diff --git a/test/coreTests/utils/sketcherUtils.js b/test/coreTests/utils/sketcherUtils.js
index 4e98c6ea..726d3801 100644
--- a/test/coreTests/utils/sketcherUtils.js
+++ b/test/coreTests/utils/sketcherUtils.js
@@ -86,7 +86,7 @@ export function addArc(ctx, cX, cY, aX, aY, bX, bY) {
 export function addCircle(ctx, cX, cY, R) {
   let [rX, rY] = modelToScreen(ctx.viewer, cX + R, cY);
   [cX, cY] = modelToScreen(ctx.viewer, cX, cY);
-  ctx.actions['addCircle'].action();
+  ctx.actions.CircleTool.invoke(ctx);
   moveAndClickXY(ctx, cX, cY);
   let circle = ctx.viewer.toolManager.tool.circle;
   moveAndClickXY(ctx, rX, rY);
@@ -98,7 +98,7 @@ export function addEllipse(ctx, aX, aY, bX, bY, rX, rY) {
   [aX, aY] = modelToScreen(ctx.viewer, aX, aY);
   [bX, bY] = modelToScreen(ctx.viewer, bX, bY);
   [rX, rY] = modelToScreen(ctx.viewer, rX, rY);
-  ctx.actions['addEllipse'].action();
+  ctx.actions.EllipseTool.invoke(ctx);
   moveAndClickXY(ctx, aX, aY);
   let ellipse = ctx.viewer.toolManager.tool.ellipse;
   moveAndClickXY(ctx, bX, bY);
@@ -111,7 +111,7 @@ export function addEllipticalArc(ctx, aX, aY, bX, bY, rX, rY) {
   [aX, aY] = modelToScreen(ctx.viewer, aX, aY);
   [bX, bY] = modelToScreen(ctx.viewer, bX, bY);
   [rX, rY] = modelToScreen(ctx.viewer, rX, rY);
-  ctx.actions['addEllipticalArc'].action();
+  ctx.actions.EllipseArcTool.invoke(ctx);
   moveAndClickXY(ctx, aX, aY);
   let ellipse = ctx.viewer.toolManager.tool.ellipse;
   moveAndClickXY(ctx, bX, bY);
diff --git a/web/app/cad/sketch/sketchModel.js b/web/app/cad/sketch/sketchModel.js
index 051ddb56..d065ff40 100644
--- a/web/app/cad/sketch/sketchModel.js
+++ b/web/app/cad/sketch/sketchModel.js
@@ -7,6 +7,7 @@ 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 '../../../../modules/math/l3space';
+import CSys from "../../../../modules/math/csys";
 
 const RESOLUTION = 20;
 
@@ -21,11 +22,14 @@ class SketchPrimitive {
   }
 
   tessellate(resolution) {
-    const tessellation = this.tessellateImpl(resolution);
-    if (this.inverted) {
-      tessellation.reverse();
-    }
-    return tessellation;
+    return this.toNurbs(CSys.ORIGIN).tessellate();
+    // return brepCurve.impl.verb.tessellate().map(p => new Vector().set3(p) );
+
+    // const tessellation = this.tessellateImpl(resolution);
+    // if (this.inverted) {
+    //   tessellation.reverse();
+    // }
+    // return tessellation;
   }
 
   get isCurve() {
@@ -64,7 +68,7 @@ export class Segment extends SketchPrimitive {
     this.b = b;
   }
 
-  tessellateImpl(resolution) {
+  tessellate(resolution) {
     return [this.a, this.b];
   }
 
@@ -81,33 +85,6 @@ export class Arc extends SketchPrimitive {
     this.c = c;
   }
 
-  tessellateImpl(resolution) {
-    return Arc.tessellateArc(this.a, this.b, this.c, resolution);
-  }
-
-  static tessellateArc(ao, bo, c, resolution) {
-    var a = ao.minus(c);
-    var b = bo.minus(c);
-    var points = [ao];
-    var abAngle = Math.atan2(b.y, b.x) - Math.atan2(a.y, a.x);
-    if (abAngle > Math.PI * 2) abAngle = Math.PI / 2 - abAngle;
-    if (abAngle < 0) abAngle = Math.PI * 2 + abAngle;
-
-    var r = a.length();
-    resolution = 1;
-    //var step = Math.acos(1 - ((resolution * resolution) / (2 * r * r)));
-    var step = resolution / (2 * Math.PI);
-    var k = Math.round(abAngle / step);
-    var angle = Math.atan2(a.y, a.x) + step;
-
-    for (var i = 0; i < k - 1; ++i) {
-      points.push(new Point(c.x + r*Math.cos(angle), c.y + r*Math.sin(angle)));
-      angle += step;
-    }
-    points.push(bo);
-    return points;
-  }
-
   toVerbNurbs(tr, csys) {
     
     const basisX = csys.x;
@@ -143,69 +120,42 @@ export class BezierCurve extends SketchPrimitive {
     this.cp2 = cp2;
   }
 
-  tessellateImpl(resolution) {
-    return LUT(this.a, this.b, this.cp1, this.cp2, 10);
-  }
-
   toVerbNurbs(tr) {
     return new verb.geom.BezierCurve([tr(this.a).data(), tr(this.cp1).data(), tr(this.cp2).data(), tr(this.b).data()], null);
   }
 }
 
 export class EllipticalArc extends SketchPrimitive {
-  constructor(id, ep1, ep2, a, b, r) {
+  constructor(id, c, rx, ry, rot, a, b) {
     super(id);
-    this.ep1 = ep1;
-    this.ep2 = ep2;
+    this.c = c;
+    this.rx = rx;
+    this.ry = ry;
+    this.rot = rot;
     this.a = a;
     this.b = b;
-    this.r = r;
   }
 
-  tessellateImpl(resolution) {
-    return EllipticalArc.tessEllipticalArc(this.ep1, this.ep2, this.a, this.b, this.r, resolution);
-  }
+  toVerbNurbs(tr, csys) {
+    const ax = Math.cos(this.rot);
+    const ay = Math.sin(this.rot);
 
-  static tessEllipticalArc(ep1, ep2, ao, bo, radiusY, resolution) {
-    const axisX = ep2.minus(ep1);
-    const radiusX = axisX.length() * 0.5;
-    axisX._normalize();
-    const c = ep1.plus(axisX.multiply(radiusX));
-    const a = ao.minus(c);
-    const b = bo.minus(c);
-    const points = [ao];
-    const rotation = Math.atan2(axisX.y, axisX.x);
-    let abAngle = Math.atan2(b.y, b.x) - Math.atan2(a.y, a.x);
-    if (abAngle > Math.PI * 2) abAngle = Math.PI / 2 - abAngle;
-    if (abAngle < 0) abAngle = Math.PI * 2 + abAngle;
+    const xAxis = new Vector(ax, ay)._multiply(this.rx);
+    const yAxis = new Vector(-ay, ax)._multiply(this.ry);
 
-    const sq = (a) => a * a;
+    const startAngle = Math.atan2(this.a.y - this.c.y, this.a.x - this.c.x) - this.rot;
+    const endAngle  = Math.atan2(this.b.y - this.c.y, this.b.x - this.c.x) - this.rot;
 
-    resolution = 1;
+    if (startAngle > endAngle) {
 
-    const step = resolution / (2 * Math.PI);
-    const k = Math.round(abAngle / step);
-    let angle = Math.atan2(a.y, a.x) + step - rotation;
-
-    for (let i = 0; i < k - 1; ++i) {
-      const r = Math.sqrt(1/( sq(Math.cos(angle)/radiusX) + sq(Math.sin(angle)/radiusY)));
-      points.push(new Point(c.x + r*Math.cos(angle + rotation), c.y + r*Math.sin(angle + rotation)));
-      angle += step;
     }
-    points.push(bo);
-    return points;
-  }
-  
-  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);
 
-    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(tr(center).data(), tr(xAxis).data(), tr(yAxis).data(), startAngle, endAngle);
-    return adjustEnds(arc, tr(this.a), tr(this.b))
+    // let arc = new verb.geom.EllipseArc(tr(this.c).data(), tr(xAxis).data(), tr(yAxis).data(), startAngle, endAngle);
+    let arc = new verb.geom.EllipseArc(this.c.data(), xAxis.data(), yAxis.data(), startAngle, endAngle);
+    arc = arc.transform(csys.outTransformation.toArray());
+
+    return arc;
+    // return adjustEnds(arc, tr(this.a), tr(this.b))
   }
 }
 
@@ -216,25 +166,6 @@ export class Circle extends SketchPrimitive {
     this.r = r;
   }
 
-  tessellateImpl(resolution) {
-    return Circle.tessCircle(this.c, this.r, resolution);
-  }
-
-  static tessCircle(c, r, resolution) {
-    var points = [];
-    resolution = 1;
-    //var step = Math.acos(1 - ((resolution * resolution) / (2 * r * r)));
-    var step = resolution / (2 * Math.PI);
-    var k = Math.round((2 * Math.PI) / step);
-
-    for (var i = 0, angle = 0; i < k; ++i, angle += step) {
-      points.push(new Point(c.x + r*Math.cos(angle), c.y + r*Math.sin(angle)));
-    }
-    points.push(points[0]); // close it
-    return points;
-  }
-
-
   toVerbNurbs(tr, csys) {
     const basisX = csys.x;
     const basisY = csys.y;
@@ -243,22 +174,23 @@ export class Circle extends SketchPrimitive {
 }
 
 export class Ellipse extends SketchPrimitive {
-  constructor(id, ep1, ep2, r) {
+  constructor(id, c, rx, ry, rot) {
     super(id);
-    this.ep1 = ep1;
-    this.ep2 = ep2;
-    this.r = r;
-  }
-
-  tessellateImpl(resolution) {
-    return EllipticalArc.tessEllipticalArc(this.ep1, this.ep2, this.ep1, this.ep1, this.r, resolution);
+    this.c = c;
+    this.rx = rx;
+    this.ry = ry;
+    this.rot = rot;
   }
 
   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);
-    return new verb.geom.Ellipse(tr(center).data(), tr(xAxis).data(), tr(yAxis).data());
+
+    const ax = Math.cos(this.rot);
+    const ay = Math.sin(this.rot);
+
+    const xAxis = new Vector(ax, ay)._multiply(this.rx);
+    const yAxis = new Vector(-ay, ax)._multiply(this.ry);
+
+    return new verb.geom.Ellipse(tr(this.c).data(), tr(xAxis).data(), tr(yAxis).data());
   }
 }
 
@@ -295,7 +227,7 @@ export class Contour {
     const tessellation = [];
     for (let segment of this.segments) {
       const segmentTessellation = segment.tessellate(resolution);
-      //skip last one cuz it's guaranteed to be closed
+      //skip last one because it's guaranteed to be closed
       for (let i = 0; i < segmentTessellation.length - 1; ++i) {
         tessellation.push(segmentTessellation[i]);
       }
diff --git a/web/app/cad/sketch/sketchReader.js b/web/app/cad/sketch/sketchReader.js
index 45db93da..a285c973 100644
--- a/web/app/cad/sketch/sketchReader.js
+++ b/web/app/cad/sketch/sketchReader.js
@@ -85,11 +85,16 @@ export function ReadSketch(sketch, sketchId, readConstructionSegments) {
       const arcCenter = ReadSketchPoint(data.c);
       out.connections.push(new sm.Arc(getID(obj), arcA, arcB, arcCenter));
     } else if (obj.type === 'EllipticalArc') {
-      const ep1 = ReadSketchPoint(data.ep1);
-      const ep2 = ReadSketchPoint(data.ep2);
+      if (data.ep1) {
+        continue;
+      }
+      const c = ReadSketchPoint(data.c);
+      const rx = readSketchFloat(data.rx);
+      const ry = readSketchFloat(data.ry);
+      const rot = readSketchFloat(data.rot);
       const a = ReadSketchPoint(data.a);
       const b = ReadSketchPoint(data.b);
-      out.connections.push(new sm.EllipticalArc(getID(obj), ep1, ep2, a, b, readSketchFloat(data.r)));
+      out.loops.push(new sm.EllipticalArc(getID(obj), c, rx, ry, rot, a, b));
     } else if (obj.type === 'BezierCurve') {
       const a = ReadSketchPoint(data.cp1);
       const b = ReadSketchPoint(data.cp4);
@@ -100,9 +105,14 @@ export function ReadSketch(sketch, sketchId, readConstructionSegments) {
       const circleCenter = ReadSketchPoint(data.c);
       out.loops.push(new sm.Circle(getID(obj), circleCenter, readSketchFloat(data.r)));
     } else if (obj.type === 'Ellipse') {
-      const ep1 = ReadSketchPoint(data.ep1);
-      const ep2 = ReadSketchPoint(data.ep2);
-      out.loops.push(new sm.Ellipse(getID(obj), ep1, ep2, readSketchFloat(data.r)));
+      if (data.ep1) {
+        continue;
+      }
+      const c = ReadSketchPoint(data.c);
+      const rx = readSketchFloat(data.rx);
+      const ry = readSketchFloat(data.ry);
+      const rot = readSketchFloat(data.rot);
+      out.loops.push(new sm.Ellipse(getID(obj), c, rx, ry, rot));
     }
   }
   return out;
diff --git a/web/app/sketcher/shapes/bezier-curve.js b/web/app/sketcher/shapes/bezier-curve.js
index c7a60701..9f59bd11 100644
--- a/web/app/sketcher/shapes/bezier-curve.js
+++ b/web/app/sketcher/shapes/bezier-curve.js
@@ -10,17 +10,17 @@ import {EndPoint} from "./point";
 
 export class BezierCurve extends SketchObject {
 
-  constructor(ax, ay, bx, by, cp1x, cp1y, cp2x, cp2y, id) {
+  constructor(ax, ay, cp1x, cp1y, cp2x, cp2y, bx, by, id) {
     super(id);
     const s1 = new Segment(ax, ay, cp1x, cp1y, this.id + ':1');
     const s2 = new Segment(bx, by, cp2x, cp2y, this.id + ':2');
     this.addChild(s1);
     this.addChild(s2);
 
-    this.a = this.s1.a;
-    this.b = this.s2.b;
-    this.cp1 = this.s1.b;
-    this.cp2 = this.s2.a;
+    this.a = s1.a;
+    this.b = s2.b;
+    this.cp1 = s1.b;
+    this.cp2 = s2.a;
     
     for (let c of this.children) {
       c.role = 'objectConstruction';
diff --git a/web/app/sketcher/shapes/ellipse.js b/web/app/sketcher/shapes/ellipse.js
index b67f3497..e1d2cee9 100644
--- a/web/app/sketcher/shapes/ellipse.js
+++ b/web/app/sketcher/shapes/ellipse.js
@@ -2,60 +2,64 @@ import {SketchObject} from './sketch-object'
 
 import * as math from '../../math/math';
 import {Param} from "./param";
-import {SketchSegmentSerializationData} from "./segment";
 import {EndPoint} from "./point";
 
 export class Ellipse extends SketchObject {
 
-  constructor(x1, y1, x2, y2, r, id) {
+  constructor(cx, cy, rx, ry, rot, id) {
     super(id);
-    this.ep1 = new EndPoint(x1, y1, this.id + ':1');
-    this.ep2 = new EndPoint(x2, y2, this.id + ':2');
-    this.addChild(this.ep1);
-    this.addChild(this.ep2);
-    this.r = new Param(r === undefined ? 0 : this.radiusX * 0.5, 'R');
-    this.r.enforceVisualLimit = true;
+
+    this.c = new EndPoint(cx, cy, this.id + ':C');
+
+    this.addChild(this.c);
+
+    this.rot = new Param(rot, 'A');
+    this.rx = new Param(rx, 'Rx');
+    this.ry = new Param(ry, 'Rx');
+
+    this.rx.enforceVisualLimit = true;
+    this.ry.enforceVisualLimit = true;
   }
 
   recoverIfNecessary() {
     let recovered = false;
-    if (math.distanceAB(this.ep1, this.ep2) <= math.TOLERANCE) {
-      this.ep1.translate(-RECOVER_LENGTH, -RECOVER_LENGTH);
-      this.ep2.translate(RECOVER_LENGTH, RECOVER_LENGTH);
+    if (this.radiusX <= 0.1) {
+      this.rx.set(RECOVER_LENGTH);
       recovered = true;
     }
     if (this.radiusY <= 0.1) {
-      this.r.set(RECOVER_LENGTH);
+      this.ry.set(RECOVER_LENGTH);
       recovered = true;
     }
     return recovered;
   }
 
   visitParams(callback) {
-    this.ep1.visitParams(callback);
-    this.ep2.visitParams(callback);
-    callback(this.r);
+    this.c.visitParams(callback);
+    callback(this.rx);
+    callback(this.ry);
+    callback(this.rot);
   }
 
 
   get rotation() {
-    return Math.atan2(this.ep2.y - this.ep1.y, this.ep2.x - this.ep1.x);
+    return this.rot.get();
   }
 
   get radiusX() {
-    return math.distance(this.ep1.x, this.ep1.y, this.ep2.x, this.ep2.y) * 0.5;
+    return this.rx.get();
   }
 
   get radiusY() {
-    return this.r.get();
+    return this.ry.get();
   }
 
   get centerX() {
-    return this.ep1.x + (this.ep2.x - this.ep1.x) * 0.5; 
+    return this.c.x;
   }
 
   get centerY() {
-    return this.ep1.y + (this.ep2.y - this.ep1.y) * 0.5;
+    return this.c.y;
   }
 
   drawImpl(ctx, scale) {
@@ -92,19 +96,23 @@ export class Ellipse extends SketchObject {
 
   write() {
     return {
-      ep1: this.ep1.write(),
-      ep2: this.ep2.write(),
-      r: this.r.get()
+      c: this.c.write(),
+      rx: this.rx.get(),
+      ry: this.ry.get(),
+      rot: this.rot.get(),
     };
   }
 
   static read(id, data) {
+    if (data.ep1) {
+      return readFormatV1(id, data);
+    }
     return new Ellipse(
-      data.ep1.x,
-      data.ep1.y,
-      data.ep2.x,
-      data.ep2.y,
-      data.r,
+      data.c.x,
+      data.c.y,
+      data.rx,
+      data.ry,
+      data.rot,
       id
     )
   }
@@ -114,4 +122,15 @@ Ellipse.prototype._class = 'TCAD.TWO.Ellipse';
 Ellipse.prototype.TYPE = 'Ellipse';
 
 const sq = (a) => a * a;
-const RECOVER_LENGTH = 100;
\ No newline at end of file
+const RECOVER_LENGTH = 100;
+
+function readFormatV1(id, data) {
+
+  const cx = data.ep1.x + (data.ep2.x - data.ep1.x) * 0.5;
+  const cy = data.ep1.y + (data.ep2.y - data.ep1.y) * 0.5;
+  const rx = math.distance(data.ep1.x, data.ep1.y, data.ep2.x, data.ep2.y) * 0.5;
+  const ry = data.r;
+  const rot = Math.atan2(data.ep2.y - data.ep1.y, data.ep2.x - data.ep1.x);
+
+  return new Ellipse(cx, cy, rx, ry, rot, id);
+}
\ No newline at end of file
diff --git a/web/app/sketcher/shapes/elliptical-arc.js b/web/app/sketcher/shapes/elliptical-arc.js
index 1f3fc363..b44543a1 100644
--- a/web/app/sketcher/shapes/elliptical-arc.js
+++ b/web/app/sketcher/shapes/elliptical-arc.js
@@ -1,14 +1,14 @@
 import {Ellipse} from './ellipse'
-import {Constraints} from '../parametric'
 
 import * as math from '../../math/math';
 import {swap} from '../../utils/utils'
 import {EndPoint} from "./point";
+import {AlgNumConstraint, ConstraintDefinitions} from "../constr/ANConstraints";
 
 export class EllipticalArc extends Ellipse {
 
-  constructor(x1, y1, x2, y2, ax, ay, bx, by, r, id) {
-    super(x1, y1, x2, y2, r, id);
+  constructor(cx, cy, rx, ry, rot, ax, ay, bx, by, id) {
+    super(cx, cy, rx, ry, rot, id);
     this.a = new EndPoint(ax, ay, this.id + ':A');
     this.b = new EndPoint(bx, by, this.id + ':B');
     this.addChild(this.a);
@@ -20,8 +20,14 @@ export class EllipticalArc extends Ellipse {
   }
 
   stabilize(viewer) {
-    this.stage.addConstraint(new Constraints.PointOnEllipseInternal(this.b, this));
-    this.stage.addConstraint(new Constraints.PointOnEllipseInternal(this.a, this));
+    const c1 = new AlgNumConstraint(ConstraintDefinitions.PointOnEllipse, [this.b, this]);
+    c1.internal = true;
+
+    const c2 = new AlgNumConstraint(ConstraintDefinitions.PointOnEllipse, [this.a, this]);
+    c2.internal = true;
+
+    this.stage.addConstraint(c1);
+    this.stage.addConstraint(c2);
   }
 
   drawImpl(ctx, scale) {
@@ -53,29 +59,41 @@ export class EllipticalArc extends Ellipse {
 
   write() {
     return {
-      ep1: this.ep1.write(),
-      ep2: this.ep2.write(),
+      c: this.c.write(),
+      rx: this.rx.get(),
+      ry: this.ry.get(),
+      rot: this.rot.get(),
       a: this.a.write(),
-      b: this.b.write(),
-      r: this.r.get()
-    }
+      b: this.b.write()
+    };
   }
 
   static read(id, data) {
+    if (data.ep1) {
+      return readFormatV1(id, data);
+    }
     return new EllipticalArc(
-      data.ep1.x,
-      data.ep1.y,
-      data.ep2.x,
-      data.ep2.y,
-      data.a.x,
-      data.a.y,
-      data.b.x,
-      data.b.y,
-      data.r,
+      data.c.x,
+      data.c.y,
+      data.rx,
+      data.ry,
+      data.rot,
+      data.a.x, data.a.y, data.b.x, data.b.y,
       id
-    );
+    )
   }
 }
 
+function readFormatV1(id, data) {
+
+  const cx = data.ep1.x + (data.ep2.x - data.ep1.x) * 0.5;
+  const cy = data.ep1.y + (data.ep2.y - data.ep1.y) * 0.5;
+  const rx = math.distance(data.ep1.x, data.ep1.y, data.ep2.x, data.ep2.y) * 0.5;
+  const ry = data.r;
+  const rot = Math.atan2(data.ep2.y - data.ep1.y, data.ep2.x - data.ep1.x);
+
+  return new EllipticalArc(cx, cy, rx, ry, rot, data.a.x, data.a.y, data.b.x, data.b.y, id);
+}
+
 EllipticalArc.prototype._class = 'TCAD.TWO.EllipticalArc';
 EllipticalArc.prototype.TYPE = 'EllipticalArc';
diff --git a/web/app/sketcher/tools/edit-tools-map.js b/web/app/sketcher/tools/edit-tools-map.js
index d8670ad0..8ac4b1fa 100644
--- a/web/app/sketcher/tools/edit-tools-map.js
+++ b/web/app/sketcher/tools/edit-tools-map.js
@@ -5,6 +5,7 @@ import {DragTool} from './drag'
 import {EllipseTool, STATE_RADIUS} from './ellipse'
 import {AngleBetweenDimension} from "../shapes/dim";
 import {AddAngleBetweenDimTool} from "./dim";
+import {EllipseEditTool} from "./ellipse-edit";
 
 export function GetShapeEditTool(viewer, obj, alternative) {
   if (obj instanceof Circle && !alternative) {
@@ -12,13 +13,7 @@ export function GetShapeEditTool(viewer, obj, alternative) {
     tool.circle = obj;
     return tool;
   } else if (obj instanceof Ellipse && !alternative) {
-    // even for an ell-arc we should act as it would be an ellipse to 
-    // avoid stabilize constraints added and demoing B point on move
-    // so second arg must be FALSE!
-    const tool = new EllipseTool(viewer, false);  
-    tool.ellipse = obj;
-    tool.state = STATE_RADIUS;
-    return tool;
+    return new EllipseEditTool(viewer, obj);
   } else if (obj instanceof AngleBetweenDimension && !alternative) {
     const tool = new AddAngleBetweenDimTool(viewer, viewer.dimLayer);
     tool.a = obj.a;
diff --git a/web/app/sketcher/tools/ellipse-edit.js b/web/app/sketcher/tools/ellipse-edit.js
new file mode 100644
index 00000000..67b3bec6
--- /dev/null
+++ b/web/app/sketcher/tools/ellipse-edit.js
@@ -0,0 +1,73 @@
+import {Tool} from './tool'
+
+export class EllipseEditTool extends Tool {
+
+  constructor(viewer, ellipse) {
+    super('edit ellipse', viewer);
+    this.ellipse = ellipse;
+  }
+  
+  restart() {
+    // this.sendHint('specify a center of the ellipse')
+  }
+
+  cleanup(e) {
+  }
+
+  mousedown(e) {
+    const p = this.viewer.screenToModel(e);
+
+    const dx = p.x - this.ellipse.c.x;
+    const dy = p.y - this.ellipse.c.y;
+
+    this.dRot = this.ellipse.rot.get() - Math.atan2(dy, dx);
+
+  }
+
+  mouseup(e) {
+    this.solveRequest(false);
+    this.viewer.toolManager.releaseControl();
+  }
+
+  mousemove(e) {
+    const p = this.viewer.screenToModel(e);
+
+    const dx = p.x - this.ellipse.c.x;
+    const dy = p.y - this.ellipse.c.y;
+
+    const rot = Math.atan2(dy, dx);
+
+    const ellRot = this.dRot + rot;
+    this.ellipse.rot.set(ellRot);
+
+    const eAng = - this.dRot;
+    const rm = (eAng + 10 * Math.PI) % Math.PI;
+
+    if (rm > Math.PI / 4 && rm < 3/4*Math.PI) {
+      const axisX = - Math.sin(ellRot);
+      const axisY =   Math.cos(ellRot);
+      this.ellipse.ry.set(Math.abs(dx * axisX + dy * axisY))
+    } else {
+      const axisX =   Math.cos(ellRot);
+      const axisY =   Math.sin(ellRot);
+      this.ellipse.rx.set(Math.abs(dx * axisX + dy * axisY))
+    }
+
+    if (!Tool.dumbMode(e)) {
+      this.solveRequest(true);
+    }
+
+    this.viewer.refresh();
+  }
+
+  solveRequest(rough) {
+    this.viewer.parametricManager.prepare([{
+      visitParams: (cb) => {
+        cb(this.ellipse.rx);
+        cb(this.ellipse.ry);
+      }
+    }]);
+    this.viewer.parametricManager.solve(rough);
+  }
+
+}
\ No newline at end of file
diff --git a/web/app/sketcher/tools/ellipse.js b/web/app/sketcher/tools/ellipse.js
index eb885337..8eab4d87 100644
--- a/web/app/sketcher/tools/ellipse.js
+++ b/web/app/sketcher/tools/ellipse.js
@@ -1,26 +1,25 @@
 import {Tool} from './tool'
-import {EndPoint} from '../shapes/point'
 import {Ellipse} from '../shapes/ellipse'
 import {EllipticalArc} from '../shapes/elliptical-arc'
-import Vector from 'math/vector';
 
-export const STATE_POINT1 = 0;
-export const STATE_POINT2 = 1;
-export const STATE_RADIUS = 2;
+export const CENTER = 0;
+export const RADIUS_X = 1;
+export const RADIUS_Y = 2;
+
 
 export class EllipseTool extends Tool {
 
   constructor(viewer, arc) {
-    super(arc ? 'ellipse' : 'elliptical arc', viewer);
+    super(arc ? 'elliptical arc' : 'ellipse', viewer);
     this.arc = arc;
     this.ellipse = null;
-    this.state = STATE_POINT1;
+    this.state = CENTER;
   }
   
   restart() {
     this.ellipse = null;
-    this.state = STATE_POINT1;
-    this.sendHint('specify first major axis point')
+    this.state = CENTER;
+    this.sendHint('specify a center of the ellipse')
   }
 
   cleanup(e) {
@@ -32,8 +31,7 @@ export class EllipseTool extends Tool {
   }
   
   newEllipse(p) {
-
-    return this.arc ? new EllipticalArc(p.x, p.y, p.x, p.y, p.x, p.y, p.x, p.y) : new Ellipse(p.x, p.y, p.x, p.y);
+    return this.arc ? new EllipticalArc(p.x, p.y, 0, 0, 0, p.x, p.y, p.x, p.y) : new Ellipse(p.x, p.y, 0, 0, 0);
   }
   
   demoBPoint() {
@@ -47,26 +45,22 @@ export class EllipseTool extends Tool {
   
   mouseup(e) {
     switch (this.state) {
-      case STATE_POINT1: {
+      case CENTER: {
         const p = this.point(e);
         this.ellipse = this.newEllipse(p);
-        this.snapIfNeed(this.ellipse.ep1);
+        this.snapIfNeed(this.ellipse.c);
         this.viewer.activeLayer.add(this.ellipse);
         this.viewer.refresh();
-        this.state = STATE_POINT2;
-        this.sendHint('specify second major axis point');
+        this.state = RADIUS_X;
+        this.sendHint('specify major radius');
         break;
       }
-      case STATE_POINT2: {
-        const p = this.point(e);
-        this.ellipse.ep2.setFromPoint(p);
-        this.snapIfNeed(this.ellipse.ep2);
-        this.viewer.refresh();
-        this.state = STATE_RADIUS;
-        this.sendHint('specify minor axis radius');
+      case RADIUS_X: {
+        this.state = RADIUS_Y;
+        this.sendHint('specify minor radius');
         break;
       }
-      case STATE_RADIUS:
+      case RADIUS_Y:
         if (this.arc) {
           this.ellipse.stabilize(this.viewer);
         }
@@ -77,41 +71,47 @@ export class EllipseTool extends Tool {
   mousemove(e) {
     const p = this.viewer.screenToModel(e);
     switch (this.state) {
-      case STATE_POINT1:
+      case CENTER: {
         this.viewer.snap(p.x, p.y, []);
         break;
-      case STATE_POINT2:
-        this.ellipse.ep2.setFromPoint(this.viewer.screenToModel(e));
-        this.ellipse.r.value = this.ellipse.radiusX * 0.5;
-        this.viewer.snap(p.x, p.y, this.ellipse.children);
+      }
+      case RADIUS_X: {
+
+        const dx = p.x - this.ellipse.c.x;
+        const dy = p.y - this.ellipse.c.y;
+
+        const rot = Math.atan2(dy, dx);
+        const rx = Math.sqrt(dx*dx + dy*dy);
+
+        this.ellipse.rx.set(rx);
+        this.ellipse.rot.set(rot);
+
         if (this.arc) {
-          this.ellipse.a.setFromPoint(this.ellipse.ep2);
+          this.ellipse.a.setFromPoint(p);
           this.demoBPoint();
         }
         break;
-      case STATE_RADIUS:
-        const polarPoint = this.ellipse.toEllipseCoordinateSystem(p);
-        let minorRadius = Ellipse.findMinorRadius(this.ellipse.radiusX, polarPoint.radius, polarPoint.angle);
-        if (isNaN(minorRadius)) {
-          const projAxis = new Vector(-(this.ellipse.ep2.y - this.ellipse.ep1.y), this.ellipse.ep2.x - this.ellipse.ep1.x);
-          projAxis._normalize();
-          const v = new Vector(this.ellipse.ep2.x - p.x, this.ellipse.ep2.y - p.y);
-          minorRadius = Math.abs(projAxis.dot(v));
-        }
-        this.ellipse.r.set(minorRadius);
-        if (!Tool.dumbMode(e)) {
-          this.solveRequest(true);
-        }
+      }
+      case RADIUS_Y: {
+
+        const dx = p.x - this.ellipse.c.x;
+        const dy = p.y - this.ellipse.c.y;
+
+        const rot = this.ellipse.rotation;
+        const axisX = - Math.sin(rot);
+        const axisY =   Math.cos(rot);
+
+
+        const ry = Math.abs(dx * axisX + dy * axisY);
+
+        this.ellipse.ry.set(ry);
+
         if (this.arc) {
           this.demoBPoint();
         }
         break;
+      }
     } 
     this.viewer.refresh();
   }
-
-  solveRequest(rough) {
-    this.viewer.parametricManager.prepare([this.ellipse.r]);
-    this.viewer.parametricManager.solve(rough);
-  }
 }
\ No newline at end of file