Differences

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--- alliedhightech:mcmaster [2021/04/23 23:08] – [2021-04-23] mcmaster
+++ alliedhightech:mcmaster [2021/04/24 18:03] (current) – mcmaster
@@ Line 76: / Line 76: @@
   * Post 1.49"
     * Could I mount stopcock to it somehow?
+  * Feeler gauge test
+    * Pointed inside
+    * About 30 um variation
+    * Good enough for now: not great but not terrible
   * Main crank 40 TPI
     * Wheel is marked in um (635 um)
+  * Allied-Parallel-Lapping-Integrated-Circuits.pdf
+    * If gauge is moving its already too much pressure
+    * Instead use recommended distances
+    * Based on 500 um die
+    * Imperial Polishing Cloth, #50-150-500: 0.840 mm
+    * 277 um die => 724 + 277 = 1001 um offset?
+    * Sample load set to full
+    * Using spare holder to measure
+    * Distance from Platen to bottom of polishing fixture = Ts - Tc - Td + 0.116 mm
+      * Ts = Spacer thickness (0.500")
+      * Tc = Cloth Thickness
+      * Td = Die Thickness
+    * So...
+      * Ts: 12.65 mm
+      * Tc: 0.840 mm
+      * Td: 0.277 mm
+      * Net: 12.65 - 0.840 - 0.277 + 0.116 = 11.649
+    * ...but I'm using magnetic sheet. Not the same
+      * 50-500-500 instead of 50-150-500
+      * Magnet: 735 um
+      * Cloth: 450 um (840 um official)
+    * Let's use official number
+      * 12.65 - 0.840 - 0.735 - 0.277 + 0.116 = 10.914 mm
+      * Crank: 25.4 / 40 = 0.635 mm
+      * 10.914 / 0.635 = 17.2 cranks
+        * Remainder: 0.119 mm
+    * Settings
+      * 225 RPM CCW
+      * Rotation: full speed (8)
+      * Osc: 3
+    * 0.05 um silica
+===== 2021-04-24 =====
+Continue lapping
+same settings