1-coil.js

  // Build the spiral geometry
  for( let i = 0; i < lineSteps; i += 1 ) {

      const position = new Vector3(
          ( -( i / lineSteps ) * lineLength ) + ( lineLength / 2 ),
          radius * Math.sin( ( i / lineSteps ) * ( Math.PI * 2 * coils ) ),
          radius * Math.cos( ( i / lineSteps ) * ( Math.PI * 2 * coils ) ),
      );
      vertexGeometry.vertices.push( position );

  }

2-bulb.js

  // add the bulbs
  for( let i = 0; i < bulbsPerStrand; i += 1 ) {

      const position = new Vector3(
          ( -( i / bulbsPerStrand ) * lineLength ) + ( lineLength / 2 ),
          radius * Math.sin( ( i / bulbsPerStrand ) * ( Math.PI * 2 * coils ) ),
          radius * Math.cos( ( i / bulbsPerStrand ) * ( Math.PI * 2 * coils ) ),
      );

      bulbMesh.position.copy( position );

  }