diff --git a/Build.PL b/Build.PL
index 321a7e4dd..d220df94d 100644
--- a/Build.PL
+++ b/Build.PL
@@ -28,7 +28,6 @@ my %prereqs = qw(
 );
 my %recommends = qw(
     Class::XSAccessor               0
-    XML::SAX::ExpatXS               0
     Test::Harness                   0
 );
 
@@ -125,15 +124,7 @@ EOF
             if $module =~ /^(?:OpenGL|Test::Harness)$/;
         
         push @cmd, "$module~$version";
-        if ($module eq 'XML::SAX::ExpatXS' && $^O eq 'MSWin32') {
-            my $mingw = 'C:\dev\CitrusPerl\mingw64';
-            $mingw = 'C:\dev\CitrusPerl\mingw32' if !-d $mingw;
-            if (!-d $mingw) {
-                print "Could not find the MinGW directory at $mingw; skipping XML::SAX::ExpatXS (only needed for faster parsing of AMF files)\n";
-            } else {
-                push @cmd, sprintf('--configure-args="EXPATLIBPATH=%s\lib EXPATINCPATH=%s\include"', $mingw, $mingw);
-            }
-        }
+
         my $res = system @cmd;
         if ($res != 0) {
             if (exists $prereqs{$module}) {
diff --git a/lib/Slic3r.pm b/lib/Slic3r.pm
index 31e2c29a2..9719f1d32 100644
--- a/lib/Slic3r.pm
+++ b/lib/Slic3r.pm
@@ -62,7 +62,6 @@ use Slic3r::ExtrusionLoop;
 use Slic3r::ExtrusionPath;
 use Slic3r::Flow;
 use Slic3r::Format::AMF;
-use Slic3r::Format::OBJ;
 use Slic3r::Format::STL;
 use Slic3r::GCode::ArcFitting;
 use Slic3r::GCode::MotionPlanner;
diff --git a/lib/Slic3r/Format/AMF.pm b/lib/Slic3r/Format/AMF.pm
index 9aa0ca7c1..603a4014a 100644
--- a/lib/Slic3r/Format/AMF.pm
+++ b/lib/Slic3r/Format/AMF.pm
@@ -3,27 +3,6 @@ use Moo;
 
 use Slic3r::Geometry qw(X Y Z);
 
-sub read_file {
-    my $self = shift;
-    my ($file) = @_;
-    
-    eval qq{
-    	require Slic3r::Format::AMF::Parser;
-    	use XML::SAX::ParserFactory;
-    	1;
-    } or die "AMF parsing requires XML::SAX\n";
-    
-    Slic3r::open(\my $fh, '<', $file) or die "Failed to open $file\n";
-    
-    my $model = Slic3r::Model->new;
-    XML::SAX::ParserFactory
-        ->parser(Handler => Slic3r::Format::AMF::Parser->new(_model => $model))
-        ->parse_file($fh);
-    close $fh;
-    
-    return $model;
-}
-
 sub write_file {
     my $self = shift;
     my ($file, $model, %params) = @_;
diff --git a/lib/Slic3r/Format/AMF/Parser.pm b/lib/Slic3r/Format/AMF/Parser.pm
deleted file mode 100644
index 0ea3affb0..000000000
--- a/lib/Slic3r/Format/AMF/Parser.pm
+++ /dev/null
@@ -1,164 +0,0 @@
-package Slic3r::Format::AMF::Parser;
-use strict;
-use warnings;
-
-use base 'XML::SAX::Base';
-
-my %xyz_index = (x => 0, y => 1, z => 2); #=
-
-sub new {
-    my $self = shift->SUPER::new(@_);
-    $self->{_tree} = [];
-    $self->{_objects_map} = {};  # this hash maps AMF object IDs to object indexes in $model->objects
-    $self->{_instances} = {};   # apply these lazily to make sure all objects have been parsed
-    $self;
-}
-
-sub start_element {
-    my $self = shift;
-    my $data = shift;
-    
-    if ($data->{LocalName} eq 'object') {
-        $self->{_object} = $self->{_model}->add_object;
-        $self->{_object_vertices} = [];
-        $self->{_objects_map}{ $self->_get_attribute($data, 'id') } = $#{ $self->{_model}->objects };
-    } elsif ($data->{LocalName} eq 'vertex') {
-        $self->{_vertex} = ["", "", ""];
-    } elsif ($self->{_vertex} && $data->{LocalName} =~ /^[xyz]$/ && $self->{_tree}[-1] eq 'coordinates') {
-        $self->{_coordinate} = $data->{LocalName};
-    } elsif ($data->{LocalName} eq 'volume') {
-        $self->{_volume} = $self->{_object}->add_volume(
-            material_id => $self->_get_attribute($data, 'materialid') // undef,
-            mesh        => Slic3r::TriangleMesh->new,
-        );
-        $self->{_volume_facets} = [];
-    } elsif ($data->{LocalName} eq 'triangle') {
-        $self->{_triangle} = ["", "", ""];
-    } elsif ($self->{_triangle} && $data->{LocalName} =~ /^v([123])$/ && $self->{_tree}[-1] eq 'triangle') {
-        $self->{_vertex_idx} = $1-1;
-    } elsif ($data->{LocalName} eq 'material') {
-        my $material_id = $self->_get_attribute($data, 'id') // '_';
-        $self->{_material} = $self->{_model}->set_material($material_id);
-    } elsif ($data->{LocalName} eq 'metadata') {
-        $self->{_metadata_type} = $self->_get_attribute($data, 'type');
-        $self->{_metadata_value} = '';
-    } elsif ($data->{LocalName} eq 'constellation') {
-        $self->{_constellation} = 1; # we merge all constellations as we don't support more than one
-    } elsif ($data->{LocalName} eq 'instance' && $self->{_constellation}) {
-        my $object_id = $self->_get_attribute($data, 'objectid');
-        $self->{_instances}{$object_id} ||= [];
-        push @{ $self->{_instances}{$object_id} }, $self->{_instance} = {};
-    } elsif ($data->{LocalName} =~ /^(?:deltax|deltay|rz)$/ && $self->{_instance}) {
-        $self->{_instance_property} = $data->{LocalName};
-    }
-    
-    push @{$self->{_tree}}, $data->{LocalName};
-}
-
-sub characters {
-    my $self = shift;
-    my $data = shift;
-    
-    if ($self->{_vertex} && $self->{_coordinate}) {
-        $self->{_vertex}[ $xyz_index{$self->{_coordinate}} ] .= $data->{Data};
-    } elsif ($self->{_triangle} && defined $self->{_vertex_idx}) {
-        $self->{_triangle}[ $self->{_vertex_idx} ] .= $data->{Data};
-    } elsif ($self->{_metadata_type}) {
-        $self->{_metadata_value} .= $data->{Data};
-    } elsif ($self->{_instance_property}) {
-        $self->{_instance}{ $self->{_instance_property} } .= $data->{Data};
-    }
-}
-
-sub end_element {
-    my $self = shift;
-    my $data = shift;
-    
-    pop @{$self->{_tree}};
-    
-    if ($data->{LocalName} eq 'object') {
-        $self->{_object} = undef;
-        $self->{_object_vertices} = undef;
-    } elsif ($data->{LocalName} eq 'vertex') {
-        push @{$self->{_object_vertices}}, $self->{_vertex};
-        $self->{_vertex} = undef;
-    } elsif ($self->{_coordinate} && $data->{LocalName} =~ /^[xyz]$/) {
-        $self->{_coordinate} = undef;
-    } elsif ($data->{LocalName} eq 'volume') {
-        $self->{_volume}->mesh->ReadFromPerl($self->{_object_vertices}, $self->{_volume_facets});
-        $self->{_volume}->mesh->repair;
-        $self->{_volume} = undef;
-        $self->{_volume_facets} = undef;
-    } elsif ($data->{LocalName} eq 'triangle') {
-        push @{$self->{_volume_facets}}, $self->{_triangle};
-        $self->{_triangle} = undef;
-    } elsif (defined $self->{_vertex_idx} && $data->{LocalName} =~ /^v[123]$/) {
-        $self->{_vertex_idx} = undef;
-    } elsif ($data->{LocalName} eq 'material') {
-        $self->{_material} = undef;
-    } elsif ($data->{LocalName} eq 'metadata') {
-        my $value = $self->{_metadata_value};
-        if ($self->{_metadata_type} eq 'slic3r.layer_height_profile') {
-            my @layer_height_profile = split(';', $value);
-            $self->{_object}->set_layer_height_profile(\@layer_height_profile) if ($self->{_object});
-        } elsif ($self->{_metadata_type} =~ /^slic3r\.(.+)/) {
-            my $opt_key = $1;
-            if (exists $Slic3r::Config::Options->{$opt_key}) {
-                my $config;
-                if ($self->{_material}) {
-                    $config = $self->{_material}->config;
-                } elsif ($self->{_volume}) {
-                    $config = $self->{_volume}->config;
-                } elsif ($self->{_object}) {
-                    $config = $self->{_object}->config;
-                }
-                
-                $config->set_deserialize($opt_key, $value) if defined $config;
-            } elsif ($opt_key eq 'modifier' && $self->{_volume}) {
-                $self->{_volume}->set_modifier($value);
-            }
-        } elsif ($self->{_metadata_type} eq 'name') {
-            my $obj = $self->{_volume} // $self->{_object};
-            $obj->set_name($value) if $obj;
-        } elsif ($self->{_material}) {
-            $self->{_material}->set_attribute($self->{_metadata_type}, $value);
-        }
-        $self->{_metadata_type} = undef;
-        $self->{_metadata_value} = undef;
-    } elsif ($data->{LocalName} eq 'constellation') {
-        $self->{_constellation} = undef;
-    } elsif ($data->{LocalName} eq 'instance') {
-        $self->{_instance} = undef;
-    } elsif ($data->{LocalName} =~ /^(?:deltax|deltay|rz)$/ && $self->{_instance}) {
-        $self->{_instance_property} = undef;
-    }
-}
-
-sub end_document {
-    my $self = shift;
-    
-    foreach my $object_id (keys %{ $self->{_instances} }) {
-        my $new_object_id = $self->{_objects_map}{$object_id};
-        if (!defined $new_object_id) {
-            warn "Undefined object $object_id referenced in constellation\n";
-            next;
-        }
-        
-        foreach my $instance (@{ $self->{_instances}{$object_id} }) {
-            next if !defined($instance->{deltax}) || !defined($instance->{deltay});
-            $self->{_model}->objects->[$new_object_id]->add_instance(
-                rotation => $instance->{rz} || 0,
-                offset   => Slic3r::Pointf->new($instance->{deltax} || 0, $instance->{deltay} || 0),
-            );
-        }
-    }
-}
-
-sub _get_attribute {
-    my $self = shift;
-    my ($data, $name) = @_;
-    
-    return +(map $_->{Value}, grep $_->{Name} eq $name, values %{$data->{Attributes}})[0];
-}
-
-1;
diff --git a/lib/Slic3r/Format/OBJ.pm b/lib/Slic3r/Format/OBJ.pm
deleted file mode 100644
index 616b38cdc..000000000
--- a/lib/Slic3r/Format/OBJ.pm
+++ /dev/null
@@ -1,34 +0,0 @@
-package Slic3r::Format::OBJ;
-use Moo;
-
-use File::Basename qw(basename);
-
-sub read_file {
-    my $self = shift;
-    my ($file) = @_;
-    
-    Slic3r::open(\my $fh, '<', $file) or die "Failed to open $file\n";
-    my $vertices = [];
-    my $facets = [];
-    while (<$fh>) {
-        if (/^v ([^ ]+)\s+([^ ]+)\s+([^ ]+)/) {
-            push @$vertices, [$1, $2, $3];
-        } elsif (/^f (\d+).*? (\d+).*? (\d+).*?/) {
-            push @$facets, [ $1-1, $2-1, $3-1 ];
-        }
-    }
-    close $fh;
-    
-    my $mesh = Slic3r::TriangleMesh->new;
-    $mesh->ReadFromPerl($vertices, $facets);
-    $mesh->repair;
-    
-    my $model = Slic3r::Model->new;
-    
-    my $basename = basename($file);
-    my $object = $model->add_object(input_file => $file, name => $basename);
-    my $volume = $object->add_volume(mesh => $mesh, name => $basename);
-    return $model;
-}
-
-1;
diff --git a/lib/Slic3r/Format/STL.pm b/lib/Slic3r/Format/STL.pm
index 11928d8b2..a6a1836e4 100644
--- a/lib/Slic3r/Format/STL.pm
+++ b/lib/Slic3r/Format/STL.pm
@@ -3,28 +3,6 @@ use Moo;
 
 use File::Basename qw(basename);
 
-sub read_file {
-    my $self = shift;
-    my ($file) = @_;
-    
-    my $path = Slic3r::encode_path($file);
-    die "Failed to open $file\n" if !-e $path;
-    
-    my $mesh = Slic3r::TriangleMesh->new;
-    $mesh->ReadSTLFile($path);
-    $mesh->repair;
-    
-    die "This STL file couldn't be read because it's empty.\n"
-        if $mesh->facets_count == 0;
-    
-    my $model = Slic3r::Model->new;
-    
-    my $basename = basename($file);
-    my $object = $model->add_object(input_file => $file, name => $basename);
-    my $volume = $object->add_volume(mesh => $mesh, name => $basename);
-    return $model;
-}
-
 sub write_file {
     my $self = shift;
     my ($file, $mesh, %params) = @_;
diff --git a/utils/amf-to-stl.pl b/utils/amf-to-stl.pl
index b421dd33a..8b26cedb3 100755
--- a/utils/amf-to-stl.pl
+++ b/utils/amf-to-stl.pl
@@ -25,7 +25,7 @@ my %opt = ();
 }
 
 {
-    my $model = Slic3r::Format::AMF->read_file($ARGV[0]);
+    my $model = Slic3r::Model->load_amf(Slic3r::encode_path($ARGV[0]));
     my $output_file = $ARGV[0];
     $output_file =~ s/\.amf(?:\.xml)?$/\.stl/i;