The 1/3rd Scale Curtiss R3C-2 Returns Home

History

In 1988, Larry Tate, Bob Martin, John Hanks, Jerry Leciej, Bob Whelan and J.T. Scott built a 1/3rd scale replica of the Curtiss R3C2 Schneider Trophy Racer that Jimmy Doolittle won the 1925 Schneider Trophy race. It was built as a promotional vehicle for the first ever Giant Scale Schneider Cup Re-Enactment. Prior to the first event, it was sold to HL Skates (Penn Int’l Chem) and competed in the 1989 Schneider Cup Re-enactment event in Lake Havasu, AZ and appeared on the cover of many RC magazines. It won the 1990 event but never returned to defend its’ championship in the Schneider Cup Re-enactment.

Discovery

As one of the original builders, I am pleased to chronicle the following journey.
Bob Martin

It has been 18 years since this storied airplane won the Schneider Cup Re-Enactment and disappeared. Initially, it hung in a hobby shop, but when the hobby shop closed, the fate of the Curtiss was unknown until recently when it was discovered that it was hanging in a storage unit in Mountain View, Ca.

I am very pleased and excited to announce that the 1/3rd scale Curtiss R3C-2 used as the promotional vehicle for the Schneider Cup Re-Enactment has been found, purchased and returned home to Lake Havasu City.

My sincere thanks to Jim Vice for informing us as to who the owner was, Reggie Dell-Aquila who had owned it for the past 10 plus years and allowing us to purchase it back and most importantly Jim and Scott of Xtreme Power Systems of Lake Havasu City for making it possible.

This addition to the Schneider Cup website will chronicle the discovery, recovery, and transition of this historic airplane into a modern state of the art RC electric showpiece.

Recovery

After locating the missing Curtiss, negotiations were underway to purchase the aircraft back from the current owner. Reggie Dell-Aquila, the owner, was somewhat reluctant to part with the Curtiss. Although he owns many big and expensive aircraft, the Curtiss represented a historic place in RC history. He eventually was persuaded to sell the Curtiss to us and John Hanks and I made plans to drive 600 miles to Mountain View, Ca. to transport the Curtiss home.

Reggie was kind enough to give us measurements of the Curtiss so we would make sure we could get the Curtiss inside a vehicle without removing the floats. The Curtiss is 90 inches long, 38 inches wide and 43 inched high with the wings off.

Johns truck was long enough, but the shell was only 39 inches high. My Dodge Grand Caravan was tall enough, but if Reg was off more than a couple of inches in length, we would be in trouble. As it turned out, we had about 1 inch to spare.

On July 9th, 2009, 6 am John and I left Lake Havasu City, AZ. and headed west to Barstow, CA. Our trip would take us through Mohave and Bakersfield before turning north on I-5, near Los Banos we head west over the Pacheco Pass to Gilroy, north again through San Jose and on to Mountain View. We had called Reggie and apprised him of our approximate arrival time and he was waiting for us at the storage facility.

When Reggie opened the storage door, John and I were excited to see our old friend hanging there in what appeared to be excellent shape.

She seemed to have weathered these past twenty years better than we had. We also felt she was saying “get me down, get this dust off me and let’s go home.” She was covered with 10 plus years of dust so Reggie, John and I began removing as much dust as possible. She was still dirty, but we were taking her home and would give her a proper bath and polish once we get home to Lake Havasu.

 

 

The Restoration Begins

After we got about 9 1/2 years of dust and crud off the Curtiss, we began disassembling it. There are a number of flying and landing wires that needed to be removed. It was amazing how taut the rigging was after all those years, as Reg says it has never been apart. Next we removed the top wing, stood her on her nose and removed the bottom wing. John and Reg are discussing here on whether it will fit into a Dodge MiniVan.

Once the wings were removed we opened the two side doors and the rear door and gently slid the Curtiss in tail first. The elevators were against the back of the front seats and when we carefully closed the rear door we had about an inch and a half. We wrapped the wings in blankets and carefully loaded them, one on either side of the floats. We paid Reggie and thanked him for his assistance and we headed home.

We had left Lake Havasu that morning at 6 AM and drove 600 miles to pick up the Curtiss. It is now about 4 PM when we started back. The plan was to drive out of traffic somewhere south of San Jose and spend the night. We would then get up early and drive home on Friday. John keeps saying “We can be home tonight Bob!” I am concerned about John, he is 84 years old and I am only 64 years old. I should be the one with the energy but John keeps bugging me so I concede and agree to drive home tonight. Around 3 AM Friday morning, we arrive in Lake Havasu City, just 21 hours from when we left. We were tired but we had our baby home.

Friday morning I called Scott and told him we were back in town. He says come on down. I brought the Curtiss down to Xtreme Power Systems where we will bring our Curtiss back to flying status and with electric. Scott is anxiously waiting when I arrive. Scott had never seen the plane, only pictures. He seemed impressed and we immediately unloaded it around in the back. The Curtiss is too big to fit through normal doors. Once inside the air-conditioned area, we were to work in (Havasu in the summer runs over 100 degrees every day) placed the wings and fuselage with floats on tables that Scott had set up anticipating our arrival.

Scott immediately began cleaning the Curtiss with a spray cleaner and microfiber cloths. He followed up with Pledge Clean and Polish. WOW! When he completed one part he moved on to another. Soon the Curtiss looked like the day we finished her. AMAZING. This 20-year-old airplane looks great.

Next, we removed all of the flight surfaces, checking linkage and replacing the 20-year-old batteries, switches, receiver, and servos.

It is now time to begin the disassembly process. The old Gas engine, fuel tank, and lines, throttle cable etc. all need to be removed and cleaned up. The 4.2cc Sachs engine, motor mount, and tank weighed over 8 lbs.

The servos of choice twenty years ago were FP-S134 Futaba giant scale servos. They were the best we could get back then and boasted a massive 112 in.oz of torque. We are replacing them with Coreless digital, titanium geared Hitec 5955TG servos with over 300 in. oz of torque. 1/3rd the size, 3 times the torque. New servo trays were fabricated to accommodate the smaller more efficient servos, better linkage was assembled for pushrods for the ailerons but the original pull system for the elevator and rudder remained the same.

Cleaning the Curtiss R3C-2

Scott is shown here removing the rudder. Notice how shiny the Curtiss is. The fiberglass cowl has been removed. A new one will be made that will allow easy access to the batteries that will power the Curtiss.

Here John is preparing to open up the wings to replace the servos. Scott checked out the radio system on the Curtiss and found that all servos worked but they were so old and slow it confirmed our thoughts about updating all of the electronics. The original aircraft wing was covered in lightweight ceconite with nitrate dope and finished with butyrate dope. The servos were sealed inside the wing, so in order to change them, we had to cut into the wing, remove the old servos, build a hatch and new removable servo tray and install our new servos. What a difference in speed the new servos make.

Here Scott is removing part of the firewall to allow for the batteries. The firewall is 2 – 1/4″ 5 ply aircraft plywood pieces laminated together. This would be very difficult to remove without the aid of an air saw.

It is the 1st of August and Lake Havasu is running a little warm, about 115 degrees F and too hot to repaint the wing tips. It was decided that we would return the Curtiss to the colors we had on her when we first built her. Our Certified Chrome Yellow Dope has arrived from Aircraft Spruce and Specialty so we are ready when the weather gets a little cooler.

So at this point, I am cleaning and polishing the flying and landing wires while we wait for our new motor mount to be built and the arrival of our electric motor. When we built the Curtiss in 1988, there were no flying wires of the strength we needed. Our first flight was done with Proctor flying wires and brass turnbuckles. These proved inadequate for this large aircraft. We had a local machinist make the clevises out of steel, sheered 314 stainless .060 sheet into strips, sanded them smooth, braised them to the clevises and used the new DuBro steel turnbuckles for the flying and landing wires.

Transition and Rebirth

The Curtiss has been found, recovered, returned, thoroughly cleaned, stripped of old electronics, engine, fuel tank, disassembled, inspected and patiently waiting for her new upgrades and coat of paint.

The folks at Xtreme Power Systems are heavily involved in electric everything. They have electric fixed wing aircraft, small and giant, all sizes of electric ducted fans, electric helicopters and electric performance boats. You name it and they are or have been doing it for some time.

In electric, you want to have a margin between what you need to fly and what you have. My Dad always told me that there is no excuse for lack of horsepower. Scott explained that we are going to use a Steve Neu 2330 1.5Y with 6.7:1 planetary gearbox. This motor is of the highest quality and efficiency and will be considerably more power than we need. If you have run electric, you know that heat is always an issue so if you can fly at 50% throttle, your heat build up will be less and duration of flight will be greater. The controller will be a Jeti Spin 200amp. The batteries will be XPS Pro LiPos, 15S 2P 10,000mah packs.

The New motor should be here around August 20th, shortly thereafter the motor mount will be manufactured and we can begin installation of the motor and engineer a battery box for the LiPos.

The original Curtiss cowl that we made was one piece that prevented any easy access to the front of the firewall and engine. It is necessary to be able to remove, charge and replace the batteries, without removing the spinner and prop so a new mold needed to be made to make a two piece cowl. The plug is finished and the dams added for the top part of the cowl. A mold for the top part will be complete in a few weeks, then we build a mold for the bottom of the cowl. Having been in the full-size boat business you make friends that have the facilities and materials to assist on the mold building and layup process. My sincere thanks go to Gary Lynch at Lynch’s Fiberglass Fabrication here in Lake Havasu.

Steve Neu Motor SizeThe Steve Neu motor arrived a few days early and we thought you might enjoy seeing what we had in the Curtiss and what we are replacing it with. On the top left is the 4.2 Sachs we removed and below it the new more powerful Steve Neu electric geared motor. A Graupner MX16 transmitter is to offer size comparison.

The Sachs 4.2 was driving a 24X10 prop and the Steve Neu geared electric will begin with a 27X20 prop. After we fly the Curtiss, we will adjust the prop for best performance. These props are huge compared with earlier gas engines. Want to see incredible? Check out the full-scale propeller and the 1/3rd scale comparison below.

 

HISTORICAL NOTE:

The propeller that Doolittle had on his Curtiss was:
Diameter: 92 in. ( 237 cm )                Pitch: 112 in. (284 cm)

Our 1/3rd Scale model would be:
Diameter: 30.66 in. (79 cm)               Pitch: 37.3 in. (94.67 cm)

The molds for the cowl have been completed and our first set of parts made. We will mount the bottom part to the fuselage and do the final trim and fit of the top. Below you can see the new parts. The air intake (rounded triangle at the upper part of the cowl, will be filled with metal screen and painted black. This is what we did on the original cowl and it worked quite well. You can see it on the Building and Flying the Curtiss. In the photo on the right with the top removed you can see the 1/2″recessed area that runs down and across the front of the cowl that the top will attach to.

We are also going to return the wing tips to the chrome yellow that they were painted when this model was built in 1988 as this is an upgrade of that original aircraft and not an attempt to enter a scale competition.

This next week we will be completing the mounting of the motor/motor mount, building the battery box for the lithium batteries, shaping the screen that goes into the cowl for the air inlet, hooking up the final linkage for the rudder, balancing and installing the flying/landing wires and tuning them.

We hope to be able to make the first flights of the Curtiss by the 24th of October.

The custom motor mount arrived and what a beauty, precision machined from aluminum it is light yet robust to handle the more powerful Steve Neu electric geared motor. This motor is capable of up to 20hp. We are going to use 14S2P 10,000ma XPS Pro Lipos. The system will run on 58 volts, approximately 150 amps and 8000 watts. That is approximately 11.8 h.p. ( 746watts = 1 h.p.). This is approximately twice the thrust and hp we had with the gas engine.

We can now mount the motor and prepare to attach the lower part of the cowl once the air outlet has been cut and the screen installed.

R3C-2 wing

The wings are now the Chrome Yellow we desired. The ailerons are hinged with Dubro hinges that came with cotter pins in the hinge. We replaced them with long .045″ piano wire so we could pull the one wire and remove the ailerons if need be. The ailerons were removed for painting and here Bob is inserting the piano wire to remount the ailerons.

After the ailerons were remounted, we connected the control horn to the servo. The ailerons are barn door, hinged at the top and just above Bob’s thumb, you can see the horn on the aileron. These are all internal and do not protrude beyond the surface as do most RC planes. This is also true of the rudder and the elevator is a bell crank inside of the fuselage.

Jim and Scott

There are two critical items that still need to be installed. We bring in the big hitters for the installation of the speed controller and the massive battery pack.

Seen on the left are JD and Scott of Xtreme Power Systems planning the final major electric conversion components for this historic transformation? Keeping the new electric components in the air flow and still being able to place them advantageously for the balance of the plane requires smart planning.

Once the speed control is securely mounted the problem of placing the battery pack is tackled. On the Curtiss, we created a new cowl that allowed access to the batteries by removing the top of the cowl.

On the Curtiss, when assembled and rigged (the flying and landing wires are functional) it would be extremely difficult and time-consuming to remove the top wing to access, remove and charge the batteries so the reason for the two piece cowl. Now that the top of the cowl is removable, we needed to find a place for the large battery pack that would both be easily removed for charging and assist in the balancing of the aircraft. It was determined that the aircraft was balanced pretty closely prior to installing the large power battery packs. This means that the pack would have to be inserted by removing the top cowl, through the firewall and into the fuselage back at the CG location. This proved challenging but the Dream Team came up with a unique and clever solution.

Pictured here is the laser cut battery tray with the six battery packs held in place with Velcro. This slides into the fuselage of the Curtiss and is secured by two screws.

When the original Curtiss was built back in 1988, the elevator and rudder servos were installed on a platform at the CG of the aircraft. It was a convenient place to work with the top wing off. It worked great back then, but now we need to get 1/2 of the battery pack behind the CG and the other in front to not change the balance of the aircraft without moving the servos as a complex set of bell cranks are employed to operate the rudder and elevators. As mentioned before, the Dream Team was up to the challenge by creating a removable battery box that inserts at an angle through the cowl opening, down through the firewall, two bulkheads and stops below and behind the elevator/rudder servo platform. It slides in and is supported by rails with one set of batteries behind the CG and the other in front. JD measured, designed and laser-cut the platform with lightening holes and slots for the velcro straps to secure the batteries.

Now that all of the major components are installed, a trial run of the motor seems in order. We installed the lower cowl and it barely cleared the motor mount and speed control. We then installed the collet, spinner backplate, propeller, front plate and main lock nut and tightened everything up. We chose to leave the spinner cone off for initial motor tests. Initially, we had run out issues but after removing and remounting all components, the run out was nearly perfect. We installed the spinner cone and began amp tests. It was determined that operating at approximately 50 volts that the Amp draw was below expectations. Having been one of the original builders and flyers of the 1988 4.2 Sachs gas powered Curtiss, during the run-up tests, it felt as though the pull on the aircraft was nearly equal to what we had with the Sachs at full throttle and when I looked at the transmitter Scott had only shown about 1/2 throttle and the Amps were only reading 63, approximately 1/3 of the projected draw at full throttle. WOW….this is one powerful machine.

The excitement is growing rapidly, even JD seems to be getting excited. Scott and I are both bi-plane fans and the history that was made and will again be made with this airplane is quite special to us. After the motor run and amp checks, we assembled all of the components of the Curtiss for the first time since we brought her home and began the transformation. What a beautiful plane in her new colors.

All that is left before her maiden flight with electric will be the mounting of the airborne batteries and receiver, and the re-rig of the flying and landing wires. The rigging is made of 304 stainless wires with Dubro steel turnbuckles that have to be adjusted and tuned just as a full-scale biplane is. Once complete and ready to fly we need to notify the local newspaper and a whole bunch of local people of the when and where this historic event will take place. The Today Herald Newspaper ran an article about our discovery and the return of this aircraft to Lake Havasu and will be running a follow-up article about the completion and first flight of the Curtiss and its part in the upcoming London Bridge Seaplane Classic.

After the motor run, current draw, battery checks the battery tray was secured with wing nuts in the fuselage and the top cowl was installed. Further tests show that the air inlets and outlets seem to provide adequate ventilation through the fuselage for cooling of the motor, speed controller and batteries.

John Hanks is our resident rigging expert and he is seen below tuning the rigging and safety wiring all of the turnbuckles. The fairings around the struts and rigging on the floats were replaced. A final check of all systems showed that the Curtiss is ready for her flight tests. We ended up gaining a little weight and now she weighs exactly 50 lbs. but considering the nearly 3,000 sq. in. of wing area, and the new increased power system, we expect a great flyer.

The Curtiss is ready to fly but the weather gods have decided that we must wait. A huge storm off the Washington coast has brought high winds, 20 to 50 mph and the forecast is for the winds to continue for a few more days. The forecast for next week is for calm and warm conditions that are supposed to carry through the London Bridge Seaplane Classic so we will be able to test fly the Curtiss and also be able to showcase it at the event. If you can, attend the LBSC event and see her strut her stuff live.

It is November 2nd, Monday 7 A.M. and the wind Gods have relented however the lake has not yet calmed down. There is a pretty good chop but the V bottom floats and long legs on the Curtiss should not prove to be a big problem. All the talk is over, no more excuses, will she fly as an electric?

Pictured below, our Curtiss is ready to go and is being transported in her new limo resting on soft memory foam. Boy, these Extreme Power Systems guys really know how to treat a lady!


Above right, Scott is lowering the ramp to let the Curtiss out. Below pictured is our Curtiss’s Limo

Jim and Scott carefully carry the Curtiss out of the Limo. On the right, the Curtiss poses with Jim, Bob, and Scott but she is looking a little apprehensive.

After we carried the Curtiss down to the beach and Scott was walking a mile away checking the range on the Graupner XPS 2.4 G, I was reassuring her that the new equipment was the best there is and I was confident she still knew how to fly. She says that she feels twitchy and I informed her it was those new quick powerful digital servos. She seemed to calm down and said it was good to be out in the sunshine, near water and liked her new bright yellow wing tips. She wiggled her ailerons and confidently said: “Let’s get it on!”

Prepping for the first flightThe Curtiss R3C-2 is back in the water again

Final adjustments and we put our Curtiss in the water. She handles the chop well. Notice the up elevator.

Taxied into position for takeoff Scott eases the throttle forward. The Coots in the background watching as Curtiss begins to accelerate. They do not want anything to do with this big black bird.

Ready for takeoffQuickly the electric motor accelerates the Curtiss as spray flies off the floats and she is airborne much quicker than ever before with the gas engines. Scott gently banks and turns the Curtiss and flies several scale like laps around the bay. Scott reports that the controls are quite sensitive but one or two clicks of up elevator and she was flying great.

 

In the air at least

Landing the Curtiss R3C-2After approximately 5 minutes of flight, Scott brought her down. A little hot but a nice landing.

Some final radio tuning and she will be ready for her debut as a modern electric Schneider Cup Racer.

This concludes our coverage of the recovery and transformation of the Curtiss R3C-2, except for a few more pics of her at the event. Thanks for following along and we hope you enjoyed the trip as much as we did. If you have any questions about what we did or how we did it, please send us your comments or questions.

Note:
Although the electric conversion was somewhat successful, the additional weight of the batteries and where we had to install them made landings impossible. The Curtiss is a long-legged beauty but no matter how fast or slow we tried to land, the heavy mass of the batteries and their inertia in the fuselage would cause the Curtiss to rock forward on the floats at touchdown. The floats, especially being V bottom, would dig into the water, swerve one way or another and the Curtiss would end up, upside down in the water. The electric conversion taught us a lot and the power was impressive as was the near scale prop length. If we had started from scratch and designed the floats to carry the batteries we believe it would have worked beautifully. I visited the Curtiss the other day and it looked so sad incomplete without its’ engine and prop. Discussions were that we are going to return the Curtiss to gas. There are a lot of newer engines available these days and we will hopefully have the Curtiss ready for the 2014 London Bridge Seaplane Classic here in Lake Havasu City, AZ
If you want to see this historic and impressive airplane fly, come to join us next year early in November.

 

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