diff --git a/app-proto/src/assembly.rs b/app-proto/src/assembly.rs
index 1684716..24f9b93 100644
--- a/app-proto/src/assembly.rs
+++ b/app-proto/src/assembly.rs
@@ -315,7 +315,7 @@ impl Assembly {
         // step each element along the mass shell geodesic that matches its
         // velocity in the deformation found above
         /* KLUDGE */
-        // since our test assemblies only include spheres, we assume that every
+        // since our test assemblies only involve spheres, we assume that every
         // element is on the 1 mass shell
         for (_, elt) in self.elements.get_clone_untracked() {
             elt.representation.update_silent(|rep| {
diff --git a/app-proto/src/display.rs b/app-proto/src/display.rs
index 673985c..184b29e 100644
--- a/app-proto/src/display.rs
+++ b/app-proto/src/display.rs
@@ -126,10 +126,6 @@ pub fn Display() -> View {
     // manipulation
     let translate_neg_x = create_signal(0.0);
     let translate_pos_x = create_signal(0.0);
-    let translate_neg_y = create_signal(0.0);
-    let translate_pos_y = create_signal(0.0);
-    let translate_neg_z = create_signal(0.0);
-    let translate_pos_z = create_signal(0.0);
     
     // change listener
     let scene_changed = create_signal(true);
@@ -288,10 +284,6 @@ pub fn Display() -> View {
             // get the manipulation state
             let translate_neg_x_val = translate_neg_x.get();
             let translate_pos_x_val = translate_pos_x.get();
-            let translate_neg_y_val = translate_neg_y.get();
-            let translate_pos_y_val = translate_pos_y.get();
-            let translate_neg_z_val = translate_neg_z.get();
-            let translate_pos_z_val = translate_pos_z.get();
             
             // update the assembly's orientation
             let ang_vel = {
@@ -326,21 +318,17 @@ pub fn Display() -> View {
                 let rep = state.assembly.elements.with_untracked(
                     |elts| elts[sel].representation.get_clone_untracked()
                 );
+                let vel_field_x = DMatrix::from_column_slice(5, 5, &[
+                    0.0, 0.0, 0.0, 0.0, 1.0,
+                    0.0, 0.0, 0.0, 0.0, 0.0,
+                    0.0, 0.0, 0.0, 0.0, 0.0,
+                    2.0, 0.0, 0.0, 0.0, 0.0,
+                    0.0, 0.0, 0.0, 0.0, 0.0
+                ]);
                 let translate_x = translate_pos_x_val - translate_neg_x_val;
-                let translate_y = translate_pos_y_val - translate_neg_y_val;
-                let translate_z = translate_pos_z_val - translate_neg_z_val;
-                if translate_x != 0.0 || translate_y != 0.0 || translate_z != 0.0 {
-                    let vel_field = {
-                        let u = Vector3::new(translate_x, translate_y, translate_z).normalize();
-                        DMatrix::from_column_slice(5, 5, &[
-                                 0.0,      0.0,      0.0, 0.0, u[0],
-                                 0.0,      0.0,      0.0, 0.0, u[1],
-                                 0.0,      0.0,      0.0, 0.0, u[2],
-                            2.0*u[0], 2.0*u[1], 2.0*u[2], 0.0,  0.0,
-                                 0.0,      0.0,      0.0, 0.0,  0.0
-                        ])
-                    };
-                    let elt_motion: DVector<f64> = time_step * TRANSLATION_SPEED * vel_field * rep;
+                if translate_x != 0.0 {
+                    let vel = translate_x * vel_field_x * rep;
+                    let elt_motion: DVector<f64> = time_step * TRANSLATION_SPEED * vel;
                     assembly_for_raf.deform(vec![(sel, elt_motion.as_view())]);
                     scene_changed.set(true);
                 }
@@ -486,14 +474,9 @@ pub fn Display() -> View {
     
     let set_manip_signal = move |event: &KeyboardEvent, value: f64| {
         let mut manipulating = true;
-        let shift = event.shift_key();
         match event.key().as_str() {
-            "d" | "D" => translate_pos_x.set(value),
-            "a" | "A" => translate_neg_x.set(value),
-            "w" | "W" if shift => translate_neg_z.set(value),
-            "s" | "S" if shift => translate_pos_z.set(value),
-            "w" | "W" => translate_pos_y.set(value),
-            "s" | "S" => translate_neg_y.set(value),
+            "d" => translate_pos_x.set(value),
+            "a" => translate_neg_x.set(value),
             _ => manipulating = false
         };
         if manipulating {
@@ -512,7 +495,6 @@ pub fn Display() -> View {
             tabindex="0",
             on:keydown=move |event: KeyboardEvent| {
                 if event.key() == "Shift" {
-                    // swap navigation inputs
                     roll_cw.set(yaw_right.get());
                     roll_ccw.set(yaw_left.get());
                     zoom_in.set(pitch_up.get());
@@ -521,12 +503,6 @@ pub fn Display() -> View {
                     yaw_left.set(0.0);
                     pitch_up.set(0.0);
                     pitch_down.set(0.0);
-                    
-                    // swap manipulation inputs
-                    translate_pos_z.set(translate_neg_y.get());
-                    translate_neg_z.set(translate_pos_y.get());
-                    translate_pos_y.set(0.0);
-                    translate_neg_y.set(0.0);
                 } else {
                     if event.key() == "Enter" { /* BENCHMARKING */
                         turntable.set_fn(|turn| !turn);
@@ -538,7 +514,6 @@ pub fn Display() -> View {
             },
             on:keyup=move |event: KeyboardEvent| {
                 if event.key() == "Shift" {
-                    // swap navigation inputs
                     yaw_right.set(roll_cw.get());
                     yaw_left.set(roll_ccw.get());
                     pitch_up.set(zoom_in.get());
@@ -547,12 +522,6 @@ pub fn Display() -> View {
                     roll_ccw.set(0.0);
                     zoom_in.set(0.0);
                     zoom_out.set(0.0);
-                    
-                    // swap manipulation inputs
-                    translate_pos_y.set(translate_neg_z.get());
-                    translate_neg_y.set(translate_pos_z.get());
-                    translate_pos_z.set(0.0);
-                    translate_neg_z.set(0.0);
                 } else {
                     set_nav_signal(&event, 0.0);
                     set_manip_signal(&event, 0.0);