diff --git a/lib/Slic3r/Config.pm b/lib/Slic3r/Config.pm
index fab693b122..d1aeb38cfc 100644
--- a/lib/Slic3r/Config.pm
+++ b/lib/Slic3r/Config.pm
@@ -432,6 +432,9 @@ sub read_ini {
     return $ini;
 }
 
+package Slic3r::Config::GCode;
+use parent 'Slic3r::Config';
+
 package Slic3r::Config::Print;
 use parent 'Slic3r::Config';
 
diff --git a/lib/Slic3r/GCode.pm b/lib/Slic3r/GCode.pm
index 117cf25b55..f78e39b595 100644
--- a/lib/Slic3r/GCode.pm
+++ b/lib/Slic3r/GCode.pm
@@ -1,3 +1,176 @@
+package Slic3r::GCode::Base;
+use Moo;
+
+use List::Util qw(min max first);
+
+has 'gcode_config'          => (is => 'ro', default => sub { Slic3r::Config::GCode->new });
+has '_extrusion_axis'       => (is => 'rw', default => sub { 'E' });
+has '_extruders'            => (is => 'ro', default => sub {{}});
+has '_extruder'             => (is => 'rw');
+has '_multiple_extruders'   => (is => 'rw', default => sub { 0 });
+has '_last_acceleration'    => (is => 'rw', default => sub { 0 });
+has '_last_fan_speed'       => (is => 'rw', default => sub { 0 });
+
+sub apply_print_config {
+    my ($self, $print_config) = @_;
+    
+    $self->gcode_config->apply_print_config($print_config);
+    
+    if ($self->gcode_config->gcode_flavor eq 'mach3') {
+        $self->_extrusion_axis('A');
+    } elsif ($self->gcode_config->gcode_flavor eq 'no-extrusion') {
+        $self->_extrusion_axis('');
+    } else {
+        $self->_extrusion_axis($self->gcode_config->extrusion_axis);
+    }
+}
+
+sub set_extruders {
+    my ($self, $extruder_ids) = @_;
+    
+    foreach my $i (@$extruder_ids) {
+        $self->_extruders->{$i} = my $e = Slic3r::Extruder->new($i, $self->config);
+    }
+    
+    # we enable support for multiple extruder if any extruder greater than 0 is used
+    # (even if prints only uses that one) since we need to output Tx commands
+    # first extruder has index 0
+    $self->_multiple_extruders(max(@$extruder_ids) > 0);
+}
+
+sub set_temperature {
+    my ($self, $temperature, $wait, $tool) = @_;
+    
+    return "" if $wait && $self->gcode_config->gcode_flavor =~ /^(?:makerware|sailfish)$/;
+    
+    my ($code, $comment) = ($wait && $self->gcode_config->gcode_flavor ne 'teacup')
+        ? ('M109', 'wait for temperature to be reached')
+        : ('M104', 'set temperature');
+    my $gcode = sprintf "$code %s%d %s; $comment\n",
+        ($self->gcode_config->gcode_flavor eq 'mach3' ? 'P' : 'S'), $temperature,
+        (defined $tool && ($self->_multiple_extruders || $self->gcode_config->gcode_flavor =~ /^(?:makerware|sailfish)$/)) ? "T$tool " : "";
+    
+    $gcode .= "M116 ; wait for temperature to be reached\n"
+        if $self->gcode_config->gcode_flavor eq 'teacup' && $wait;
+    
+    return $gcode;
+}
+
+sub set_bed_temperature {
+    my ($self, $temperature, $wait) = @_;
+    
+    my ($code, $comment) = ($wait && $self->gcode_config->gcode_flavor ne 'teacup')
+        ? (($self->gcode_config->gcode_flavor =~ /^(?:makerware|sailfish)$/ ? 'M109' : 'M190'), 'wait for bed temperature to be reached')
+        : ('M140', 'set bed temperature');
+    my $gcode = sprintf "$code %s%d ; $comment\n",
+        ($self->gcode_config->gcode_flavor eq 'mach3' ? 'P' : 'S'), $temperature;
+    
+    $gcode .= "M116 ; wait for bed temperature to be reached\n"
+        if $self->gcode_config->gcode_flavor eq 'teacup' && $wait;
+    
+    return $gcode;
+}
+
+sub set_fan {
+    my ($self, $speed, $dont_save) = @_;
+    
+    if ($self->_last_fan_speed != $speed || $dont_save) {
+        $self->_last_fan_speed($speed) if !$dont_save;
+        if ($speed == 0) {
+            my $code = $self->gcode_config->gcode_flavor eq 'teacup'
+                ? 'M106 S0'
+                : $self->gcode_config->gcode_flavor =~ /^(?:makerware|sailfish)$/
+                    ? 'M127'
+                    : 'M107';
+            return sprintf "$code%s\n", ($self->gcode_config->gcode_comments ? ' ; disable fan' : '');
+        } else {
+            if ($self->gcode_config->gcode_flavor =~ /^(?:makerware|sailfish)$/) {
+                return sprintf "M126%s\n", ($self->gcode_config->gcode_comments ? ' ; enable fan' : '');
+            } else {
+                return sprintf "M106 %s%d%s\n", ($self->gcode_config->gcode_flavor eq 'mach3' ? 'P' : 'S'),
+                    (255 * $speed / 100), ($self->gcode_config->gcode_comments ? ' ; enable fan' : '');
+            }
+        }
+    }
+    return "";
+}
+
+sub set_acceleration {
+    my ($self, $acceleration) = @_;
+    
+    return "" if !$acceleration || $acceleration == $self->_last_acceleration;
+    
+    $self->_last_acceleration($acceleration);
+    return sprintf "M204 S%s%s\n",
+        $acceleration, ($self->gcode_config->gcode_comments ? ' ; adjust acceleration' : '');
+}
+
+sub need_toolchange {
+    my ($self, $extruder_id) = @_;
+    
+    # return false if this extruder was already selected
+    return (!defined $self->_extruder) || ($self->_extruder->id != $extruder_id);
+}
+
+sub set_extruder {
+    my ($self, $extruder_id) = @_;
+    
+    return "" if !$self->need_toolchange;
+    return $self->_toolchange($extruder_id);
+}
+
+sub _toolchange {
+    my ($self, $extruder_id) = @_;
+    
+    # set the new extruder
+    $self->_extruder($self->_extruders->{$extruder_id});
+    
+    # return the toolchange command
+    # if we are running a single-extruder setup, just set the extruder and return nothing
+    my $gcode = "";
+    if ($self->_multiple_extruders) {
+        $gcode .= sprintf "%s%d%s\n",
+            ($self->gcode_config->gcode_flavor eq 'makerware'
+                ? 'M135 T'
+                : $self->gcode_config->gcode_flavor eq 'sailfish'
+                    ? 'M108 T'
+                    : 'T'),
+            $extruder_id,
+            ($self->gcode_config->gcode_comments ? ' ; change extruder' : '');
+        
+        $gcode .= $self->reset_e;
+    }
+    return $gcode;
+}
+
+sub reset_e {
+    my ($self) = @_;
+    
+    return "" if $self->config->gcode_flavor =~ /^(?:mach3|makerware|sailfish)$/;
+    
+    $self->_extruder->set_E(0) if $self->_extruder;
+    if ($self->_extrusion_axis ne '' && !$self->gcode_config->use_relative_e_distances) {
+        return sprintf "G92 %s0%s\n", $self->gcode_config->extrusion_axis, ($self->config->gcode_comments ? ' ; reset extrusion distance' : '');
+    } else {
+        return "";
+    }
+}
+
+sub has_multiple_extruders {
+    my ($self) = @_;
+    return $self->_multiple_extruders;
+}
+
+sub extruder {
+    my ($self) = @_;
+    return $self->_extruder;
+}
+
+sub extruders {
+    my ($self) = @_;
+    return [ sort { $a->id <=> $b->id } values %{$self->_extruders} ];
+}
+
 package Slic3r::GCode;
 use Moo;
 
@@ -9,12 +182,14 @@ use Slic3r::Geometry qw(epsilon scale unscale scaled_epsilon points_coincide PI
 use Slic3r::Geometry::Clipper qw(union_ex offset_ex);
 use Slic3r::Surface ':types';
 
+extends 'Slic3r::GCode::Base';
+
 has 'config'             => (is => 'ro', default => sub { Slic3r::Config::Full->new });
 has 'placeholder_parser' => (is => 'rw', default => sub { Slic3r::GCode::PlaceholderParser->new });
 has 'standby_points'     => (is => 'rw');
 has 'enable_loop_clipping' => (is => 'rw', default => sub {1});
 has 'enable_wipe'        => (is => 'rw', default => sub {0});   # at least one extruder has wipe enabled
-has 'layer_count'        => (is => 'ro', required => 1 );
+has 'layer_count'        => (is => 'ro');
 has '_layer_index'       => (is => 'rw', default => sub {-1});  # just a counter
 has 'layer'              => (is => 'rw');
 has '_layer_islands'     => (is => 'rw');
@@ -23,9 +198,6 @@ has '_seam_position'     => (is => 'ro', default => sub { {} });  # $object => p
 has 'shift_x'            => (is => 'rw', default => sub {0} );
 has 'shift_y'            => (is => 'rw', default => sub {0} );
 has 'z'                  => (is => 'rw');
-has 'extruders'          => (is => 'ro', default => sub {{}});
-has 'multiple_extruders' => (is => 'rw', default => sub {0});
-has 'extruder'           => (is => 'rw');
 has 'external_mp'        => (is => 'rw');
 has 'layer_mp'           => (is => 'rw');
 has 'new_object'         => (is => 'rw', default => sub {0});
@@ -33,22 +205,22 @@ has 'straight_once'      => (is => 'rw', default => sub {1});
 has 'elapsed_time'       => (is => 'rw', default => sub {0} );  # seconds
 has 'lifted'             => (is => 'rw', default => sub {0} );
 has 'last_pos'           => (is => 'rw', default => sub { Slic3r::Point->new(0,0) } );
-has 'last_fan_speed'     => (is => 'rw', default => sub {0});
-has 'last_acceleration'  => (is => 'rw', default => sub {0});
 has 'wipe_path'          => (is => 'rw');
 
+sub apply_print_config {
+    my ($self, $print_config) = @_;
+    
+    $self->SUPER::apply_print_config($print_config);
+    $self->config->apply_print_config($print_config);
+}
+
 sub set_extruders {
-    my ($self, $extruder_ids, $print_config) = @_;
+    my ($self, $extruder_ids) = @_;
     
-    foreach my $i (@$extruder_ids) {
-        $self->extruders->{$i} = my $e = Slic3r::Extruder->new($i, $print_config);
-        $self->enable_wipe(1) if $e->wipe;
-    }
+    $self->SUPER::set_extruders($extruder_ids);
     
-    # we enable support for multiple extruder if any extruder greater than 0 is used
-    # (even if prints only uses that one) since we need to output Tx commands
-    # first extruder has index 0
-    $self->multiple_extruders(max(@$extruder_ids) > 0);
+    # enable wipe path generation if any extruder has wipe enabled
+    $self->enable_wipe(defined first { $_->wipe } values %{$self->_extruders});
 }
 
 sub set_shift {
@@ -82,7 +254,7 @@ sub change_layer {
     }
     
     my $gcode = "";
-    if ($self->config->gcode_flavor =~ /^(?:makerware|sailfish)$/) {
+    if ($self->config->gcode_flavor =~ /^(?:makerware|sailfish)$/ && defined $self->layer_count) {
         # TODO: cap this to 99% and add an explicit M73 P100 in the end G-code
         $gcode .= sprintf "M73 P%s%s\n",
             int(99 * ($self->_layer_index / ($self->layer_count - 1))),
@@ -110,7 +282,7 @@ sub move_z {
         # in both cases, we're going to the nominal Z of the next layer
         $self->lifted(0);
         
-        if ($self->extruder->retract_layer_change) {
+        if ($self->_extruder->retract_layer_change) {
             # this retraction may alter $self->z
             $gcode .= $self->retract(move_z => $z);
             $current_z = $self->z;  # update current z in case retract() changed it
@@ -154,7 +326,7 @@ sub extrude_loop {
     } elsif ($self->config->seam_position eq 'nearest' || $self->config->seam_position eq 'aligned') {
         # simplify polygon in order to skip false positives in concave/convex detection
         my $polygon = $loop->polygon;
-        my @simplified = @{$polygon->simplify(scale $self->extruder->nozzle_diameter/2)};
+        my @simplified = @{$polygon->simplify(scale $self->_extruder->nozzle_diameter/2)};
         
         # concave vertices have priority
         my @candidates = map @{$_->concave_points(PI*4/3)}, @simplified;
@@ -200,7 +372,7 @@ sub extrude_loop {
     # if polyline was shorter than the clipping distance we'd get a null polyline, so
     # we discard it in that case
     my $clip_length = $self->enable_loop_clipping
-        ? scale($self->extruder->nozzle_diameter) * &Slic3r::LOOP_CLIPPING_LENGTH_OVER_NOZZLE_DIAMETER
+        ? scale($self->_extruder->nozzle_diameter) * &Slic3r::LOOP_CLIPPING_LENGTH_OVER_NOZZLE_DIAMETER
         : 0;
     
     # get paths
@@ -234,7 +406,7 @@ sub extrude_loop {
         # we make sure we don't exceed the segment length because we don't know
         # the rotation of the second segment so we might cross the object boundary
         my $first_segment = Slic3r::Line->new(@$last_path_polyline[0,1]);
-        my $distance = min(scale($self->extruder->nozzle_diameter), $first_segment->length);
+        my $distance = min(scale($self->_extruder->nozzle_diameter), $first_segment->length);
         my $point = $first_segment->point_at($distance);
         $point->rotate($angle, $last_path_polyline->first_point);
         
@@ -290,8 +462,8 @@ sub _extrude_path {
     }
     
     # calculate extrusion length per distance unit
-    my $e = $self->extruder->e_per_mm3 * $path->mm3_per_mm;
-    $e = 0 if !$self->config->get_extrusion_axis;
+    my $e = $self->_extruder->e_per_mm3 * $path->mm3_per_mm;
+    $e = 0 if !$self->_extrusion_axis;
     
     # set speed
     my $F;
@@ -323,10 +495,10 @@ sub _extrude_path {
     $gcode .= ";_BRIDGE_FAN_START\n" if $path->is_bridge;
     my $path_length = unscale $path->length;
     {
-        $gcode .= $path->gcode($self->extruder, $e, $F,
-            $self->shift_x - $self->extruder->extruder_offset->x,
-            $self->shift_y - $self->extruder->extruder_offset->y,  #,,
-            $self->config->get_extrusion_axis,
+        $gcode .= $path->gcode($self->_extruder, $e, $F,
+            $self->shift_x - $self->_extruder->extruder_offset->x,
+            $self->shift_y - $self->_extruder->extruder_offset->y,  #,,
+            $self->_extrusion_axis,
             $self->config->gcode_comments ? " ; $description" : "");
 
         if ($self->enable_wipe) {
@@ -358,7 +530,7 @@ sub travel_to {
     
     # skip retraction if the travel move is contained in an island in the current layer
     # *and* in an island in the upper layer (so that the ooze will not be visible)
-    if ($travel->length < scale $self->extruder->retract_before_travel
+    if ($travel->length < scale $self->_extruder->retract_before_travel
         || ($self->config->only_retract_when_crossing_perimeters
             && $self->config->fill_density > 0
             && (first { $_->contains_line($travel) } @{$self->_upper_layer_islands})
@@ -423,26 +595,28 @@ sub _plan {
 sub retract {
     my ($self, %params) = @_;
     
+    return "" if !defined $self->_extruder;
+    
     # get the retraction length and abort if none
     my ($length, $restart_extra, $comment) = $params{toolchange}
-        ? ($self->extruder->retract_length_toolchange,  $self->extruder->retract_restart_extra_toolchange,  "retract for tool change")
-        : ($self->extruder->retract_length,             $self->extruder->retract_restart_extra,             "retract");
+        ? ($self->_extruder->retract_length_toolchange,  $self->_extruder->retract_restart_extra_toolchange,  "retract for tool change")
+        : ($self->_extruder->retract_length,             $self->_extruder->retract_restart_extra,             "retract");
     
     # if we already retracted, reduce the required amount of retraction
-    $length -= $self->extruder->retracted;
+    $length -= $self->_extruder->retracted;
     return "" unless $length > 0;
     my $gcode = "";
     
     # wipe
     my $wipe_path;
-    if ($self->extruder->wipe && $self->wipe_path) {
+    if ($self->_extruder->wipe && $self->wipe_path) {
         my @points = @{$self->wipe_path};
         $wipe_path = Slic3r::Polyline->new($self->last_pos, @{$self->wipe_path}[1..$#{$self->wipe_path}]);
-        $wipe_path->clip_end($wipe_path->length - $self->extruder->scaled_wipe_distance($self->config->travel_speed));
+        $wipe_path->clip_end($wipe_path->length - $self->_extruder->scaled_wipe_distance($self->config->travel_speed));
     }
     
     # prepare moves
-    my $retract = [undef, undef, -$length, $self->extruder->retract_speed_mm_min, $comment];
+    my $retract = [undef, undef, -$length, $self->_extruder->retract_speed_mm_min, $comment];
     my $lift    = ($self->config->retract_lift->[0] == 0 || defined $params{move_z}) && !$self->lifted
         ? undef
         : [undef, $self->z + $self->config->retract_lift->[0], 0, $self->config->travel_speed*60, 'lift plate during travel'];
@@ -455,17 +629,17 @@ sub retract {
             my $segment_length = $line->length;
             # reduce retraction length a bit to avoid effective retraction speed to be greater than the configured one
             # due to rounding
-            my $e = $retract->[2] * ($segment_length / $self->extruder->scaled_wipe_distance($self->config->travel_speed)) * 0.95;
+            my $e = $retract->[2] * ($segment_length / $self->_extruder->scaled_wipe_distance($self->config->travel_speed)) * 0.95;
             $retracted += $e;
             $gcode .= $self->G1($line->b, undef, $e, $self->config->travel_speed*60*0.8, $retract->[3] . ";_WIPE");
         }
         if ($retracted > $retract->[2]) {
             # if we retracted less than we had to, retract the remainder
             # TODO: add regression test
-            $gcode .= $self->G1(undef, undef, $retract->[2] - $retracted, $self->extruder->retract_speed_mm_min, $comment);
+            $gcode .= $self->G1(undef, undef, $retract->[2] - $retracted, $self->_extruder->retract_speed_mm_min, $comment);
         }
         $gcode .= $self->reset_e;
-    } elsif ($self->config->use_firmware_retraction) {
+    } elsif ($self->gcode_config->use_firmware_retraction) {
         $gcode .= "G10 ; retract\n";
     } else {
         $gcode .= $self->G1(@$retract);
@@ -483,8 +657,8 @@ sub retract {
             $gcode .= $self->G1(@$lift);
         }
     }
-    $self->extruder->set_retracted($self->extruder->retracted + $length);
-    $self->extruder->set_restart_extra($restart_extra);
+    $self->_extruder->set_retracted($self->_extruder->retracted + $length);
+    $self->_extruder->set_restart_extra($restart_extra);
     $self->lifted($self->config->retract_lift->[0]) if $lift;
     
     $gcode .= "M103 ; extruder off\n" if $self->config->gcode_flavor eq 'makerware';
@@ -503,46 +677,27 @@ sub unretract {
         $self->lifted(0);
     }
     
-    my $to_unretract = $self->extruder->retracted + $self->extruder->restart_extra;
+    my $to_unretract = $self->_extruder->retracted + $self->_extruder->restart_extra;
     if ($to_unretract) {
-        if ($self->config->use_firmware_retraction) {
+        if ($self->gcode_config->use_firmware_retraction) {
             $gcode .= "G11 ; unretract\n";
             $gcode .= $self->reset_e;
-        } elsif ($self->config->get_extrusion_axis) {
+        } elsif ($self->_extrusion_axis) {
             # use G1 instead of G0 because G0 will blend the restart with the previous travel move
             $gcode .= sprintf "G1 %s%.5f F%.3f",
-                $self->config->get_extrusion_axis,
-                $self->extruder->extrude($to_unretract),
-                $self->extruder->retract_speed_mm_min;
+                $self->_extrusion_axis,
+                $self->_extruder->extrude($to_unretract),
+                $self->_extruder->retract_speed_mm_min;
             $gcode .= " ; compensate retraction" if $self->config->gcode_comments;
             $gcode .= "\n";
         }
-        $self->extruder->set_retracted(0);
-        $self->extruder->set_restart_extra(0);
+        $self->_extruder->set_retracted(0);
+        $self->_extruder->set_restart_extra(0);
     }
     
     return $gcode;
 }
 
-sub reset_e {
-    my ($self) = @_;
-    return "" if $self->config->gcode_flavor =~ /^(?:mach3|makerware|sailfish)$/;
-    
-    $self->extruder->set_E(0) if $self->extruder;
-    return sprintf "G92 %s0%s\n", $self->config->get_extrusion_axis, ($self->config->gcode_comments ? ' ; reset extrusion distance' : '')
-        if $self->config->get_extrusion_axis && !$self->config->use_relative_e_distances;
-}
-
-sub set_acceleration {
-    my ($self, $acceleration) = @_;
-    
-    return "" if !$acceleration || $acceleration == $self->last_acceleration;
-    
-    $self->last_acceleration($acceleration);
-    return sprintf "M204 S%s%s\n",
-        $acceleration, ($self->config->gcode_comments ? ' ; adjust acceleration' : '');
-}
-
 sub G0 {
     my $self = shift;
     return $self->G1(@_) if !($self->config->g0 || $self->config->gcode_flavor eq 'mach3');
@@ -559,8 +714,8 @@ sub _G0_G1 {
     
     if ($point) {
         $gcode .= sprintf " X%.3f Y%.3f", 
-            ($point->x * &Slic3r::SCALING_FACTOR) + $self->shift_x - $self->extruder->extruder_offset->x,
-            ($point->y * &Slic3r::SCALING_FACTOR) + $self->shift_y - $self->extruder->extruder_offset->y; #**
+            ($point->x * &Slic3r::SCALING_FACTOR) + $self->shift_x - $self->_extruder->extruder_offset->x,
+            ($point->y * &Slic3r::SCALING_FACTOR) + $self->shift_y - $self->_extruder->extruder_offset->y; #**
         $self->last_pos($point->clone);
     }
     if (defined $z && (!defined $self->z || $z != $self->z)) {
@@ -577,8 +732,8 @@ sub _Gx {
     $gcode .= sprintf " F%.3f", $F;
     
     # output extrusion distance
-    if ($e && $self->config->get_extrusion_axis) {
-        $gcode .= sprintf " %s%.5f", $self->config->get_extrusion_axis, $self->extruder->extrude($e);
+    if ($e && $self->_extrusion_axis) {
+        $gcode .= sprintf " %s%.5f", $self->_extrusion_axis, $self->_extruder->extrude($e);
     }
     
     $gcode .= " ; $comment" if $comment && $self->config->gcode_comments;
@@ -588,29 +743,26 @@ sub _Gx {
 sub set_extruder {
     my ($self, $extruder_id) = @_;
     
-    # return nothing if this extruder was already selected
-    return "" if (defined $self->extruder) && ($self->extruder->id == $extruder_id);
+    return "" if !$self->need_toolchange($extruder_id);
     
     # if we are running a single-extruder setup, just set the extruder and return nothing
-    if (!$self->multiple_extruders) {
-        $self->extruder($self->extruders->{$extruder_id});
-        return "";
+    if (!$self->_multiple_extruders) {
+        return $self->_toolchange($extruder_id);
     }
     
-    # trigger retraction on the current extruder (if any) 
-    my $gcode = "";
-    $gcode .= $self->retract(toolchange => 1) if defined $self->extruder;
+    # prepend retraction on the current extruder
+    my $gcode = $self->retract(toolchange => 1);
     
     # append custom toolchange G-code
-    if (defined $self->extruder && $self->config->toolchange_gcode) {
+    if (defined $self->_extruder && $self->config->toolchange_gcode) {
         $gcode .= sprintf "%s\n", $self->placeholder_parser->process($self->config->toolchange_gcode, {
-            previous_extruder   => $self->extruder->id,
+            previous_extruder   => $self->_extruder->id,
             next_extruder       => $extruder_id,
         });
     }
     
     # set the current extruder to the standby temperature
-    if ($self->standby_points && defined $self->extruder) {
+    if ($self->standby_points && defined $self->_extruder) {
         # move to the nearest standby point
         {
             my $last_pos = $self->last_pos->clone;
@@ -622,92 +774,25 @@ sub set_extruder {
         
         if ($self->config->standby_temperature_delta != 0) {
             my $temp = defined $self->layer && $self->layer->id == 0
-                ? $self->extruder->first_layer_temperature
-                : $self->extruder->temperature;
+                ? $self->_extruder->first_layer_temperature
+                : $self->_extruder->temperature;
             # we assume that heating is always slower than cooling, so no need to block
             $gcode .= $self->set_temperature($temp + $self->config->standby_temperature_delta, 0);
         }
     }
     
-    # set the new extruder
-    $self->extruder($self->extruders->{$extruder_id});
-    $gcode .= sprintf "%s%d%s\n", 
-        ($self->config->gcode_flavor eq 'makerware'
-            ? 'M135 T'
-            : $self->config->gcode_flavor eq 'sailfish'
-                ? 'M108 T'
-                : 'T'),
-        $extruder_id,
-        ($self->config->gcode_comments ? ' ; change extruder' : '');
-    
-    $gcode .= $self->reset_e;
+    # append the toolchange command
+    $gcode .= $self->_toolchange($extruder_id);
     
     # set the new extruder to the operating temperature
     if ($self->config->ooze_prevention && $self->config->standby_temperature_delta != 0) {
         my $temp = defined $self->layer && $self->layer->id == 0
-            ? $self->extruder->first_layer_temperature
-            : $self->extruder->temperature;
+            ? $self->_extruder->first_layer_temperature
+            : $self->_extruder->temperature;
         $gcode .= $self->set_temperature($temp, 1);
     }
     
     return $gcode;
 }
 
-sub set_fan {
-    my ($self, $speed, $dont_save) = @_;
-    
-    if ($self->last_fan_speed != $speed || $dont_save) {
-        $self->last_fan_speed($speed) if !$dont_save;
-        if ($speed == 0) {
-            my $code = $self->config->gcode_flavor eq 'teacup'
-                ? 'M106 S0'
-                : $self->config->gcode_flavor =~ /^(?:makerware|sailfish)$/
-                    ? 'M127'
-                    : 'M107';
-            return sprintf "$code%s\n", ($self->config->gcode_comments ? ' ; disable fan' : '');
-        } else {
-            if ($self->config->gcode_flavor =~ /^(?:makerware|sailfish)$/) {
-                return sprintf "M126%s\n", ($self->config->gcode_comments ? ' ; enable fan' : '');
-            } else {
-                return sprintf "M106 %s%d%s\n", ($self->config->gcode_flavor eq 'mach3' ? 'P' : 'S'),
-                    (255 * $speed / 100), ($self->config->gcode_comments ? ' ; enable fan' : '');
-            }
-        }
-    }
-    return "";
-}
-
-sub set_temperature {
-    my ($self, $temperature, $wait, $tool) = @_;
-    
-    return "" if $wait && $self->config->gcode_flavor =~ /^(?:makerware|sailfish)$/;
-    
-    my ($code, $comment) = ($wait && $self->config->gcode_flavor ne 'teacup')
-        ? ('M109', 'wait for temperature to be reached')
-        : ('M104', 'set temperature');
-    my $gcode = sprintf "$code %s%d %s; $comment\n",
-        ($self->config->gcode_flavor eq 'mach3' ? 'P' : 'S'), $temperature,
-        (defined $tool && ($self->multiple_extruders || $self->config->gcode_flavor =~ /^(?:makerware|sailfish)$/)) ? "T$tool " : "";
-    
-    $gcode .= "M116 ; wait for temperature to be reached\n"
-        if $self->config->gcode_flavor eq 'teacup' && $wait;
-    
-    return $gcode;
-}
-
-sub set_bed_temperature {
-    my ($self, $temperature, $wait) = @_;
-    
-    my ($code, $comment) = ($wait && $self->config->gcode_flavor ne 'teacup')
-        ? (($self->config->gcode_flavor =~ /^(?:makerware|sailfish)$/ ? 'M109' : 'M190'), 'wait for bed temperature to be reached')
-        : ('M140', 'set bed temperature');
-    my $gcode = sprintf "$code %s%d ; $comment\n",
-        ($self->config->gcode_flavor eq 'mach3' ? 'P' : 'S'), $temperature;
-    
-    $gcode .= "M116 ; wait for bed temperature to be reached\n"
-        if $self->config->gcode_flavor eq 'teacup' && $wait;
-    
-    return $gcode;
-}
-
 1;
diff --git a/lib/Slic3r/GCode/Layer.pm b/lib/Slic3r/GCode/Layer.pm
index 5f3531d6dc..2f70a4a4b4 100644
--- a/lib/Slic3r/GCode/Layer.pm
+++ b/lib/Slic3r/GCode/Layer.pm
@@ -63,8 +63,7 @@ sub process_layer {
     $self->gcodegen->enable_loop_clipping(!defined $self->spiralvase || !$self->spiralvase->enable);
     
     if (!$self->second_layer_things_done && $layer->id == 1) {
-        for my $extruder_id (sort keys %{$self->extruders}) {
-            my $extruder = $self->extruders->{$extruder_id};
+        for my $extruder (@{$self->extruders}) {
             $gcode .= $self->gcodegen->set_temperature($extruder->temperature, 0, $extruder->id)
                 if $extruder->temperature && $extruder->temperature != $extruder->first_layer_temperature;
         }
@@ -83,7 +82,7 @@ sub process_layer {
     if (((values %{$self->skirt_done}) < $self->print->config->skirt_height || $self->print->config->skirt_height == -1)
         && !$self->skirt_done->{$layer->print_z}) {
         $self->gcodegen->set_shift(@{$self->shift});
-        my @extruder_ids = sort keys %{$self->extruders};
+        my @extruder_ids = map { $_->id } @{$self->extruders};
         $gcode .= $self->gcodegen->set_extruder($extruder_ids[0]);
         # skip skirt if we have a large brim
         if ($layer->id < $self->print->config->skirt_height || $self->print->config->skirt_height == -1) {
@@ -136,7 +135,7 @@ sub process_layer {
         
         # tweak region ordering to save toolchanges
         my @region_ids = 0 .. ($self->print->region_count-1);
-        if ($self->gcodegen->multiple_extruders) {
+        if ($self->gcodegen->has_multiple_extruders) {
             my $last_extruder = $self->gcodegen->extruder;
             my $best_region_id = first { $self->print->regions->[$_]->config->perimeter_extruder-1 eq $last_extruder } @region_ids;
             @region_ids = ($best_region_id, grep $_ != $best_region_id, @region_ids) if $best_region_id;
@@ -176,7 +175,7 @@ sub process_layer {
                 # give priority to infill if we were already using its extruder and it wouldn't
                 # be good for perimeters
                 if ($self->print->config->infill_first
-                    || ($self->gcodegen->multiple_extruders && $region->config->infill_extruder-1 == $self->gcodegen->extruder->id && $region->config->infill_extruder != $region->config->perimeter_extruder)) {
+                    || ($self->gcodegen->has_multiple_extruders && $region->config->infill_extruder-1 == $self->gcodegen->extruder->id && $region->config->infill_extruder != $region->config->perimeter_extruder)) {
                     $gcode .= $self->_extrude_infill($infill_by_island[$i], $region);
                     $gcode .= $self->_extrude_perimeters($perimeters_by_island[$i], $region);
                 } else {
diff --git a/lib/Slic3r/Print.pm b/lib/Slic3r/Print.pm
index 4c3a041075..110d198783 100644
--- a/lib/Slic3r/Print.pm
+++ b/lib/Slic3r/Print.pm
@@ -773,8 +773,8 @@ sub write_gcode {
         placeholder_parser  => $self->placeholder_parser,
         layer_count         => $layer_count,
     );
-    $gcodegen->config->apply_print_config($self->config);
-    $gcodegen->set_extruders($self->extruders, $self->config);
+    $gcodegen->apply_print_config($self->config);
+    $gcodegen->set_extruders($self->extruders);
     
     print $fh "G21 ; set units to millimeters\n" if $self->config->gcode_flavor ne 'makerware';
     print $fh $gcodegen->set_fan(0, 1) if $self->config->cooling && $self->config->disable_fan_first_layers;
@@ -935,14 +935,13 @@ sub write_gcode {
     }
     
     # write end commands to file
-    print $fh $gcodegen->retract if $gcodegen->extruder;  # empty prints don't even set an extruder
+    print $fh $gcodegen->retract;
     print $fh $gcodegen->set_fan(0);
     printf $fh "%s\n", $gcodegen->placeholder_parser->process($self->config->end_gcode);
     
     $self->total_used_filament(0);
     $self->total_extruded_volume(0);
-    foreach my $extruder_id (@{$self->extruders}) {
-        my $extruder = $gcodegen->extruders->{$extruder_id};
+    foreach my $extruder (@{$gcodegen->extruders}) {
         # the final retraction doesn't really count as "used filament"
         my $used_filament = $extruder->absolute_E + $extruder->retract_length;
         my $extruded_volume = $extruder->extruded_volume($used_filament);
diff --git a/xs/src/libslic3r/PrintConfig.cpp b/xs/src/libslic3r/PrintConfig.cpp
index 3486afc223..f5b2771349 100644
--- a/xs/src/libslic3r/PrintConfig.cpp
+++ b/xs/src/libslic3r/PrintConfig.cpp
@@ -960,6 +960,7 @@ t_optiondef_map PrintConfigDef::def = PrintConfigDef::build_def();
 REGISTER_CLASS(DynamicPrintConfig, "Config");
 REGISTER_CLASS(PrintObjectConfig, "Config::PrintObject");
 REGISTER_CLASS(PrintRegionConfig, "Config::PrintRegion");
+REGISTER_CLASS(GCodeConfig, "Config::GCode");
 REGISTER_CLASS(PrintConfig, "Config::Print");
 REGISTER_CLASS(FullPrintConfig, "Config::Full");
 #endif
diff --git a/xs/src/libslic3r/PrintConfig.hpp b/xs/src/libslic3r/PrintConfig.hpp
index cdc3d7173c..7b29d9b593 100644
--- a/xs/src/libslic3r/PrintConfig.hpp
+++ b/xs/src/libslic3r/PrintConfig.hpp
@@ -306,7 +306,35 @@ class PrintRegionConfig : public virtual StaticPrintConfig
     };
 };
 
-class PrintConfig : public virtual StaticPrintConfig
+class GCodeConfig : public virtual StaticPrintConfig
+{
+    public:
+    ConfigOptionString              extrusion_axis;
+    ConfigOptionBool                gcode_comments;
+    ConfigOptionEnum<GCodeFlavor>   gcode_flavor;
+    ConfigOptionBool                use_firmware_retraction;
+    ConfigOptionBool                use_relative_e_distances;
+    
+    GCodeConfig() : StaticPrintConfig() {
+        this->extrusion_axis.value                               = "E";
+        this->gcode_comments.value                               = false;
+        this->gcode_flavor.value                                 = gcfRepRap;
+        this->use_firmware_retraction.value                      = false;
+        this->use_relative_e_distances.value                     = false;
+    };
+    
+    ConfigOption* option(const t_config_option_key opt_key, bool create = false) {
+        if (opt_key == "extrusion_axis")                             return &this->extrusion_axis;
+        if (opt_key == "gcode_comments")                             return &this->gcode_comments;
+        if (opt_key == "gcode_flavor")                               return &this->gcode_flavor;
+        if (opt_key == "use_firmware_retraction")                    return &this->use_firmware_retraction;
+        if (opt_key == "use_relative_e_distances")                   return &this->use_relative_e_distances;
+        
+        return NULL;
+    };
+};
+
+class PrintConfig : public GCodeConfig
 {
     public:
     ConfigOptionBool                avoid_crossing_perimeters;
@@ -324,7 +352,6 @@ class PrintConfig : public virtual StaticPrintConfig
     ConfigOptionFloat               extruder_clearance_height;
     ConfigOptionFloat               extruder_clearance_radius;
     ConfigOptionPoints              extruder_offset;
-    ConfigOptionString              extrusion_axis;
     ConfigOptionFloats              extrusion_multiplier;
     ConfigOptionBool                fan_always_on;
     ConfigOptionInt                 fan_below_layer_time;
@@ -336,8 +363,6 @@ class PrintConfig : public virtual StaticPrintConfig
     ConfigOptionInts                first_layer_temperature;
     ConfigOptionBool                g0;
     ConfigOptionBool                gcode_arcs;
-    ConfigOptionBool                gcode_comments;
-    ConfigOptionEnum<GCodeFlavor>   gcode_flavor;
     ConfigOptionFloat               infill_acceleration;
     ConfigOptionBool                infill_first;
     ConfigOptionString              layer_gcode;
@@ -372,13 +397,11 @@ class PrintConfig : public virtual StaticPrintConfig
     ConfigOptionInt                 threads;
     ConfigOptionString              toolchange_gcode;
     ConfigOptionFloat               travel_speed;
-    ConfigOptionBool                use_firmware_retraction;
-    ConfigOptionBool                use_relative_e_distances;
     ConfigOptionFloat               vibration_limit;
     ConfigOptionBools               wipe;
     ConfigOptionFloat               z_offset;
     
-    PrintConfig() : StaticPrintConfig() {
+    PrintConfig() : GCodeConfig() {
         this->avoid_crossing_perimeters.value                    = false;
         this->bed_shape.values.push_back(Pointf(0,0));
         this->bed_shape.values.push_back(Pointf(200,0));
@@ -398,7 +421,6 @@ class PrintConfig : public virtual StaticPrintConfig
         this->extruder_clearance_radius.value                    = 20;
         this->extruder_offset.values.resize(1);
         this->extruder_offset.values[0]                          = Pointf(0,0);
-        this->extrusion_axis.value                               = "E";
         this->extrusion_multiplier.values.resize(1);
         this->extrusion_multiplier.values[0]                     = 1;
         this->fan_always_on.value                                = false;
@@ -415,8 +437,6 @@ class PrintConfig : public virtual StaticPrintConfig
         this->first_layer_temperature.values[0]                  = 200;
         this->g0.value                                           = false;
         this->gcode_arcs.value                                   = false;
-        this->gcode_comments.value                               = false;
-        this->gcode_flavor.value                                 = gcfRepRap;
         this->infill_acceleration.value                          = 0;
         this->infill_first.value                                 = false;
         this->layer_gcode.value                                  = "";
@@ -460,8 +480,6 @@ class PrintConfig : public virtual StaticPrintConfig
         this->threads.value                                      = 2;
         this->toolchange_gcode.value                             = "";
         this->travel_speed.value                                 = 130;
-        this->use_firmware_retraction.value                      = false;
-        this->use_relative_e_distances.value                     = false;
         this->vibration_limit.value                              = 0;
         this->wipe.values.resize(1);
         this->wipe.values[0]                                     = false;
@@ -484,7 +502,6 @@ class PrintConfig : public virtual StaticPrintConfig
         if (opt_key == "extruder_clearance_height")                  return &this->extruder_clearance_height;
         if (opt_key == "extruder_clearance_radius")                  return &this->extruder_clearance_radius;
         if (opt_key == "extruder_offset")                            return &this->extruder_offset;
-        if (opt_key == "extrusion_axis")                             return &this->extrusion_axis;
         if (opt_key == "extrusion_multiplier")                       return &this->extrusion_multiplier;
         if (opt_key == "fan_always_on")                              return &this->fan_always_on;
         if (opt_key == "fan_below_layer_time")                       return &this->fan_below_layer_time;
@@ -496,8 +513,6 @@ class PrintConfig : public virtual StaticPrintConfig
         if (opt_key == "first_layer_temperature")                    return &this->first_layer_temperature;
         if (opt_key == "g0")                                         return &this->g0;
         if (opt_key == "gcode_arcs")                                 return &this->gcode_arcs;
-        if (opt_key == "gcode_comments")                             return &this->gcode_comments;
-        if (opt_key == "gcode_flavor")                               return &this->gcode_flavor;
         if (opt_key == "infill_acceleration")                        return &this->infill_acceleration;
         if (opt_key == "infill_first")                               return &this->infill_first;
         if (opt_key == "layer_gcode")                                return &this->layer_gcode;
@@ -532,17 +547,20 @@ class PrintConfig : public virtual StaticPrintConfig
         if (opt_key == "threads")                                    return &this->threads;
         if (opt_key == "toolchange_gcode")                           return &this->toolchange_gcode;
         if (opt_key == "travel_speed")                               return &this->travel_speed;
-        if (opt_key == "use_firmware_retraction")                    return &this->use_firmware_retraction;
-        if (opt_key == "use_relative_e_distances")                   return &this->use_relative_e_distances;
         if (opt_key == "vibration_limit")                            return &this->vibration_limit;
         if (opt_key == "wipe")                                       return &this->wipe;
         if (opt_key == "z_offset")                                   return &this->z_offset;
         
+        // look in parent class
+        ConfigOption* opt;
+        if ((opt = GCodeConfig::option(opt_key, create)) != NULL) return opt;
+        
         return NULL;
     };
 };
 
-class FullPrintConfig : public PrintObjectConfig, public PrintRegionConfig, public PrintConfig {
+class FullPrintConfig : public PrintObjectConfig, public PrintRegionConfig, public PrintConfig
+{
     public:
     ConfigOption* option(const t_config_option_key opt_key, bool create = false) {
         ConfigOption* opt;
@@ -551,15 +569,6 @@ class FullPrintConfig : public PrintObjectConfig, public PrintRegionConfig, publ
         if ((opt = PrintConfig::option(opt_key, create)) != NULL) return opt;
         return NULL;
     };
-    
-    std::string get_extrusion_axis() {
-        if (this->gcode_flavor == gcfMach3) {
-            return std::string("A");
-        } else if (this->gcode_flavor == gcfNoExtrusion) {
-            return std::string("");
-        }
-        return this->extrusion_axis;
-    }
 };
 
 }
diff --git a/xs/xsp/Config.xsp b/xs/xsp/Config.xsp
index 4c56e10c89..b11533e36a 100644
--- a/xs/xsp/Config.xsp
+++ b/xs/xsp/Config.xsp
@@ -28,6 +28,27 @@
     void normalize();
 };
 
+%name{Slic3r::Config::GCode} class GCodeConfig {
+    GCodeConfig();
+    ~GCodeConfig();
+    bool has(t_config_option_key opt_key);
+    SV* as_hash();
+    SV* get(t_config_option_key opt_key);
+    SV* get_at(t_config_option_key opt_key, int i);
+    bool set(t_config_option_key opt_key, SV* value);
+    bool set_deserialize(t_config_option_key opt_key, SV* str);
+    std::string serialize(t_config_option_key opt_key);
+    double get_abs_value(t_config_option_key opt_key);
+    %name{get_abs_value_over}
+        double get_abs_value(t_config_option_key opt_key, double ratio_over);
+    void apply_print_config(PrintConfig* other)
+        %code{% THIS->apply(*other, true); %};
+    void apply_dynamic(DynamicPrintConfig* other)
+        %code{% THIS->apply(*other, true); %};
+    std::vector<std::string> get_keys()
+        %code{% THIS->keys(&RETVAL); %};
+};
+
 %name{Slic3r::Config::Print} class PrintConfig {
     PrintConfig();
     ~PrintConfig();
@@ -112,7 +133,6 @@
         %code{% THIS->apply(*other, true); %};
     std::vector<std::string> get_keys()
         %code{% THIS->keys(&RETVAL); %};
-    std::string get_extrusion_axis();
 };
 
 %package{Slic3r::Config};
diff --git a/xs/xsp/Extruder.xsp b/xs/xsp/Extruder.xsp
index 582b39b996..621924a5c6 100644
--- a/xs/xsp/Extruder.xsp
+++ b/xs/xsp/Extruder.xsp
@@ -6,7 +6,9 @@
 %}
 
 %name{Slic3r::Extruder} class Extruder {
-    Extruder(int id, PrintConfig *config);
+    // We don't need a Perl constructor with PrintConfig at the moment
+    //Extruder(int id, PrintConfig *config);
+    Extruder(int id, FullPrintConfig *config);
     ~Extruder();
     void reset();
     double extrude(double dE);
diff --git a/xs/xsp/my.map b/xs/xsp/my.map
index a7264c62e4..41476ca2cb 100644
--- a/xs/xsp/my.map
+++ b/xs/xsp/my.map
@@ -29,6 +29,9 @@ Ref<PrintObjectConfig>     O_OBJECT_SLIC3R_T
 PrintRegionConfig*         O_OBJECT_SLIC3R
 Ref<PrintRegionConfig>     O_OBJECT_SLIC3R_T
 
+GCodeConfig*               O_OBJECT_SLIC3R
+Ref<GCodeConfig>           O_OBJECT_SLIC3R_T
+
 PrintConfig*               O_OBJECT_SLIC3R
 Ref<PrintConfig>           O_OBJECT_SLIC3R_T
 
diff --git a/xs/xsp/typemap.xspt b/xs/xsp/typemap.xspt
index 57c321bb49..87283debf2 100644
--- a/xs/xsp/typemap.xspt
+++ b/xs/xsp/typemap.xspt
@@ -40,6 +40,8 @@
 %typemap{Ref<PrintObjectConfig>}{simple};
 %typemap{PrintRegionConfig*};
 %typemap{Ref<PrintRegionConfig>}{simple};
+%typemap{GCodeConfig*};
+%typemap{Ref<GCodeConfig>}{simple};
 %typemap{PrintConfig*};
 %typemap{Ref<PrintConfig>}{simple};
 %typemap{FullPrintConfig*};