diff --git a/follow_focus.py b/follow_focus.py
index 02600ae..04bae4f 100644
--- a/follow_focus.py
+++ b/follow_focus.py
@@ -18,10 +18,13 @@ fastener_height=     3.5
 fastener_length=     20
 fastener_h_spacing=  .2
 fastener_gap=        .2
+hex_diameter=        8.5
+hex_depth=           4
 
 # NEMA 17 stepper motor
 stepper_motor_size=  42.0
 stepper_hole_width=  31.0
+stepper_mount_dia=   22.5
 
 # Case
 part_thinkness=      20
@@ -74,7 +77,8 @@ support_x = (support_y-b)/slope
 
 lg_x = support_x-stepper_center[0]
 lg_y = support_y-stepper_center[1]
-lg_radius = (math.sqrt(lg_x**2 + lg_y**2)-sg_teeth*mod/2)
+sg_radius = sg_teeth*mod/2
+lg_radius = (math.sqrt(lg_x**2 + lg_y**2)-sg_radius)
 
 def findRodInter(n_x, n_y):
     p = Point(center_x, center_y)
@@ -138,7 +142,7 @@ base = base.faces('<<Z[0]').workplane().vLine(offset+loop_width, forConstruction
                                        .close().cutBlind(-lid_thicknesss)
 
 base = base.faces('>>Z[0]').workplane().center(stepper_center[0], -stepper_center[1])\
-                                       .circle(22.5/2)\
+                                       .circle(stepper_mount_dia/2)\
                                        .pushPoints([(stepper_hole_radius*math.cos(math.radians(45+slant_degree)),\
                                                      stepper_hole_radius*math.sin(math.radians(45+slant_degree))),\
                                                     (stepper_hole_radius*math.cos(math.radians(135+slant_degree)),\
@@ -157,7 +161,7 @@ lid = lid.faces('>Z[0]').shell(.000001-wall_width)
 lid = lid.add(copy)
 
 lid = lid.faces('>Z[1]').workplane().center(stepper_center[0], -stepper_center[1])\
-                                    .circle(5).extrude(lid_thicknesss-wall_width)
+                                    .circle(sg_radius+mod).extrude(lid_thicknesss-wall_width)
 lid = lid.faces('>Z[0]').workplane().circle(5/2).cutThruAll()
 
 base = base.faces('<Z[1]').workplane().center(lg_x, lg_y).circle(lg_radius+2*mod).cutBlind(-gear_thinkness-gear_gap)
@@ -182,8 +186,8 @@ fastener = fastener.faces('<<Y[-1]').workplane().center(-fastener_length,0)\
                                                 .close().extrude(-fastener_height)
 fastener = fastener.faces('<<Y[-1]').workplane().circle(fastener_width/6).extrude(-fastener_height)
 fastener = fastener.faces('<<Y[-1]').center(fastener_length,0)\
-                                    .sketch().regularPolygon(8.5/2,6,tag='outer')\
-                                             .finalize().cutBlind(-4)
+                                    .sketch().regularPolygon(hex_diameter/2,6)\
+                                             .finalize().cutBlind(-hex_depth)
 fastener = fastener.faces('<<Y[-6]').workplane().circle(5/2).cutThruAll()
 
 # Lid large gear mount point
@@ -219,7 +223,7 @@ s_gear = cq.Workplane('XY').gear(SpurGear(module=mod,
 tab_distance = 2
 shaft_diameter = 5
 copy = s_gear.faces('<Z[0]').workplane().vLine(tab_distance, forConstruction=True)\
-                                        .hLine(10).vLine(-10).hLine(-20).vLine(10)\
+                                        .hLine(lg_radius).vLine(-lg_radius).hLine(-lg_radius*2).vLine(lg_radius)\
                                                                         .close().cutThruAll()
 s_gear = s_gear.faces('<Z[0]').sketch().circle(shaft_diameter/2).finalize().cutThruAll()
 s_gear = s_gear.add(copy)
@@ -232,3 +236,9 @@ show_object(fastener, name='Follow Focus Fastener')
 show_object(l_gear, name='Follow Focus Large Gear')
 show_object(s_gear, name='Follow Focus Small Gear')
 
+# Export STL
+cq.exporters.export(base, 'follow-focus-base.stl')
+cq.exporters.export(lid, 'follow-focus-lid.stl')
+cq.exporters.export(fastener, 'follow-focus-fastener.stl')
+cq.exporters.export(l_gear, 'follow-focus-large_gear.stl')
+cq.exporters.export(s_gear, 'follow-focus-small_gear.stl')