|One-hundred-eighty inches of carbon-fiber blades are spinning at 1,600rpm. The sound is intense a blender filled with metal, gears and morphine. The small crowd, gathered just a few minutes ago, has now taken cover behind their cars. Little kids plug their ears. It’s hard to believe this day has finally come. It’s time to maiden the Dauphin. Backtrack to 14 months ago, and you’d find Dennis Ideue in his well-equipped workshop in Fullerton, CA. “I saw a video of a Dauphin lifting off” recalls Ideue. “I’d never seen anything like it. And that tail looked incredible. That really did it the tail. I had to build one.” Sometimes,|
|it’s the shape of a wing, the curve of a canopy, or the arc of a fuselage. Other times, there’s no rational explanation at all. Why we are drawn to certain aircraft is a personal thing. For Dennis Ideue, it was the Fenestron tail of the Dauphin N4. A brief history: the Dauphin series of helicopters is manufactured by Eurocopter and has been made in N1 through N4 models. The Coast Guard actually uses an upgraded Dauphin N1 variant that’s known in the U.S. as the HH-65C. The newest version of the helicopter, the Dauphin N4 (also known as the EC 155) has never been procured by the Coast Guard, and that allowed Ideue to envision an upgraded version with glass cockpits, an upgraded Night Sun searchlight and a newer crane mounting. Over 12 months, Ideue’s obsession took shape. After spending most of each day as CEO of a very active tech firm, Ideue spent long nights researching the project. Every part would be the finest available whatever the cost. I ordered up one of Len Mount’s award-winning 80-inch kits, says Ideue. Calling it a ‘kit’ was a bit of a stretch though for me, anyway. Basically, what I got was a coffin-size box of fiberglass parts. The instructions were simply a few CDs with pictures of a real Dauphin and a list of necessary tools and components stuff like sandpaper, epoxy, electronic bits. All I could think was what the hell did I get into? Until then, the most complex heli Ideue had built was a T-Rex 450. This one promised to be a bit more complicated. A normal person would have admitted defeat and walked away. Ideue isn’t normal. As a former aeronautical and electrical engineer in the Marines, Ideue cut his teeth on machines like the F-4 Phantom. He had worked on projects tougher than this. And he didn’t want his buddies to know he had given up. In a neighborhood of RC geeks, the heckling would be unbearable. This aircraft is based on a T-Rex 700 helicopter the chassis often used in high-end film production. Although designed for a gas engine, it was converted to electric with the HeliDirect.com system. Spinning overhead is a Century 5-blade head with an OF swashplate and a Vario follower all driven by Futaba brushless servos. A Scorpion 4035 to 560Kv motor and Castle 110HV controller are at its core. Ideue got it flying without a problem and moved on.MECHANICS
The parts weren’t quite ready to leap into the body. The mechanics had to be mounted off-center at the bottom, so the rotor was centered at the top, where the shaft leaves the fuselage. Ideue designed a baseplate with an angle to offset the inherent lean. The landing gear went in early on. Using proportional servos rather than retract servos allows their actuation to be slowed down with the JR 12X transmitter so they operate realistically. The Robart retracts have a locking mechanism so the servos do not have to work to keep them fully up or down. Using West System 24-hour epoxy, West System filler, fiberglass and carbon, the tail was attached to the rest of the fuselage. The horizontal fins have two supporting carbon-fiber rods passing completely through the fuselage for strength. The navigation lights and the Xenon tail strobe were all mounted at this time so that they could be assembled with the remaining components. Stuffing the Align 700 mechanics into the fuse was far from a plug-andplay exercise. The tail output shaft
|needed to drop some 6 inches. While a drop-down gearbox could work, it relies on a less robust belt-drive input rather than a torque tube. Dr. Tim of Approach Engineering offered a brilliant solution: use a few off-the-shelf tail gearboxes. This was just too obvious!, recalled Ideue. I’d spent hours looking for gearboxes online. Instead of using expensive 90-degree gearboxes I could use the manufacturer’s own inexpensive and off the shelf. I got a bunch of Align tail boxes and fabricated a bracket to connect them. The Fenestron mechanics are from CineScale.com. The Vario articulating mechanism was modified and coupled to the Align torque tube. The rudder control rod is a double- laminated carbon-fiber tube (two carbon tubes fitted one inside the other) epoxied over a stainless-steel rod. Attaching it to the mechanics was straightforward and required two of the shortest torque tubes in the world. The mounting plate that supports the mechanics is removable with locating pins for registration. Neighbor and master machinist Bryan Barba of Bryan’s Custom Restoration fabricated many of the necessary small bits|
|PAINTING & FINISHINGWith the basic mechanics sorted, it was time for paint prep. The components were removed and the body sprayed in Barba’s shop booth. The dull-yellow undercoat is based on a high-end automotive blend, the same stuff Barba uses on his award-winning street rods. More sanding, more filling. Barba used the two-part Evercoat metal glaze for larger areas and Squadron Green putty for smaller voids. Ideue mounted KJ Magnetics N-52-grade magnets in the doors and made the larger side door slides out of rectangular brass stock. Under the second layer of primer, Ideue built up the details with carefully cut pieces of aluminum tape. The rivets are white glue applied with a hypodermic syringe. Barba first shot the white base coat and then applied the custom mixed International Orange used by the Coast Guard (supposedly the same hue as the Golden Gate Bridge). The cabin was sprayed with standard Navy gray. Lettering and logos were made using Ambient Graphics dry transfers and feature a resolution near 2400 dpi. Beneath several coats of clear, the lettering and artwork appear to be hand-applied with the world’s smallest paintbrush, and that was Ideue’s intention.NIGHT SUN
Prior to wiring this monster, the Night Sun and crane searchlight had to be installed. The spotlight is a Vario searchlight shell and gimbal, a Baumann crane mount and the LED and reflector from an LED Maglite. It’s finished in Tamiya gunmetal gray and black. The crane is from Heliscale.ch in Switzerland, and it features a very strong mount. This winch also includes a solid-state controller that makes integration with the existing electronics easier than using the standard servo and 3-position switch approach. Assuming that this N-4 would be a next-generation Coast Guard heli, it would contain sizable large glass displays and a few conventional instruments as backups. The bezels are formed styrene, and their graphics were printed on transparent film using a color laser printer. A pair of white Luxeon LEDs light things up while a few spaced sheets of scuffed plastic act as diffusers. A DeLight controller from Dimension Engineering gets tucked away inside the instrument panel, leaving only one servo connection to illuminate the entire panel. A series of fiber-optic strands provides the smaller auxiliary lights. The retractable landing lights from HeliFactory.com of Germany are machined out of billet aluminum brilliant pieces with the rotating part of the light mounted directly on the servo shaft. As the gear is extended, these intense lights slowly rotate in position. Spectators typically stare, mouths open and dumbfounded at the awesomeness. The Lexan windows are held in place by a rubber flange from Tower Hobbies that can be glued to the fuselage. Like those on the real heli, the overhead windows were tinted green with a mix of green and blue Tamiya paint and automotive clear.
With the cabin and body sorted, it was time to determine the CG. Ideue suspended the heli from ceiling joists using a custom-fabbed fixture that he bolted to the head. Given its dimensions, the Dauphin needed only 5 ounces of nose lead. Let’s hear it for Len Mount’s sound design! It was determined that rotor blades from OF Helitechnik in Germany would provide the best performance, and a matched set of five was ordered through Starwood Models. The 800mm semisymmetrical blades feature a 14mm root, and 5mm bolt holes. (No, you won’t find these at your local hobby shop.) In addition to custom paint, Ideue balanced each blade with small squares of sprayed clearcoat until all five rotors weighed within a few tenths of a gram of one another. Ideue figures that he has invested more than 1,000 hours in this build. During that time, his workshop became a sort of hangout for neighbors and friends. Typically working until 11 p.m., they could always count on him for a spare part or tech support. Neighbors have described it as shopping at Dennis RC. All stores should be so well stocked and have such helpful staff! Ideue finished the project shortly before the photo shoot. As with any large scale project, it takes more than a few test sorties to debug the beast. As I write this, the heli flies just like its full-scale counterpart. As far as the crowd was concerned, it was the real thing. That’s probably the best compliment any modeler can hope for.
|SUMMARYThe Dauphin N-4 built by Dennis Ideue is a scale masterpiece. With its weight, rotor size and Helicommand stabilization system, it is very stable in the air. At nearly 40 pounds, it is very easy to fly in a scale fashion and almost impossible to fly otherwise. Construction time: 11.5 months.|
|SPECSHELICOPTER: Dauphin N4
MANUFACTURER: Len Mount (fabricated by Starwood Models)
DISTRIBUTOR: Starwood Models
TYPE: Scale Coastguard Search & Rescue
FLYING WEIGHT: 39.5 lb.
LENGTH: 80 in.
BLADES: 800mm OF Helitechnik semisymmetrical blades
ROTOR SPAN: 72 in.
ROTOR DISK AREA: 4,071.5 sq. in.
ROTOR DISK LOADING: 22.3 oz./sq. ft.
RADIO: Flown w/JR 12X transmitter, JR1211 receiver, Futaba 611 gyro; 3 Futaba 351 brushless servos (for cyclic), 1 Futaba 251 (rudder), 3 400 oz.-in. JR DS8711 servos (landing gear), 2 Futaba 3114 servos (landing lights), 1 Robbe servo (winch assembly)
POWER SYSTEM: Scorpion 4035-560Kv motor, Castle Creations 110HV speed controller, 2 Thunder Power 5000mAh 6S1P LiPo batteries wired in series for 12S power to the Motor/ESC, 2 Thunder Power 5000mAh 2S1P batteries in parallel with twin BECs for receiver and servos; a third 5000mAh 2S1P LiPo powers winch, Night Sun spotlight and lights.
MAX RPM: 1,800
CRUISING RPM: 1,500-1,600
DURATION: 7 min.
COST: $24,661.50, including tools & consumables
|ADDITIONAL PARTS USEDFUSELAGEBaumann windshield wipers BVM aluminum wheels HeliFactory retractable landing lights HeliScale.ch electric winch Len Mount Dauphin fuselage Robart retracts Robart Robo-Struts Starwood Dauphin antenna set Vario Night Sun scale spotlight
Align T-Rex 700N chassis Century Helicopters 5-blade head HeliDirect electric T-Rex conversion kit OF Helitechnik swashplate Vario swashplate follower
3 Align 6A BECs 3 DeLight LED controllers 2 PicoSwitches 3 JR Matchboxes 1 Robbe winch controller 3 BLS 351 brushless servos 1 BLS 251 brushless rudder servo Xenon strobe controller 2 Helifactory landing lights 1 Helicommand Rigid 3 JR DS8711 servos
Align torque tube Cine-Scale Fenestron Custom blades Kyosho Boot Vario tail gear box
West System epoxy 3M Guide Coat Jamestown Distributors carbon-fiber tape
Ambient Graphics, www.ambientgraphics.net, (866) 429-2242Approach Engineering, www.ApproachEngineering.com Dimension Engineering, www.dimensionengineering.comEast Coast Scale Helicopters, www.eastcoastvario.com, (508) 520-1140HeliCommand, www.helicommand.com
HeliDirect, www.helidirect.com, (877) 439-4354
K & J Magnetics, www.kjmagnetics.com, 888-746-7556
Starwood Scale Models, www.starwoodmodels.com, (650) 851-9027
Tower Hobbies, www.towerhobbies.com, (800) 637-6050
West System Epoxy, www.westsystem.com, (989) 684-7286