diff --git a/dist/index.html b/dist/index.html
index 1ed5ab3..fa709c0 100644
--- a/dist/index.html
+++ b/dist/index.html
@@ -25,7 +25,6 @@
   <script src="app.bundle.js"></script>
   <script src="scene.bundle.js"></script>
   <script src="solver.js"></script>
-  <script src="lz-string.min.js"></script>
 </body>
 
 </html>
\ No newline at end of file
diff --git a/src/Sketch.js b/src/Sketch.js
index 49cd3cb..c9c866d 100644
--- a/src/Sketch.js
+++ b/src/Sketch.js
@@ -280,14 +280,7 @@ class Sketch {
         this.deleteSelected()
         break;
       case 'z':
-        var string = JSON.stringify(this.toJSON());
-        window.string = string;
-        alert("Size of sample is: " + string.length);
-        window.compressed = LZString.compress(string);
-        alert("Size of compressed sample is: " + compressed.length);
-        string = LZString.decompress(compressed);
-        alert("Sample is: " + string);
-
+        console.log('undo would be nice')
         break;
     }
   }
diff --git a/src/react/fileExporter.js b/src/react/fileExporter.js
index ce19e82..1e9a465 100644
--- a/src/react/fileExporter.js
+++ b/src/react/fileExporter.js
@@ -13,13 +13,15 @@ function save(blob, filename) {
 
 function saveArrayBuffer( buffer, filename ) {
 
-  save( new Blob( [ buffer ], { type: 'application/octet-stream' } ), filename );
+  // save( new Blob( [ buffer ], { type: 'application/octet-stream' } ), filename );
+  save( new Blob( [ buffer ], { type: 'model/stl' } ), filename );
 
 }
 
 function saveString( text, filename ) {
 
-  save( new Blob( [ text ], { type: 'text/plain' } ), filename );
+  // save( new Blob( [ text ], { type: 'text/plain' } ), filename );
+  save( new Blob( [ text ], { type: 'application/json' } ), filename );
 
 }
 
@@ -32,8 +34,7 @@ export function STLExport() {
 
 
 export function savePart() {
-  const string = sc.saveString()
-  
-  saveString( LZString.compress(string), 'test2.bin' );
+
+  saveString( sc.saveString(), 'uncomp.json' );
 
 }
\ No newline at end of file
diff --git a/todo.txt b/todo.txt
index 8215d91..3c0d59f 100644
--- a/todo.txt
+++ b/todo.txt
@@ -56,6 +56,7 @@ add cancle soft button for line arc
 auto snap
 constraint labels,equal
 
+add download button, different from save button
 parallel // need to add antoher button to feature ,or  empty placeholder