User Manual

❏ 2. With the wing attached to the fuselage, all parts
of the model installed (ready to fly) and an empty fuel tank, place the model upside-down on the CG Machine, or lift the model upside-down with your finger tips on the tape line.
❏ 3. When viewing the model from the side, the
horizontal stabilizer should be level. If the tail is low, the model is “tail heavy” and the battery pack and/or receiver must be shifted forward or weight must be added to the nose to balance. If the tail is high, the model is “nose heavy” and the battery pack and/or receiver must be shifted aft or weight must be added to the tail to balance. If additional weight is required, Great Planes (GPMQ4485) “stick-on” lead may be
added where necessary. If nose-weight is required attach it to the firewall (don’t attach weight to the cowl—it is not intended to support weight). If tail- weight is required it could be attached to the inside of the fuselage through the tail gear door opening. In either case, do not rely upon the adhesive on the back of the lead weight to permanently hold it in place. Over time, fuel and exhaust residue may soften the adhesive and cause the weight to fall off. Instead, use #2 sheet-metal screws, RTV silicone or epoxy to permanently hold the weight in place.
❏ 4. IMPORTANT: If you found it necessary to add
any weight, recheck the C.G. after the weight has been installed.
Balance the Model Laterally ❏ 1. With the wing level, have an assistant help you
lift the model by the engine propeller shaft and the bottom of the fuse under the TE of the fin. Do this several times.
❏ 2. If one wing always drops when you lift the
model, it means that side is heavy. Balance the airplane by adding weight to the other wing tip. Weight may be temporarily adhered to the bottom of the wing tip with the adhesive foam tape that comes with it, then permanently glued inside after doing the necessary in-flight checks to determine the exact amount of weight necessary. An airplane that has been laterally balanced will track better in loops and other maneuvers.
Check the Control Directions ❏ 1. Turn on the transmitter and receiver and center
the trims. If necessary, remove the servo arms from the servos and reposition them so they are centered. Reinstall the screws that hold on the servo arms.
❏ 2. Adjust the length of any pushrods necessary
and the pull/pull cables on the tail wheel by screwing
the clevises in or out. Securely tighten all the 4-40 jam nuts on the 4-40 pushrods to lock the clevises down. This would also be a good time to study the installation of all the systems to make sure everything is secure and connected properly (air lines, servo wires, receiver antenna, etc.).
❏ 3. Make certain all the controls respond in the
correct direction. If any of the controls respond in the wrong direction, use the servo reversing in the transmitter to reverse the servos connected to those controls. Be certain the control surfaces have remained centered. Adjust if necessary.
Set the Control Throws Use a Great Planes AccuThrow (or a ruler) to accurately measure and set the control throw of each control surface as indicated in the chart that follows. NOTE: The throws are measured at the widest part of the elevators, rudder ailerons and flaps.
This is where your model should balance for the first flights. Later, you may wish to experiment by shifting the C.G. up to 5/16" [8mm] forward or 5/16" [8mm] back to change the flying characteristics. Moving the C.G. forward may improve the smoothness and stability, but the model may then require more speed for takeoff and make it more difficult to slow for landing. Moving the C.G. aft makes the model more maneuverable, but could also cause it to become too difficult to control. In any case, start at the recommended balance point and do not at any time balance the model outside the specified range. Note: If flying the model at the forward C.G. location, you should land with the elevator throws (provided on page 40) set to the high rate. If the model is nose-heavy the low-rate throws may not provide enough control to flair upon landing.
- 39 -