From c9705864963f4a3a3c946bf55e657211009daeff Mon Sep 17 00:00:00 2001
From: xengineering <me@xengineering.eu>
Date: Sat, 23 Dec 2023 16:17:10 +0100
Subject: mech: pcb_case: Add nut tolerance test

This part can be used to fine-tune the tolerance for the used nuts which
have to fit tightly into a 3D-printed part.
---
 mech/mech.mk           |  2 +-
 mech/pcb_case/nut.scad | 23 ++++++++++++++++++++++-
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/mech/mech.mk b/mech/mech.mk
index 6807c03..c92ef7b 100644
--- a/mech/mech.mk
+++ b/mech/mech.mk
@@ -1,5 +1,5 @@
 MECH_BUILD_DIR := $(BUILD_DIR)/mech
-PARTS := bottom top back front
+PARTS := bottom top back front pcb_case/nut
 STL := $(PARTS:%=$(MECH_BUILD_DIR)/%.stl)
 GCODE := $(PARTS:%=$(MECH_BUILD_DIR)/%.gcode)
 
diff --git a/mech/pcb_case/nut.scad b/mech/pcb_case/nut.scad
index bfd5b3d..407ab09 100644
--- a/mech/pcb_case/nut.scad
+++ b/mech/pcb_case/nut.scad
@@ -1,9 +1,30 @@
 nut_h = 3;
 nut_d = 4.15;
 nut_r = nut_d / 2;
+nut_d_tol = 0.5;
 
 module nut() {
 	cylinder(d=nut_d,h=nut_h);
 }
 
-nut();
+module nut_tolerance_test() {
+	steps = 3;
+	step_width = 0.1;
+
+	for(i = [-steps : steps]) {
+		tol = nut_d_tol + i * step_width;
+		translate([i*5*nut_d,0,0])
+			difference() {
+				cube([5*nut_d, 5*nut_d, 2*nut_h]);
+				translate([2.5*nut_d,2.5*nut_d,0]) {
+					union() {
+						cylinder(d=nut_d,h=2*nut_h,$fn=50);
+						translate([0,0,nut_h])
+							cylinder(d=nut_d_tol+nut_d,h=nut_h,$fn=50);
+					}
+				}
+			}
+	}
+}
+
+nut_tolerance_test();
-- 
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