make the blow target adjustable

blow a bit below layer printed to target the neighborhood instead of
the very nozzle

1 files changed, 5 insertions, 4 deletions

diff --git a/fanduct.scad b/fanduct.scad
index 7fc1ff4..f4bb705 100644
--- a/fanduct.scad
+++ b/fanduct.scad
@@ -1,22 +1,23 @@
 use <snapper.scad>;
 extrusion_width=.5; layer_height=.2;		// print parameters
 
 epsilon=.005;		// for finer cuts
 
 heater_w = 16;		// heatblock width
 heater_l = 20;		// heatblock length
 nozzle_offset=4.5;	// nozzle offset from the edge of heatblock
 
 fanduct_elevation = 3;							// fanduct elevation above nozzle tip
+fanduct_blowtarget = -2;						// what to blow at
 fanduct_h = 6;								// inner height of the duct
 fanduct_w = 7;								// inner width of the duct
 fanduct_shell=1.2;							// shell thickness
 fanduct_ir = sqrt(pow(heater_w/2,2)+pow(heater_l-nozzle_offset,2))+5;	// inner radius
 
 jet_angle = 60;		// angular width of the jet
 
 inlet_w = 12.5;		// inlet width
 inlet_h = 17;		// inlet height
 inlet_l = 7;		// inlet length of protrusion (or depth of intrusion:))
 inlet_away = 15;	// how far away inlet is
 
@@ -72,41 +73,41 @@ module fanduct(type=type) {
     cylinder(d=2*extrusion_width,h=2*fanduct_shell+inlet_h,$fn=6);
    }
    xyxyxy=concat(xyxy,[[0,0]]);
    for(i=[0:1:len(xyxyxy)-2])
     hull() for(j=[i,i+1]) pin(xyxyxy[j]);
   }
 
   module circus(what) {
    if(what=="in") {
     difference() {
      rotate_extrude($fn=smooth_f)
       polygon([
-       [0,-fanduct_elevation],
+       [0,-fanduct_elevation+fanduct_blowtarget+epsilon],
        [fanduct_ir+fanduct_shell,fanduct_shell+fanduct_h/2],
        [fanduct_ir+fanduct_shell+fanduct_w/2,0],
-       [0,-fanduct_elevation-.1]]);
+       [0,-fanduct_elevation+fanduct_blowtarget-epsilon]]);
      translate([0,0,-1])
      cylinder(r=hotend_clearance,h=fanduct_h+2*fanduct_shell+2,$fn=smooth_f);
      mirror([0,0,1])
      translate([0,0,-epsilon])
      cylinder(r=fanduct_ir+fanduct_shell+1,h=fanduct_elevation+.1+2);
     }
    }else if(what=="out") {
     rotate_extrude($fn=smooth_f)
     polygon([
-     [0,-fanduct_elevation],
+     [0,-fanduct_elevation+fanduct_blowtarget+epsilon],
      [fanduct_ir+fanduct_shell+1,fanduct_h/2],
      [fanduct_ir+fanduct_w/2+fanduct_shell+1,fanduct_shell],
-     [0,-fanduct_elevation-.1]]);
+     [0,-fanduct_elevation+fanduct_blowtarget-epsilon]]);
    }else if(what=="airguides") {
     inr = fanduct_ir+fanduct_shell; our = inr+fanduct_w;
     union() {
      for(my=[0,1]) mirror([0,my,0]) {
       guideline([
        [-our,inlet_w/6],
        [-inr*sin(60),inr*cos(60)]
       ]);
       a0=30; as=15; a1=180;
       for(a=[a0+as:as:a1]) {
        f = as/(a1-a+as);
        rotate([0,0,a]) guideline([[-inr-fanduct_w*f,0]]);