In an earlier post, I mentioned that I was installing heat tees that had movable flaps inside them to allow me to send heat to one side of the plane, the other, or both. Well, tonight, I figured out how I was going to control that flap and do the actual install.
Just like the Aerosport Naca valve, I’m using standard RC servos. They will all be controlled with whatever Arduino solution I come up with. That comes later. For now, we’re just getting them bolted into the plane.
Basically, I made little brackets out of some aluminum U channel that allowed hold the servo tightly, and that bracket in turn gets attached to the heat tees with hose clamps. I then made up some pushrods with z-bends in them to attach the servo horn to the valve control arm. I got fancy and used some silicone fuel line to keep the pushrod tight in the large hole of the valve control arm, but it’s probably not needed.
It’s simple, and I think it’s going to work well. The only concern I have is that these tee’s get very hot when in use, and I’m not sure how well the servos will hold up. In the worst case scenario, the servos keep failing due to heat, and I’ll have to come up with a new mounting position with the servo farther away. With a little work, these tees will all be accessible after the plane is complete.
Some video of the the valves in action, both on the bench and in the plane:
And the timelapse to finish things off: