Differences

This shows you the differences between two versions of the page.

--- mcmaster:lapping [2015/09/26 20:43] – created mcmaster
+++ mcmaster:lapping [2015/09/26 21:39] (current) – mcmaster
@@ Line 31: / Line 31: @@
   * Bulk package removed via hotplate + pliers: https://twitter.com/johndmcmaster/status/642406536854138880
   * Original chips: https://twitter.com/johndmcmaster/status/641020243159052288
+  * Sample:
+    * Thickness: 0.331 mm min, possibly as high as 0.335 mm
+    * WH: 19.9 x 20.4 mm
+    * Cut 20.5 x 20.5?
 Lapping stencil
@@ Line 36: / Line 40: @@
   * Requires making a stencil to hold die in place
   * Use wax to affix stencil to fixture
+  * Still using lapping films.  Looking into getting condition rings + cast iron plate
+  * All material: 0.01" => 0.254 mm
+    * Should be < sample height but close to it
+  * Kimwipe: 0.056 mm
+    * Must be < stencil thickness
+Lapping jig stencil holder?
+  * Should the stencil itself by held by a retention ring that slides up and down?
+  * For now just lightly wax it on
+    * How much height will this add?
+    * Propose make slightly larger than sample holder and wax along top edge
+Stencil cutting holder
+  * Hold stencil in place on milling machine
+  * Lapping surface 2" => 50.8 mm diameter
+    * 50.6 mm measured
+  * Lapping jig cavity: 57.1 mm
+  * Lapping stencil target diameter: 54 mm
+    * Add 1.5 mm to each side w/ 1.5 mm clearance
+  * Support at least entire cavity size + 1/8" endmill => 57.1 + 1/8 * 25.4 = 60.3 mm
+  * Add some good clearance so I don't mill the jig: 5 mm each side => 70 mm total ID => 2.75"
+  * 0.5" each side => 3.75" Al square stock
+  * 1.5" from sherline t-slot to slot
+    * 10-32 (0.1900") close fit => #9 drill (0.1960")