Radio Technique
OWNERS of MRC772 systems will find a bunch of useful ideas in figures 1 and 2. The positions of the sticks in Fig. 1 tell the story. Observe the right-hand stick: Normally it moves left/right across the case. In this case, the stick assembly has been removed, rotated 90º clockwise, and reinstalled (a simple matter of removing and replacing four screws). The stick has also been freed to move in two directions, hence its position in the corner of the opening. Notice the left-hand stick: Normally it moves only up/down relative to the case. It, too has been removed, rotated 90º and reinstalled. Note also that the left-hand stick is deflected full right, even though no finger is touching it. Fig. 2 gives the secret away. A pair of clevises, some Nyrod inner tubing, a couple of pieces of bent wire and some scraps of wood and epoxy have coupled the two sticks mechanically, converting the system to normal two-axis operation at very little cost. If you have one of these systems, and the photos tell you all you need to know to make a similar mod, then go to it with our blessings. If not, better leave it alone.
Radio Technique . . .
"Servo-reversing" is the term we will use to describe any method that can be used to change the direction of motion of a control surface (e.g. the elevator) with respect to a given motion of the control stick on the transmitter. Servo-reversing can be introduced at several points in the link from your hand to the control surface, to wit: (1) At the control stick, (2) Inside the transmitter electronic package, (3) Inside the receiver electronic package, (4) Between the receiver and the servo, (5) Inside the servo electronic package, (6) At the servo/pushrod interface, and (7) At the control surface.
Radio Technique
EACH week I receive two or three nice letters from readers. Some of them ask questions that become the nucleus of a column. Here is a letter from Tom Waller of the Blue Angels R/C Club which asks a question that seems to be making the rounds: ". . . I'm building a Sig-designed Piper J-3 Cub. By that I mean I'm using the plans from the kit, but otherwise it's scratch-built. Since it has a 72-in. wing span I want to install individual aileron servos out in each wing. This may allow induction of stray RF currents in the long (almost 24 inches in each wing panel) servo leads. I've read somewhere that to prevent it one should use choke coils in the leads. OK! But what size and how many? If so, where? In all three wires? At the servo end or the receiver end?
Radio Technique
WHAT'S NEW? The big event in the dreary passage from Christmas to Spring here in the Northeast, is the Eastern States R/C Jamboree, better known as the
Radio Technique
AS A practical matter, FAA is to model aviation as FCC is to CB radio. Therefore, they would prefer to control AMA while AMA controls model aviation. There is ample precedent for this in the FAA/EAA relationship. For those who don't know, the EAA (Experimental Aviation Association-people who build man-carrying aircraft from kits, or from scratch) works to keep the FAA from FARing the homebuilder out of the skies. Part of its action is to teach correct principles. Another part of its activity is a certification of plans and kits for suitability. This is just beginning, but it is a reaction to man-killing failures of design and materials. I have personal knowledge of only a few instances of model airplanes killing or maiming anyone. Most that I know of concerned U-control models that either struck someone, or that came in contact with a high-voltage electric line and electrocuted the pilot. RC pilots have been very fortunate so far. I've never heard any substantiated tale of death, and the injuries have been extremely rare. Professor Sabin's column "You and the Law" in RCM related one of the very few cases of personal injury. But that doesn't mean there is no danger.
