diff --git a/.gitignore b/.gitignore
index 96374c4..94fdf03 100644
--- a/.gitignore
+++ b/.gitignore
@@ -41,3 +41,7 @@ $RECYCLE.BIN/
 Network Trash Folder
 Temporary Items
 .apdisk
+
+# inventor
+
+*.lck
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diff --git a/ThreeFingerGripper/README.md b/ThreeFingerGripper/README.md
new file mode 100644
index 0000000..6fd097c
--- /dev/null
+++ b/ThreeFingerGripper/README.md
@@ -0,0 +1,6 @@
+Autodesk Inventor 2016 files.
+
+You can open them with Autodesk Fusion 360. It's available for free.
+
+Watch the make videos:
+[https://youtu.be/pmE4PjirRWE](https://youtu.be/pmE4PjirRWE "https://youtu.be/pmE4PjirRWE")
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