I'VE USED A RUBBER SANDING BELT CLEANER (BIG ERASER) TO SUPPORT THIS TYPE OF DRILLING . IT WILL FOLLOW THE CONTOUR IF YOU APPLY ENOUGH PRESSURE AND THE RUBBER IS THIN ENOUGH (1" OR SO). HOWEVER , I FIND THE BEST RESULT, IS TO PLAN AHEAD AND DRILL BEFORE YOU CARVE . I DO THE SAME FOR BODY ROUTS...