Hi Mauricio,
There is a CCC property that allows to set the size of the axis of the chart, in this case is orthoAxisSize.
In your chart, in the extension points, add this property and the value in pixels that you want, try 100 and increase or decrease until you got it right.
You can check the documentation Community Chart Components | Pentaho Community for all the available options for each type of CCC Chart.
Best regards