From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Tue, 15 Sep 2020 22:47:34 +0000 (+0100)
Subject: pin-hinge: wip
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=46fb2db6a0757b63f9eb0cd44956f69e5196be1e;p=reprap-play.git

pin-hinge: wip

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---

diff --git a/pin-hinge.scad b/pin-hinge.scad
index 9fa22de..bf9aa7b 100644
--- a/pin-hinge.scad
+++ b/pin-hinge.scad
@@ -3,6 +3,7 @@
 $hinge_pin_dia = 0.795 + 0.35;
 $hinge_main_dia = 4.0;
 $hinge_inter_gap = 0.50;
+$hinge_prong_minwidth = 3.5;
 $hinge_noncrit_gap = 1.0;
 
 $fa = 3;
@@ -13,14 +14,11 @@ module HingePinPlan(){
 }
 
 module HingeProngPlan(behind){
-  difference(){
-    hull(){
-      circle(r= $hinge_main_dia/2);
-      polygon([[0,0],
-	       [-$hinge_main_dia/2, -behind],
-	       [+$hinge_main_dia/2, -behind]]);
-    }
-    HingePinPlan();
+  hull(){
+    circle(r= $hinge_main_dia/2);
+    polygon([[0,0],
+	     [-$hinge_main_dia/2, -behind],
+	     [+$hinge_main_dia/2, -behind]]);
   }
 }
 
@@ -31,6 +29,26 @@ module HingeGapPlan() {
 module PlanDemo(){
   HingeProngPlan(5);
   %HingeGapPlan();
+  translate([0,0,1]) color("red") HingePinPlan();
+}
+
+module HingePositive(l){
+  linetr_x_yz(0, l)
+    HingeProngPlan();
+}  
+
+module HingeNegative(l){
+  eff_l = l + $hionge_inter_gap;
+  pairs = floor(eff_l / (2*($hinge_prong_minwidth + $hinge_inter_gap)));
+  stride = eff_l / pairs;
+  prong_width = stride/2 - $hinge_inter_gap;
+  linextr_x_ayz(-0.1, l+0.1)
+    HingePinPlan();
+  for (i=[0:pairs-1]) {
+    translate(stride * i * [1,0,0])
+      linextr_x_yz(0, prong_width + $hinge_inter_gap)
+      HingeGapPlan();
+  }
 }
 
 PlanDemo();