Jeremy
Well-Known Member
I'm trying to work around a elevon control linkage problem, one where I want to be able to rotate the wing for transport/storage without disconnecting the controls.
The obvious way around this is to use Teleflex cables, but they are still pretty stiff and quite heavy. The maximum control system forces are very low, around 100lbsf at the control horn.
It occurred to me that using hydraulic actuators might be an option, as these would allow a pretty simple installation. I'm not talking about a powered system, just something similar in principle to a hydraulic brake set-up, but with double acting cylinders.
The system pressure would be pretty low, most probably no more than 100 - 150psi at the very most, so I was sort of thinking about using lightweight pneumatic actuators operating with a suitable mineral oil. My guess is that I could build a light system this way, particularly if it were plumbed with lightweight Teflon hose, but I will admit straight off that I have absolutely no experience of hydraulics!
The advantages are primarily that the system could be really very simple, with actuator cylinders directly driving the elevons and the driven cylinders connected directly to the stick.
The potential disadvantages might be a small weight penalty plus my own uncertainty about such a systems reliability. Hydraulic brake systems seem to be extremely reliable, so perhaps my worries about reliability are unfounded - maybe it's just fear of using something unusual.
Does anyone know if this has been tried before? I've searched the archives here and not found a direct mention of such an idea.
Jeremy
The obvious way around this is to use Teleflex cables, but they are still pretty stiff and quite heavy. The maximum control system forces are very low, around 100lbsf at the control horn.
It occurred to me that using hydraulic actuators might be an option, as these would allow a pretty simple installation. I'm not talking about a powered system, just something similar in principle to a hydraulic brake set-up, but with double acting cylinders.
The system pressure would be pretty low, most probably no more than 100 - 150psi at the very most, so I was sort of thinking about using lightweight pneumatic actuators operating with a suitable mineral oil. My guess is that I could build a light system this way, particularly if it were plumbed with lightweight Teflon hose, but I will admit straight off that I have absolutely no experience of hydraulics!
The advantages are primarily that the system could be really very simple, with actuator cylinders directly driving the elevons and the driven cylinders connected directly to the stick.
The potential disadvantages might be a small weight penalty plus my own uncertainty about such a systems reliability. Hydraulic brake systems seem to be extremely reliable, so perhaps my worries about reliability are unfounded - maybe it's just fear of using something unusual.
Does anyone know if this has been tried before? I've searched the archives here and not found a direct mention of such an idea.
Jeremy