Trying to find some way of gettin the ramp on my hovercraft to go up and down using a sail servo but i dont have much room for the mechanics and i would like to do it dicretly as possible any tips see http://www.flickr.com/photos/19759955@N07/2639335303/ for setup

Tim,

One thought would be to use a pnuematic cylinder much like the airplane guys use for retracts (Robarts) and power it that way.

Pete

how about this,,,,thread a piece of 4-40 rod into the screw hole in the sail servo and discard the horn/arm. glue the rod into place making sure not to get any glue in the servo itself. then thread a sleeve nut onto the rod 4-40 nut about an inch long. support the other end of the rod in a bearing or piece of brass tubing. the sleeve nut will need an arm across its width so it doesnt spin witht the rod. attach the ramp line to the arm on the sleeve nut and when your servo is activated it will rotate the rod which will spin inside the sleeve nut,since the arm wont allow the sleeve nut to rotate the nut will move up or down the length of the rod pulling the line,,,let me know if this sounds any good. this method only requires enough space for the servo and the thickness of what ever arm you use. the arm can be mounted in whatever position you need to accomidate the shape of the hull. thomas @ rmdesignworks

thomas

your method works real well!! i used it for a 1/14 king hauler tow truck
boom and the telascopeing part of the boom. up and down and in and out
smooth as butter

altough it seems to be taking the easy way out i have decided not to do this anymore after talking to the origonal pilot he told me the ramp was only operated by a hand winch for those interested this is the progress so far