diff --git a/web/app/brep/brep-builder.js b/web/app/brep/brep-builder.js
index b8de05dd..deb07bf6 100644
--- a/web/app/brep/brep-builder.js
+++ b/web/app/brep/brep-builder.js
@@ -102,7 +102,7 @@ export function createBoundingSurface(points, plane) {
   return createBoundingSurfaceFrom2DPoints(points2d, plane);
 }
 
-export function createBoundingSurfaceFrom2DPoints(points2d, plane, minWidth, minHeight, offset = 0, ) {
+export function createBoundingSurfaceFrom2DPoints(points2d, plane, minWidth, minHeight, offset = 0) {
   let bBox = new BBox();
   points2d.forEach(p => bBox.checkPoint(p));
 
diff --git a/web/app/brep/brep-primitives.js b/web/app/brep/brep-primitives.js
index a00c7163..37aabcb6 100644
--- a/web/app/brep/brep-primitives.js
+++ b/web/app/brep/brep-primitives.js
@@ -3,6 +3,7 @@ import {Plane} from './geom/impl/plane'
 import {createPrism, enclose} from './brep-enclose'
 import {AXIS, Matrix3} from '../math/l3space'
 import {Circle} from '../cad/sketch/sketchModel'
+import CSys from '../math/csys';
 
 export function box(w, h, d, tr) {
   const wh = w * 0.5;
@@ -22,7 +23,11 @@ export function box(w, h, d, tr) {
 
 export function cylinder(r, h, tr) {
   tr = tr || IDENTITY;
-  let circle1 = new Circle(-1, new Point(0,0,0), r).toNurbs( new Plane(tr.apply(AXIS.Z), h));
+  let normal = tr.apply(AXIS.Z);
+  let plane = new Plane(normal, h);
+  let csys = CSys.fromNormalAndDir(normal.multiply(h), normal, plane.basis()[0]);
+  
+  let circle1 = new Circle(-1, new Point(0,0,0), r).toNurbs(csys);
   let circle2 = circle1.translate(tr.apply(new Point(0,0,-h)));
   return enclose([circle1], [circle2]);
 }
diff --git a/web/app/brep/geom/surfaces/nurbsSurface.js b/web/app/brep/geom/surfaces/nurbsSurface.js
index d77c23a1..00b652a5 100644
--- a/web/app/brep/geom/surfaces/nurbsSurface.js
+++ b/web/app/brep/geom/surfaces/nurbsSurface.js
@@ -40,7 +40,7 @@ export default class NurbsSurface {
   }
 
   eval(u, v, order) {
-    this.verb.derivatives(u, v, order);
+    return this.verb.derivatives(u, v, order);
   }
   
   normal(u, v) {
diff --git a/web/app/cad/craft/cutExtrude/cutExtrude.js b/web/app/cad/craft/cutExtrude/cutExtrude.js
index 16bab5c6..a4f1e400 100644
--- a/web/app/cad/craft/cutExtrude/cutExtrude.js
+++ b/web/app/cad/craft/cutExtrude/cutExtrude.js
@@ -19,32 +19,26 @@ export function doOperation(params, {cadRegistry, sketcher}, cut) {
   let sketch = sketcher.readSketch(face.id);
   if (!sketch) throw 'illegal state';
 
-  let plane = face.surface.tangentPlane(0, 0);
-  const details = getEncloseDetails(params, sketch.fetchContours(), plane, !cut, false);
+  const details = getEncloseDetails(params, sketch.fetchContours(), face.csys, face.surface, !cut, false);
   const operand = combineShells(details.map(d => enclose(d.basePath, d.lidPath, d.baseSurface, d.lidSurface)));
   return BooleanOperation(face, solid, operand, cut ? 'subtract' : 'union');
 }
 
-export function getEncloseDetails(params, contours, sketchSurface, invert) {
+export function getEncloseDetails(params, contours, csys, sketchSurface, invert) {
   let value = params.value;
   if (value < 0) {
     value = Math.abs(value);
     invert = !invert;
   }
 
-  const baseSurface = invert ? sketchSurface.invert() : sketchSurface;
-
-  let target;
+  const targetDir = invert ? csys.z : csys.z.negate();
   
-  let baseSurfaceNormal = baseSurface.normal;
-
-  const targetDir = baseSurfaceNormal.negate();
+  let target;
 
   if (params.rotation !== 0) {
-    const basis = sketchSurface.basis();
-    target = Matrix3.rotateMatrix(params.rotation * Math.PI / 180, basis[0], ORIGIN).apply(targetDir);
+    target = Matrix3.rotateMatrix(params.rotation * Math.PI / 180, csys.x, ORIGIN).apply(targetDir);
     if (params.angle !== 0) {
-      target = Matrix3.rotateMatrix(params.angle * Math.PI / 180, basis[2], ORIGIN)._apply(target);
+      target = Matrix3.rotateMatrix(params.angle * Math.PI / 180, csys.z, ORIGIN)._apply(target);
     }
     target._multiply(value);
   } else {
@@ -54,7 +48,7 @@ export function getEncloseDetails(params, contours, sketchSurface, invert) {
   let details = [];
   for (let contour of contours) {
     if (invert) contour.reverse();
-    const basePath = contour.transferOnSurface(sketchSurface);
+    const basePath = contour.transferInCoordinateSystem(csys);
     if (invert) contour.reverse();
 
     const lidPath = [];
@@ -68,6 +62,7 @@ export function getEncloseDetails(params, contours, sketchSurface, invert) {
       lidPath.push(lidCurve);
     }
 
+    const baseSurface = sketchSurface.tangentPlane(0, 0);
     const lidSurface = baseSurface.translate(target).invert();
     details.push({basePath, lidPath, baseSurface, lidSurface});
   }
diff --git a/web/app/cad/craft/cutExtrude/previewer.js b/web/app/cad/craft/cutExtrude/previewer.js
index dc10222c..29b41cfa 100644
--- a/web/app/cad/craft/cutExtrude/previewer.js
+++ b/web/app/cad/craft/cutExtrude/previewer.js
@@ -14,7 +14,7 @@ export function createPreviewGeomProvider(inversed) {
     if (!face) return null;
     let sketch = face.sketch.fetchContours();
 
-    const encloseDetails = getEncloseDetails(params, sketch, face.surface.tangentPlane(0, 0), !inversed);
+    const encloseDetails = getEncloseDetails(params, sketch, face.csys, face.surface, !inversed);
     const triangles = [];
 
     for (let {basePath, lidPath, baseSurface, lidSurface} of encloseDetails) {
diff --git a/web/app/cad/craft/primitives/plane/PlaneWizard.jsx b/web/app/cad/craft/primitives/plane/PlaneWizard.jsx
new file mode 100644
index 00000000..be08e525
--- /dev/null
+++ b/web/app/cad/craft/primitives/plane/PlaneWizard.jsx
@@ -0,0 +1,12 @@
+import React from 'react';
+import {Group} from '../../wizard/components/form/Form';
+import {NumberField, RadioButtonsField, ReadOnlyValueField} from '../../wizard/components/form/Fields';
+import SingleEntity from '../../wizard/components/form/SingleEntity';
+import {RadioButton} from 'ui/components/controls/RadioButtons';
+
+
+export default function PlaneWizard() {
+  return <Group>
+    <ReadOnlyValueField name='datum'/>
+  </Group>;
+}
\ No newline at end of file
diff --git a/web/app/cad/craft/primitives/plane/planeOpSchema.js b/web/app/cad/craft/primitives/plane/planeOpSchema.js
new file mode 100644
index 00000000..1ea295c3
--- /dev/null
+++ b/web/app/cad/craft/primitives/plane/planeOpSchema.js
@@ -0,0 +1,6 @@
+export default {
+  datum: {
+    type: 'datum',
+    defaultValue: {type: 'selection'}
+  }
+}
\ No newline at end of file
diff --git a/web/app/cad/craft/primitives/plane/planeOperation.js b/web/app/cad/craft/primitives/plane/planeOperation.js
new file mode 100644
index 00000000..fd76c043
--- /dev/null
+++ b/web/app/cad/craft/primitives/plane/planeOperation.js
@@ -0,0 +1,52 @@
+import {createMeshGeometry} from 'scene/geoms';
+import {Plane} from '../../../../brep/geom/impl/plane';
+import Vector from 'math/vector';
+import PlaneWizard from './PlaneWizard';
+import {MOpenFaceShell} from '../../../model/mopenFace';
+import schema from './planeOpSchema';
+import {CSysPlaneSurfacePrototype} from '../../../model/surfacePrototype';
+
+const WIDTH = 750;
+const HEIGHT = 750;
+
+function createPlane(params, services) {
+  let mDatum = services.cadRegistry.findDatum(params.datum);
+
+  return {
+    outdated: [mDatum],
+    created: [new MOpenFaceShell(new CSysPlaneSurfacePrototype(mDatum.csys), mDatum.csys)]
+  }
+}
+
+function previewGeomProvider(params, services) {
+  let mDatum = services.cadRegistry.findDatum(params.datum);
+
+  if (!mDatum) {
+    return null;
+  }
+
+  let tr = mDatum.csys.outTransformation;
+  
+  const a = tr._apply(new Vector(0, 0, 0));
+  const b = tr._apply(new Vector(WIDTH, 0, 0));
+  const c = tr._apply(new Vector(WIDTH, HEIGHT, 0));
+  const d = tr._apply(new Vector(0, HEIGHT, 0));
+  
+  let trs = [[a, b, c], [a, c, d]];
+  return createMeshGeometry(trs);
+}
+
+export default {
+  id: 'PLANE_FROM_DATUM',
+  label: 'Plane',
+  icon: 'img/cad/plane',
+  info: 'creates new object plane off of datum',
+  paramsInfo: ({datum}) => `(${datum})`,
+  previewGeomProvider,
+  run: createPlane,
+  form: PlaneWizard,
+  schema
+};
+
+
+
diff --git a/web/app/cad/craft/primitives/PlaneWizard.jsx b/web/app/cad/craft/primitives/simplePlane/SimplePlaneWizard.jsx
similarity index 66%
rename from web/app/cad/craft/primitives/PlaneWizard.jsx
rename to web/app/cad/craft/primitives/simplePlane/SimplePlaneWizard.jsx
index 6ef03dd3..94ad4ca4 100644
--- a/web/app/cad/craft/primitives/PlaneWizard.jsx
+++ b/web/app/cad/craft/primitives/simplePlane/SimplePlaneWizard.jsx
@@ -1,7 +1,7 @@
 import React from 'react';
-import {Group} from '../wizard/components/form/Form';
-import {NumberField, RadioButtonsField} from '../wizard/components/form/Fields';
-import SingleEntity from '../wizard/components/form/SingleEntity';
+import {Group} from '../../wizard/components/form/Form';
+import {NumberField, RadioButtonsField} from '../../wizard/components/form/Fields';
+import SingleEntity from '../../wizard/components/form/SingleEntity';
 import {RadioButton} from 'ui/components/controls/RadioButtons';
 
 
diff --git a/web/app/cad/craft/primitives/planeOpSchema.js b/web/app/cad/craft/primitives/simplePlane/simplePlaneOpSchema.js
similarity index 100%
rename from web/app/cad/craft/primitives/planeOpSchema.js
rename to web/app/cad/craft/primitives/simplePlane/simplePlaneOpSchema.js
diff --git a/web/app/cad/craft/primitives/planeOperation.js b/web/app/cad/craft/primitives/simplePlane/simplePlaneOperation.js
similarity index 80%
rename from web/app/cad/craft/primitives/planeOperation.js
rename to web/app/cad/craft/primitives/simplePlane/simplePlaneOperation.js
index 50c371e3..52ada59d 100644
--- a/web/app/cad/craft/primitives/planeOperation.js
+++ b/web/app/cad/craft/primitives/simplePlane/simplePlaneOperation.js
@@ -1,11 +1,11 @@
 import {createMeshGeometry} from 'scene/geoms';
-import {STANDARD_BASES} from '../../../math/l3space';
-import {Plane} from '../../../brep/geom/impl/plane';
+import {STANDARD_BASES} from '../../../../math/l3space';
+import {Plane} from '../../../../brep/geom/impl/plane';
 import Vector from 'math/vector';
-import PlaneWizard from './PlaneWizard';
-import {MOpenFaceShell} from '../../model/mopenFace';
-import schema from './planeOpSchema';
-import {PlaneSurfacePrototype} from '../../model/surfacePrototype';
+import PlaneWizard from './SimplePlaneWizard';
+import {MOpenFaceShell} from '../../../model/mopenFace';
+import schema from './simplePlaneOpSchema';
+import {PlaneSurfacePrototype} from '../../../model/surfacePrototype';
 
 function paramsToPlane({orientation, parallelTo, depth}, cadRegistry) {
   let face = null;
diff --git a/web/app/cad/legacy/brep/revolve.js b/web/app/cad/legacy/brep/revolve.js
index 7d53dffb..43c4415f 100644
--- a/web/app/cad/legacy/brep/revolve.js
+++ b/web/app/cad/legacy/brep/revolve.js
@@ -9,27 +9,27 @@ export function Revolve(app, params) {
   const surface = face.surface;
 
   const sketch = ReadSketchFromFace(app, face);
-  const pivot = evalPivot(params.pivot, sketch, surface);
+  const pivot = evalPivot(params.pivot, sketch, face.csys);
 
   const shells = [];
   const contours = sketch.fetchContours();
   for (let contour of contours) {
-    const basePath = contour.transferOnSurface(surface);
+    const basePath = contour.transferInCoordinateSystem(face.csys);
     const shell = revolve(basePath, surface, pivot.p0, pivot.v, params.angle);
     shells.push(shell);
   }
 
-  const operand = combineShells(shells)
+  const operand = combineShells(shells);
   return BooleanOperation(face, solid, operand, 'union');
 }
 
-export function evalPivot(pivot, sketch, surface) {
+export function evalPivot(pivot, sketch, csys) {
   const segment = sketch.findById(pivot);
   if (segment == null) {
     return null;
   }
-  const tr = surface.get3DTransformation();
+  const tr = csys.outTransformation;
   const p0 = tr.apply(segment.a);
-  const v = tr.apply(segment.b).minus(p0)._normalize()
+  const v = tr.apply(segment.b).minus(p0)._normalize();
   return {p0, v}
 }
diff --git a/web/app/cad/model/mface.js b/web/app/cad/model/mface.js
index 49f52788..69a3ce79 100644
--- a/web/app/cad/model/mface.js
+++ b/web/app/cad/model/mface.js
@@ -10,40 +10,63 @@ export class MFace extends MObject {
 
   static TYPE = 'face';
 
-  constructor(id, shell, surface) {
+  constructor(id, shell, surface, csys) {
     super(id);
     this.id = id;
     this.shell = shell;
     this.surface = surface;
     this.sketchObjects = [];
+    this._csys = csys
   }
 
   normal() {
-    return this.surface.normalInMiddle();
+    return this.csys.z;
   }
 
   depth() {
-    return this.surface.tangentPlaneInMiddle().w;
+    this.evalCSys();
+    return this.w;
   }
 
-  calcBasis() {
-    return BasisForPlane(this.normal());
-  };
-
   basis() {
     if (!this._basis) {
-      this._basis = this.calcBasis();
+      this._basis = [this.csys.x, this.csys.y, this.csys.z];
     }
     return this._basis;
   }
 
   get csys() {
-    if (!this._csys) {
-      let [x,y,z] = this.basis();
-      this._csys = new CSys(this.normal().multiply(this.depth()), x, y, z);
-    }
+    this.evalCSys();
     return this._csys;
   }
+
+  get isPlaneBased() {
+    return this.surface.simpleSurface && this.surface.simpleSurface.isPlane;
+  }
+  
+  evalCSys() {
+    if (!this._csys) {
+      if (this.isPlaneBased) {
+        let [x, y, z] = this.surface.simpleSurface.basis();
+        let origin = z.multiply(this.surface.simpleSurface.w);
+        this._csys = new CSys(origin, x, y, z);
+      } else {
+        let origin = this.surface.southWestPoint();
+        let z = this.surface.normalUV(0, 0);
+        let derivatives = this.surface.impl.eval(0, 0, 1);
+        let x = new Vector().set3(derivatives[1][0])._normalize();
+        let y = new Vector().set3(derivatives[0][1])._normalize();
+
+        if (this.surface.inverted) {
+          const t = x;
+          x = y;
+          y = t;
+        }
+        this._csys = new CSys(origin, x, y, z);
+      }
+      this.w = this.csys.w();
+    }
+  }
   
   setSketch(sketch) {
     this.sketch = sketch;
@@ -76,14 +99,22 @@ export class MFace extends MObject {
 
   get sketchToWorldTransformation() {
     if (!this._sketchToWorldTransformation) {
-      this._sketchToWorldTransformation = this.surface.tangentPlaneInMiddle().get3DTransformation();
+      if (this.isPlaneBased) {
+        this._sketchToWorldTransformation = this.csys.outTransformation;
+      } else {
+        throw 'sketches are supported only for planes yet';
+      }
     }
     return this._sketchToWorldTransformation;
   }
   
   get worldToSketchTransformation() {
     if (!this._worldToSketchTransformation) {
-      this._worldToSketchTransformation = this.sketchToWorldTransformation.invert();
+      if (this.isPlaneBased) {
+        this._worldToSketchTransformation = this.csys.inTransformation;
+      } else {
+        throw 'sketches are supported only for planes yet';
+      }
     }
     return this._worldToSketchTransformation;
   }
diff --git a/web/app/cad/model/mopenFace.js b/web/app/cad/model/mopenFace.js
index d61226da..07ed97d7 100644
--- a/web/app/cad/model/mopenFace.js
+++ b/web/app/cad/model/mopenFace.js
@@ -3,11 +3,11 @@ import {MFace} from './mface';
 
 export class MOpenFaceShell extends MShell {
   
-  constructor(surfacePrototype) {
+  constructor(surfacePrototype, csys) {
     super();
     this.surfacePrototype = surfacePrototype;
     this.faces.push(new MFace(this.id + '/SURFACE', this, 
-      surfacePrototype.boundTo([], 100, 100)));
+      surfacePrototype.boundTo([], 100, 100), csys));
   }
   
   get face() {
diff --git a/web/app/cad/model/surfacePrototype.js b/web/app/cad/model/surfacePrototype.js
index c6ec0d5d..74160d85 100644
--- a/web/app/cad/model/surfacePrototype.js
+++ b/web/app/cad/model/surfacePrototype.js
@@ -1,4 +1,6 @@
 import {createBoundingSurfaceFrom2DPoints} from '../../brep/brep-builder';
+import NurbsSurface from '../../brep/geom/surfaces/nurbsSurface';
+import {BrepSurface} from '../../brep/geom/surfaces/brepSurface';
 
 export class SurfacePrototype {
   
@@ -18,4 +20,35 @@ export class PlaneSurfacePrototype extends SurfacePrototype {
   boundTo(points2dOnSurface, minWidth, minHeight, offset) {
     return createBoundingSurfaceFrom2DPoints(points2dOnSurface, this.plane, minWidth, minHeight, offset);        
   }
+}
+
+/*
+ * The only difference PlaneSurfacePrototype is show phony surface 
+ * when no sketching from csys origin for estetic purposes. 
+ * When sketch exists behaves like PlaneSurfacePrototype using csys transformation though
+ */
+export class CSysPlaneSurfacePrototype extends SurfacePrototype {
+
+  constructor(csys) {
+    super();
+    this.csys = csys;
+    this.plane = {
+      get3DTransformation: () => this.csys.outTransformation 
+    }
+  }
+
+  boundTo(points2dOnSurface, minWidth, minHeight, offset) {
+    
+    if (points2dOnSurface.length === 0) {
+      let dx = this.csys.x.multiply(minWidth);
+      let dy = this.csys.y.multiply(minHeight);
+      let origin = this.csys.origin;
+      return new BrepSurface(new NurbsSurface(verb.geom.NurbsSurface.byKnotsControlPointsWeights( 1, 1, [0,0,1,1], [0,0,1,1],
+        [ [ origin.plus(dy).data(), origin.plus(dx)._plus(dy).data()] ,
+          [ origin.data(),          origin.plus(dx ).data() ] ] )));
+
+    }
+    
+    return createBoundingSurfaceFrom2DPoints(points2dOnSurface, this.plane, minWidth, minHeight, offset);
+  }
 }
\ No newline at end of file
diff --git a/web/app/cad/part/menuConfig.js b/web/app/cad/part/menuConfig.js
index 9cf10aa7..0f7e43a6 100644
--- a/web/app/cad/part/menuConfig.js
+++ b/web/app/cad/part/menuConfig.js
@@ -43,7 +43,7 @@ export default [
     label: 'datum',
     cssIcons: ['magic'],
     info: 'operations on datum',
-    actions: ['DATUM_ROTATE', 'DATUM_MOVE']
+    actions: ['DATUM_ROTATE', 'DATUM_MOVE', '-', 'PLANE_FROM_DATUM']
     // actions: ['DATUM_MOVE', 'DATUM_ROTATE', 'DATUM_REBASE', '-', 'PLANE_FROM_DATUM', 'BOX', 'SPHERE', 'TORUS', 
     //   'CONE', 'CYLINDER']
   },
diff --git a/web/app/cad/part/partOperationsPlugin.js b/web/app/cad/part/partOperationsPlugin.js
index d6ee32dc..42a2b26e 100644
--- a/web/app/cad/part/partOperationsPlugin.js
+++ b/web/app/cad/part/partOperationsPlugin.js
@@ -1,12 +1,13 @@
 import boxOperation from '../craft/primitives/boxOperation';
 import extrudeOperation from '../craft/cutExtrude/extrudeOperation';
 import cutOperation from '../craft/cutExtrude/cutOperation';
-import planeOperation from '../craft/primitives/planeOperation';
+import planeOperation from '../craft/primitives/simplePlane/simplePlaneOperation';
 import filletOperation from '../craft/fillet/filletOperation';
 import revolveOperation from '../craft/revolve/revolveOperation';
 import createDatumOperation from '../craft/datum/create/createDatumOperation';
 import moveDatumOperation from '../craft/datum/move/moveDatumOperation';
 import rotateDatumOperation from '../craft/datum/rotate/rotateDatumOperation';
+import datumOperation from '../craft/primitives/plane/planeOperation';
 
 export function activate({services}) {
   services.operation.registerOperations([
@@ -18,6 +19,7 @@ export function activate({services}) {
     filletOperation,
     createDatumOperation,
     moveDatumOperation,
-    rotateDatumOperation
+    rotateDatumOperation,
+    datumOperation
   ])
 }
\ No newline at end of file
diff --git a/web/app/cad/sketch/sketchModel.js b/web/app/cad/sketch/sketchModel.js
index c30e8fd1..fd93ae42 100644
--- a/web/app/cad/sketch/sketchModel.js
+++ b/web/app/cad/sketch/sketchModel.js
@@ -6,6 +6,7 @@ import {LUT} from '../../math/bezier-cubic'
 import {distanceAB, isCCW, makeAngle0_360} from '../../math/math'
 import {normalizeCurveEnds} from '../../brep/geom/impl/nurbs-ext';
 import Vector from '../../../../modules/math/vector';
+import {AXIS, ORIGIN} from '../../math/l3space';
 
 const RESOLUTION = 20;
 
@@ -31,8 +32,8 @@ class SketchPrimitive {
     return this.constructor.name !== 'Segment';
   }
 
-  toNurbs(plane) {
-    let verbNurbs = this.toVerbNurbs(plane, to3DTrFunc(plane));
+  toNurbs(csys) {
+    let verbNurbs = this.toVerbNurbs(csys.outTransformation.apply, csys);
     if (this.inverted) {
       verbNurbs = verbNurbs.reverse();
     }
@@ -43,7 +44,7 @@ class SketchPrimitive {
     return new BrepCurve(new NurbsCurve(verbNurbs));
   }
 
-  toVerbNurbs(plane, _3dtr) {
+  toVerbNurbs(tr) {
     throw 'not implemented'
   }
 
@@ -63,8 +64,8 @@ export class Segment extends SketchPrimitive {
     return [this.a, this.b];
   }
 
-  toVerbNurbs(plane, _3dtr) {
-    return new verb.geom.Line(_3dtr(this.a).data(), _3dtr(this.b).data());
+  toVerbNurbs(tr) {
+    return new verb.geom.Line(tr(this.a).data(), tr(this.b).data());
   }
 }
 
@@ -103,8 +104,11 @@ export class Arc extends SketchPrimitive {
     return points;
   }
 
-  toVerbNurbs(plane, _3dtr) {
-    const basis = plane.basis();
+  toVerbNurbs(tr, csys) {
+    
+    const basisX = csys.x;
+    const basisY = csys.y;
+    
     const startAngle = makeAngle0_360(Math.atan2(this.a.y - this.c.y, this.a.x - this.c.x));
     const endAngle = makeAngle0_360(Math.atan2(this.b.y - this.c.y, this.b.x - this.c.x));
 
@@ -113,16 +117,16 @@ export class Arc extends SketchPrimitive {
       angle = Math.PI * 2 + angle;
     }
     function pointAtAngle(angle) {
-      const dx = basis[0].multiply(Math.cos(angle));
-      const dy = basis[1].multiply(Math.sin(angle));
+      const dx = basisX.multiply(Math.cos(angle));
+      const dy = basisY.multiply(Math.sin(angle));
       return dx.plus(dy);
     }
     const xAxis = pointAtAngle(startAngle);
     const yAxis = pointAtAngle(startAngle + Math.PI * 0.5);
 
-    let arc = new verb.geom.Arc(_3dtr(this.c).data(), xAxis.data(), yAxis.data(), distanceAB(this.c, this.a), 0, Math.abs(angle));
+    let arc = new verb.geom.Arc(tr(this.c).data(), xAxis.data(), yAxis.data(), distanceAB(this.c, this.a), 0, Math.abs(angle));
     
-    return adjustEnds(arc, _3dtr(this.a), _3dtr(this.b))
+    return adjustEnds(arc, tr(this.a), tr(this.b))
   }
 }
 
@@ -184,7 +188,7 @@ export class EllipticalArc extends SketchPrimitive {
     return points;
   }
   
-  toVerbNurbs(plane, _3dtr) {
+  toVerbNurbs(tr) {
     const xAxis = this.ep2.minus(this.ep1)._multiply(0.5);
     const yAxis = new Vector(xAxis.y, xAxis.x)._normalize()._multiply(this.r) ;
     const center = this.ep1.plus(xAxis);
@@ -192,8 +196,8 @@ export class EllipticalArc extends SketchPrimitive {
     const startAngle = makeAngle0_360(Math.atan2(this.a.y - center.y, this.a.x - center.x));
     const endAngle = makeAngle0_360(Math.atan2(this.b.y - center.y, this.b.x - center.x));
     
-    let arc = new verb.geom.EllipseArc(_3dtr(center).data(), _3dtr(xAxis).data(), _3dtr(yAxis).data(), startAngle, endAngle);
-    return adjustEnds(arc, _3dtr(this.a), _3dtr(this.b))
+    let arc = new verb.geom.EllipseArc(tr(center).data(), tr(xAxis).data(), tr(yAxis).data(), startAngle, endAngle);
+    return adjustEnds(arc, tr(this.a), tr(this.b))
   }
 }
 
@@ -223,9 +227,10 @@ export class Circle extends SketchPrimitive {
   }
 
 
-  toVerbNurbs(plane, _3dtr) {
-    const basis = plane.basis();
-    return new verb.geom.Circle(_3dtr(this.c).data(), basis[0].data(), basis[1].data(), this.r);
+  toVerbNurbs(tr, csys) {
+    const basisX = csys.x;
+    const basisY = csys.y;
+    return new verb.geom.Circle(tr(this.c).data(), basisX.data(), basisY.data(), this.r);
   }
 }
 
@@ -252,9 +257,9 @@ export class Contour {
     this.segments.push(obj);
   }
 
-  tessellateOnSurface(surface) {
+  tessellateOnSurface(csys) {
     const cc = new CompositeCurve();
-    const tr = to3DTrFunc(surface);
+    const tr = csys.outTransformation;
 
     let prev = null;
     let firstPoint = null;
@@ -273,7 +278,7 @@ export class Contour {
         tessellation[n - 1] = firstPoint;
       }
 
-      cc.add(segment.toNurbs(surface), prev, segment);
+      cc.add(segment.toNurbs(csys), prev, segment);
       prev = tessellation[n - 1];
 
       //It might be an optimization for segments
@@ -286,14 +291,11 @@ export class Contour {
     return cc;
   }
 
-  transferOnSurface(surface) {
+  transferInCoordinateSystem(csys) {
     const cc = [];
-
-    let prev = null;
-    let firstPoint = null;
     for (let segIdx = 0; segIdx < this.segments.length; ++segIdx) {
       let segment = this.segments[segIdx];
-      cc.push(segment.toNurbs(surface));
+      cc.push(segment.toNurbs(csys));
     }
     return cc;
   }
@@ -320,13 +322,6 @@ export class Contour {
   }
 }
 
-function to3DTrFunc(surface) {
-  const _3dTransformation = surface.get3DTransformation();
-  return function (v) {
-    return _3dTransformation.apply(v);
-  }
-}
-
 class CompositeCurve {
 
   constructor() {
diff --git a/web/app/math/csys.js b/web/app/math/csys.js
index d3df8a95..25e288dd 100644
--- a/web/app/math/csys.js
+++ b/web/app/math/csys.js
@@ -17,21 +17,25 @@ export default class CSys {
     this.z = z;
   }
   
-  get inTransformation() {
+  w() {
+    return this.z.dot(this.origin);
+  }
+  
+  get outTransformation() {
     if (!this._inTr) {
       const basis = new Matrix3().setBasis([this.x, this.y, this.z]);
       const translate = new Matrix3();
-      translate.tx = this.origin.x;
-      translate.ty = this.origin.y;
-      translate.tz = this.origin.z;
-      this._inTr = basis.combine(translate);
+      basis.tx = this.origin.x;
+      basis.ty = this.origin.y;
+      basis.tz = this.origin.z;
+      this._inTr = basis;//basis.combine(translate);
     }
     return this._inTr;
   }
 
-  get outTransformation() {
+  get inTransformation() {
     if (!this._outTr) {
-      this._outTr = this.inTransformation().invert();
+      this._outTr = this.outTransformation.invert();
     }
     return this._outTr;
   }
diff --git a/web/app/math/l3space.js b/web/app/math/l3space.js
index c716807e..50aa930e 100644
--- a/web/app/math/l3space.js
+++ b/web/app/math/l3space.js
@@ -19,9 +19,12 @@ export const STANDARD_BASES = freeze({
 });
 
 
-/** @constructor */
-function Matrix3() {
-  this.reset();
+class Matrix3 {
+  constructor() {
+    this.reset();
+  }
+
+  apply = vector => this.__apply(vector, new Vector());
 }
 
 Matrix3.prototype.reset = function() {
@@ -181,10 +184,6 @@ Matrix3.prototype.combine = function(transform, out) {
   return m;
 };
 
-Matrix3.prototype.apply = function(vector) {
-  return this.__apply(vector, new Vector())
-};
-
 Matrix3.prototype._apply = function(vector) {
   return this.__apply(vector, vector);
 };