diff --git a/nhf/build.py b/nhf/build.py
index 5da3d01..c3b0e4a 100644
--- a/nhf/build.py
+++ b/nhf/build.py
@@ -2,25 +2,69 @@
 The NHF build system
 
 Usage: For any parametric assembly, inherit the `Model` class, and mark the
-output objects with the `@target` decorator
+output objects with the `@target` decorator. Each marked function should only
+take `self` as an argument.
+```python
+class BuildScaffold(Model):
+
+    @target(name="obj1")
+    def o1(self):
+        return Cq.Solid.makeBox(10, 10, 10)
+
+    def o2(self):
+        return Cq.Solid.makeCylinder(10, 20)
+```
 """
+from enum import Enum
 from pathlib import Path
 from typing import Union
 from functools import wraps
 from colorama import Fore, Style
 import cadquery as Cq
 
+class TargetKind(Enum):
+
+    STL = "stl",
+    DXF = "dxf",
+
+    def __init__(self, ext: str):
+        self.ext = ext
+
 class Target:
 
     def __init__(self,
                  method,
-                 name: str):
+                 name: str,
+                 kind: TargetKind = TargetKind.STL,
+                 **kwargs):
         self._method = method
         self.name = name
+        self.kind = kind
+        self.kwargs = kwargs
     def __str__(self):
         return f"<target {self.name}>"
     def __call__(self, obj, *args, **kwargs):
+        """
+        Raw call function which passes arguments directly to `_method`
+        """
         return self._method(obj, *args, **kwargs)
+    def file_name(self, file_name):
+        return f"{file_name}.{self.kind.ext}"
+    def write_to(self, obj, path: str):
+        x = self._method(obj)
+        if self.kind == TargetKind.STL:
+            assert isinstance(x, Union[
+                Cq.Workplane, Cq.Shape, Cq.Compound, Cq.Assembly])
+            if isinstance(x, Cq.Workplane):
+                x = x.val()
+            if isinstance(x, Cq.Assembly):
+                x = x.toCompound()
+            x.exportStl(path, **self.kwargs)
+        elif self.kind == TargetKind.DXF:
+            assert isinstance(x, Cq.Workplane)
+            Cq.exporters.exportDXF(x, path, **self.kwargs)
+        else:
+            assert False, f"Invalid kind: {self.kind}"
 
     @classmethod
     def methods(cls, subject):
@@ -49,13 +93,6 @@ def target(name, **deco_kwargs):
         return wrapper
     return f
 
-def _to_shape(x: Union[Cq.Workplane, Cq.Shape, Cq.Compound, Cq.Assembly]) -> Cq.Shape:
-    if isinstance(x, Cq.Workplane):
-        x = x.val()
-    if isinstance(x, Cq.Assembly):
-        x = x.toCompound()
-    return x
-
 
 class Model:
     """
@@ -76,22 +113,21 @@ class Model:
             total += 1
         return total
 
-    def build_all(self, output_dir: Union[Path, str] ="build", verbose=1):
+    def build_all(self, output_dir: Union[Path, str] = "build", verbose=1):
         """
         Build all targets in this model
         """
         output_dir = Path(output_dir)
         output_dir.mkdir(exist_ok=True, parents=True)
-        for k, f in Target.methods(self).items():
-            output_file = output_dir / f"{k}.stl"
+        for k, target in Target.methods(self).items():
+            output_file = output_dir / target.file_name(k)
             if output_file.is_file():
                 if verbose >= 1:
                     print(f"{Fore.GREEN}Skipping{Style.RESET_ALL} {output_file}")
                 continue
 
-            model = f(self)
             if verbose >= 1:
                 print(f"{Fore.BLUE}Building{Style.RESET_ALL} {output_file}")
-            _to_shape(model).exportStl(str(output_file))
+            target.write_to(self, str(output_file))
             if verbose >= 1:
                 print(f"{Fore.GREEN}Built{Style.RESET_ALL} {output_file}")
diff --git a/nhf/touhou/houjuu_nue/__init__.py b/nhf/touhou/houjuu_nue/__init__.py
index 37a91a4..ba99b00 100644
--- a/nhf/touhou/houjuu_nue/__init__.py
+++ b/nhf/touhou/houjuu_nue/__init__.py
@@ -33,7 +33,7 @@ from dataclasses import dataclass, field
 import unittest
 import cadquery as Cq
 from nhf import Material
-from nhf.build import Model, target
+from nhf.build import Model, TargetKind, target
 from nhf.parts.joints import HirthJoint
 from nhf.parts.handle import Handle
 import nhf.touhou.houjuu_nue.wing as MW
@@ -113,11 +113,6 @@ class Parameters(Model):
             "Wing root must be large enough to accomodate joint"
 
 
-    def print_geometries(self):
-        return [
-            self.hs_joint_parent()
-        ]
-
     def harness_profile(self) -> Cq.Sketch:
         """
         Creates the harness shape
@@ -148,6 +143,7 @@ class Parameters(Model):
             )
         return sketch
 
+    @target(name="harness", kind=TargetKind.DXF)
     def harness(self) -> Cq.Shape:
         """
         Creates the harness shape
@@ -249,7 +245,8 @@ class Parameters(Model):
         result.faces("<Z").tag("base")
         return result
 
-    def wing_root(self) -> Cq.Shape:
+    @target(name="wing_root")
+    def wing_root(self) -> Cq.Assembly:
         """
         Generate the wing root which contains a Hirth joint at its base and a
         rectangular opening on its side, with the necessary interfaces.