Hi all,
Instead of using the standard Bowden cable to open and close the heat box valve, I have been daydreaming about cobbling together an automotive-style rotary heat valve control knob... similar to the example shown in this photo of a Cirrus panel.
Problem is, I have no idea how Cirrus does this. It would be super easy to whip up a circuit to drive a hefty RC airplane servo based on a potentiometer position, but I am reluctant to go with an all-electric solution (what do you if there's a fire and you can't close the hole in the firewall because your little servo is melted or without power?). I know in automobiles they typically use vacuum for this application, but that's obviously out in my all-electric airplane. It seems like there ought to be somebody out there who makes a purely manual rotary-to-linear mechanism, but an evening of googling has not turned one up. I suppose that with enough effort I could throw together some kind of rack-and-pinion thingy, but I'm hoping that one already exists for me to just buy. Anybody have any ideas?
thanks,
mcb
Instead of using the standard Bowden cable to open and close the heat box valve, I have been daydreaming about cobbling together an automotive-style rotary heat valve control knob... similar to the example shown in this photo of a Cirrus panel.
Problem is, I have no idea how Cirrus does this. It would be super easy to whip up a circuit to drive a hefty RC airplane servo based on a potentiometer position, but I am reluctant to go with an all-electric solution (what do you if there's a fire and you can't close the hole in the firewall because your little servo is melted or without power?). I know in automobiles they typically use vacuum for this application, but that's obviously out in my all-electric airplane. It seems like there ought to be somebody out there who makes a purely manual rotary-to-linear mechanism, but an evening of googling has not turned one up. I suppose that with enough effort I could throw together some kind of rack-and-pinion thingy, but I'm hoping that one already exists for me to just buy. Anybody have any ideas?
thanks,
mcb