Case: 4.2 mm insert holes, M3x8 base screws with the feet

The 4.0 mm holes printed too tight for CNC Kitchen M3x5.7 inserts.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

case/README.md

@@ -27,15 +27,16 @@ works if the case stays out of the sun.
 
 ## Hardware
 
-- 12 × M3 heat-set inserts (about 4.6 mm OD, 5.7 mm long; the holes are 4.0 mm
+- 12 × M3 heat-set inserts, CNC Kitchen M3 × 5.7 (about 4.6 mm OD; the holes
-  and 6 mm deep):
+  are 4.2 mm and 6 mm deep, set by `insert_d` if your printer runs tighter or
+  looser):
   - 4 in the bezel's display bosses
   - 2 in the bezel's feet
   - 2 in the body's rear corners
   - 4 on the base's board standoffs
 - 4 × M3×6 to bolt the display to the bezel
 - 4 × M3×6 to hold the D1 board on its standoffs
-- 4 × M3×8 to hold the base on, from below; **M3×10** with the TPU feet
+- 4 × M3×8 to hold the base on, from below (also with the TPU feet)
 
 ## Assembly
 
@@ -48,8 +49,8 @@ works if the case stays out of the sun.
    the anchor on the base.
 6. Put the body on the base and screw it together from below. The base holds
    the bezel in place. With the feet, put a foot on each screw first (the
-   spigot faces the base) and use M3×10. Tighten until the foot is snug; the
+   spigot faces the base); M3×8 is still long enough. Tighten until the foot
-   TPU only needs light compression.
+   is snug; the TPU only needs light compression.
 
 ## Measure before printing
 

case/vfd-case.scad

@@ -55,14 +55,14 @@ win_r = 2;
 win_chamfer = 1.5;
 
 /* [Heat-set inserts, M3] */
-insert_d = 4.0;         // hole for the insert
+insert_d = 4.2;         // hole for the insert (CNC Kitchen M3x5.7; 4.0 printed too tight)
 insert_depth = 6;
 boss_d = 7;             // display bosses (larger would touch the glass)
 screw_d = 3.4;          // M3 clearance
 head_d = 6.2;           // M3 head counterbore in the base
 head_depth = 2;
 
-/* [TPU feet, held by the base screws (use M3x10 instead of M3x8)] */
+/* [TPU feet, held by the base screws (M3x8 still fits)] */
 foot_d = 14;            // fits inside the base outline at the rear corners
 foot_h = 4.5;           // below the base
 foot_spigot_h = 1.8;    // locates in the base's screw counterbore