hop of those help? No, there is no bug in the Chart control; the error is in your logic. You expect the axis to grow but it never needs to grow beyond the maximum of your data. And since your data are limited by the pixel coordinates once you hit the limit the axes will stay where they are.

You also fail to convert the pixel coordinates to the value coordinates of your axes.

code :

```
private void chart2_MouseMove(object sender, MouseEventArgs e)
{
Axis ax = chart1.ChartAreas[0].AxisX;
Axis ay = chart1.ChartAreas[0].AxisY;
if (e.Button.HasFlag(MouseButtons.Left)) // only draw when the button is pressed
{
// convert pixels to values!
chart1.Series[0].Points.AddXY(ax.PixelPositionToValue(e.X),
ay.PixelPositionToValue(e.Y));
if (chart1.Series[0].Points.Count > 200)
{
chart1.Series[0].Points.RemoveAt(0);
}
}
```

```
private void timer1_Tick(object sender, EventArgs e)
{
Point cp = Control.MousePosition;
chart1.Series[0].Points.AddXY(cp.X, -cp.Y);
if (chart1.Series[0].Points.Count > 200)
{
chart1.Series[0].Points.RemoveAt(0);
}
chart1.ChartAreas[0].RecalculateAxesScale(); // <<-------
}
```