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Our kit arrived on Santa's sled on Christmas 2003. This is the U-Can-Do 3D from Great Planes! Someone must have been a good boy because it was quite a surprise. This is a model that is designed to help teach flying 3D. If you have had a chance to watch one of the Model R/C air shows where Chip Hyde, and others put their 40 lb planes through the paces, you probably caught the "gotta learn this" bug. Of course these pilots use specially designed models for their demos... Just like this one.

Here's the Specifications:
Wingspan: 65 in (1650mm)
Wing Area: 1024 sq in (66.1 dm2)
Weight: 7-7.5 lb (3180-3400g)
Wing Loading: 16-17 oz/sq ft (49-52g/dm2)
Length: 68 in (1725mm)
Engine Required: 2-stroke .61-.91 cu in (10-15cc) or 4-stroke .70-.91 cu in (11.5-15 cc)
Radio Required: 4-channel w/6 servos

The_box   This is one large box! It measures 66x14x7 inches and weighs 11 lbs (4996 gm.)
In_the_Box   The contents are well protected and the box is reinforced with 1/8-inch wood. Pretty well done. Still, one of the wing tips was crushed somehow. We'll repair this area and look for other problem areas as well. Any we find, we'll fix. We noticed some of the main wing balsa center sheeting was loose also...
Wingtip_Repair   We repaired the wing tip first. A razor blade was used to slit through the MonoCote covering at the training edge of the wing. The wood was moved into place as best as possible, then water was wicked into the exposed wood. A heat gun was used to heat the area. Once the balsa wood was back into the shape it needed to b to match the other wing tip, thin CA glue was wicked into the exposed wood. Finally, a sanding bar was used to even the wing tip edge with the rest of the main wing trailing edge. Once repaired you can hardly tell there was any damage...
Shrinking_Monocote   The first thing we did after opening the box was to read the instruction manual from front to back. Then we inventoried the contents of the box against the included list. We followed the instructions and used the sock covered covering iron set to 360 degrees to reshrink the covering. We also used the heat gun to sped the process of removing major sags and wrinkles.
CA_Hinges2   Rather than cutting CA hinges from the supplied sheet, we used some of the hinges purchased on ebay a while ago. These hinges are larger and have more glue surface area. We also know they work well - none have failed on the many models we've built and repaired using them. Besides, using precut ones saves time. It took no longer to use these, since the slots had to be chased out with a #11 blade, drilled out with a 3/32 inch drill, then glued with thin CA. We used our Robart hinge pin drill guide for drilling the recommended 3/32-inch holes in the center of the slots. We also didn't remove the covering from the edges that the instructions called for. The CA will wick into the hinges we used just fine. Also, we didn't need to worry about sealing the exposed wood to keep the fuel residue out.
MainWing_Hinging   Here's a look at all the items we used to mount the ailerons to the main wing. We used 6 drops of thin CA adhesive on each side of every hinge, just as the directions suggested. We moved the ailerons back and forth as the CA was setting up to make sure that the hinge allowed enough travel. No accelerator was used with the CA, even though it is included in the picture. After the CA adhesive set, we pulled on the ailerons to make sure they were firmly attached. Pins could be pushed into the trailing edge of the wing to make sure the hinges are secured as an option (we didn't).
Trim_Iron   We actually used the small trim iron to open the servo, wiring, and mounting holes. The iron set on high would easily cut through the covering and iron it down. This is much butter than cutting the covering. It seals the wood as well.
Extension_Cable   We made sure the servo extension for the ailerons wouldn't come loose by wrapping the connection with electrical tape and then tying the connectors together with some cotton string. A drop of CA was put on the knot. The connectors shouldn't come apart from vibration.
Pulling_Aileron_Servo_wires.jpg   We used needle nose pliers to pull the reinstalled string out of the aileron servo holes. Then the string was taped to the servo extension. Both servo extensions were secured to the pull string before trying to pull the wired out the top of the wing. A welding rod was used to pull the pull string out of the wings.
Aileron_Servos_Programmer   We will use the Hitec HS-5925MG Servos. A Hitec Servo Programmer is used to set up the digital servos. We will use the Hitec HS-5925MG Servos. The specifications at 6 Volts:
Design: Dual Ball Bearing Coreless, 3 metal gears, 1 resin gear
Operating voltage: 4.8-6.0 VDC
Speed: 0.08 sec/60 degrees
Torque 127.76 oz/in
Weight 1.97 oz
Dimensions 1.55" x 0.78" x 1.48"
Notice that the brass grommets are installed from the bottom of the servo. This forms a vibration isolation barrier between the brass grommet and the screw head, slightly compressing the rubber servo insert. Some modelers install these incorrectly on the top of the servo. This eliminates any vibration damping that the mounting is supposed to provide.

Pulling_Servo_Wires2   This is the top of the wing showing both aileron extensions pulled through the wing. We put red electricians tape on the right aileron servo wire and blue tape on the left aileron servo wire. Since we will use the flaperon wing type on the JR PCM10x transmitter, this will help to make sure we connect the servos to the correct channels in the receiver. Having reversed aileron servo wires is a sure recipe to ruining a otherwise great model!
CarbonFiber_Pushrod   For the aileron pushrods, we decided to use carbon fiber ones with 4-40 titanium ends. The clevises are Dubro locking 4-40 ones. We eventually changes the clevis on the servo end to a ball stud arrangement to reduce friction and eliminate the bending forces as the control was moved from one extreme to the other. This should keep the linkage pretty rigid.
Aileron_Pushrod   We used a pair of balsa strips rubber banded together to hold the aileron in its centered position as we installed the pushrods. A square was used to make sure the pushrod is at 90 degrees from the servo. Once lined up with the control horn holes centered over the hinge joint, holes were drilled and the 2-56 cap screws were installed.
Aileron_Servo_Pushrod_Right   We preformed the same operation on the right side. The Hitec Servo Programmer was used to reverse the throw of one of the servos. Also the deadband and speed were matched on the servos. The linkage was left unconnected and a receiver was connected to the aileron servos. We turned on the transmitter, then the receiver. this allowed the servos to center themselves. Then we connected the linkage. The throws were about 2 inches or so... A good start. We will set the throws (all three - low, high and 3D) later.
Covering_Elevator_Mounting   We followed the directions to locate the holes and cut the fill piece for the horizontal stabilizer from the fuselage. The hardware for this model seemed to be SAE (Standard American English) rather than metric. Knowing this helps select the correct tool for removing the Allen screws. Once the filler piece was removed, we folded the excess covering over and ironed it down.
Elevator_Hinging   The elevator halves are hinged using the same technique used for the ailerons. First the covering is shrunk using the covering iron set to around 360 degrees F. Then the hinge slots are cleaned out using a #11 blade in the razor knife, then a 3/32-inch hole is drilled. Finally the hinges are installed and 6 drops of thin CA area added to each side of the hinge. Note the rather large surface area of the elevators compared to the horizontal stabilizer. This will provide a lot of control throw and a huge control surface area. We will use exponential on our JR PCM-10X. The three trim settings will allow us to have settings for low, high and 3D for each surface area.
Page 2 - more assembly notes.

 


Kit started 12/26/2003
Last Updated 1/1/2004

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