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Started work on microcar suspension

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This commit is contained in:
Simon Brooke 2026-09-01 20:59:01 +01:00
parent be42bd388f
commit 66e772172b
2 changed files with 139 additions and 10 deletions
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109
microcar/suspension.scad Normal file
View file

@ -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();

40
microcar/tub.scad
View file

@ -11,7 +11,11 @@ bb_width = 260; // internal width of battery box
* moment I'm making the simlifying assumption that it
* is horizontal.
****************************************************/
cowl_height = 550;
// slope of the cowl
cowl_angle = -70;
// maximum height of the cowl (at the A pillar)
cowl_height = 450;
floor_length = 1100;
floor_width = 1500;
@ -21,8 +25,10 @@ floor_width = 1500;
* which bonds to the front or rear bulkhead from the
* layback angles, but I'm being lazy for now
****************************************************/
layback_angle_f = 60;
layback_angle_r = 60;
// angle of the front bulkhead to vertical
layback_angle_f = 30;
// angle of the rear bulkhead to vertical
layback_angle_r = 45;
sheet_thickness = 8;
sill_max_height = bb_height;
@ -31,27 +37,31 @@ sill_width = 150;
module battery_box_side( floor_length = 1100) {
fhl = (floor_length/2);
top_hl = 800; // calculate this later
top_hlf = (bb_height * tan(layback_angle_f)) + fhl;
top_hlr = (bb_height * tan(layback_angle_r)) + fhl;
rotate([90, 0 , 0])
linear_extrude( height=sheet_thickness) {
polygon([[ 0 - fhl, 0],
[ fhl, 0],
[ top_hl, bb_height],
[ 0 - top_hl, bb_height]]);
[ top_hlr, bb_height],
[ 0 - top_hlf, bb_height]]);
}
}
module battery_box( floor_length = 1100) {
top_hl = 800; // calculate this later
hbbw = bb_width/2;
bias = (layback_angle_f == layback_angle_r) ? 0 : bb_height * ( tan(layback_angle_r) - tan(layback_angle_f))/2;
translate([0, hbbw, 0])
battery_box_side( floor_length);
translate([0, 0 - (hbbw + sheet_thickness), 0])
battery_box_side( floor_length);
translate([0, 0 - hbbw, 0])
cube([sheet_thickness, bb_width, bb_height]);
translate([0, 0 - sheet_thickness, bb_height])
cube([1600, bb_width + (sheet_thickness * 2),
translate([bias, 0 - sheet_thickness, bb_height])
cube([floor_length + (bb_height * tan(layback_angle_f)) +
(bb_height * tan(layback_angle_r)), bb_width + (sheet_thickness * 2),
sheet_thickness],
center = true);
}
@ -59,13 +69,14 @@ module battery_box( floor_length = 1100) {
module sill( floor_length = 1100) {
cr = 5000;
fhl = (floor_length/2);
top_hl = 800; // calculate this later
top_hl = fhl + (cowl_height * tan(layback_angle_f));
top_hlr = fhl + (sill_max_height * tan(layback_angle_r));
difference() {
rotate([90, 0 , 0])
linear_extrude( height=sill_width) {
polygon([[ 0 - fhl, 0],
[ fhl, 0],
[ top_hl, sill_max_height],
[ top_hlr, sill_max_height],
[ 0, sill_min_height],
[ a_pillar_y, sill_min_height],
[ a_pillar_y, cowl_height],
@ -79,6 +90,14 @@ module sill( floor_length = 1100) {
}
module front_bulkhead() {
e = cowl_height / cos(layback_angle_f);
translate([ 0 - floor_length/2, 0 -floor_width/2, 0])
rotate([0, 0- layback_angle_f, 0])
cube([sheet_thickness, floor_width, e]);
}
module rear_bulkhead() {
}
@ -94,3 +113,4 @@ mirror([0, 1, 0])
( floor_width/2) + (sill_width/2), 0])
sill();
front_bulkhead();