How can I change the size of the ChemDraw Crosshair grid?

The size of the grid is determined by the measurement units used in ChemDraw.  If your default setting is set to inches, the lines on the grid will be more separated.

To change this setting:

1. Launch ChemDraw
2. Click "File > Preferences"
3. Under the General Tab, change the units from Inches to cm 
4. Click 'OK'