public Tuple6b getGridStart() throws GkException {
   Unit<Length> unit = GokoPreference.getInstance().getLengthUnit();
   Tuple6b start = new Tuple6b(unit, SI.DEGREE_ANGLE);
   start.setX(NumberQuantity.of(new BigDecimal(getString(GRID_START_X)), unit));
   start.setY(NumberQuantity.of(new BigDecimal(getString(GRID_START_Y)), unit));
   start.setZ(NumberQuantity.of(new BigDecimal(getString(GRID_START_Z)), unit));
   return start;
 }
 public Tuple6b getGridEnd() throws GkException {
   Unit<Length> unit = GokoPreference.getInstance().getLengthUnit();
   Tuple6b end = new Tuple6b(unit, SI.DEGREE_ANGLE);
   end.setX(NumberQuantity.of(new BigDecimal(getString(GRID_END_X)), unit));
   end.setY(NumberQuantity.of(new BigDecimal(getString(GRID_END_Y)), unit));
   end.setZ(NumberQuantity.of(new BigDecimal(getString(GRID_END_Z)), unit));
   return end;
 }
 /** @param rotaryAxisPosition the rotaryAxisPosition to set */
 public void setRotaryAxisPosition(Tuple6b rotaryAxisPosition) {
   this.rotaryAxisPosition = rotaryAxisPosition;
   setValue(ROTARY_AXIS_POSITION_X, rotaryAxisPosition.getX().getValue().toPlainString());
   setValue(ROTARY_AXIS_POSITION_Y, rotaryAxisPosition.getY().getValue().toPlainString());
   setValue(ROTARY_AXIS_POSITION_Z, rotaryAxisPosition.getZ().getValue().toPlainString());
 }