$fn = 200;

d1 = 5; // schraubendicke
d2 = 25; // aussendurchmesser
d4 = 8;
dicke = 8;

difference(){
    scale([d2, d2, 1])
    scale([0.025, 0.025, 1])
    difference(){
        cylinder(dicke*2, 40, 40); 
        for ( i = [1 : 7] ){ 
        
            translate([0,0,-1])     
        
            rotate([0,0,45*i-90])
        
            linear_extrude(30)
        
            hull(){
                translate([0,14,0])circle(r=3);
                translate([0,28,0])circle(r=7);
                }
    }
}

translate([0,0,-1])cylinder(dicke*2+2, d1, d1); // loch mitte
translate([d2-d4*0.5,0,3])cylinder(dicke*2, d4, d4);
// anfasen
translate([d2-d4*0.5+3+4.5, 2,dicke]) cylinder(dicke*2, d4+1, d4+1);
translate([d2-d4*0.5+3+4.5,-2,dicke]) cylinder(dicke*2, d4+1, d4+1);

for ( i = [1 : 0.1 :10.5] ){
    translate([d2-d4*0.5-0.3*i,0,3]) 
    cylinder(dicke*2, d4, d4);
}

};




difference(){
    union(){
        //color("red");
        //cylinder(dicke*2, d2, d2); 
        translate([d2-d4*0.5,0,0])
        cylinder(dicke, d4+3, d4+3);
    }
    translate([d2-d4*0.5,0,3]) 
    cylinder(dicke*2, d4, d4);
for ( i = [1 : 0.1 :10.5] ){
    translate([d2-d4*0.5-0.3*i,0,3]) 
    cylinder(dicke*2, d4, d4);
}


}