From 5d5649ab487a5c2a29b5b26cbbdc387c3123950b Mon Sep 17 00:00:00 2001
From: Simon Brooke <simon@journeyman.cc>
Date: Fri, 5 Sep 2025 12:31:41 +0100
Subject: [PATCH] Added a model of an epicyclic.

---
 model/epicyclic.scad | 53 ++++++++++++++++++++++++++++++++++++++++++++
 model/fourbar.scad   |  3 +++
 model/subframe.scad  |  9 ++++++++
 3 files changed, 65 insertions(+)
 create mode 100644 model/epicyclic.scad

diff --git a/model/epicyclic.scad b/model/epicyclic.scad
new file mode 100644
index 0000000..7d96857
--- /dev/null
+++ b/model/epicyclic.scad
@@ -0,0 +1,53 @@
+// epicyclic.scad
+
+// an epicyclic gearbox, similar to a Rohloff or Shimano Nexus 11
+// dimensions in millimetres, mostly from https://www.rohloff.de/en/service/handbook/speedhub/technical-data
+// (c) Simon Brooke 2025; CC-BY-SA
+
+include <Library/SprocketGenerator2/files/Sprocket_Generator_v2_example_10.scad>
+
+module epicyclic (olnd=135, disc=1) {
+    
+    body_width=116; 
+    spoke_flange_width=3.2;
+    
+    // axle
+    color("grey")
+    cylinder(h=(olnd + 12), r=6, center=true);
+    
+    // locknuts, etc
+    color("black")
+    cylinder(h=olnd, r=15, center=true);
+    
+    // epicyclic body
+    color("red")
+    cylinder(h=body_width, r=46, center=true);
+
+    // spoke flanges. TODO: yes, they need spoke holes.
+    translate([0, 0, (body_width/2) - spoke_flange_width])
+        color("red")
+        cylinder(h=spoke_flange_width, r=54);
+    
+    translate([0, 0, 0 - (body_width/2)])
+        color("red")
+        cylinder(h=spoke_flange_width, r=54);
+
+    // primary chain sprocket, obvs
+    translate([0, 0, 3 - (olnd/2)])
+        color("grey")
+        sprocket(teeth=20, roller=7.9, pitch=12.7);
+        
+    translate([0, 0, 0 - ((body_width/2) - spoke_flange_width)])
+        color("grey")
+        sprocket(teeth=30, roller=7.9, pitch=12.7);
+        
+    // disc brake, if present. TODO: details of disc spider
+    if (disc==1) {
+        translate([0, 0, (olnd/2) - 7])
+        color("silver")
+        cylinder(h=1.5, r=75);
+    }
+}
+
+// rotate([90, 0, 0])
+//   epicyclic();
\ No newline at end of file
diff --git a/model/fourbar.scad b/model/fourbar.scad
index 4cd7e7e..9fc1f4c 100644
--- a/model/fourbar.scad
+++ b/model/fourbar.scad
@@ -1,5 +1,8 @@
 // fourbar.scad
 
+// (c) Simon Brooke 2025; CC-BY-SA
+
+
 include <Library/BentSim/Bike_accessories.scad>
 include <Library/NACAAirfoils/files/Naca4.scad>
 include <Library/skew.scad>
diff --git a/model/subframe.scad b/model/subframe.scad
index c5a11df..34d874c 100644
--- a/model/subframe.scad
+++ b/model/subframe.scad
@@ -1,9 +1,14 @@
 // tricycle.scad: 
 
+// (c) Simon Brooke 2025; CC-BY-SA
+
+
 include <Library/BentSim/Bike_accessories.scad>
 
 include <Library/SprocketGenerator2/files/Sprocket_Generator_v2_example_10.scad>
 
+include <epicyclic.scad>
+
 module subframe () {
     // front leg (supports cross-shaft, epicyclic, motor
     translate([-25, 1820, -550])
@@ -83,6 +88,10 @@ module subframe () {
         rotate([0,90,0])
         cylinder(h=80,r=4);
         
+     rotate([0,90,0])
+        translate([450, 1900, 31])
+        epicyclic();   
+        
 }
 
 subframe();