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.
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.
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 removeable battery box that inserts at an angle through the cowl opening, down through the firewall, two bulkhead 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.
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.
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 back plate, propeller, front plate and main lock nut and tightened every thing 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 showed 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.