// -*- C -*- module FArcSegment_mask(beta) { for (i=[0 : 0.75 : 3]) { rotate(i*beta/4) polygon([[0, 0], [1, 0], [cos(beta/4), sin(beta/4)]]); } } module FArcSegment(xc,yc,inrad,outrad,alpha,delta) { translate([xc,yc]) { intersection() { difference() { circle(r=outrad); circle(r=inrad); } rotate(alpha) scale(outrad*2) { FArcSegment_mask(delta); } } } } tubeheight = 30; tubewidth = 15; mainthick = 4; clipthick = 2; clipang = 120; bend = 5; tuberad = tubewidth/2; mainoutrad = tuberad + mainthick; module Plan(){ dy = tubeheight - tuberad*2; FArcSegment(0, dy, tuberad, mainoutrad, -1, 181); FArcSegment(0, 0, tuberad, mainoutrad, -bend, bend+1); translate([tuberad, 0]) square(center=false, size=[mainthick,dy]); FArcSegment(0, 0, tuberad, tuberad + clipthick, 360-clipang, clipang+1); } Plan(); //FArcSegment(0, 20, 20,30, 20,160);