I've got a Skeeter HLG I've *just* finished, that's ready to go in the air. All I lack is a V-tail mixer (yeah, I couldn't let well enough alone, and I built her as a vtail) Can't seem to find any electronic mixers in town- surely it's got to be a simple circuit?

From : Don Stackhouse

Watt Age sells one through Hobby People that's only 5 grams and not very expensive (about $20 or $30).

It's not difficult to make a mechanical mixer for a fuselage layout like the Skeeter's. Just mount the rudder servo on rails so the elevator servo can slide it back and forth, then connect both ruddervator pushrods to opposite arms of the rudder servo. The elevator servo will move the rudder servo and both pushrods in the same direction for pitch inputs, and the rudder servo will move the pushrods in opposite directions for rudder commands.

An easy way to make rails is to mount two parallel pieces of that small yellow nylon tubing that comes with the lightweight Sullivan pushrods to the side of the rudder servo (or mount the tubing to a small square of thin plywood, then mount the rudder servo to the plywood). Make the rails from thin music wire (anything from .020" to .032" dia. and about 2" long each should work fine). Put a small Z-bend in the ends of the rails to space them out from the fuselage side a little, or use a small plywood shim (this is so the yellow nylon tubes won't rub and bind on the fuselage side) and use slow C/A or epoxy to glue the tips of the rails to the fuselage sides. Couple the elevator pushrod to the rudder servo's case, and the ruddervator pushrods to the rudder servo and you're all done!

Alternatively, Du-bro makes a mechanical v-tail mixer taht works well: http://www.dubro.com/

Don Stackhouse
DJ Aerotech