diff --git a/modules/math/vector.js b/modules/math/vector.js
index 626bec75..c8cf55fe 100644
--- a/modules/math/vector.js
+++ b/modules/math/vector.js
@@ -132,6 +132,12 @@ export default class Vector {
   toArray() {
     return [this.x, this.y, this.z];
   }
+
+  copyToData(data) {
+    data[0] = this.x;
+    data[1] = this.y;
+    data[2] = this.z;
+  }
   
   static fromData(arr) {
     return new Vector().set3(arr);
diff --git a/web/app/cad/craft/craftEnginePlugin.js b/web/app/cad/craft/craftEnginePlugin.js
new file mode 100644
index 00000000..ac75417e
--- /dev/null
+++ b/web/app/cad/craft/craftEnginePlugin.js
@@ -0,0 +1,6 @@
+import defaultCraftEngine from './defaultCraftEngine';
+
+
+export function activate(ctx) {
+  ctx.services.craftEngine = defaultCraftEngine
+}
\ No newline at end of file
diff --git a/web/app/cad/craft/defaultCraftEngine.js b/web/app/cad/craft/defaultCraftEngine.js
new file mode 100644
index 00000000..8d8681ce
--- /dev/null
+++ b/web/app/cad/craft/defaultCraftEngine.js
@@ -0,0 +1,14 @@
+
+export default {
+
+  createBox: params => notImplemented,
+  createSphere: params => notImplemented,
+  createCone: params => notImplemented,
+  createCylinder: params => notImplemented,
+  createTorus: params => notImplemented,
+  
+}
+
+function notImplemented() {
+  throw "engine doesn't support this operation"
+}
\ No newline at end of file
diff --git a/web/app/cad/craft/primitives/box/boxOperation.js b/web/app/cad/craft/primitives/box/boxOperation.js
index 3c9e120a..c56cfab1 100644
--- a/web/app/cad/craft/primitives/box/boxOperation.js
+++ b/web/app/cad/craft/primitives/box/boxOperation.js
@@ -2,14 +2,16 @@ import BoxWizard from './BoxWizard';
 import {BoxGeometry} from 'three';
 import schema from './boxOpSchema';
 import primitivePreviewer from '../primitivePreviewer';
+import CSys from '../../../../math/csys';
+import datumConsumingOperation from '../datumConsumingOperation';
 
 function run(params, services) {
-  let mDatum = params.datum && services.cadRegistry.findDatum(params.datum);
-
-  return {
-    outdated: mDatum ? [mDatum] : [],
-    created: []
-  }
+  return datumConsumingOperation(params, services, csys => services.craftEngine.createBox({
+    csys,
+    width: params.width,
+    height: params.height,
+    depth: params.depth
+  }));
 }
 
 export default {
diff --git a/web/app/cad/craft/primitives/cone/coneOperation.js b/web/app/cad/craft/primitives/cone/coneOperation.js
index f9446720..05616160 100644
--- a/web/app/cad/craft/primitives/cone/coneOperation.js
+++ b/web/app/cad/craft/primitives/cone/coneOperation.js
@@ -4,14 +4,15 @@ import ConeWizard from './ConeWizard';
 import {IMAGINARY_SURFACE_MATERIAL} from '../../../preview/scenePreviewer';
 import CSys from '../../../../math/csys';
 import * as SceneGraph from '../../../../../../modules/scene/sceneGraph';
+import datumConsumingOperation from '../datumConsumingOperation';
 
 function run(params, services) {
-  let mDatum = params.datum && services.cadRegistry.findDatum(params.datum);
-
-  return {
-    outdated: mDatum ? [mDatum] : [],
-    created: []
-  }
+  return datumConsumingOperation(params, services, csys => services.craftEngine.createCone({
+    csys,
+    radius: params.radius,
+    frustum: params.frustum,
+    height: params.height
+  }));
 }
 
 function previewer(ctx, initialParams) {
diff --git a/web/app/cad/craft/primitives/cylinder/cylinderOperation.js b/web/app/cad/craft/primitives/cylinder/cylinderOperation.js
index 096f27f0..a1be3947 100644
--- a/web/app/cad/craft/primitives/cylinder/cylinderOperation.js
+++ b/web/app/cad/craft/primitives/cylinder/cylinderOperation.js
@@ -2,14 +2,14 @@ import {CylinderGeometry} from 'three';
 import schema from './cylinderOpSchema';
 import primitivePreviewer from '../primitivePreviewer';
 import CylinderWizard from './CylinderWizard';
+import datumConsumingOperation from '../datumConsumingOperation';
 
 function run(params, services) {
-  let mDatum = params.datum && services.cadRegistry.findDatum(params.datum);
-
-  return {
-    outdated: mDatum ? [mDatum] : [],
-    created: []
-  }
+  return datumConsumingOperation(params, services, csys => services.craftEngine.createCylinder({
+    csys,
+    radius: params.radius,
+    height: params.height
+  }));
 }
 
 export default {
diff --git a/web/app/cad/craft/primitives/datumConsumingOperation.js b/web/app/cad/craft/primitives/datumConsumingOperation.js
new file mode 100644
index 00000000..7b1ba2db
--- /dev/null
+++ b/web/app/cad/craft/primitives/datumConsumingOperation.js
@@ -0,0 +1,8 @@
+export default function datumConsumingOperation(params, services, run) {
+  let mDatum = params.datum && services.cadRegistry.findDatum(params.datum);
+  let res = run(mDatum.csys);
+  if (mDatum) {
+    res.outdated.push(mDatum);
+  }
+  return res;
+}
\ No newline at end of file
diff --git a/web/app/cad/craft/primitives/sphere/sphereOperation.js b/web/app/cad/craft/primitives/sphere/sphereOperation.js
index 31038616..0e9394bc 100644
--- a/web/app/cad/craft/primitives/sphere/sphereOperation.js
+++ b/web/app/cad/craft/primitives/sphere/sphereOperation.js
@@ -2,14 +2,13 @@ import {SphereGeometry} from 'three';
 import schema from './sphereOpSchema';
 import primitivePreviewer from '../primitivePreviewer';
 import SphereWizard from './SphereWizard';
+import datumConsumingOperation from '../datumConsumingOperation';
 
 function run(params, services) {
-  let mDatum = params.datum && services.cadRegistry.findDatum(params.datum);
-
-  return {
-    outdated: mDatum ? [mDatum] : [],
-    created: []
-  }
+  return datumConsumingOperation(params, services, csys => services.craftEngine.createSphere({
+    csys,
+    radius: params.radius,
+  }));
 }
 
 export default {
diff --git a/web/app/cad/craft/primitives/torus/torusOperation.js b/web/app/cad/craft/primitives/torus/torusOperation.js
index 613f48f0..0d354233 100644
--- a/web/app/cad/craft/primitives/torus/torusOperation.js
+++ b/web/app/cad/craft/primitives/torus/torusOperation.js
@@ -4,14 +4,14 @@ import TorusWizard from './TorusWizard';
 import {IMAGINARY_SURFACE_MATERIAL} from '../../../preview/scenePreviewer';
 import CSys from '../../../../math/csys';
 import * as SceneGraph from '../../../../../../modules/scene/sceneGraph';
+import datumConsumingOperation from '../datumConsumingOperation';
 
 function run(params, services) {
-  let mDatum = params.datum && services.cadRegistry.findDatum(params.datum);
-
-  return {
-    outdated: mDatum ? [mDatum] : [],
-    created: []
-  }
+  return datumConsumingOperation(params, services, csys => services.craftEngine.createTorus({
+    csys,
+    radius: params.radius,
+    tube: params.tube
+  }));
 }
 
 function previewer(ctx, initialParams) {
diff --git a/web/app/cad/init/startApplication.js b/web/app/cad/init/startApplication.js
index 7feaf96e..1567b087 100644
--- a/web/app/cad/init/startApplication.js
+++ b/web/app/cad/init/startApplication.js
@@ -41,9 +41,9 @@ export default function startApplication(callback) {
     UiEntryPointsPlugin,
     MenuPlugin,
     KeyboardPlugin,
-    ExtensionsPlugin,
     OperationPlugin,
     CraftPlugin,
+    ExtensionsPlugin,
     WizardPlugin,
     PreviewPlugin,
     CraftUiPlugin,
diff --git a/web/app/math/vec.js b/web/app/math/vec.js
index e37ff5a0..573fb423 100644
--- a/web/app/math/vec.js
+++ b/web/app/math/vec.js
@@ -120,6 +120,25 @@ export function length(v) {
   return Math.sqrt(lengthSq(v));
 }
 
+export function copy(to, from) {
+  for (let i = 0; i < v.length; i++) {
+    to[i] = from(v[i]);
+  }
+  return to;
+}
+
+export function clone(v) {
+  return copy(create(v.length), v);
+}
+
+export function create(dim) {
+  let out = [];
+  for (let i = 0; i < dim; i++) {
+    out[i] = 0;
+  }
+  return out;
+}
+
 const sq = v => v * v; 
 
 export function distanceSq(v1, v2) {