From e61be357ee15f2fdf791676cddafc6251a25c92e Mon Sep 17 00:00:00 2001
From: Roberto Alsina <roberto.alsina@gmail.com>
Date: Sat, 23 Jul 2022 14:05:21 -0300
Subject: [PATCH] Good upper arm

---
 monitor/upper_arm.py | 42 ++++++++++++++++++------------------------
 1 file changed, 18 insertions(+), 24 deletions(-)

diff --git a/monitor/upper_arm.py b/monitor/upper_arm.py
index e3208f3..89b8152 100644
--- a/monitor/upper_arm.py
+++ b/monitor/upper_arm.py
@@ -1,4 +1,4 @@
-# This is the arm from the tripod to the "elbow"
+# This is the arm from the monitor to the "elbow"
 
 import cadquery2 as cq
 from cadquery2 import exporters
@@ -9,52 +9,46 @@ from hinge import hinge_gap, hinge_w, hinge_profile_1, hinge_profile_2, hinge_t
 inner_monitor_hinge = 3.2 / 2
 outer_monitor_hinge = hinge_w / 2
 
-# tripod hinge dimensions
-inner_tripod_hinge = 7.5 / 2
-outer_tripod_hinge = 17.5 / 2
-tripod_hinge_width = 5.5
-
-
 monitor_hinge_shape = (
     cq.Sketch().circle(outer_monitor_hinge).circle(inner_monitor_hinge, mode="s")
 )
 
-tripod_hinge_shape = (
-    cq.Sketch().circle(outer_tripod_hinge).circle(inner_tripod_hinge, mode="s")
+# Both hinges are the same shape, just one is outer and the other inner
+elbow_hinge_shape = (
+    cq.Sketch().circle(outer_monitor_hinge).circle(inner_monitor_hinge, mode="s")
 )
 
-arm_width = min(tripod_hinge_width, hinge_gap)
 arm_length = 150
+arm_width = hinge_gap
 
 lower_arm = (
     cq.Workplane("XY")
-    .rect(arm_width, arm_width)
+    .rect(hinge_w, hinge_gap)
     .extrude(arm_length)
     .edges("|Z or <Z or >Z")
     .fillet(0.25)
     .faces(">Y")
     # Add hinge that connects to the monitor
-    .workplane(
-        centerOption="CenterOfBoundBox", offset=(hinge_gap - arm_width) / 2
-    )
+    .workplane(centerOption="CenterOfBoundBox")
     .center(0, arm_length / 2 + (outer_monitor_hinge - inner_monitor_hinge))
     .placeSketch(monitor_hinge_shape)
     .extrude(-hinge_gap)
-    .center(0, -(arm_length + outer_tripod_hinge))
-    # Undo previous offset + new offset
-    .workplane(
-        offset=-(hinge_gap - arm_width - tripod_hinge_width + arm_width) / 2
-    )
-    # Add hinge that connects to the tripod
-    # Hinge integration
-    .transformed(rotate=cq.Vector(0, 0, 90))
-    .center(-hinge_w / 2, 0).tag("hingeplane")
+    .center(0, -(arm_length + outer_monitor_hinge))
+    # Add hinge that connects to the elbow
+    .transformed(rotate=cq.Vector(0, 0, 180))
+    .workplane(offset=(20 - arm_width) / 2)
+    .center(-hinge_w / 2, 0)
+    .tag("hingeplane")
     .placeSketch(hinge_profile_1)
     .extrude(-hinge_t)
     .workplaneFromTagged("hingeplane")
-    .workplane(offset=-hinge_t - hinge_w)
+    .workplane(offset=-hinge_t - hinge_gap)
     .placeSketch(hinge_profile_2)
     .extrude(-hinge_t)
+    .workplaneFromTagged("hingeplane")
+    .center(+hinge_w / 2, 0)
+    .rect(hinge_w, hinge_w + 6)
+    .extrude(-(2 * hinge_t + hinge_gap))
 )
 
 exporters.export(lower_arm, "upper_arm.stl")