From 91ff34a5c7e5207c1d4ce34adbb9552a352a06d3 Mon Sep 17 00:00:00 2001
From: Sasza Stanczew <sasza@stanczew.com>
Date: Tue, 16 Dec 2025 22:47:46 +0100
Subject: [PATCH] b

---
 Neptune4/filament_detector_guide.scad | 53 ++++++++++++++++++---------
 1 file changed, 35 insertions(+), 18 deletions(-)

diff --git a/Neptune4/filament_detector_guide.scad b/Neptune4/filament_detector_guide.scad
index 9d4d124..b1e73fa 100644
--- a/Neptune4/filament_detector_guide.scad
+++ b/Neptune4/filament_detector_guide.scad
@@ -6,51 +6,68 @@ rounding = 1;
 
 // base to connect to the printer
 base_hole_distance = 40;
-base_hole_d = 4.5;
-base_dim = [62,25,12];
+base_frame_hole_d = 4.5;
+base_dim = [61,23,12];
 
-det_offset = 4;
+// I had a M3x30 screw, with a head diameter of ~5.5mm
+base_det_screw_l = 30;
+base_det_screw_d = 3.5;
+base_det_screw_head = 6;
+
+det_offset = 4; // offset to the left, because the Elegoo filament detector is not centered
 
 
 difference() {
     // base
     cuboid(base_dim, rounding=rounding, anchor=TOP);
     // holes for screws
-    left(base_hole_distance/2) cyl(d=base_hole_d, h=base_dim[2], chamfer=-1, anchor=TOP);
-    right(base_hole_distance/2) cyl(d=base_hole_d, h=base_dim[2], chamfer=-1, anchor=TOP);
+    left(base_hole_distance/2) cyl(d=base_frame_hole_d, h=base_dim[2], chamfer=-1, anchor=TOP);
+    right(base_hole_distance/2) cyl(d=base_frame_hole_d, h=base_dim[2], chamfer=-1, anchor=TOP);
+    
+    down(base_dim[2]/2) left(det_offset) union() {
+        // hole for screw for filament detector
+        ycyl(d=base_det_screw_d, h=base_dim[1]);
+        // hole for the screw head
+        back(base_det_screw_l - 10) ycyl(d=base_det_screw_head, h=base_dim[1]);
+    }
     
-    // hole for screw for filament detector
-    down(base_dim[2]/2) left(det_offset) ycyl(d=base_hole_d, h=base_dim[1]);
 }
 
 // ball bearing holder
 bear_up = 25;
 bear_fwd = 15;
 
+// 608 bearing
 bear_od = 22;
-bear_cover_od = 35; // I have a cover/guide printed on my 608 bearings
+bear_cover_od = 32;
 bear_id = 8;
-bear_w = 8;// bearing is 7mm, +1 for clearance
-
-// bearing mockup to see clearance
-// up(bear_up) fwd(bear_fwd) xcyl(d=bear_cover_od);
+bear_w = 7;
 
 difference() {
     // base for bearing
     chain_hull() {
-        up(bear_up) fwd(bear_fwd) xcyl(d=bear_od, h=bear_w+2*t, rounding=rounding);
-        cuboid([bear_w + 2*t, base_dim[1],2]);
+        up(bear_up) fwd(bear_fwd) xcyl(d=bear_od, h=bear_w+1+2*t, rounding=rounding);
+        cuboid([bear_w+1 + 2*t, base_dim[1],2]);
     }
     // cutout for bearing
-    up(bear_up) fwd(bear_fwd) xcyl(d=bear_cover_od + t, h=bear_w);
+    up(bear_up) fwd(bear_fwd) xcyl(d=bear_cover_od + t, h=bear_w+1);
     // hole for screw to hold bearing
-    up(bear_up) fwd(bear_fwd) xcyl(d=bear_id, h=bear_w + 2*t+0.1);
+    up(bear_up) fwd(bear_fwd) xcyl(d=bear_id, h=bear_w+1 + 2*t+0.1);
+}
+
+// bearing cover
+up(bear_up) fwd(bear_fwd) difference() {
+    union() {
+        xcyl(h=bear_w, d1=bear_od, d2=bear_cover_od);
+        xcyl(h=bear_w, d2=bear_od, d1=bear_cover_od);
+    }
+    xcyl(d=bear_od, h=bear_w);
 }
 
 // PTFE tube holder
-ptfe_dim = [bear_w + 2*t,9,37];
+ptfe_dim = [bear_w+1 + 2*t,9,37];
 filament_od = 2.5;
-ptfe_od = 4.2;
+ptfe_od = 4.4;
 
 difference() {
     union() {