X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=reprap-play.git;a=blobdiff_plain;f=pawn.scad;h=6f1bf992d1135d329acca796f8c01718a6cde050;hp=805c5f383127e92d767566ebb988e77b94c855ef;hb=e94b783e6ed98e7922daa8c4c3025c9c8f42be63;hpb=10f8e0629cc165bcc0224695239a5ceaea9d20c2;ds=sidebyside

diff --git a/pawn.scad b/pawn.scad
index 805c5f3..6f1bf99 100644
--- a/pawn.scad
+++ b/pawn.scad
@@ -2,56 +2,78 @@
 
 // shape parameters
 
-r1 =  3;
-r2 =  6; a2 = 30;
+r1 =  2.85;
+r2 =  4; a2 = 27;
 r3 = r2;
-r4 =  8; a4 = 30;
-r5 = 12;
-h6 =  5; a6 = 5;
+r4 =  4; a4 = 18;
+r5 = 30;
+h6 = 7; a6 = 4;
 
 // coordinates
 
-                       z1 =  0;
-h2 = r2 * sin(a2);     z2 = z1 - h2;
-h3 = r3 * sin(a2);     z3 = z2 - h3;
-h4 = r4 * sin(a4);     z4 = z3 - h4;
-h5 = r5 * sin(a4-a6);  z5 = z4 - h5;
-                       z6 = z5 - h6;
+                                z1 =  0;
+h2 = r2 * sin(a2);              z2 = z1 - h2;
+h3 = r3 * sin(a2);              z3 = z2 - h3;
+h4 = r4 * sin(a4);              z4 = z3 - h4;
+
+zc5 = z4 - r5 * sin(a4);
+z5 = zc5 + r5 * sin(a6);        z6 = z5 - h6;
 
 x1 =  0 - r1;
 x2 = x1 + r2 * (1-cos(a2));
 x3 = x2 + r3 * (1-cos(a2));
 x4 = x3 - r4 * (1-cos(a4));
-x5 = x4 - r5 * (1-cos(a4-a6));
+
+xc5 = x4 + r5 * cos(a4);
+x5 = xc5 - r5 * cos(a6);
+
 x6 = x5 - h6 * tan(a6);
 
+htotal = r1 - z6;
+echo("height", htotal);
+
+d = 0.01;
+
 $fa=1;
 $fs=0.1;
 
+module SegmentBasisSquare(zmin, zmax, xmin){
+  translate([xmin, zmin-d]) square([-xmin+d, zmax-zmin+d*2]);
+}
 module ConvexSegment(xc, zc, r, zmin, zmax){
   intersection(){
     translate([xc,zc]) circle(r=r);
-    translate([-50,zmin-0.01]) square([55,zmax-zmin+0.02]);
+    SegmentBasisSquare(zmin,zmax,-50);
+  }
+}
+module ConcaveSegment(xc, zc, r, zmin, zmax){
+  difference(){
+    SegmentBasisSquare(zmin,zmax, xc);
+    translate([xc,zc]) circle(r=r);
   }
 }
 
 module PawnTemplate(){
-  intersection(){
-    union(){
-      ConvexSegment(x1 + r1, z1, r1, z1, 50);
-      ConvexSegment(x1 + r2, z1, r2, z2, z1);
-      translate([x5 + r5 * cos(a6), z5]) circle(r=r5);
-      polygon([[x6,z6-1],
-	       [x5,z5],
-	       [1,z5],
-	       [1,z6-1]]);
-      difference(){
-	translate([-50,z4]) square([52,z2-z4]);
-//	circle(
+  ConvexSegment(  x1 + r1,  z1,   r1, z1, 50);
+  ConvexSegment(  x1 + r2,  z1,   r2, z2, z1);
+  ConcaveSegment( x3 - r3,  z3,   r3, z3, z2);
+  ConcaveSegment( x3 - r4,  z3,   r4, z4, z3);
+  ConvexSegment(  xc5,      zc5,  r5, z5, z4);
+  polygon([[x6, z6],
+	   [x5, z5+d],
+	   [d, z5+d],
+	   [d, z6]]);
+}
+
+module Pawn(h=htotal){
+  scale(h/htotal) {
+    rotate_extrude(convexity=10, $fn=50){
+      assign($fn=undef){
+	PawnTemplate();
       }
     }
-    translate([-100,z6]) square([100.1, 200]);
   }
 }
 
-PawnTemplate();
+Pawn(h=20);
+//PawnTemplate();