diff --git a/app-proto/src/add_remove.rs b/app-proto/src/add_remove.rs
index 4972d3c..deac2bb 100644
--- a/app-proto/src/add_remove.rs
+++ b/app-proto/src/add_remove.rs
@@ -4,7 +4,7 @@ use web_sys::{console, wasm_bindgen::JsValue};
 use crate::{
     engine,
     AppState,
-    assembly::{Assembly, Element}
+    assembly::{Assembly, Element, ProductRegulator}
 };
 
 /* DEBUG */
@@ -189,7 +189,9 @@ pub fn AddRemove() -> View {
                             .try_into()
                             .unwrap()
                     );
-                    state.assembly.insert_new_product_regulator(subjects);
+                    state.assembly.insert_regulator(
+                        ProductRegulator::new(subjects, &state.assembly)
+                    );
                     state.selection.update(|sel| sel.clear());
                 }
             ) { "🔗" }
diff --git a/app-proto/src/assembly.rs b/app-proto/src/assembly.rs
index be52461..0eb3e64 100644
--- a/app-proto/src/assembly.rs
+++ b/app-proto/src/assembly.rs
@@ -155,6 +155,29 @@ pub struct ProductRegulator {
     pub set_point: Signal<SpecifiedValue>
 }
 
+impl ProductRegulator {
+    pub fn new(subjects: [ElementKey; 2], assembly: &Assembly) -> ProductRegulator {
+        let measurement = assembly.elements.map(
+            move |elts| {
+                let representations = subjects.map(|subj| elts[subj].representation);
+                representations[0].with(|rep_0|
+                    representations[1].with(|rep_1|
+                        rep_0.dot(&(&*Q * rep_1))
+                    )
+                )
+            }
+        );
+        
+        let set_point = create_signal(SpecifiedValue::from_empty_spec());
+        
+        ProductRegulator {
+            subjects: subjects,
+            measurement: measurement,
+            set_point: set_point
+        }
+    }
+}
+
 impl Regulator for ProductRegulator {
     fn subjects(&self) -> Vec<ElementKey> {
         self.subjects.into()
@@ -192,6 +215,23 @@ pub struct HalfCurvatureRegulator {
     pub set_point: Signal<SpecifiedValue>
 }
 
+impl HalfCurvatureRegulator {
+    pub fn new(subject: ElementKey, assembly: &Assembly) -> HalfCurvatureRegulator {
+        const CURVATURE_COMPONENT: usize = 3;
+        let measurement = assembly.elements.map(
+            move |elts| elts[subject].representation.with(|rep| rep[CURVATURE_COMPONENT])
+        );
+        
+        let set_point = create_signal(SpecifiedValue::from_empty_spec());
+        
+        HalfCurvatureRegulator {
+            subject: subject,
+            measurement: measurement,
+            set_point: set_point
+        }
+    }
+}
+
 impl Regulator for HalfCurvatureRegulator {
     fn subjects(&self) -> Vec<ElementKey> {
         vec![self.subject]
@@ -285,7 +325,7 @@ impl Assembly {
         self.elements_by_id.update(|elts_by_id| elts_by_id.insert(id, key));
         
         // regulate the sphere's curvature
-        self.insert_new_half_curvature_regulator(key);
+        self.insert_regulator(HalfCurvatureRegulator::new(key, &self));
         
         key
     }
@@ -323,7 +363,7 @@ impl Assembly {
         );
     }
     
-    fn insert_regulator<T: Regulator + 'static>(&self, regulator: T) {
+    pub fn insert_regulator<T: Regulator + 'static>(&self, regulator: T) {
         // add the regulator to the assembly's regulator list
         let regulator_rc = Rc::new(regulator);
         let key = self.regulators.update(
@@ -377,39 +417,6 @@ impl Assembly {
         });
     }
     
-    pub fn insert_new_product_regulator(&self, subjects: [ElementKey; 2]) {
-        // create and insert a new product regulator
-        let measurement = self.elements.map(
-            move |elts| {
-                let representations = subjects.map(|subj| elts[subj].representation);
-                representations[0].with(|rep_0|
-                    representations[1].with(|rep_1|
-                        rep_0.dot(&(&*Q * rep_1))
-                    )
-                )
-            }
-        );
-        let set_point = create_signal(SpecifiedValue::from_empty_spec());
-        self.insert_regulator(ProductRegulator {
-            subjects: subjects,
-            measurement: measurement,
-            set_point: set_point
-        });
-    }
-    
-    pub fn insert_new_half_curvature_regulator(&self, subject: ElementKey) {
-        // create and insert a new half-curvature regulator
-        let measurement = self.elements.map(
-            move |elts| elts[subject].representation.with(|rep| rep[3])
-        );
-        let set_point = create_signal(SpecifiedValue::from_empty_spec());
-        self.insert_regulator(HalfCurvatureRegulator {
-            subject: subject,
-            measurement: measurement,
-            set_point: set_point
-        });
-    }
-    
     // --- realization ---
     
     pub fn realize(&self) {