A lot more work on the Microcar design. I'm not yet at all satisfied with this.

microcar/shockabsorber.scad

@@ -0,0 +1,40 @@
+/**
+ * shockabsorber.scad
+ *
+ * First sketch of a microcar spring/shock absorber unit. Ideally I
+ * would want to use linked hydropneumatic units, but that would be
+ * *absurdly* over expensive for a one off prototype. Air or conventional
+ * spring units would be far more pragmatic.
+ */
+
+include <BOSL2/std.scad>
+
+eye_inner_diameter = 25/3; // to make it the same as pivot_radius defined
+                            // in suspension.scad
+
+module eye( eid=eye_inner_diameter) {
+    rotate([0, 90, 0]) {
+        difference() {
+            cylinder( h=eid, r=eid, center=true);
+            cylinder( h=2*eid, d=eid, center=true);
+        }
+    }
+}
+
+module shockabsorber( length=150, eid=eye_inner_diameter, coil_over=true) {
+    short_length=length-(eid*4);
+    
+    translate([0,0,eid]) {
+        // cylinder
+        cylinder(h=short_length/2, r=short_length/16);
+        // rod
+        cylinder(h=short_length, r=short_length/32);
+        
+        translate([0,0,0-eid]) {
+            eye(eid);
+        }
+        translate([0,0, short_length+eid]) {
+            eye(eid);
+        }
+    }
+}