diff --git a/server/server.js b/server/server.js
index f83d848..09f55fd 100755
--- a/server/server.js
+++ b/server/server.js
@@ -913,6 +913,23 @@ app.post('/api/homing/run', async (req, res) => {
   if (!res.writableEnded) res.end();
 });
 
+/**
+ * Konvertiert den FK-State (von 4b_revolute_angle.py / 5_pose_estimation.py)
+ * in die G92-Driver-Konvention (appRobotDriver/doc/Info_G92.md).
+ *
+ * Unterschiede:
+ *   b: FK b=0 = gerade Hand; Driver B=180° = gerade Hand  → B = 180 − b
+ *   c: FK c=0 = neutral Roll; Driver C=90° = neutral       → C = c + 90
+ *   z: 4b misst Ellbogen RELATIV zu Arm1; Driver braucht absoluten Winkel → Z = y + z
+ */
+function fkStateToDriverG92(s) {
+  const d = { ...s };
+  if (d.b != null) d.b = 180 - d.b;
+  if (d.c != null) d.c = d.c + 90;
+  if (d.z != null && d.y != null) d.z = d.y + d.z;
+  return d;
+}
+
 /**
  * POST /api/homing/send-state
  * Baut aus { state: { x, y, z, a, b[, c, e] } } ein G92 und sendet es als
@@ -929,7 +946,7 @@ app.post('/api/homing/send-state', async (req, res) => {
     if (!isDriverConfigured())
       return res.status(501).json({ error: 'DRIVER_WS_URL ist nicht konfiguriert' });
 
-    const gcode = buildG92(state);
+    const gcode = buildG92(fkStateToDriverG92(state));
     const result = await sendGcode(gcode);
     if (!result.ok)
       return res.status(502).json({ error: `Robot-Fehler: ${result.error}`, gcode });