Initial commit

.gitignore

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+PinionRimProtection.FCStd
+*.FCBak

PinionChainProtection.scad

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+/* Pinion chain protection */
+
+/* Gates rim parameter */
+DiameterFront=152;              /* mm */
+DiameterBack=109;               /* mm */
+CenterDistanceFrontBack=475;    /* mm */
+GateRimWidth=13;                /* mm */
+rimSpace=3;                     /* mm */
+
+/* Pinon parameter */
+pinionTop=106;      /* mm */
+pinionBottom=38;    /* mm */
+pinonHeight=98;     /* mm */
+pinionRotation=45;  /* degrees */
+pinionWith=50;      /* mm (dummy value, not used) */
+$fn=180;
+
+/* Bike Parameter */
+bikeRearHorizontal=48;
+bikeRearRotation=99;
+bikeRearOffset=70;
+
+module drawRim(dBack, dFront, width) {
+    hull() {
+        translate([CenterDistanceFrontBack/2, 0, 0]) cylinder(d=dFront, h = width, center = true);
+        translate([-CenterDistanceFrontBack/2, 0, 0]) cylinder(d=dBack, h = width, center = true);
+    }
+}
+
+difference() {
+    drawRim(dBack=DiameterBack+rimSpace*2, 
+            dFront=DiameterFront+rimSpace*2,
+            width=GateRimWidth+rimSpace*2);
+    union() {
+        translate([0,0, rimSpace/2]) drawRim(dBack=DiameterBack, 
+            dFront=DiameterFront,
+            width=GateRimWidth+rimSpace*2);
+        translate([CenterDistanceFrontBack/2, 0, 0]) rotate([0, 0, pinionRotation])    translate([pinionBottom, 0, 0]) cube([pinionTop+pinionBottom, pinonHeight, pinionWith], center=true);
+    translate([bikeRearOffset, 0, 0]) rotate([0, bikeRearRotation, 0]) cylinder(d=bikeRearHorizontal, h=CenterDistanceFrontBack, center=true);
+        
+    }
+}