Started work on microcar suspension

2026-09-01 20:59:01 +01:00 · 2026-09-01 20:59:01 +01:00 · 66e772172b
commit 66e772172b
parent be42bd388f
2 changed files with 139 additions and 10 deletions
--- a/microcar/suspension.scad
+++ b/microcar/suspension.scad
@ -0,0 +1,109 @@
+/**
+ * suspension.scad
+ *
+ * First sketch of a microcar suspension subframe.
+ *
+ * The purpose of the subframe is sumply to carry the inner ends of the
+ * wishbones, so it is simply the minimum size required to do that.
+ */
+ 
+ // assumes we're building out of square section aluminium tobe;
+ // the section width of that tube.
+ stock_section = 25;
+ 
+ lug_thickness = stock_section/6;
+ 
+ // radius of suspension pivots
+ pivot_radius = stock_section/3; //for now
+ 
+ module lug() {
+    difference() {
+         union() {
+             translate([0, stock_section/2, 0]){
+                cube([ stock_section, stock_section, lug_thickness], center=true);
+             }
+             
+             cylinder( r=stock_section/2, h=stock_section/4, center=true);
+                 
+         }
+         cylinder( r=pivot_radius, h=stock_section, center=true);
+     }
+}
+ 
+ module wishbone(l, w) {
+     ssd2 = stock_section/2;
+     ssm2 = stock_section * 2;
+     ssm3 = stock_section * 3;
+     
+     translate([ (l - lug_thickness)/2, stock_section, ssd2])
+         rotate([180,90,0])
+            lug();
+     translate([ 0 - (l - lug_thickness)/2, stock_section, ssd2])
+         rotate([180,90,0])
+            lug();
+     
+     color("silver")
+     union() {
+         intersection(){
+             linear_extrude(stock_section)
+                polygon( points=[[0-(l/2), ssd2], [l/2, ssd2],
+                        [3*ssd2, w-(3*ssd2)], [0-(3*ssd2), w-(3*ssd2)],
+                        // hole in the middle
+                        [0-(l/2 - 3*ssd2), 3*ssd2],
+                        [l/2 - 3*ssd2, 3*ssd2],
+                        [ssd2, w-(5*ssd2)], [0-ssd2, w-(5*ssd2)]], 
+                    paths=[[0, 1, 2, 3], [4, 5, 6, 7]]);
+            translate([0 - (l - ssd2)/2, 0, 0 - stock_section])
+                cube([l-ssd2, w, ssm3]);
+         }
+         translate([-3*ssd2, w-3*ssd2, 0])
+            cube( [stock_section, 3*ssd2, stock_section]);
+         translate([ssd2, w-3*ssd2, 0])
+            cube( [stock_section, 3*ssd2, stock_section]);
+    };
+    color("darkgray")
+    translate([0, stock_section, ssd2])
+        rotate([0, 90, 0])
+            cylinder(h=l, r=pivot_radius, center=true);
+    color("darkgray")    
+    translate([0, w - ssd2, ssd2])
+        rotate([0, 90, 0])
+            cylinder(h=ssm3, r=pivot_radius, center=true);
+    
+}
+ 
+ module subframe(l, w, h) {
+     q = stock_section * 2;
+     color( "silver")
+     difference() {
+         cube([l,w,h], center=true);
+         cube([l+200, w-q, h-q], center=true);
+         cube([l-q, w+200, h-q], center=true);
+         cube([l-q, w-q, h+200], center=true);
+     }
+ }
+ 
+ module suspension( l = 300, w = 300, h = 300,
+        track = 1400, hub_width = 135, wheel_diameter=600) {
+     subframe(l,w,h);
+     
+     // Upper wishbones
+     translate([0, w/2, (h/2) - stock_section])
+        wishbone( l, 500);
+     mirror([0,1, 0]) {
+         translate([0, w/2, (h/2) - stock_section])
+            wishbone( l, 500);
+     }
+
+      // lower wishbones
+     translate([0, w/2, 0 -(h/2)])
+        wishbone( l, 500);
+     mirror([0,1, 0]) {
+         translate([0, w/2, 0 -(h/2)])
+            wishbone( l, 500);
+     }
+ }
+ 
+ lug();
+ 
+suspension();