diff --git a/convertSTL.rb b/convertSTL.rb
new file mode 100755
index 0000000..5a77d7c
--- /dev/null
+++ b/convertSTL.rb
@@ -0,0 +1,127 @@
+#!/usr/bin/env ruby
+# convertSTL.rb - Converts STL files between binary and ASCII encoding
+# by Chris Polis
+#
+# This script detects which encoding the stl file is in and converts it to
+#  the opposite encoding and saves the file as *-ascii.stl or *-binary.stl.
+#  I wrote this script to save disk space and bandwidth when using stl files. 
+# 
+# USAGE: 
+#  $ ruby convertSTL.rb [filename of .stl to be converted]
+#  or 'chmod +x' and run as ./convertSTL.rb
+# 
+
+
+# Helper methods
+class Float
+  def to_sn # to scientific notation
+    "%E" % self
+  end
+
+  def self.from_sn str # generate a float from scientific notation
+    ("%f" % str).to_f
+  end
+end
+
+# Pass in filename as only argument
+if ARGV.size != 1 
+  puts "Usage: ./converSTL.rb [stl filename]"
+  exit
+end
+
+# Read file
+begin
+  original = File.new(ARGV[0], "r")
+  
+  # Read first line - check binary or ASCII
+  tempLine = original.gets
+  if tempLine.include? "solid"
+    outFilename = ARGV[0].sub(/\.stl/i, '-binary.stl')
+    puts "#{ARGV[0]} is in ASCII format, converting to BINARY: #{outFilename}"
+    outFile = File.new(outFilename, "w")
+    outFile.write("\0" * 80) # 80 bit header - ignored
+    outFile.write("FFFF")   # 4 bit integer # of triangles - filled later
+    triCount = 0
+
+    # ASCII STL format (from Wikipedia):
+    # solid name(optional)
+    #
+    # [foreach triangle]
+    # facet normal ni nj nk
+    # outer loop
+    # vertex v1x v1y v1z
+    # vertex v2x v2y v2z
+    # vertex v3x v3y v3z
+    # endloop
+    # endfacet
+    # endsolid name(optional)
+
+    while temp = original.gets
+      next if temp =~ /^\s*$/ or temp.include? 'endsolid' # ignore whitespace
+      temp.sub! /facet normal/, ''
+      normal = temp.split(' ').map{ |num| Float.from_sn num }
+      triCount += 1
+      temp = original.gets # 'outer loop'
+
+      temp = original.gets
+      vertexA = temp.sub(/vertex/, '').split(' ').map{ |num| Float.from_sn num }
+      temp = original.gets
+      vertexB = temp.sub(/vertex/, '').split(' ').map{ |num| Float.from_sn num }
+      temp = original.gets
+      vertexC = temp.sub(/vertex/, '').split(' ').map{ |num| Float.from_sn num }
+
+      temp = original.gets # 'endsolid'
+      temp = original.gets # 'endfacet'
+
+      outFile.write(normal.pack("FFF"))
+      outFile.write(vertexA.pack("FFF"))
+      outFile.write(vertexB.pack("FFF"))
+      outFile.write(vertexC.pack("FFF"))
+      outFile.write("\0\0")
+    end
+    outFile.seek(80, IO::SEEK_SET)
+    outFile.write([ triCount ].pack("V"))
+    outFile.close
+
+  else
+    outFilename = ARGV[0].sub(/\.stl/i, '-ascii.stl')
+    puts "#{ARGV[0]} is in BINARY format, converting to ASCII: #{outFilename}"
+    outFile = File.new(outFilename, "w")
+    outFile.write("solid \n")
+
+    # Binary STL format (from Wikipedia):
+    # UINT8[80] – Header
+    # UINT32 – Number of triangles
+    # 
+    # foreach triangle
+    # REAL32[3] – Normal vector
+    # REAL32[3] – Vertex 1
+    # REAL32[3] – Vertex 2
+    # REAL32[3] – Vertex 3
+    # UINT16 – Attribute byte count
+    # end
+    original.seek(80, IO::SEEK_SET)
+    triCount = original.read(4).unpack('V')[0]
+    triCount.times do |triNdx|
+      normal = original.read(12).unpack('FFF')
+      vertexA = original.read(12).unpack('FFF')
+      vertexB = original.read(12).unpack('FFF')
+      vertexC = original.read(12).unpack('FFF')
+      original.seek(2, IO::SEEK_CUR)
+
+      outFile.write("  facet normal #{normal[0].to_sn} #{normal[1].to_sn} #{normal[2].to_sn}\n")
+      outFile.write("    outer loop\n")
+      outFile.write("      vertex #{vertexA[0].to_sn} #{vertexA[1].to_sn} #{vertexA[2].to_sn}\n")
+      outFile.write("      vertex #{vertexB[0].to_sn} #{vertexB[1].to_sn} #{vertexB[2].to_sn}\n")
+      outFile.write("      vertex #{vertexC[0].to_sn} #{vertexC[1].to_sn} #{vertexC[2].to_sn}\n")
+      outFile.write("    endloop\n")
+      outFile.write("  endfacet\n")
+    end
+
+    outFile.write("endsolid \n")
+    outFile.close
+  end
+  original.close
+rescue => error
+  puts "Error: #{error}"
+end