feat(cad): add the 3dfiles package and the original drive shaft mount

cad/.envrc

@@ -0,0 +1 @@
+use flake ..#cad

cad/build.py

@@ -0,0 +1,33 @@
+# pyright: reportUnusedCallResult=false, reportWildcardImportFromLibrary=false
+from build123d import *
+
+hole_offset = 20
+hole_diameter = 22
+
+width = 40
+thickness = 20
+
+assert (hole_offset - hole_diameter / 2) > 0
+assert (width - hole_diameter) > 0
+
+
+with BuildPart() as builder:
+    with BuildSketch() as sketch:
+        with BuildLine() as profile:
+            l1 = Polyline(
+                (0,0),
+                (width / 2, 0),
+                (width / 2, hole_offset)
+            )
+            l2 = CenterArc((0, hole_offset), width / 2, 90, -90)
+            mirror(profile.line, Plane.YZ)
+        make_face()
+
+        with Locations((0, hole_offset)):
+            Circle(hole_diameter / 2, mode=Mode.SUBTRACT)
+
+    extrude(amount=thickness / 2)
+    mirror(about=Plane.XY)
+
+assert builder.part is not None
+export_step(builder.part, "drive shaft mount.step")

flake.nix

@@ -21,6 +21,7 @@
     flake-parts.lib.mkFlake {inherit inputs;} {
       imports = [
         project-templates.flakeModules.rust-esp32-c6
+        project-templates.flakeModules.cad
       ];
 
       systems = ["aarch64-linux" "x86_64-linux" "aarch64-darwin"];
@@ -37,6 +38,14 @@
           # runtimeDeps = with pkgs; [];
           # buildDeps = with pkgs; [];
         };
+
+        krantz.cad = {
+          enable = true;
+          builder = ./cad/build.py;
+
+          devShell.name = "cad";
+          package.name = "3dfiles";
+        };
       };
     };
 }