Incorrect normals derived from simple raycasting

I am using the raycaster to project a circle onto a geometry primitive (cone). The black circle is correctly cast onto the cone surface and rendered in yellow. Using the intersect object from the raycast, I have the intersected points on the cone and the unit normal of the intersected faces. From these I am attempting to draw the normal at 100 points along the curve on the cone. However, either I am rendering the normal lines incorrectly or the face normals from the intersect object are off. Any help or insight appreciated. Code segment of interest follows the snip.

var spline = new Array(); // stores pts for the curve

    for (i = 0; i < thePoints.length; i++) { //thePoints holds all the pts on the black circle
        var thispt = new THREE.Vector3(thePoints[i].x, thePoints[i].y, 120); // a point on the black circle
        raycaster.set(thispt, new THREE.Vector3(0,0,-1)); // set up raycaster, use thispt as origin and 0,0,-1 as directional unit vector
        var intersects = raycaster.intersectObject(scene.getObjectByName("mysurf")); // get intersect object
        // console.log(intersects);
        spline.push(intersects[0].point); // push the intersected pt to storage

        // intersect object provides intersected pt and face normal
        var ptOnCurve = intersects[0].point; // intersected pt 
        var faceNormal = intersects[0].face.normal.normalize(); // face normal

        // draw the normal
        var normalPts = [];
        p1 = new THREE.Vector3(ptOnCurve.x, ptOnCurve.y, ptOnCurve.z).clone();
        p2 = faceNormal.clone().multiplyScalar(10).add(p1);

        var linematerial = new THREE.LineBasicMaterial({ color: 0x0000ff });
        var linegeometry = new THREE.BufferGeometry().setFromPoints(normalPts);
        var line = new THREE.Line(linegeometry, linematerial);
        scene.add(line); // add the blue normal line to scene

It wouldn’t surprise me if the face normal from the intersected object really are off. Are you computing the face normals on the “mysurf” object’s geomery? If not, a call to computeFaceNormals on the geometry (or computing them yourself) might do the trick.

A way to double-check visually if the face normals are set up correctly is to attach a FaceNormalsHelper; see