I've been researching ways to have hidden control linkages. The Fulcrum linkage concept has been used by some of the jet guys. Obviously this type of setup will not give you very large surface throws that the 3D designs require.
If anyone is a physics whiz on this geometry set-up and can point out
the pros and cons that would be great... Mith... I'm calling you out!
There are a lot of competing issues with this linkage.
1) It is desireable to have a long linkage so there is a lot of overlap between the rod and the tube. If the overlap is short, then slop in diameter difference between the rod and tube result in control surface slop.
2) A short linkage is desired so that you can even get modest control surface deflections.
3) Vibration will erode the performance of this linkage as it will wear. Even if lubricated, in our deseret environment, the lube simply attracts dirt and creates lapping compound.
If I needed a subcutaneous linkage that was very tight, I would go with a Pull-Pull with Kevlar twine and a pully on the servo.
If I were to utilize this type of linkage, I would not be using a sliding aluminum tube over a carbo rod, but rather use a ball bearing in a slot in an aluminum arm, like the anal guy with the SU29 from Germany did on his flaps.
With these linkages it appears that the power and holding power get greater as the surface moves away from center, and there is a sort of "built in" exponential to the throw as well.
If I were to utilize this type of linkage, I would not be using a sliding aluminum tube over a carbo rod, but rather use a ball bearing in a slot in an aluminum arm, like the anal guy with the SU29 from Germany did on his flaps.
With these linkages it appears that the power and holding power get greater as the surface moves away from center, and there is a sort of "built in" exponential to the throw as well.
Indeed.. but it is a sort of "Anti-Expo"... very touchy around neutral... very "Numb" near the extreme throws.
Fulcrum Linkage?
Linear Mode
