diff --git a/src/libslic3r/BeltGCodeWriter.cpp b/src/libslic3r/BeltGCodeWriter.cpp
index a2322c9243..7c645edf43 100644
--- a/src/libslic3r/BeltGCodeWriter.cpp
+++ b/src/libslic3r/BeltGCodeWriter.cpp
@@ -38,7 +38,11 @@ void BeltGCodeWriter::set_machine_frame_transform(const PrintConfig &config)
 Vec3d BeltGCodeWriter::to_machine_coords(const Vec3d &pos) const
 {
     // Step 1+2: To Cartesian (back_transform + axis_remap).
-    Vec3d after_back = m_belt_back_transform.apply(pos);
+    // In world-coordinates mode (PA line / PA pattern calibration) the input
+    // already describes a point relative to the belt surface, so the
+    // slicer->world back-transform is skipped and only the machine kinematics
+    // (axis remap + frame shear/scale) are applied.
+    Vec3d after_back = m_world_coordinates ? pos : m_belt_back_transform.apply(pos);
     Vec3d result     = apply_axis_remap(after_back);
     Vec3d after_remap = result;
     // Step 3: Machine-frame transform (belt frame tilt) applied LAST so it acts
diff --git a/src/libslic3r/BeltGCodeWriter.hpp b/src/libslic3r/BeltGCodeWriter.hpp
index 30159f4f33..ff7428d062 100644
--- a/src/libslic3r/BeltGCodeWriter.hpp
+++ b/src/libslic3r/BeltGCodeWriter.hpp
@@ -23,6 +23,14 @@ public:
     void set_machine_frame_transform(const PrintConfig &config);
     Vec3d to_machine_coords(const Vec3d &pos) const;
 
+    // World-coordinates mode: incoming coordinates are treated as points
+    // relative to the physical belt surface (X across, Y along the belt,
+    // Z height above it) instead of slicing-frame coordinates — the
+    // slicer->world back-transform is skipped. Used by the PA line / PA
+    // pattern calibration generators, whose logical bed coordinates describe
+    // first-layer drawings on the build surface.
+    void set_world_coordinates(bool enable) { m_world_coordinates = enable; }
+
     // First-layer plane: when set to a non-null active evaluator, travel
     // speed selection consults the plane per-move and uses
     // initial_layer_travel_speed for points within first_layer_height_mm
@@ -47,6 +55,7 @@ protected:
 private:
     BeltBackTransform     m_belt_back_transform;
     MachineFrameTransform m_machine_frame_transform;
+    bool                  m_world_coordinates = false;
     // Borrowed pointer; lifetime owned by GCode.  null = inactive.
     const FirstLayerPlane *m_first_layer_plane = nullptr;
     double          m_first_layer_thickness_mm = 0.;
diff --git a/src/libslic3r/GCode.cpp b/src/libslic3r/GCode.cpp
index 3f21616bbb..af59428c89 100644
--- a/src/libslic3r/GCode.cpp
+++ b/src/libslic3r/GCode.cpp
@@ -1834,6 +1834,12 @@ std::vector<GCode::LayerToPrint> GCode::collect_layers_to_print(const PrintObjec
             last_extrusion_layer = &layers_to_print.back();
     }
 
+    // ORCA-Belt: objects print at their position along the belt, so the first
+    // extrusions legitimately start far above Z=0. Drop the spurious
+    // "empty layers from the bed" range while keeping genuine mid-print gaps.
+    if (skip_empty_first_layer && !warning_ranges.empty() && warning_ranges.front().first == 0.)
+        warning_ranges.erase(warning_ranges.begin());
+
     if (! warning_ranges.empty()) {
         std::string warning;
         size_t i = 0;
@@ -3307,7 +3313,16 @@ void GCode::_do_export(Print& print, GCodeOutputStream &file, ThumbnailsGenerato
 
         pa_test.set_speed(fast_speed, slow_speed);
         pa_test.draw_numbers() = print.calib_params().print_numbers;
+
+        // ORCA-Belt: the PA line test draws directly on the build surface in
+        // logical bed coordinates — on a belt printer that surface is the
+        // belt plane, not the slicing plane.
+        BeltGCodeWriter* belt_writer = dynamic_cast<BeltGCodeWriter*>(m_writer.get());
+        if (belt_writer != nullptr)
+            belt_writer->set_world_coordinates(true);
         gcode += pa_test.generate_test(params.start, params.step, std::llround(std::ceil((params.end - params.start) / params.step)) + 1);
+        if (belt_writer != nullptr)
+            belt_writer->set_world_coordinates(false);
 
         file.write(gcode);
     } else {
@@ -4653,31 +4668,57 @@ LayerResult GCode::process_layer(
     gcode += ";_SET_FAN_SPEED_CHANGING_LAYER\n";
 
     //Calibration Layer-specific GCode
+    // ORCA-Belt: on belt printers the calibration object is counter-rotated to
+    // stand upright in slicing space on top of a support wedge, so its first
+    // layer starts above Z=0 (at its position along the belt) with support-only
+    // layers below it. Reference the per-height calibration bands to the bottom
+    // of the object so they keep their designed meaning; on regular printers
+    // the object base is at Z=0 and calib_z == print_z.
+    double calib_z = print_z;
+    if (m_config.belt_printer.value && print.calib_mode() != CalibMode::Calib_None) {
+        // Skip empty ghost layers the grid may produce below the object.
+        for (const Layer* l : layer.object()->layers())
+            if (!l->lslices.empty()) {
+                calib_z = print_z - (l->print_z - l->height);
+                break;
+            }
+    }
     switch (print.calib_mode()) {
         case CalibMode::Calib_PA_Tower: {
-            gcode += writer().set_pressure_advance(print.calib_params().start + static_cast<int>(print_z) * print.calib_params().step);
+            gcode += writer().set_pressure_advance(print.calib_params().start + static_cast<int>(std::max(0.0, calib_z)) * print.calib_params().step);
             break;
         }
         case CalibMode::Calib_Temp_Tower: {
-            gcode += writer().set_temperature(this->interpolate_value_across_layers(static_cast<float>(print.calib_params().start), static_cast<float>(print.calib_params().end), 5.0f));
+            // ORCA-Belt: the sectioned variant prints each temperature as its
+            // own object in native belt orientation, with the temperature
+            // encoded in the object name ("temp_230") — step per object
+            // instead of ramping per layer band.
+            int sectioned_temp = 0;
+            if (m_config.belt_printer.value &&
+                sscanf(layer.object()->model_object()->name.c_str(), "temp_%d", &sectioned_temp) == 1 &&
+                sectioned_temp > 0) {
+                gcode += writer().set_temperature(static_cast<unsigned int>(sectioned_temp));
+            } else {
+                gcode += writer().set_temperature(this->interpolate_value_across_layers(static_cast<float>(print.calib_params().start), static_cast<float>(print.calib_params().end), 5.0f));
+            }
             break;
         }
         case CalibMode::Calib_VFA_Tower: {
-            auto _speed = print.calib_params().start + std::floor(print_z / 5.0) * print.calib_params().step;
+            auto _speed = print.calib_params().start + std::floor(std::max(0.0, calib_z) / 5.0) * print.calib_params().step;
             m_calib_config.set_key_value("outer_wall_speed", new ConfigOptionFloat(std::round(_speed)));
             break;
         }
         case CalibMode::Calib_Vol_speed_Tower: {
-            auto _speed = print.calib_params().start + print_z * print.calib_params().step;
+            auto _speed = print.calib_params().start + std::max(0.0, calib_z) * print.calib_params().step;
             m_calib_config.set_key_value("outer_wall_speed", new ConfigOptionFloat(std::round(_speed)));
             break;
         }
         case CalibMode::Calib_Retraction_tower: {
-            auto _length = print.calib_params().start + std::floor(std::max(0.0,print_z-0.4)) * print.calib_params().step;
+            auto _length = print.calib_params().start + std::floor(std::max(0.0,calib_z-0.4)) * print.calib_params().step;
             DynamicConfig _cfg;
             _cfg.set_key_value("retraction_length", new ConfigOptionFloats{_length});
             writer().config.apply(_cfg);
-            sprintf(buf, "; Calib_Retraction_tower: Z_HEIGHT: %g, length:%g\n", print_z, _length);
+            sprintf(buf, "; Calib_Retraction_tower: Z_HEIGHT: %g, length:%g\n", calib_z, _length);
             gcode += buf;
             break;
         }
@@ -7415,25 +7456,39 @@ std::string GCode::extrusion_role_to_string_for_parser(const ExtrusionRole & rol
 // Step = 0 means gradual interpolation finishing at last value.
 float GCode::interpolate_value_across_layers(float start_value, float end_value, float step) const
 {
-    if (m_layer_index <= 1) {
+    float ratio;
+    // ORCA-Belt: counter-rotated calibration objects stand on a support wedge,
+    // so support-only layers below the object would stretch a layer-index
+    // interpolation. Use the object's own Z span instead, so the value ramps
+    // across the test geometry only.
+    if (m_config.belt_printer.value && m_layer != nullptr && !m_layer->object()->layers().empty()) {
+        const auto& layers = m_layer->object()->layers();
+        // Skip empty ghost layers the grid may produce below the object.
+        double z_min = layers.front()->print_z;
+        for (const Layer* l : layers)
+            if (!l->lslices.empty()) { z_min = l->print_z; break; }
+        const double z_max = layers.back()->print_z;
+        if (m_layer->print_z <= z_min + EPSILON || z_max - z_min <= EPSILON)
+            return start_value;
+        ratio = float(std::min(1.0, (m_layer->print_z - z_min) / (z_max - z_min)));
+    } else if (m_layer_index <= 1) {
         return start_value;
+    } else {
+        ratio = m_layer_index / (m_layer_count - 1.f);
     }
-    else {
-        bool use_steps = step > 0.f;
-        if (use_steps) {
-            if (start_value > end_value) {
-                start_value += step;
-            } else {
-                end_value += step;
-            }
+    bool use_steps = step > 0.f;
+    if (use_steps) {
+        if (start_value > end_value) {
+            start_value += step;
+        } else {
+            end_value += step;
         }
-        float ratio = m_layer_index / (m_layer_count - 1.f);
-        float value = start_value + ratio * (end_value - start_value);
-        if (use_steps) {
-            value = trunc(value / step) * step;
-        }
-        return value;
     }
+    float value = start_value + ratio * (end_value - start_value);
+    if (use_steps) {
+        value = trunc(value / step) * step;
+    }
+    return value;
 }
 
 std::string encodeBase64(uint64_t value)
diff --git a/src/libslic3r/PrintObjectSlice.cpp b/src/libslic3r/PrintObjectSlice.cpp
index 7e5203d624..1212100eac 100644
--- a/src/libslic3r/PrintObjectSlice.cpp
+++ b/src/libslic3r/PrintObjectSlice.cpp
@@ -966,7 +966,14 @@ void PrintObject::slice()
             // correct machine-frame coordinates whether or not a global mode is active.
             double belt_surface_z = BeltTransformPipeline::has_preslice_remap(pcfg)
                 ? BeltTransformPipeline::remap_bbox(*this->model_object(), pcfg).min.z() : 0.;
-            double belt_z_shift = m_belt_min_z - belt_surface_z;
+            // The compensation must mirror the Z-shift actually applied, which
+            // is max(0, -m_belt_min_z): when the transformed mesh starts ABOVE
+            // slicer Z=0 (m_belt_min_z > 0 — possible for counter-rotated or
+            // asymmetric geometry whose centered-frame minimum lands positive)
+            // no lift was applied, and an unclamped m_belt_min_z here would
+            // leak straight into the layer Z values, floating the whole object
+            // off the belt by exactly that amount.
+            double belt_z_shift = std::min(m_belt_min_z, 0.) - belt_surface_z;
             double global_z_offset = belt_z_shift;
 
             // Centering correction: trafo_centered pretranslates by
diff --git a/src/libslic3r/Support/TreeSupport.cpp b/src/libslic3r/Support/TreeSupport.cpp
index e8009cf5c5..8c0fe205a4 100644
--- a/src/libslic3r/Support/TreeSupport.cpp
+++ b/src/libslic3r/Support/TreeSupport.cpp
@@ -1801,8 +1801,7 @@ void TreeSupport::generate()
     {
         BeltFloorContext ctx;
         if (ctx.init(m_slicing_params, *m_print_config)
-            && m_print_config->belt_support_floor_mode.value == BeltSupportFloorMode::GeneratorOnly
-            && m_object->support_layer_count() > 0) {
+            && m_print_config->belt_support_floor_mode.value == BeltSupportFloorMode::GeneratorOnly) {
             const auto &sp = m_slicing_params;
             // Find the lowest non-empty, non-brim support layer.
             ExPolygons source_areas;
@@ -1830,16 +1829,61 @@ void TreeSupport::generate()
                     }
                 }
             }
+            // ORCA-Belt calibration: a counter-rotated calibration object
+            // stands on a support wedge that lies entirely below the object's
+            // first layer, where the tree pipeline has no layers at all — so
+            // no support content can exist yet. Seed the extension directly
+            // from the floating portion of the first layer (anything more
+            // than one layer height above the belt floor). For objects whose
+            // first layer rests on the belt the floating region is empty and
+            // behavior is unchanged.
+            double first_z = m_object->support_layer_count() > 0 ? m_object->get_support_layer(0)->print_z : 0.;
+            bool   seeded  = false;
+            if (source_areas.empty() && m_object_config->enable_support.value && !m_object->layers().empty()) {
+                // The layer grid may start with an empty ghost layer just below
+                // the object (grid rounding against the belt global Z offset) —
+                // anchor the seed to the first layer that has geometry. Object
+                // layer print_z and the floor plane are both in the globally
+                // offset frame here (belt_floor_z_shift was adjusted alongside
+                // the layer Z values in PrintObject::slice()).
+                const Layer *first_layer = nullptr;
+                for (const Layer *l : m_object->layers())
+                    if (!l->lslices_extrudable.empty()) { first_layer = l; break; }
+                if (first_layer != nullptr) {
+                    ExPolygons floating = diff_ex(first_layer->lslices_extrudable,
+                                                  ctx.surface_polygon(first_layer->bottom_z() - first_layer->height));
+                    BOOST_LOG_TRIVIAL(debug) << "[BELT-CALIB] wedge seed: obj=" << m_object->model_object()->name
+                        << " bottom_z=" << first_layer->bottom_z() << " floating=" << floating.size();
+                    if (!floating.empty()) {
+                        source_areas = std::move(floating);
+                        first_z      = first_layer->bottom_z();
+                        seeded       = true;
+                    }
+                }
+            }
             if (!source_areas.empty()) {
                 BoundingBoxf3 bb = belt_remapped_bbox(*m_object->model_object(), m_object->print()->config());
                 double from_extent = std::abs(bb.min(ctx.from_axis()));
                 double bb_min_z    = std::abs(bb.min.z());
-                double first_z = m_object->get_support_layer(0)->print_z;
                 // Depth = from-axis extent + pre-shear bbox Z offset (ensure_on_bed
                 // distance) + 10mm safety margin.  The 10mm is a bodge to avoid
                 // small cutoff artifacts — ideally computed exactly from belt geometry.
                 double extra_depth = std::min(from_extent + bb_min_z + 10., std::max(0., first_z));
+                if (seeded) {
+                    // Seeded wedge: the depth is known exactly — down to the lowest
+                    // belt-floor point under the floating footprint. The bbox
+                    // heuristic above under-estimates it for meshes centered
+                    // around their origin (every object loaded through the GUI).
+                    double min_floor = first_z;
+                    for (const ExPolygon &ep : source_areas)
+                        for (const Point &pt : ep.contour.points)
+                            min_floor = std::min(min_floor, ctx.floor_print_z(pt));
+                    extra_depth = std::min(std::max(0., first_z), first_z - min_floor + 2.);
+                }
                 int num_extra = std::max(0, (int)std::ceil(extra_depth / sp.layer_height));
+                // Seeded wedge: top layers become a dense support interface so the
+                // object's floating first layer bridges a roof, not sparse infill.
+                const int interface_layers = seeded ? std::max(0, m_object_config->support_interface_top_layers.value) : 0;
                 ExPolygons prev_areas = source_areas;
                 // Build belt extension layers (lowest Z first).
                 SupportLayerPtrs belt_ext_layers;
@@ -1853,8 +1897,15 @@ void TreeSupport::generate()
                     sl->base_areas = clipped;
                     // Populate area_groups — generate_toolpaths() iterates these,
                     // not base_areas directly.
-                    for (auto &expoly : sl->base_areas)
-                        sl->area_groups.emplace_back(&expoly, SupportLayer::BaseType, 0);
+                    // Note: base areas only get infill when support_base_pattern
+                    // is explicitly set (with the default pattern tree bases are
+                    // walls-only) — the calibration flow sets rectilinear.
+                    const bool roof = i <= interface_layers;
+                    for (auto &expoly : sl->base_areas) {
+                        sl->area_groups.emplace_back(&expoly, roof ? SupportLayer::RoofType : SupportLayer::BaseType, 0);
+                        if (roof)
+                            sl->area_groups.back().interface_id = i & 1;
+                    }
                     sl->lslices = clipped;
                     sl->lslices_bboxes.reserve(clipped.size());
                     for (const ExPolygon &ep : clipped)
@@ -1865,6 +1916,9 @@ void TreeSupport::generate()
                 if (!belt_ext_layers.empty()) {
                     auto &sl_vec = m_object->support_layers();
                     sl_vec.insert(sl_vec.begin(), belt_ext_layers.begin(), belt_ext_layers.end());
+                    BOOST_LOG_TRIVIAL(debug) << "[BELT-CALIB] wedge ext layers=" << belt_ext_layers.size()
+                        << " z=" << belt_ext_layers.front()->print_z << ".." << belt_ext_layers.back()->print_z
+                        << " seeded=" << seeded;
                 }
             }
         }
diff --git a/src/libslic3r/calib.cpp b/src/libslic3r/calib.cpp
index 4b3e05df8d..3509b32257 100644
--- a/src/libslic3r/calib.cpp
+++ b/src/libslic3r/calib.cpp
@@ -1,4 +1,5 @@
 #include "calib.hpp"
+#include "BeltGCodeWriter.hpp"
 #include "BoundingBox.hpp"
 #include "Config.hpp"
 #include "Model.hpp"
@@ -587,21 +588,21 @@ CustomGCode::Info CalibPressureAdvancePattern::generate_custom_gcodes(const Dyna
 
         refresh_setup(config, is_bbl_machine, object, origin);
 
-    gcode << move_to(Vec2d(m_starting_point.x(), m_starting_point.y()), m_writer, "Move to start XY position");
-    gcode << m_writer.travel_to_z(height_first_layer() + height_z_offset(), "Move to start Z position");
-    gcode << m_writer.set_pressure_advance(m_params.start);
+    gcode << move_to(Vec2d(m_starting_point.x(), m_starting_point.y()), *m_writer, "Move to start XY position");
+    gcode << m_writer->travel_to_z(height_first_layer() + height_z_offset(), "Move to start Z position");
+    gcode << m_writer->set_pressure_advance(m_params.start);
 
     const DrawBoxOptArgs default_box_opt_args(wall_count(), height_first_layer(), line_width_first_layer(),
                                               speed_adjust(speed_first_layer()));
 
     // create anchoring frame
-    gcode << draw_box(m_writer, m_starting_point.x(), m_starting_point.y(), print_size_x(), frame_size_y(), default_box_opt_args);
+    gcode << draw_box(*m_writer, m_starting_point.x(), m_starting_point.y(), print_size_x(), frame_size_y(), default_box_opt_args);
 
     // create tab for numbers
     DrawBoxOptArgs draw_box_opt_args = default_box_opt_args;
     draw_box_opt_args.is_filled      = true;
     draw_box_opt_args.num_perimeters = wall_count();
-    gcode << draw_box(m_writer, m_starting_point.x(), m_starting_point.y() + frame_size_y() + line_spacing_first_layer(),
+    gcode << draw_box(*m_writer, m_starting_point.x(), m_starting_point.y() + frame_size_y() + line_spacing_first_layer(),
                       print_size_x(),
                       max_numbering_height() + line_spacing_first_layer() + m_glyph_padding_vertical * 2, draw_box_opt_args);
 
@@ -627,15 +628,15 @@ CustomGCode::Info CalibPressureAdvancePattern::generate_custom_gcodes(const Dyna
             gcode = std::stringstream(); // reset for next layer contents
             gcode << "; start pressure advance pattern for layer\n";
 
-            gcode << m_writer.travel_to_z(layer_height, "Move to layer height");
-            gcode << m_writer.reset_e();
+            gcode << m_writer->travel_to_z(layer_height, "Move to layer height");
+            gcode << m_writer->reset_e();
         }
 
         // line numbering
         if (i == 1) {
             m_number_len = max_numbering_length();
 
-            gcode << m_writer.set_pressure_advance(m_params.start);
+            gcode << m_writer->set_pressure_advance(m_params.start);
 
             double number_e_per_mm = e_per_mm(line_width(), height_layer(),
                                               m_config.option<ConfigOptionFloats>("nozzle_diameter")->get_at(0),
@@ -646,20 +647,20 @@ CustomGCode::Info CalibPressureAdvancePattern::generate_custom_gcodes(const Dyna
             for (int j = 0; j < num_patterns; j += 2) {
                 gcode << draw_number(glyph_start_x(j), m_starting_point.y() + frame_size_y() + m_glyph_padding_vertical + line_width(),
                                      m_params.start + (j * m_params.step), m_draw_digit_mode, line_width(), number_e_per_mm,
-                                     speed_first_layer(), m_writer);
+                                     speed_first_layer(), *m_writer);
             }
 
             // flow value
             int line_num = num_patterns + 2;
             gcode << draw_number(glyph_start_x(line_num), m_starting_point.y() + frame_size_y() + m_glyph_padding_vertical + line_width(),
                                  flow_val(), m_draw_digit_mode, line_width(), number_e_per_mm,
-                                 speed_first_layer(), m_writer);
+                                 speed_first_layer(), *m_writer);
 
             // acceleration
             line_num = num_patterns + 4;
             gcode << draw_number(glyph_start_x(line_num), m_starting_point.y() + frame_size_y() + m_glyph_padding_vertical + line_width(),
                                  accel, m_draw_digit_mode, line_width(), number_e_per_mm,
-                                 speed_first_layer(), m_writer);
+                                 speed_first_layer(), *m_writer);
         }
 
 
@@ -678,20 +679,20 @@ CustomGCode::Info CalibPressureAdvancePattern::generate_custom_gcodes(const Dyna
             /* Draw a line at slightly slower accel and speed in order to trick gcode writer to force update acceleration and speed.
              * We do this since several tests may be generated by their own gcode writers which are
              * not aware about their neighbours updating acceleration/speed */
-            gcode << m_writer.set_print_acceleration(std::max<int>(1, accel - 1));
-            gcode << move_to(Vec2d(m_starting_point.x(), m_starting_point.y()), m_writer, "Move to starting point", zhop_height, layer_height);
-            gcode << draw_line(m_writer, Vec2d(m_starting_point.x(), m_starting_point.y() + frame_size_y()), line_width(), height_layer(), speed_adjust(std::max<int>(1, speed_perimeter() - 1)), "Accel/flow trick line");
-            gcode << m_writer.set_print_acceleration(accel);
+            gcode << m_writer->set_print_acceleration(std::max<int>(1, accel - 1));
+            gcode << move_to(Vec2d(m_starting_point.x(), m_starting_point.y()), *m_writer, "Move to starting point", zhop_height, layer_height);
+            gcode << draw_line(*m_writer, Vec2d(m_starting_point.x(), m_starting_point.y() + frame_size_y()), line_width(), height_layer(), speed_adjust(std::max<int>(1, speed_perimeter() - 1)), "Accel/flow trick line");
+            gcode << m_writer->set_print_acceleration(accel);
         }
 
         double initial_x = to_x;
         double initial_y = to_y;
 
-        gcode << move_to(Vec2d(to_x, to_y), m_writer, "Move to pattern start",zhop_height,layer_height);
+        gcode << move_to(Vec2d(to_x, to_y), *m_writer, "Move to pattern start",zhop_height,layer_height);
 
         for (int j = 0; j < num_patterns; ++j) {
             // increment pressure advance
-            gcode << m_writer.set_pressure_advance(m_params.start + (j * m_params.step));
+            gcode << m_writer->set_pressure_advance(m_params.start + (j * m_params.step));
 
             for (int k = 0; k < wall_count(); ++k) {
                 to_x += std::cos(to_radians(m_corner_angle) / 2) * side_length;
@@ -701,27 +702,27 @@ CustomGCode::Info CalibPressureAdvancePattern::generate_custom_gcodes(const Dyna
                 auto draw_line_arg_line_width = line_width(); // don't use line_width_first_layer so results are consistent across all layers
                 auto draw_line_arg_speed   = i == 0 ? speed_adjust(speed_first_layer()) : speed_adjust(speed_perimeter());
                 auto draw_line_arg_comment = "Print pattern wall";
-                gcode << draw_line(m_writer, Vec2d(to_x, to_y), draw_line_arg_line_width, draw_line_arg_height, draw_line_arg_speed, draw_line_arg_comment);
+                gcode << draw_line(*m_writer, Vec2d(to_x, to_y), draw_line_arg_line_width, draw_line_arg_height, draw_line_arg_speed, draw_line_arg_comment);
 
                 to_x -= std::cos(to_radians(m_corner_angle) / 2) * side_length;
                 to_y += std::sin(to_radians(m_corner_angle) / 2) * side_length;
 
-                gcode << draw_line(m_writer, Vec2d(to_x, to_y), draw_line_arg_line_width, draw_line_arg_height, draw_line_arg_speed, draw_line_arg_comment);
+                gcode << draw_line(*m_writer, Vec2d(to_x, to_y), draw_line_arg_line_width, draw_line_arg_height, draw_line_arg_speed, draw_line_arg_comment);
 
                 to_y = initial_y;
                 if (k != wall_count() - 1) {
                     // perimeters not done yet. move to next perimeter
                     to_x += line_spacing_angle();
-                    gcode << move_to(Vec2d(to_x, to_y), m_writer, "Move to start next pattern wall", zhop_height, layer_height); // Call move to command with XY as well as z hop and layer height to invoke and undo z lift
+                    gcode << move_to(Vec2d(to_x, to_y), *m_writer, "Move to start next pattern wall", zhop_height, layer_height); // Call move to command with XY as well as z hop and layer height to invoke and undo z lift
                 } else if (j != num_patterns - 1) {
                     // patterns not done yet. move to next pattern
                     to_x += m_pattern_spacing + line_width();
-                    gcode << move_to(Vec2d(to_x, to_y), m_writer, "Move to next pattern", zhop_height, layer_height); // Call move to command with XY as well as z hop and layer height to invoke and undo z lift
+                    gcode << move_to(Vec2d(to_x, to_y), *m_writer, "Move to next pattern", zhop_height, layer_height); // Call move to command with XY as well as z hop and layer height to invoke and undo z lift
                 } else if (i != m_num_layers - 1) {
                     // layers not done yet. move back to start
                     to_x = initial_x;
-                    gcode << move_to(Vec2d(to_x, to_y), m_writer, "Move back to start position", zhop_height, layer_height); // Call move to command with XY as well as z hop and layer height to invoke and undo z lift
-                    gcode << m_writer.reset_e(); // reset extruder before printing placeholder cube to avoid over extrusion
+                    gcode << move_to(Vec2d(to_x, to_y), *m_writer, "Move back to start position", zhop_height, layer_height); // Call move to command with XY as well as z hop and layer height to invoke and undo z lift
+                    gcode << m_writer->reset_e(); // reset extruder before printing placeholder cube to avoid over extrusion
                 } else {
                     // everything done
                 }
@@ -729,7 +730,7 @@ CustomGCode::Info CalibPressureAdvancePattern::generate_custom_gcodes(const Dyna
         }
     }
 
-    gcode << m_writer.set_pressure_advance(m_params.start);
+    gcode << m_writer->set_pressure_advance(m_params.start);
     gcode << "; end pressure advance pattern for layer\n";
 
     CustomGCode::Item item;
@@ -796,13 +797,36 @@ void CalibPressureAdvancePattern::_refresh_writer(bool is_bbl_machine, const Mod
     PrintConfig print_config;
     print_config.apply(m_config, true);
 
-    m_writer.apply_print_config(print_config);
-    m_writer.set_xy_offset(origin(0), origin(1));
-    m_writer.set_is_bbl_machine(is_bbl_machine);
+    // ORCA-Belt: the pattern is drawn in logical bed coordinates directly on
+    // the build surface — on a belt printer that means the belt plane, which
+    // needs the machine kinematics (axis remap + frame shear/scale) with the
+    // coordinates interpreted as world points (see set_world_coordinates).
+    if (print_config.belt_printer.value) {
+        auto belt_writer = std::make_shared<BeltGCodeWriter>();
+        belt_writer->set_belt_back_transform(print_config);
+        belt_writer->set_machine_frame_transform(print_config);
+        belt_writer->set_world_coordinates(true);
+        const int rx = int(print_config.gcode_remap_x.value);
+        const int ry = int(print_config.gcode_remap_y.value);
+        const int rz = int(print_config.gcode_remap_z.value);
+        if (rx != 0 || ry != 1 || rz != 2) {
+            belt_writer->set_axis_remap(rx, ry, rz);
+            BoundingBoxf bbox_bed(print_config.printable_area.values);
+            belt_writer->set_build_volume_max(Vec3d(bbox_bed.max.x(), bbox_bed.max.y(),
+                                                    print_config.printable_height.value));
+        }
+        m_writer = std::move(belt_writer);
+    } else if (dynamic_cast<BeltGCodeWriter*>(m_writer.get()) != nullptr) {
+        m_writer = std::make_shared<GCodeWriter>();
+    }
+
+    m_writer->apply_print_config(print_config);
+    m_writer->set_xy_offset(origin(0), origin(1));
+    m_writer->set_is_bbl_machine(is_bbl_machine);
 
     const unsigned int extruder_id = object.volumes.front()->extruder_id();
-    m_writer.set_extruders({extruder_id});
-    m_writer.set_extruder(extruder_id);
+    m_writer->set_extruders({extruder_id});
+    m_writer->set_extruder(extruder_id);
 }
 
 double CalibPressureAdvancePattern::object_size_x() const
diff --git a/src/libslic3r/calib.hpp b/src/libslic3r/calib.hpp
index cbac1d3f86..b36c75db62 100644
--- a/src/libslic3r/calib.hpp
+++ b/src/libslic3r/calib.hpp
@@ -358,7 +358,10 @@ private:
 
     const Calib_Params &m_params;
 
-    GCodeWriter        m_writer;
+    // Polymorphic so belt printers get a BeltGCodeWriter in world-coordinates
+    // mode (_refresh_writer); shared_ptr keeps the class copyable — the writer
+    // is rebuilt by refresh_setup() before every use anyway.
+    std::shared_ptr<GCodeWriter> m_writer{std::make_shared<GCodeWriter>()};
     Vec3d              m_starting_point;
     bool               m_is_start_point_fixed = false;
 
diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index 823deb0aea..6bc6a30f0f 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -12594,8 +12594,181 @@ void Plater::add_model(bool imperial_units, std::string fname)
     }
 }
 
+// ORCA-Belt: belt-printer handling for the desktop calibration tests.
+//
+// Belt slicing applies a global pre-slice rotation R(angle, axis) to every
+// mesh (see BeltTransform.hpp) so the slicing planes match the tilted gantry.
+// Calibration models are designed for upright slicing: their per-height test
+// bands and XY-plane quality features assume slicer Z is the model's own Z
+// axis. Counter-rotating each calibration object by the inverse rotation in
+// world space cancels the global rotation, so in slicing space the object
+// stands upright exactly as on a flat-bed printer and every test keeps its
+// designed meaning. Physically the object then leans over the belt with its
+// bottom face overhanging, so per-object supports fill the wedge between the
+// bottom face and the belt. The wedge prints entirely below the object's base
+// plane and leaves the test geometry untouched. Manual tree support is used
+// so the deliberate bridge/overhang features of the test models stay
+// unsupported; the wedge under the floating bottom face is built by the
+// belt-floor extension in TreeSupport::generate(), which stacks the floating
+// first-layer footprint down to the belt surface.
+static bool belt_calib_rotation_params(double& angle_rad, Vec3d& axis)
+{
+    const auto& printer_config = wxGetApp().preset_bundle->printers.get_edited_preset().config;
+    const auto* belt_opt = printer_config.option<ConfigOptionBool>("belt_printer");
+    if (belt_opt == nullptr || !belt_opt->value)
+        return false;
+    const auto* axis_opt  = printer_config.option<ConfigOptionEnum<BeltRotationAxis>>("belt_slice_rotation");
+    const auto* angle_opt = printer_config.option<ConfigOptionFloat>("belt_slice_rotation_angle");
+    if (axis_opt == nullptr || angle_opt == nullptr)
+        return false;
+    switch (axis_opt->value) {
+    case BeltRotationAxis::X: axis = Vec3d::UnitX(); break;
+    case BeltRotationAxis::Y: axis = Vec3d::UnitY(); break;
+    // Z rotation is an in-plane spin and None means no tilt; objects already
+    // slice upright in those cases and need no special handling.
+    default: return false;
+    }
+    angle_rad = -Geometry::deg2rad(angle_opt->value);
+    return std::abs(angle_rad) > EPSILON;
+}
+
+// ORCA-Belt: flip the ringing tower 180° about Z before the belt
+// counter-rotation — its sloped face then leans over the belt and the
+// support wedge gets much smaller.
+static void belt_calib_flip_ringing_tower(Model &model)
+{
+    double angle_rad = 0.;
+    Vec3d  axis      = Vec3d::UnitX();
+    if (belt_calib_rotation_params(angle_rad, axis) && !model.objects.empty())
+        model.objects.front()->rotate(M_PI, Vec3d::UnitZ());
+}
+
+void Plater::_calib_apply_belt_mode()
+{
+    double angle_rad = 0.;
+    Vec3d  axis      = Vec3d::UnitX();
+    if (!belt_calib_rotation_params(angle_rad, axis))
+        return;
+
+    auto print_config = &wxGetApp().preset_bundle->prints.get_edited_preset().config;
+    // Spiral vase stays enabled where the tests request it: the support wedge
+    // lies strictly below the object, support layers never spiralize
+    // (spiral_vase_enable requires an object layer), and the spiral/support
+    // exclusivity check only applies to globally enabled supports — the wedge
+    // uses per-object supports.
+    // A skirt would be drawn in the first slicing plane, which lies mostly
+    // above the belt surface.
+    print_config->set_key_value("skirt_loops", new ConfigOptionInt(0));
+
+    const Matrix3d cancel_rotation = Eigen::AngleAxisd(angle_rad, axis).toRotationMatrix();
+    std::vector<size_t> obj_idxs;
+    for (size_t i = 0; i < model().objects.size(); ++i) {
+        ModelObject* obj = model().objects[i];
+        if (obj->instances.size() != 1)
+            continue;
+        obj_idxs.emplace_back(i);
+
+        // Manual tree support: only the floating bottom face gets a support
+        // wedge (via the belt-floor extension in TreeSupport::generate()),
+        // leaving the test features untouched. The style is pinned to hybrid
+        // because the default style resolves to organic, which bypasses the
+        // non-organic generator that hosts the belt-floor extension.
+        obj->config.set_key_value("enable_support", new ConfigOptionBool(true));
+        obj->config.set_key_value("support_type", new ConfigOptionEnum<SupportType>(stTree));
+        obj->config.set_key_value("support_style", new ConfigOptionEnum<SupportMaterialStyle>(smsTreeHybrid));
+        obj->config.set_key_value("support_on_build_plate_only", new ConfigOptionBool(false));
+        // With the default base pattern, tree support base areas print as
+        // hollow outlines (no infill) — the wedge needs a real pattern.
+        obj->config.set_key_value("support_base_pattern", new ConfigOptionEnum<SupportMaterialPattern>(smpRectilinear));
+
+        // Counter-rotate exactly the way the rotate gizmo would: rotation on
+        // the instance, then a plain drop to the bed. This leaves the object
+        // in the same state shape as any manually rotated object, which the
+        // belt pipeline is known to handle.
+        ModelInstance* inst = obj->instances.front();
+        inst->rotate(cancel_rotation);
+        obj->invalidate_bounding_box();
+        obj->ensure_on_bed();
+
+        {
+            const BoundingBoxf3 rb = obj->raw_bounding_box();
+            const Vec3d         io = inst->get_offset();
+            const Vec3d         ir = inst->get_rotation();
+            BOOST_LOG_TRIVIAL(debug) << "[BELT-CALIB] helper exit: obj=" << obj->name
+                << " inst_offset=(" << io.x() << "," << io.y() << "," << io.z() << ")"
+                << " inst_rot=(" << ir.x() << "," << ir.y() << "," << ir.z() << ")"
+                << " vol0_offset=(" << obj->volumes.front()->get_offset().x() << ","
+                << obj->volumes.front()->get_offset().y() << "," << obj->volumes.front()->get_offset().z() << ")"
+                << " raw_bbox=(" << rb.min.x() << "," << rb.min.y() << "," << rb.min.z()
+                << ")..(" << rb.max.x() << "," << rb.max.y() << "," << rb.max.z() << ")"
+                << " min_z=" << obj->min_z();
+        }
+    }
+
+    // Each object's support wedge extends upstream of it by roughly its own
+    // depth (at 45°), so the tight flat-bed layouts of the multi-part tests
+    // leave wedges intersecting the neighbouring parts. Keep the grid rows of
+    // the test layouts together and open up the space between rows just
+    // enough for the wedge shadow.
+    if (obj_idxs.size() > 1) {
+        std::vector<ModelObject*> sorted_objs;
+        sorted_objs.reserve(obj_idxs.size());
+        for (size_t i : obj_idxs)
+            sorted_objs.emplace_back(model().objects[i]);
+        std::sort(sorted_objs.begin(), sorted_objs.end(), [](const ModelObject* a, const ModelObject* b) {
+            return a->instances.front()->get_offset(Y) < b->instances.front()->get_offset(Y);
+        });
+        std::vector<std::vector<ModelObject*>> rows;
+        double row_y = std::numeric_limits<double>::quiet_NaN();
+        for (ModelObject* o : sorted_objs) {
+            const double oy = o->instances.front()->get_offset(Y);
+            if (rows.empty() || oy - row_y > 1.)
+                rows.emplace_back();
+            rows.back().emplace_back(o);
+            row_y = oy;
+        }
+        const double wedge_factor = std::abs(std::tan(angle_rad));
+        double       cursor       = std::numeric_limits<double>::quiet_NaN();
+        for (std::vector<ModelObject*>& row : rows) {
+            double rmin = std::numeric_limits<double>::max();
+            double rmax = std::numeric_limits<double>::lowest();
+            for (ModelObject* o : row) {
+                const BoundingBoxf3 bb = o->instance_bounding_box(0);
+                rmin = std::min(rmin, bb.min.y());
+                rmax = std::max(rmax, bb.max.y());
+            }
+            if (std::isnan(cursor))
+                cursor = rmin; // the first row anchors the layout
+            const double shift = cursor - rmin;
+            for (ModelObject* o : row) {
+                ModelInstance* inst = o->instances.front();
+                inst->set_offset(Y, inst->get_offset(Y) + shift);
+                o->invalidate_bounding_box();
+            }
+            cursor += (rmax - rmin) * (1. + wedge_factor) + 5.;
+        }
+    }
+
+    wxGetApp().get_tab(Preset::TYPE_PRINT)->update_dirty();
+    wxGetApp().get_tab(Preset::TYPE_PRINT)->reload_config();
+    changed_objects(obj_idxs);
+}
+
 void Plater::calib_pa(const Calib_Params& params)
 {
+    // ORCA-Belt: PA Line / PA Pattern have the belt plumbing in place
+    // (BeltGCodeWriter::set_world_coordinates draws them on the belt surface)
+    // but are not validated yet — keep them gated to the PA Tower for now.
+    {
+        double angle_rad = 0.;
+        Vec3d  axis      = Vec3d::UnitX();
+        if (belt_calib_rotation_params(angle_rad, axis) && params.mode != CalibMode::Calib_PA_Tower) {
+            MessageDialog msg_dlg(nullptr, _L("PA Line and PA Pattern tests are not enabled yet on belt printers.\nPlease use the PA Tower method instead."),
+                                  wxEmptyString, wxICON_WARNING | wxOK);
+            msg_dlg.ShowModal();
+            return;
+        }
+    }
     const auto calib_pa_name = wxString::Format(L"Pressure Advance Test");
     new_project(false, false, calib_pa_name);
     wxGetApp().mainframe->select_tab(size_t(MainFrame::tp3DEditor));
@@ -12927,6 +13100,7 @@ void Plater::_calib_pa_tower(const Calib_Params& params) {
         cut_horizontal(0, 0, new_height, ModelObjectCutAttribute::KeepLower);
     }
 
+    _calib_apply_belt_mode();
     _calib_pa_select_added_objects();
 }
 
@@ -13104,6 +13278,8 @@ void Plater::calib_flowrate(bool is_linear, int pass, InfillPattern pattern) {
     auto printer_config = &wxGetApp().preset_bundle->printers.get_edited_preset().config;
     printer_config->set_key_value("resonance_avoidance", new ConfigOptionBool{false});
 
+    _calib_apply_belt_mode();
+
     // Refresh object after scaling
     const std::vector<size_t> object_idx(boost::counting_iterator<size_t>(0), boost::counting_iterator<size_t>(model().objects.size()));
     changed_objects(object_idx);
@@ -13120,7 +13296,19 @@ void Plater::calib_temp(const Calib_Params& params) {
     wxGetApp().mainframe->select_tab(size_t(MainFrame::tp3DEditor));
     if (params.mode != CalibMode::Calib_Temp_Tower)
         return;
-    
+
+    // ORCA-Belt: a counter-rotated tower would cantilever every block off a
+    // support wedge — print the temperature blocks as separate objects in
+    // native belt orientation instead.
+    {
+        double belt_angle_rad = 0.;
+        Vec3d  belt_axis      = Vec3d::UnitX();
+        if (belt_calib_rotation_params(belt_angle_rad, belt_axis)) {
+            _calib_temp_belt_sectioned(params, std::abs(belt_angle_rad));
+            return;
+        }
+    }
+
     add_model(false, Slic3r::resources_dir() + "/calib/temperature_tower/temperature_tower.drc");
     auto printer_config = &wxGetApp().preset_bundle->printers.get_edited_preset().config;
     auto filament_config = &wxGetApp().preset_bundle->filaments.get_edited_preset().config;
@@ -13190,6 +13378,107 @@ void Plater::calib_temp(const Calib_Params& params) {
     p->background_process.fff_print()->set_calib_params(params);
 }
 
+// ORCA-Belt: sectioned temperature test. Each temperature gets its own block
+// cut out of the temperature tower model, printed in native belt orientation
+// (no counter-rotation, no support wedge) and spaced along the belt so the
+// blocks' layer ranges are disjoint — they print strictly one after another,
+// starting with the start temperature closest to the gantry. The temperature
+// is encoded in the object name ("temp_230") and applied per object by the
+// Calib_Temp_Tower handler at G-code time, replacing the per-layer-band ramp
+// that only makes sense for a monolithic upright tower.
+void Plater::_calib_temp_belt_sectioned(const Calib_Params& params, double belt_angle_rad)
+{
+    constexpr double base_temp_tower_nozzle_diameter = 0.4;
+    constexpr double base_temp_tower_block_height = 10.0;
+    constexpr int base_temp_tower_temp_step = 5;
+
+    auto printer_config  = &wxGetApp().preset_bundle->printers.get_edited_preset().config;
+    auto filament_config = &wxGetApp().preset_bundle->filaments.get_edited_preset().config;
+    auto print_config    = &wxGetApp().preset_bundle->prints.get_edited_preset().config;
+
+    const long start_temp = lround(params.start);
+    const long end_temp   = lround(params.end);
+    const int  n_blocks   = std::max(1, int((start_temp - end_temp) / base_temp_tower_temp_step) + 1);
+
+    const ConfigOptionFloats* nozzle_diameter_config = printer_config->option<ConfigOptionFloats>("nozzle_diameter");
+    size_t nozzle_id = static_cast<size_t>(std::max(params.extruder_id, 0));
+    double nozzle_diameter = base_temp_tower_nozzle_diameter;
+    if (nozzle_diameter_config && !nozzle_diameter_config->values.empty()) {
+        nozzle_id = std::min(nozzle_id, nozzle_diameter_config->values.size() - 1);
+        nozzle_diameter = nozzle_diameter_config->values[nozzle_id];
+    }
+    if (nozzle_diameter <= 0.0)
+        nozzle_diameter = base_temp_tower_nozzle_diameter;
+    const double nozzle_scale = nozzle_diameter / base_temp_tower_nozzle_diameter;
+
+    std::vector<size_t> obj_idxs;
+    for (int i = 0; i < n_blocks; ++i) {
+        const long temp = start_temp - long(i) * base_temp_tower_temp_step;
+        const size_t count_before = model().objects.size();
+        add_model(false, Slic3r::resources_dir() + "/calib/temperature_tower/temperature_tower.drc");
+        if (model().objects.size() <= count_before)
+            break; // model failed to load — don't index into an empty list
+        // The cut replaces the object at the END of the list, so re-acquire
+        // the index after every operation.
+        size_t obj_idx = model().objects.size() - 1;
+
+        // Isolate this temperature's block (full-tower coordinates, the same
+        // 500-down-to-temp indexing the monolithic flow cuts with).
+        const double block_bottom = double(lround(double(500 - temp) / base_temp_tower_temp_step)) * base_temp_tower_block_height;
+        auto obj_bb = model().objects[obj_idx]->bounding_box_exact();
+        if (block_bottom + base_temp_tower_block_height < obj_bb.size().z()) {
+            cut_horizontal(obj_idx, 0, block_bottom + base_temp_tower_block_height - EPSILON, ModelObjectCutAttribute::KeepLower);
+            obj_idx = model().objects.size() - 1;
+        }
+        if (block_bottom > 0) {
+            cut_horizontal(obj_idx, 0, block_bottom + EPSILON, ModelObjectCutAttribute::KeepUpper);
+            obj_idx = model().objects.size() - 1;
+        }
+
+        ModelObject* obj = model().objects[obj_idx];
+        if (std::abs(nozzle_scale - 1.0) > EPSILON)
+            obj->scale(nozzle_scale, nozzle_scale, nozzle_scale);
+        obj->name = std::string("temp_") + std::to_string(temp);
+        obj->config.set_key_value("layer_height", new ConfigOptionFloat(nozzle_diameter / 2));
+        obj->config.set_key_value("alternate_extra_wall", new ConfigOptionBool(false));
+        obj->config.set_key_value("seam_slope_type", new ConfigOptionEnum<SeamScarfType>(SeamScarfType::None));
+        obj->config.set_key_value("overhang_reverse", new ConfigOptionBool(false));
+        obj->config.set_key_value("precise_z_height", new ConfigOptionBool(false));
+        obj->ensure_on_bed();
+        obj_idxs.emplace_back(obj_idx);
+    }
+
+    // Space the blocks along the belt with strictly increasing layer ranges:
+    // each block must start past the previous block's highest slicing plane,
+    // which trails its far edge by height / tan(angle). Anchor the row near
+    // the gantry so the whole test stays in the plate area.
+    const double cot_a  = 1. / std::max(0.1, std::tan(belt_angle_rad));
+    double       cursor = 20.;
+    for (size_t idx : obj_idxs) {
+        ModelObject*        obj  = model().objects[idx];
+        ModelInstance*      inst = obj->instances.front();
+        const BoundingBoxf3 bb   = obj->instance_bounding_box(0);
+        inst->set_offset(Y, inst->get_offset(Y) + (cursor - bb.min.y()));
+        obj->invalidate_bounding_box();
+        cursor += bb.size().y() + bb.size().z() * cot_a + 5.;
+    }
+
+    printer_config->set_key_value("resonance_avoidance", new ConfigOptionBool{false});
+    filament_config->set_key_value("nozzle_temperature_initial_layer", new ConfigOptionInts(1, (int)start_temp));
+    filament_config->set_key_value("nozzle_temperature", new ConfigOptionInts(1, (int)start_temp));
+    print_config->set_key_value("enable_wrapping_detection", new ConfigOptionBool(false));
+    print_config->set_key_value("initial_layer_print_height", new ConfigOptionFloat(nozzle_diameter / 2));
+    print_config->set_key_value("skirt_loops", new ConfigOptionInt(0));
+
+    changed_objects(obj_idxs);
+    wxGetApp().get_tab(Preset::TYPE_PRINT)->update_dirty();
+    wxGetApp().get_tab(Preset::TYPE_FILAMENT)->update_dirty();
+    wxGetApp().get_tab(Preset::TYPE_PRINT)->reload_config();
+    wxGetApp().get_tab(Preset::TYPE_FILAMENT)->reload_config();
+
+    p->background_process.fff_print()->set_calib_params(params);
+}
+
 void Plater::calib_max_vol_speed(const Calib_Params& params)
 {
     const auto calib_vol_speed_name = wxString::Format(L"Max volumetric speed test");
@@ -13256,6 +13545,8 @@ void Plater::calib_max_vol_speed(const Calib_Params& params)
         cut_horizontal(0, 0, height, ModelObjectCutAttribute::KeepLower);
     }
 
+    _calib_apply_belt_mode();
+
     auto new_params  = params;
     auto mm3_per_mm  = Flow(line_width, layer_height, nozzle_diameter).mm3_per_mm() * filament_config->option<ConfigOptionFloatsNullable>("filament_flow_ratio")->get_at(0);
     new_params.end   = params.end / mm3_per_mm;
@@ -13320,6 +13611,7 @@ void Plater::calib_retraction(const Calib_Params& params)
         cut_horizontal(0, 0, height, ModelObjectCutAttribute::KeepLower);
     }
 
+    _calib_apply_belt_mode();
     p->background_process.fff_print()->set_calib_params(params);
 }
 
@@ -13365,6 +13657,7 @@ void Plater::calib_VFA(const Calib_Params& params)
         cut_horizontal(0, 0, height, ModelObjectCutAttribute::KeepLower);
     }
 
+    _calib_apply_belt_mode();
     p->background_process.fff_print()->set_calib_params(params);
 }
 
@@ -13377,6 +13670,8 @@ void Plater::calib_input_shaping_freq(const Calib_Params& params)
         return;
 
     add_model(false, Slic3r::resources_dir() + (params.test_model < 1 ? "/calib/input_shaping/ringing_tower.drc" : "/calib/input_shaping/fast_tower_test.drc"));
+    if (params.test_model < 1)
+        belt_calib_flip_ringing_tower(model());
     auto print_config = &wxGetApp().preset_bundle->prints.get_edited_preset().config;
     auto filament_config = &wxGetApp().preset_bundle->filaments.get_edited_preset().config;
     auto printer_config  = &wxGetApp().preset_bundle->printers.get_edited_preset().config;
@@ -13428,6 +13723,7 @@ void Plater::calib_input_shaping_freq(const Calib_Params& params)
     wxGetApp().get_tab(Preset::TYPE_PRINT)->update_ui_from_settings();
     wxGetApp().get_tab(Preset::TYPE_FILAMENT)->update_ui_from_settings();
 
+    _calib_apply_belt_mode();
     p->background_process.fff_print()->set_calib_params(params);
 }
 
@@ -13440,6 +13736,8 @@ void Plater::calib_input_shaping_damp(const Calib_Params& params)
         return;
 
     add_model(false, Slic3r::resources_dir() + (params.test_model < 1 ? "/calib/input_shaping/ringing_tower.drc" : "/calib/input_shaping/fast_tower_test.drc"));
+    if (params.test_model < 1)
+        belt_calib_flip_ringing_tower(model());
     auto print_config = &wxGetApp().preset_bundle->prints.get_edited_preset().config;
     auto filament_config = &wxGetApp().preset_bundle->filaments.get_edited_preset().config;
     auto printer_config  = &wxGetApp().preset_bundle->printers.get_edited_preset().config;
@@ -13490,6 +13788,7 @@ void Plater::calib_input_shaping_damp(const Calib_Params& params)
     wxGetApp().get_tab(Preset::TYPE_PRINT)->update_ui_from_settings();
     wxGetApp().get_tab(Preset::TYPE_FILAMENT)->update_ui_from_settings();
 
+    _calib_apply_belt_mode();
     p->background_process.fff_print()->set_calib_params(params);
 }
 
@@ -13505,6 +13804,8 @@ void Plater::Calib_Cornering(const Calib_Params& params)
         ? "/calib/input_shaping/ringing_tower.drc"
         : (params.test_model == 1 ? "/calib/input_shaping/fast_tower_test.drc" : "/calib/cornering/SCV-V2.drc");
     add_model(false, Slic3r::resources_dir() + cornering_model_path);
+    if (params.test_model == 0)
+        belt_calib_flip_ringing_tower(model());
     auto print_config = &wxGetApp().preset_bundle->prints.get_edited_preset().config;
     auto filament_config = &wxGetApp().preset_bundle->filaments.get_edited_preset().config;
     auto printer_config  = &wxGetApp().preset_bundle->printers.get_edited_preset().config;
@@ -13555,6 +13856,7 @@ void Plater::Calib_Cornering(const Calib_Params& params)
     wxGetApp().get_tab(Preset::TYPE_PRINT)->update_ui_from_settings();
     wxGetApp().get_tab(Preset::TYPE_FILAMENT)->update_ui_from_settings();
 
+    _calib_apply_belt_mode();
     p->background_process.fff_print()->set_calib_params(params);
 }
 
diff --git a/src/slic3r/GUI/Plater.hpp b/src/slic3r/GUI/Plater.hpp
index f2089c1c4f..a718d39464 100644
--- a/src/slic3r/GUI/Plater.hpp
+++ b/src/slic3r/GUI/Plater.hpp
@@ -951,6 +951,8 @@ private:
     void _calib_pa_pattern_gen_gcode();
     void _calib_pa_tower(const Calib_Params& params);
     void _calib_pa_select_added_objects();
+    void _calib_apply_belt_mode();
+    void _calib_temp_belt_sectioned(const Calib_Params& params, double belt_angle_rad);
 
     void cut_horizontal(size_t obj_idx, size_t instance_idx, double z, ModelObjectCutAttributes attributes);
 
diff --git a/src/slic3r/GUI/calib_dlg.cpp b/src/slic3r/GUI/calib_dlg.cpp
index 5a06b24427..870b078aa1 100644
--- a/src/slic3r/GUI/calib_dlg.cpp
+++ b/src/slic3r/GUI/calib_dlg.cpp
@@ -78,6 +78,19 @@ std::vector<wxString> make_shaper_type_labels()
     return labels;
 }
 
+// ORCA-Belt: PA Line / PA Pattern have belt plumbing in place (drawn on the
+// belt surface via BeltGCodeWriter world-coordinates mode) but are not
+// validated yet — belt printers are restricted to the PA Tower for now.
+bool is_belt_printer_selected()
+{
+    if (auto* preset_bundle = wxGetApp().preset_bundle) {
+        const auto& cfg = preset_bundle->printers.get_edited_preset().config;
+        const auto* opt = cfg.option<ConfigOptionBool>("belt_printer");
+        return opt != nullptr && opt->value;
+    }
+    return false;
+}
+
 }
 
 PA_Calibration_Dlg::PA_Calibration_Dlg(wxWindow* parent, wxWindowID id, Plater* plater)
@@ -288,6 +301,14 @@ void PA_Calibration_Dlg::on_start(wxCommandEvent& event) {
             m_params.mode = CalibMode::Calib_PA_Tower;
     }
 
+    // ORCA-Belt: backstop in case the selection slipped past the UI guards.
+    if (is_belt_printer_selected() && m_params.mode != CalibMode::Calib_PA_Tower) {
+        MessageDialog msg_dlg(nullptr, _L("PA Line and PA Pattern tests are not enabled yet on belt printers.\nPlease use the PA Tower method instead."),
+                              wxEmptyString, wxICON_WARNING | wxOK);
+        msg_dlg.ShowModal();
+        return;
+    }
+
     m_params.print_numbers = m_cbPrintNum->GetValue();
     ParseStringValues(m_tiBMAccels->GetTextCtrl()->GetValue().ToStdString(), m_params.accelerations);
     ParseStringValues(m_tiBMSpeeds->GetTextCtrl()->GetValue().ToStdString(), m_params.speeds);
@@ -314,6 +335,9 @@ void PA_Calibration_Dlg::on_extruder_type_changed(wxCommandEvent& event) {
     event.Skip();
 }
 void PA_Calibration_Dlg::on_method_changed(wxCommandEvent& event) {
+    // ORCA-Belt: only the PA Tower method is enabled on belt printers so far.
+    if (is_belt_printer_selected() && m_rbMethod->GetSelection() != 0)
+        m_rbMethod->SetSelection(0, true);
     PA_Calibration_Dlg::reset_params();
     event.Skip();
 }
@@ -324,6 +348,17 @@ void PA_Calibration_Dlg::on_dpi_changed(const wxRect& suggested_rect) {
 }
 
 void PA_Calibration_Dlg::on_show(wxShowEvent& event) {
+    // ORCA-Belt: the dialog is cached across printer switches, so refresh the
+    // belt restriction on every show.
+    if (is_belt_printer_selected()) {
+        m_rbMethod->SetSelection(0);
+        const wxString tip = _L("Not enabled yet on belt printers — use the PA Tower method instead.");
+        m_rbMethod->SetRadioTooltip(1, tip);
+        m_rbMethod->SetRadioTooltip(2, tip);
+    } else {
+        m_rbMethod->SetRadioTooltip(1, wxEmptyString);
+        m_rbMethod->SetRadioTooltip(2, wxEmptyString);
+    }
     PA_Calibration_Dlg::reset_params();
 }