I just bought a 3 channel radio on E-bay and thought I might put jib trim in the next boat. How big should the servo be? Is there some clever linkage so I can use a standard servo?
Thanks
Don
Don:
Jib trimmer is fairly straight forward. You can use a standard servo such as Futaba 2004. Just rig a “gun tackle” to the jib sheet using a small block such as PeKaBe 512. This seems to work best when there is a turning block mounted directly below the jib sheet deck fairlead.Instal the gun tackle block on the jib sheet,in the space between the turning block and the fairlead. Make one end of the trimmer line fast in the hull someplace. Reave the line through the gun tackle block and then to the servo arm.
More than a few sailors rig it the other way. That is with the trimmer attached to the main. Their argument is that the boat sails mostly on the jib when going to weather. Then they can trim the main independantly for best performance. Mechanism details are the same.
When you get a 4 channel radio you can add another servo to use for a “twitcher”. This is a servo mechanism that gives the jib sheet a little jerk when you are sailing directly down wind and wish to flip the jib over to wing and wing position. Depending on specific wind direction, sometimes the jib does not naturally set itself in wing attitude. Twitchers are helpful when in fierce competition on free legs.