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]]);