diff --git a/modules/math/functions.ts b/modules/math/functions.ts
new file mode 100644
index 00000000..ab6d3f1f
--- /dev/null
+++ b/modules/math/functions.ts
@@ -0,0 +1,3 @@
+import Vector from "math/vector";
+
+export type VectorTransformer = (Vector) => Vector;
\ No newline at end of file
diff --git a/modules/math/matrix.ts b/modules/math/matrix.ts
index d7b82109..4c41a920 100644
--- a/modules/math/matrix.ts
+++ b/modules/math/matrix.ts
@@ -1,5 +1,6 @@
 import Vector, {AXIS} from "math/vector";
 import {Vec3} from "math/vec";
+import {VectorTransformer} from "math/functions";
 
 export type Matrix3x4Data = [[number, number, number, number], [number, number, number, number], [number, number, number, number]];
 export type Matrix3x4FlatData = [number, number, number, number, number, number, number, number, number, number, number, number];
@@ -410,7 +411,7 @@ export class Matrix3x4 {
     return m;
   };
 
-  apply = vector => this.__apply(vector, new Vector());
+  apply: VectorTransformer = vector => this.__apply(vector, new Vector());
 
   setTranslation(tx, ty, tz) {
     this.tx = tx;
diff --git a/modules/workbenches/modeler/features/extrude/extrude.operation.ts b/modules/workbenches/modeler/features/extrude/extrude.operation.ts
index 59b7d76f..14ca7367 100644
--- a/modules/workbenches/modeler/features/extrude/extrude.operation.ts
+++ b/modules/workbenches/modeler/features/extrude/extrude.operation.ts
@@ -1,6 +1,6 @@
 import {roundValueForPresentation as r} from 'cad/craft/operationHelper';
-import {ProductionInfo} from "cad/model/productionInfo";
 import {MFace} from "cad/model/mface";
+import {ApplicationContext} from "context";
 
 interface ExtrudeParams {
   length: number;
@@ -14,7 +14,7 @@ export default {
   info: 'extrudes 2D sketch',
   paramsInfo: ({value}) => `(${r(value)})`,
   mutualExclusiveFields: ['datumAxisVector', 'edgeVector', 'sketchSegmentVector'],
-  run: (params: ExtrudeParams, ctx) => {
+  run: (params: ExtrudeParams, ctx: ApplicationContext) => {
 
     let occ = ctx.occService;
     const oci = occ.commandInterface;
@@ -24,7 +24,7 @@ export default {
     let sketch = ctx.sketchStorageService.readSketch(face.id);
     if (!sketch) throw 'sketch not found for the face ' + face.id;
 
-    const occFaces = occ.utils.sketchToFaces(sketch);
+    const occFaces = occ.utils.sketchToFaces(sketch, face.csys);
 
     const shapeNames = occ.utils.prism(occFaces, [0, 0, params.length]);
 
diff --git a/web/app/cad/craft/e0/OCCUtils.ts b/web/app/cad/craft/e0/OCCUtils.ts
index 793d67e2..5367e6c7 100644
--- a/web/app/cad/craft/e0/OCCUtils.ts
+++ b/web/app/cad/craft/e0/OCCUtils.ts
@@ -3,12 +3,13 @@ import {Vec3} from "math/vec";
 import {SketchGeom} from "cad/sketch/sketchReader";
 import {OCCService} from "cad/craft/e0/occService";
 import {CoreContext} from "context";
+import CSys from "math/csys";
 
 export interface OCCUtils {
 
   wiresToFaces(wires: string[]): string[];
 
-  sketchToFaces(sketch: SketchGeom): string[];
+  sketchToFaces(sketch: SketchGeom, csys: CSys): string[];
 
   prism(faces: string[], dir: Vec3): string[];
 
@@ -16,9 +17,9 @@ export interface OCCUtils {
 
 export function createOCCUtils(ctx: CoreContext): OCCUtils {
 
-  function sketchToFaces(sketch: SketchGeom): string[] {
+  function sketchToFaces(sketch: SketchGeom, csys: CSys): string[] {
     const occ = ctx.occService;
-    const wires = occ.io.sketchLoader.pushSketchAsWires(sketch.contours);
+    const wires = occ.io.sketchLoader.pushSketchAsWires(sketch.contours, csys);
     return wiresToFaces(wires);
   }
 
diff --git a/web/app/cad/craft/e0/occSketchLoader.ts b/web/app/cad/craft/e0/occSketchLoader.ts
index 6a094ec4..a470cbb4 100644
--- a/web/app/cad/craft/e0/occSketchLoader.ts
+++ b/web/app/cad/craft/e0/occSketchLoader.ts
@@ -1,21 +1,22 @@
 import {Contour} from "cad/sketch/sketchModel";
 import {OCCCommandInterface} from "cad/craft/e0/occCommandInterface";
+import CSys from "math/csys";
 
 export interface OCCSketchLoader {
 
-  pushSketchAsWires(sketch: Contour[]): string[];
+  pushSketchAsWires(sketch: Contour[], csys: CSys): string[];
 
-  pushContourAsWire(contour: Contour, id: string|number): string;
+  pushContourAsWire(contour: Contour, id: string|number, csys: CSys): string;
 
 }
 
 export function createOCCSketchLoader(oci: OCCCommandInterface): OCCSketchLoader {
 
-  function pushContourAsWire(contour: Contour, id: string|number): string {
+  function pushContourAsWire(contour: Contour, id: string|number, csys: CSys): string {
 
     const boundCurves = contour.segments.map(s => {
       const geomId = "SketchGeom:" + s.id;
-      s.toOCCGeometry(oci, geomId);
+      s.toOCCGeometry(oci, geomId, csys);
       return geomId;
     });
 
@@ -33,7 +34,7 @@ export function createOCCSketchLoader(oci: OCCCommandInterface): OCCSketchLoader
 
   }
 
-  const pushSketchAsWires = (sketch: Contour[]): string[] => sketch.map(pushContourAsWire);
+  const pushSketchAsWires = (sketch: Contour[], csys: CSys): string[] => sketch.map((c, i) => pushContourAsWire(c, i, csys));
 
   return {
     pushSketchAsWires, pushContourAsWire
diff --git a/web/app/cad/sketch/sketchModel.ts b/web/app/cad/sketch/sketchModel.ts
index fb91bce3..f9b0e130 100644
--- a/web/app/cad/sketch/sketchModel.ts
+++ b/web/app/cad/sketch/sketchModel.ts
@@ -7,7 +7,6 @@ import Vector from 'math/vector';
 import CSys from "math/csys";
 import {distanceAB} from "math/distance";
 import {isCCW} from "geom/euclidean";
-import {OCCService} from "cad/craft/e0/occService";
 import {OCCCommandInterface} from "cad/craft/e0/occCommandInterface";
 
 
@@ -46,7 +45,7 @@ class SketchPrimitive {
     return !this.isCurve;
   }
 
-  toNurbs(csys) {
+  toNurbs(csys: CSys) {
     let verbNurbs = this.toVerbNurbs(csys.outTransformation.apply, csys);
     if (this.inverted) {
       verbNurbs = verbNurbs.reverse();
@@ -66,12 +65,12 @@ class SketchPrimitive {
     throw 'not implemented'
   }
 
-  toOCCGeometry(oci: OCCCommandInterface, underName: string) {
+  toOCCGeometry(oci: OCCCommandInterface, underName: string, csys: CSys) {
     throw 'not implemented'
   }
 }
 
-export class Segment extends SketchPrimitive {
+export class Segment<Segment> extends SketchPrimitive {
 
   a: Vector;
   b: Vector;
@@ -90,14 +89,31 @@ export class Segment extends SketchPrimitive {
     return new verb.geom.Line(tr(this.a).data(), tr(this.b).data());
   }
 
-  toOCCGeometry(oci: OCCCommandInterface, underName: string) {
-    oci.point(underName + "_A", this.a.x, this.a.y, this.a.z);
-    oci.point(underName + "_B", this.b.x, this.b.y, this.b.z);
-    oci.gcarc(underName, "seg", underName + "_A", underName + "_B")
+  toGenericForm() {
+    const endpoints = [
+      this.a, //from endpoint
+      this.b, //to endpoint
+    ];
+    if (this.inverted) {
+      endpoints.reverse();
+    }
+    return endpoints
   }
+
+  toOCCGeometry(oci: OCCCommandInterface, underName: string, csys: CSys) {
+    const genForm = this.toGenericForm().map(csys.outTransformation.apply);
+    const [A, B] = genForm;
+    oci.point(underName + "_A", A.x, A.y, A.z);
+    oci.point(underName + "_B", B.x, B.y, B.z);
+    oci.gcarc(underName, "seg", underName + "_A", underName + "_B")}
 }
 
 export class Arc extends SketchPrimitive {
+
+  a: Vector;
+  b: Vector;
+  c: Vector;
+
   constructor(id, a, b, c) {
     super(id);
     this.a = a;
@@ -130,11 +146,42 @@ export class Arc extends SketchPrimitive {
     return adjustEnds(arc, tr(this.a), tr(this.b))
   }
 
-  toOCCGeometry(oci: OCCCommandInterface, underName: string) {
-    oci.point(underName + "_A", this.a.x, this.a.y, this.a.z);
-    oci.point(underName + "_B", this.b.x, this.b.y, this.b.z);
-    oci.point(underName + "_C", this.b.x, this.b.y, this.b.z);
-    oci.gcarc(underName, "cir", underName + "_A", underName + "_B", underName + "_C")
+  toGenericForm() {
+    const endpoints = [this.a, this.b];
+    if (this.inverted) {
+      endpoints.reverse();
+    }
+    const [a, b] = endpoints;
+    const tangent = a.minus(this.c)._perpXY() //tangent vector
+    if (this.inverted) {
+      tangent._negate();
+    }
+    return [
+      a, //from endpoint
+      b, //to endpoint
+      tangent //tangent vector
+    ]
+  }
+
+  toOCCGeometry(oci: OCCCommandInterface, underName: string, csys: CSys) {
+
+    const tr = csys.outTransformation.apply;
+    const s = this;
+    const a = tr(s.inverted ? s.b : s.a);
+    const b = tr(s.inverted ? s.a : s.b);
+    const c = tr(s.c);
+    const tangent = c.minus(a)._cross(csys.z);//._normalize();
+
+    if (s.inverted) {
+      tangent._negate();
+    }
+
+    const A_TAN = a.plus(tangent);
+    oci.point(underName + "_A", a.x, a.y, a.z);
+    oci.point(underName + "_B", b.x, b.y, b.z);
+    oci.point(underName + "_T1", a.x, a.y, a.z);
+    oci.point(underName + "_T2", A_TAN.x, A_TAN.y, A_TAN.z);
+    oci.gcarc(underName, "cir", underName + "_A", underName + "_T1", underName + "_T2", underName + "_B")
   }
 }
 
@@ -187,6 +234,9 @@ export class EllipticalArc extends SketchPrimitive {
 }
 
 export class Circle extends SketchPrimitive {
+  c: Vector;
+  r: number
+
   constructor(id, c, r) {
     super(id);
     this.c = c;
@@ -198,6 +248,12 @@ export class Circle extends SketchPrimitive {
     const basisY = csys.y;
     return new verb.geom.Circle(tr(this.c).data(), basisX.data(), basisY.data(), this.r);
   }
+
+  toOCCGeometry(oci: OCCCommandInterface, underName: string, csys: CSys) {
+    const C = csys.outTransformation.apply(this.c);
+    const DIR = csys.z;
+    oci.circle(underName, ...C.data(), ...DIR.data(), this.r);
+  }
 }
 
 export class Ellipse extends SketchPrimitive {