diff --git a/maths.cpp b/maths.cpp
index 4acb7a5..508b9c4 100644
--- a/maths.cpp
+++ b/maths.cpp
@@ -4,30 +4,24 @@ double degToRad(double deg) { return deg * M_PI / 180.0; }
 
 double radToDeg(double rad) { return rad * 180.0 / M_PI; }
 
-void angleToStep(long &stepX, long &stepY, double angleX, double angleY) {
-  // TODO remove magic numbers
-  double stepRatioX = 6000 / M_PI;
-  double stepRatioY = 6500 / M_PI;
-
+void angleToStep(double stepRatioX, double stepRatioY, long &stepX, long &stepY,
+                 double angleX, double angleY) {
   stepX = angleX * stepRatioX;
   stepY = angleY * stepRatioY;
 }
 
-void cartesianToPolar(long &stepX, long &stepY, double zeroX, double zeroY,
-                      double x, double y, double z) {
-  // TODO remove magic numbers
-  double distance = 166.0; // turret to screen
-  double offsetY = 21.0;   // laser to stand
-  double offsetX = 0.0;    // unused
-
+void cartesianToPolar(double stepRatioX, double stepRatioY, double offsetX,
+                      double offsetY, double offsetZ, long &stepX, long &stepY,
+                      double zeroX, double zeroY, double x, double y,
+                      double z) {
   // x = -x; // natural axis direction
   y = -y; // natural axis direction
   double dX = x + offsetX;
   double dY = y + offsetY;
-  double dZ = z + distance;
+  double dZ = z + offsetZ;
 
   double angleY = atan2(dZ, dY) - M_PI / 2;
   double angleX = atan2(dZ, dX) - M_PI / 2;
 
-  angleToStep(stepX, stepY, angleX, angleY);
+  angleToStep(stepRatioX, stepRatioY, stepX, stepY, angleX, angleY);
 }
diff --git a/maths.h b/maths.h
index 9ed3197..d58de39 100644
--- a/maths.h
+++ b/maths.h
@@ -1,5 +1,7 @@
 double degToRad(double deg);
 double radToDeg(double rad);
-void angleToStep(long &stepX, long &stepY, double angleX, double angleY);
-void cartesianToPolar(long &stepX, long &stepY, double zeroX, double zeroY,
-                      double x, double y, double z);
+void angleToStep(double stepRatioX, double stepRatioY, long &stepX, long &stepY,
+                 double angleX, double angleY);
+void cartesianToPolar(double stepRatioX, double stepRatioY, double offsetX,
+                      double offsetY, double offsetZ, long &stepX, long &stepY,
+                      double zeroX, double zeroY, double x, double y, double z);
diff --git a/turret.cpp b/turret.cpp
index 4fb37d1..64f8799 100644
--- a/turret.cpp
+++ b/turret.cpp
@@ -3,9 +3,11 @@
 #include "maths.h"
 #include <kissStepper.h>
 
-Turret::Turret(int pin_x_direction, int pin_x_pulse, int pin_x_enable,
-               int pin_x_home, int pin_y_direction, int pin_y_pulse,
-               int pin_y_enable, int pin_y_home, int pin_laser)
+Turret::Turret(double stepRatioX, double stepRatioY, double offsetX,
+               double offsetY, double offsetZ, int pin_x_direction,
+               int pin_x_pulse, int pin_x_enable, int pin_x_home,
+               int pin_y_direction, int pin_y_pulse, int pin_y_enable,
+               int pin_y_home, int pin_laser)
     : _stepperX(pin_x_direction, pin_x_pulse, pin_x_enable),
       _stepperY(pin_y_direction, pin_y_pulse, pin_y_enable) {
 
@@ -20,6 +22,13 @@ Turret::Turret(int pin_x_direction, int pin_x_pulse, int pin_x_enable,
   _pin_x_home = pin_x_home;
   _pin_y_home = pin_y_home;
   _pin_laser = pin_laser;
+
+  _step_ratio_x = stepRatioX;
+  _step_ratio_y = stepRatioY;
+
+  _offset_x = offsetX;
+  _offset_y = offsetY;
+  _offset_z = offsetZ;
 }
 
 Turret &Turret::init() {
@@ -106,17 +115,20 @@ Turret &Turret::moveTo(double x, double y, double z, Unit unit) {
   long stepY;
 
   if (unit == Unit::MM) {
-    cartesianToPolar(stepX, stepY, _zeroX, _zeroY, x / 10.0, y / 10.0,
-                     z / 10.0);
+    cartesianToPolar(_step_ratio_x, _step_ratio_y, _offset_x, _offset_y,
+                     _offset_z, stepX, stepY, _zeroX, _zeroY, x / 10.0,
+                     y / 10.0, z / 10.0);
   }
 
   if (unit == Unit::CM) {
-    cartesianToPolar(stepX, stepY, _zeroX, _zeroY, x, y, z);
+    cartesianToPolar(_step_ratio_x, _step_ratio_y, _offset_x, _offset_y,
+                     _offset_z, stepX, stepY, _zeroX, _zeroY, x, y, z);
   }
 
   if (unit == Unit::M) {
-    cartesianToPolar(stepX, stepY, _zeroX, _zeroY, x * 100.0, y * 100.0,
-                     z * 100.0);
+    cartesianToPolar(_step_ratio_x, _step_ratio_y, _offset_x, _offset_y,
+                     _offset_z, stepX, stepY, _zeroX, _zeroY, x * 100.0,
+                     y * 100.0, z * 100.0);
   }
 
   if (unit == Unit::STEP) {
@@ -125,11 +137,12 @@ Turret &Turret::moveTo(double x, double y, double z, Unit unit) {
   }
 
   if (unit == Unit::RAD) {
-    angleToStep(stepX, stepY, x, y);
+    angleToStep(_step_ratio_x, _step_ratio_y, stepX, stepY, x, y);
   }
 
   if (unit == Unit::DEG) {
-    angleToStep(stepX, stepY, degToRad(x), degToRad(y));
+    angleToStep(_step_ratio_x, _step_ratio_y, stepX, stepY, degToRad(x),
+                degToRad(y));
   }
 
   // TODO min(valueI, -_homeI);
diff --git a/turret.h b/turret.h
index 042a4be..4284743 100644
--- a/turret.h
+++ b/turret.h
@@ -7,9 +7,10 @@ class Turret {
 public:
   enum Unit { MM, CM, M, RAD, DEG, STEP };
 
-  Turret(int pin_x_direction, int pin_x_pulse, int pin_x_enable, int pin_x_home,
-         int pin_y_direction, int pin_y_pulse, int pin_y_enable, int pin_y_home,
-         int pin_laser);
+  Turret(double stepRatioX, double stepRatioY, double offsetX, double offsetY,
+         double offsetZ, int pin_x_direction, int pin_x_pulse, int pin_x_enable,
+         int pin_x_home, int pin_y_direction, int pin_y_pulse, int pin_y_enable,
+         int pin_y_home, int pin_laser);
 
   Turret &init();
   Turret &gotoHome();
@@ -60,6 +61,13 @@ private:
   int _pin_x_home;
   int _pin_y_home;
   int _pin_laser;
+
+  double _step_ratio_x;
+  double _step_ratio_y;
+
+  double _offset_x; // turret to screen
+  double _offset_y; // laser to stand
+  double _offset_z; // unused
 };
 
 #endif