Smaller threads, ISO standard pitch options, and more tolerance classes

README.md

@@ -1,41 +1,52 @@
 # Fusion 360 Thread Profiles for 3D-Printed Threads
 
 Fusion 360 comes with various thread standards, most of which are not a great fit for 3D printing because they are too fine to work well when printed.
-This project defines thread profiles that are aimed at 3D printing so that they work, even when printed with lower detail settings (e.g. 0.30mm layer height).
+This project defines thread profiles that are aimed at 3D printing so that they work, even when printed with lower detail settings.
 
 ## What's in the Box?
 
-The provided `3DPrintedMetricV3.xml` file contains the thread profiles listed below.
+The provided `3DPrintedMetricV4.xml` file contains the thread profiles listed below.
 Additional profiles can be easily generated from the included Python script.
 
-**Shape:** 60° trapezoidal  
-**Size (OD):** 8-50mm  
-**Pitch:** 3.5mm, 5mm  
-**Classes:** O.0, O.1, O.2, O.4, O.8
+**Shape:** 60° trapezoidal
+<br>
+**Size (OD):** 1-50mm
+<br>
+**Pitch:** Various, based on the ISO standard
+<br>
+**Classes:** O.0, O.1, O.2, 0.3, O.4, 0.5, 0.6, 0.7, O.8, 0.9
+
 
 The classes specify tolerances.
-O.0 has the tightest tolerances which are loosely based on ISO M30x3.5 6g/6H. 
+O.0 has the tightest tolerances which are loosely based on ISO M30x3.5 6g/6H.
 The number after the 'O.' specifies, in tenths of a millimeter, how much the major, minor and pitch diameters are offset compared to O.0.
 For example, O.2 would have a 0.2mm looser tolerance than O.0.
 
-`3DPrintedMetric.xml` contains old thread definitions and is provided for compatibility with older prints or models.
+If your goal is to use real metal bolts in 3D printed threaded holes, I find that **0.6** works well.
+<p align="center">
+    <img src="m4_thread_example_1.jpg" alt="M4 Thread Example 1" height="400">
+    <img src="m4_thread_example_2.jpg" alt="M4 Thread Example 2" height="400">
+</p>
 
 ## Install and Use
 
-If you just want to use the profiles with no customization, download the file `3DPrintedMetricV3.xml`, save it in the following directory and then restart Fusion 360.
+If you just want to use the profiles with no customization, download the file `3DPrintedMetricV4.xml`, save it in the following directory and then restart Fusion 360.
 
 **On Windows:**
 ```
 %localappdata%\Autodesk\webdeploy\Production\<version ID>\Fusion\Server\Fusion\Configuration\ThreadData
 ```
 
 **On Mac OS:**
-
-*Macintosh HD> Users> [Username] > Library > Application Support > Autodesk > Webdeploy > production > [Version specific ID] > Then right click on "Autodesk Fusion 360" and choose Show Package Contents > Contents > Libraries > Applications > Fusion > Fusion > Server > Fusion > Configuration >ThreadData*
+The easiest way to get to the ThreadData folder is to use the Terminal. Open a new Terminal window and paste in:
+```
+open ~/Library/Application\ Support/Autodesk/webdeploy/production/Autodesk\ Fusion.app/Contents/Libraries/Applications/Fusion/Fusion/Server/Fusion/Configuration/ThreadData
+```
+This will open the correct folder in the Finder
 
 (see also [here](https://knowledge.autodesk.com/support/fusion-360/learn-explore/caas/sfdcarticles/sfdcarticles/Custom-Threads-in-Fusion-360.html))
 
-When you now create or edit a *Thread* feature, you should be able to select the Thread Type *"3D-printed Metric Threads"*.
+When you now create or edit a *Thread* feature, you should be able to select the Thread Type *"3D-printed Metric Threads V4"*.
 
 ![Select Thread Type in Fusion 360](ss_fusion.png)
 
@@ -54,12 +65,3 @@ python main.py
 This will create a file named `output.xml` in the working directory which you can then rename and install in Fusion as described above.
 
 To customize the generated profiles, simply edit the values defined at the top of `main.py`.
-
-```python
-NAME = "3D-printed Metric Threads V3"
-UNIT = "mm"
-ANGLE = 60.0
-SIZES = list(range(8, 51))
-PITCHES = [3.5, 5.0]
-OFFSETS = [.0, .1, .2, .4, .8]
-```

main.py

@@ -2,12 +2,65 @@
 import xml.etree.ElementTree as ET
 from abc import ABC, abstractmethod
 
-NAME = "3D-printed Metric Threads V3"
+NAME = "3D-printed Metric Threads V4"
 UNIT = "mm"
 ANGLE = 60.0
-SIZES = list(range(8, 51))
-PITCHES = [3.5, 5.0]
-OFFSETS = [.0, .1, .2, .4, .8]
+SIZES = list(range(1, 51))
+# Standard ISO metric thread pitches for each size
+# Format: {size: [coarse_pitch, fine_pitch1, fine_pitch2, ...]}
+ISO_PITCHES = {
+    1: [0.25, 0.2],
+    2: [0.4, 0.25],
+    3: [0.5, 0.35],
+    4: [0.7, 0.5],
+    5: [0.8, 0.5],
+    6: [1.0, 0.75],
+    7: [1.0],  # Less common
+    8: [1.25, 1.0, 0.75],
+    9: [1.25],  # Less common
+    10: [1.5, 1.25, 1.0],
+    11: [1.5],  # Less common
+    12: [1.75, 1.5, 1.25],
+    13: [1.75],  # Less common
+    14: [2.0, 1.5],
+    15: [2.0],  # Less common
+    16: [2.0, 1.5],
+    17: [2.0],  # Less common
+    18: [2.5, 2.0, 1.5],
+    19: [2.5],  # Less common
+    20: [2.5, 2.0, 1.5],
+    21: [2.5],  # Less common
+    22: [2.5, 2.0, 1.5],
+    23: [2.5],  # Less common
+    24: [3.0, 2.0, 1.5],
+    25: [3.0],  # Less common
+    26: [3.0],  # Less common
+    27: [3.0, 2.0, 1.5],
+    28: [3.0],  # Less common
+    29: [3.0],  # Less common
+    30: [3.5, 2.0, 1.5],
+    31: [3.5],  # Less common
+    32: [3.5],  # Less common
+    33: [3.5, 2.0],
+    34: [3.5],  # Less common
+    35: [3.5],  # Less common
+    36: [4.0, 3.0],
+    37: [4.0],  # Less common
+    38: [4.0],  # Less common
+    39: [4.0, 3.0],
+    40: [4.0],  # Less common
+    41: [4.0],  # Less common
+    42: [4.5, 3.0],
+    43: [4.5],  # Less common
+    44: [4.5],  # Less common
+    45: [4.5, 3.0],
+    46: [4.5],  # Less common
+    47: [4.5],  # Less common
+    48: [5.0, 3.0],
+    49: [5.0],  # Less common
+    50: [5.0, 3.0]
+}
+OFFSETS = [.0, .1, .2, .3, .4, .5, .6, .7, .8, .9]
 
 
 def designator(val: float):
@@ -55,7 +108,9 @@ def sizes(self):
         return SIZES
 
     def designations(self, size):
-        return [Metric3Dprinted.Designation(size, pitch) for pitch in PITCHES]
+        # Get pitches for this size, default to [0.5] if not defined
+        pitches = ISO_PITCHES.get(size, [0.5])
+        return [Metric3Dprinted.Designation(size, pitch) for pitch in pitches]
 
     def threads(self, designation):
         ts = []
@@ -119,7 +174,7 @@ def generate():
                     ET.SubElement(thread_element, "TapDrill").text = "{:.4g}".format(thread.tapDrill)
 
     ET.indent(tree)
-    tree.write('3DPrintedMetricV3.xml', encoding='UTF-8', xml_declaration=True)
+    tree.write('3DPrintedMetricV4.xml', encoding='UTF-8', xml_declaration=True)
 
 
 generate()