I'm thinking of doing a simple sheet 1/2a model that will have a V tail. I got to thinking about the elevator linkage and it has me a little perplexed. What is the easiest way to it or do you usually just hook up one of the elevators.    I hate to re-invent the wheel.


John

I built a Stealth fighter that had severely swept-forward elevators--I soldered a horiz. "tee" wire on the end of the pushrod, maybe 2" long (1" ea. side of course); then put each end through its respective elevator horn.  Leave plenty of length on the "tee" for the horns to slide up and down it as the elevators move.  It worked well but you have to trust your soldering skills. Also needs a guide to keep the pushrod centered. And you may need to do some carving on surrounding structure to clear the "tee". Sounds more complicated than it is.

The most "elegant" method would be to use "Lucky Boxes".  However, your tail surfaces should probably be at least 3/16" to 1/4" thick to do that.   That is where there is a single horn with the bent ends operating freely in "boxes" inside each elevator.  Some care and planning need to be excercised so that the horn hinge line is in the correct position relative to the two elevators.  Also, if a profile fuselage is used, the resulting installation might not look too neat.

If you want both elevators to operate, the next best solution would be to use separate horns on each elevator and then run separate pushrods to each horn from the single takeoff from the bellcrank.  There will be some "flex" between on elevator to the other, but unless this is to be used as a fairly serious stunt ship, the flex will be of little consequence.

The overall simplest way to do this is just to use one elevator.  If this is just to be a sport flier and basically flying straight and level and making only minor corrections for landing, the single elevator idea will work just fine.  However, if you try to do more than just maintain level flight, the single elevator on that V-tail will result in some undesirable coupled yaw and roll tendencies.  If the elevator control is only on the right elevator, up control will tend to roll the airplane to the right (OK for counter clockwise flight) and will yaw the nose to the left (not so good for counter clockwise flight); while down elevator would result in the opposite roll and yaw.  If the elevator control is only on the left elevator, up elevator will result in a roll force to the left (not so good for clockwise flight) and a yaw force to the right (better for line tension): while down elevator would result in the opposite roll and yaw.  Again, if planned control input is minor, these roll and yaw forces will be negligible.  If, on the other hand you contemplate some form of wingovers or loops or figure eights, these forces will tend to create some unfavorable albeit "interesting" control responses.

Neat idea with a neat looking airplane that has received little attention in the model world.

Keith