// rudder.   Tried soldering 3mm steel threaded bar to copper plate, but wouldnt
// stick. Presumably needs silver solder or brass 3mm bar.

// brass bar has been ordered, but try printing something rudder shaped

// On the open water the 20mm high and 20mm long just wasn't enough, very
// little positive control. Doesn't help that the throw is +-25 degrees.

frontlen=5;
backlen=35;

height=30;

tipwidth=0.5;

// 3.8 vs 2.2 was all too small, by the time it was drilled out to 2.5mm, a side

// was splitting. Also, when on model, 20mm of height is too small.

midwidth=4.5;  // must be enough to print continuously when sliced
bardia=2.6;  // though this can be reduced and then drilled out to achieve the same

$fn=1000;

difference()
 {
hull()
 {
    translate([frontlen,0,0])
       cylinder(height,tipwidth/2,tipwidth/2);
 
    translate([-backlen,0,0]) 
        cylinder(height,tipwidth/2,tipwidth/2);

   cylinder(height,midwidth/2,midwidth/2);
 }

translate([0,0,-1])
   cylinder(height+2,bardia/2,bardia/2);
}