include <BOSL2/std.scad>

t=3;
d = 50;
h = 50;
conn = 5;
tr = 3; // trytytka szer
tr_d = 0.5;

$fn = 360;

difference() {
    torus(d_maj=d, d_min=t);
    back(d + conn/2)cuboid([2*d,2*d,2*d]);
    left(d/2) union() {
        up(conn/2) cuboid([conn,conn,conn]);
        xrot(90) tube(h=tr, id=t-tr_d, wall=t, rounding=0.3);
    }
    right(d/2) union() {
        down(conn/2) cuboid([conn,conn,conn]);
        xrot(90) tube(h=tr, id=t-tr_d, wall=t, rounding=0.3);
    }

}
for(i = [0:1] ) {
    zrot(90*i + 45) left(d/2) up(h/2) cyl(h=h, d=t);
}