diff --git a/resources/views/rd/fire-shutter-drawing/index.blade.php b/resources/views/rd/fire-shutter-drawing/index.blade.php
index a55fb4df..0fab8b6b 100644
--- a/resources/views/rd/fire-shutter-drawing/index.blade.php
+++ b/resources/views/rd/fire-shutter-drawing/index.blade.php
@@ -1182,6 +1182,52 @@ function fs3dBuild() {
             meshes.slats.add(lineGroup);
         }
 
+        // === SLAT ROLL (샤프트에 감긴 슬랫) ===
+        const rolledH = H - shutterH; // 올라간(감긴) 높이
+        if (rolledH > 0) {
+            // 철재: ㄷ자 72mm 피치로 감김 / 스크린: 얇게 1mm씩 감김
+            const wrapThick = S.productType === 'steel' ? 72 : 1;
+            const shaftR = b.shaftDia / 2;
+            // 감긴 바퀴 수 = 감긴 높이 / (샤프트 둘레 + 누적 두께 보정)
+            // 간략 계산: 감긴 총 두께 = sqrt(rolledH * wrapThick / π)
+            const rollThick = Math.sqrt(rolledH * wrapThick / Math.PI);
+            const rollOuterR = shaftR + rollThick;
+            // 롤 길이 = 주축 길이 (브라켓 사이)
+            const rollLen = mainShaftLen;
+
+            const rollGeo = new THREE.CylinderGeometry(rollOuterR, rollOuterR, rollLen, 32);
+            rollGeo.rotateZ(Math.PI / 2);
+            const rollMat = new THREE.MeshStandardMaterial({
+                color: S.productType === 'steel' ? 0x78716c : 0xa78bfa,
+                metalness: S.productType === 'steel' ? 0.3 : 0,
+                roughness: S.productType === 'steel' ? 0.6 : 0.8,
+                transparent: true,
+                opacity: 0.85,
+            });
+            meshes.slatRoll = new THREE.Mesh(rollGeo, rollMat);
+            meshes.slatRoll.position.set(msCenterX, shaftY, 0);
+            scene.add(meshes.slatRoll);
+
+            // 철재: 감긴 ㄷ자 슬랫 골 표현 (나선형 링 라인)
+            if (S.productType === 'steel' && rollThick > 10) {
+                const ringGroup = new THREE.Group();
+                const ringCount = Math.min(Math.floor(rollThick / (wrapThick * 0.15)), 12);
+                for (let i = 1; i <= ringCount; i++) {
+                    const r = shaftR + (rollThick * i / (ringCount + 1));
+                    const pts = [];
+                    for (let a = 0; a <= 64; a++) {
+                        const angle = (a / 64) * Math.PI * 2;
+                        pts.push(new THREE.Vector3(0, Math.sin(angle) * r, Math.cos(angle) * r));
+                    }
+                    const ringGeo = new THREE.BufferGeometry().setFromPoints(pts);
+                    const ring = new THREE.Line(ringGeo, new THREE.LineBasicMaterial({ color: 0x57534e, opacity: 0.5, transparent: true }));
+                    ring.position.x = msCenterX;
+                    ringGroup.add(ring);
+                }
+                meshes.slatRoll.add(ringGroup);
+            }
+        }
+
         // === BOTTOM BAR ===
         const barGeo = new THREE.BoxGeometry(W - 20, 40, 60);
         const barMat = new THREE.MeshStandardMaterial({ color: 0xf59e0b, metalness: 0.3, roughness: 0.5 });