whole look of the Revolver is a play in aircraft feature design that I believe earned Great Planes a great deal of credit for building. The Revolver 40 has to be the slickest sport model offered today. I haven't owned the 40, but the good news is that I've had my hands all over the 60-size version—and my Futaba transmitter has hardly seen rest since I got the model.
Most people are in a hurry, so I'll save you the trouble of reading this article and tell you that the Revolver 60 is dynamite. And I'm flying it on the minimum-size engine.
The O.S. 61FX has worked well and is as easy to use as a motor. The noise is cool (it has grunt), and I don't have to charge batteries between flights.
Power the Revolver with whatever pleases you; it comes out of the box ready to take electric or glow power, with zero modification. In addition, you don't need an expensive radio or servos for the model to groove like an expensive competition airplane.
I'm using sport-type Futaba S9001 servos on all surfaces. Those units have a good amount of power and are precise, thanks to the internal coreless motor that Futaba made famous.
The all-wood airframe is covered entirely with MonoKote heat-shrink material. The composite landing gear, wheel pants, and cowling are painted to match the covering colors exactly—even the Metallic Blue, which I'm told is a hard shade to match—beautifully and has stayed that way.
Assembly
I let my parts hang out in the shop (out of the packaging) for approximately a week before I started assembly. Wrinkles that showed up in the covering became obvious for Dad and me to work out. MonoKote needs extra heat, but it cleans up.
Construction is a combination of laser-cut lightweight wood and foam-core wings and decking that is fully sheeted. A lightweight carbon-fiber tube supports the two-piece wing structure. The 6.0-volt HydriMax NiMH battery is strapped in front of the Futaba elevator servo. An included Great Planes 3-inch aluminum spinner gleams on the front of the O.S. 61FX engine. The fuel tank was built with two clunks: one for the carburetor and the other for filling. The included throttle-servo tray is nested behind the fuel tank, so that minimal bends in the pushrod are required. Fuel tubing cushions the tank around the included plywood brace.
It's easy to tell that the construction includes precision engineering. The model contains super-accurate laser-cut parts and is secured with tight joints everywhere that can be seen.
I heard that one AMA member with a Revolver 60 had the firewall fall out during his first engine test. Thank goodness that the airplane wasn't in the air! He was able to fix it, but I examined the airframe closely—especially in the front end.
My airframe tested good and tight, but to be on the safe side Dad and I coated the firewall and fuel-tank area with a layer of thin epoxy resin. Aside from hitting it with a hammer, trying to shake the wood parts off of the front end seems impossible at this point.
The frame seems to have been designed with many good ideas. The long engine box goes all the way back to the large wing-tube socket. Also in that general area is the landing-gear reinforcement. Like an interlocking puzzle, every part does its job and supports the structure around it.
Lightening holes are everywhere; if the Revolver were built from a kit, I'll bet that you could produce another model from the parts punched out of all the holes in the balsa and light plywood.
The large wings plug into the fuselage, and a large hatch was smartly built into the top to allow you to get inside the model. The hatch is roughly half the size of the airplane, and it makes it easy to service every accessory that is strapped or bolted inside. The hatch and rear deck are made from exceptionally light EPS (expanded polystyrene) foam that is fully sheeted with thin balsa.
All lifting and control surfaces are completely sheeted, and all have a foam core. I understand that this makes the wing light and strong with the fewest number of parts. Plus it's an easy way to make a wing as efficient as possible, because the airfoil is consistent.
The Revolver uses a semisymmetrical airfoil. That means that the model is aerobatic but stable at slow speeds, such as during landing.
Another thing I really like about the foam-core construction is the stiffness and precision of the control surfaces. They have no warp and are easy to center on the bench, because their trailing edges align with the flying-surface tip extensions.
I want to say that building this ARF was a perfect experience, thanks to this bonus accessory called instructions. My dad actually caught me studying these instead of doing my homework and didn't complain one bit. The photos in the manual did most of the teaching, but the text answered any questions that came up.
The included CA hinges are installed in factory-made slots, so my least favorite part of the assembly didn't take too long. Dad went the extra mile, and I have to thank him, by sealing the hinge gaps with narrow strips of matching white MonoKote. He told me that if I wanted the Revolver to groove as intended, that expert step would make a serious improvement.
The only build point I have to pick on Great Planes about is its distance recommendation for the engine. The stated measurement left me with an ugly gap between the cowl and included aluminum spinner that was thicker than 1/4 inch. I'm used to tighter gaps than that. When you build your Revolver, confirm that the gap is what you like before you drill the engine mount.
Procedures, measurements, and recommendations were good for the rest of the airplane.
The giant cowling completely hides the engine, but the required cooling exits take up a lot of space on the bottom. To make sure that cooling air saturates the right spot, a cover was glued over the left-side intake opening. The cover is finished in gloss black and held in place with flexible silicone adhesive. My O.S. runs nice and cool.
Even with the lightest engine bolted up front, my five-cell receiver pack ended up being located behind the CG. The interior is wide open, so if your Revolver doesn't balance right away, there are several ballast-location options and still room inside the fuselage to play the "Mickey, You're So Fine" song.
To be honest, I didn't want to go with the smaller engine in my Revolver. I begged for the .75, would have given my braces for a .91, and would have sold my brother for a four-stroke.
In the end the 61FX was threadlocked into the nylon beam mounts, and I bet my dad a replacement engine that I wouldn't like it. And you know what? I like my O.S. .61—a lot.
It's easy to start, and the needle, which I didn't have much experience with, turned out to be simple to set. Dad played with the low-speed screw during the first tank run and was able to get the idle extremely low—count-the-blade-going-by low.
We also played around with propellers. Because the Revolver has such a large spinner, the normal 12 x 6 seemed stubby. There's plenty of clearance for a 15-inch propeller, so we dug through the box of spare Master Airscrew and APC blades to find the perfect thrust maker.
It's great that we have so many propeller choices these days. I'm told that it didn't used to be that way.
A 14-inch propeller looked perfect on the Revolver 60. The big blades kind of finished off that home-built full-scale look.
A Master Airscrew 14 x 4 had painted tips that made it easy to see, and the low pitch helped the .61 to quickly spin up the propeller to 12,000 rpm. It was noisy, though—noisy enough to scare the riders at the nearby motocross dirt track. We switched to an APC 14 x 5N and kept the thrust, but gave up that monster scream.
Flying
You know that the test flight is going to go your way when the postage scale tells you that a model comes in at the bottom of the advertised weight range.
Another good sign was that the engine ran like a top and tuned in with no complications whatsoever. It also ran cleanly, thanks to the long exhaust stacks of the Bisson Custom aluminum muffler that Great Planes recommended in the manual.
I found out what pilots mean when they tell stories about models flying off of the bench. My Revolver 60 literally flew off of the runway with merely the application of power—and only half throttle was needed, at that. Its departure from the field was so smooth that I almost didn't want to interrupt it, but the time came to turn.
The Revolver is happy being solely a crank-and-bank machine. But if you want to get all precise about it, it likes a pilot even more when rudder is used to adjust the nose.
The Futaba 10C radio has triple-rate capability, so not only did I have the recommended low and high rates at my command, but there was also the option to select "stupid" rates and have 3-D control. We also added elevator-to-flap mixing, flaps, and spoilers.
All of those mixing toys are fun and are good practice for setting up other aircraft, but I learned that the Revolver 60 flies great with none of that stuff. A bit of exponential makes the high rate feel slightly more comfortable; the model is almost as comfortable as a trainer on low rates with no exponential. It's smooth, doesn't get tossed around by the wind, and is teaching me how to appreciate precision flying.
The recommended servos offer all kinds of control authority to do whatever I want, no matter how fast or how slow. The standard servo even works great on the rudder, because I can do knife-edge loops all day long within the 10 minutes it takes to suck up a tank of Magnum #1 fuel.
The recommended CG feels to be in a good spot, and I think that moving it back is possible if you want to fly the Revolver better in 3-D. As I mentioned, flaps and spoilers are cool but completely unnecessary for landing; this model slows to a crawl. The composite landing gear has a nice "spring" to it, and the wide spread of the wheels makes ground-looping almost impossible.
The good news is that Dad doesn't owe me a new engine. I'm keeping my Revolver just the way it is.
William Ramsey [email protected]
Manufacturer/Distributor
Great Planes Model Manufacturing Box 9021 Champaign, IL 61826 (217) 398-8970 www.greatplanes.com
Transcribed from original scans by AI. Minor OCR errors may remain.
