Now with steering arms at approximately correct ackerman angle.

microcar/microcar.scad

@@ -9,12 +9,16 @@ include <BOSL2/std.scad>
 include <suspension.scad>
 include <tub.scad>
 
+wheelbase = 2000;
+track = 1400;
+
+ackerman = 90 + atan( wheelbase/( track / 2) );
 
 tub(fl=1100);
 
 translate([-900,0,130])
-    suspension();
+    suspension(aa = ackerman);
 
 translate([1100,0,130])
-    suspension(cst=0);
+    suspension(aa = 0, cst=0);
 

microcar/suspension.scad

@@ -30,7 +30,7 @@ caster_angle = 7;
 // TODO: should be calculated from hub width and wheel radius?
 camber_angle = 10;
 
-module kingpin( h = 300, r = 12.5, 
+module kingpin( aa=0, h = 300, r = 12.5, 
         cmb = camber_angle, cst = caster_angle, 
         al = 100) {
     kl = h * (1/cos(90 - cmb)) * (1/cos(90 - cst));
@@ -44,17 +44,22 @@ module kingpin( h = 300, r = 12.5,
     camber_offset = aof/tan(90-cmb);
     caster_offset = 0 - aof/tan(90-cst);
         
-            
+    // axle itself
     translate([caster_offset, al + camber_offset, 0-aof])
-    rotate([ 90, 0, 0])
-        cylinder( h=al, r=r);
+        rotate([ 90, 0, 0])
+            cylinder( h=al, r=r);
+            
+    // steering arm
+    translate([caster_offset, camber_offset, 0-aof])
+        rotate([ aa, -90, 0])
+            cylinder( h=al, d=r);
             
     translate([caster_offset, al, 0-aof])
-        wheel();
-
-    
+        wheel();    
 }
 
+// kingpin();
+// TODO: still need steering rack and track rods.
  
 module lug() {
     difference() {
@@ -145,7 +150,7 @@ module wishbone(l, w, skew = 0, is_upper = true) {
      }
  }
  
-module suspension( l = 300, w = 300, h = 300,
+module suspension( aa = 7, l = 300, w = 300, h = 300,
         track = 1400, hub_width = 135, wheel_diameter=600, 
         cmb=camber_angle, cst=caster_angle) {
     subframe(l,w,h);
@@ -187,11 +192,11 @@ module suspension( l = 300, w = 300, h = 300,
     
     translate([caster_offset/2, 
         wishbone_length + (stock_section * 4), 0])
-        kingpin(cst=cst);
+        kingpin(aa=aa, cst=cst);
     mirror([0,1, 0]) 
         translate([caster_offset/2, 
             wishbone_length + (stock_section * 4), 0])
-            kingpin(cst=cst);
+            kingpin(aa=aa, cst=cst);
 }
  
-  
+// suspesion()

microcar/tub.scad

@@ -12,6 +12,7 @@ a_pillar_y = -400;  // y location of face of 'A' pillar
 bb_height = 274;    // internal height of battery box
 bb_width = 260;     // internal width of battery box
 
+
 /*****************************************************
  * the 'cowl' is the near-horizontal panel which the
  * bottom of the windscreen is mounted to. In practice
@@ -20,8 +21,8 @@ bb_width = 260;     // internal width of battery box
  * is horizontal.
  ****************************************************/
 
-// slope of the cowl
-cowl_angle = -70;
+// slope of the cowl to horizontal
+cowl_angle = 20;
 // maximum height of the cowl (at the A pillar)
 cowl_height = 450;  
 
@@ -43,6 +44,10 @@ sill_max_height = bb_height;
 sill_min_height = 125;
 sill_width = 150;
 
+// As nearly as I can measure it, the windscreen angle
+// of the Citroen C1 is 23.8° to horizontal.
+windscreen_angle = 24;
+
 module battery_box_side( floor_length = 1100) {
     fhl = (floor_length/2);
     top_hlf = (bb_height * tan(layback_angle_f)) + fhl;