Hi Dave,
You can double click anywhere empty on the CustomPanel background when in PanelBuilder Edit mode. This will open the Edit Component window, and select the top level abs node in the tree. You can then open the Source tab on the right, and edit the gridsize attribute. By default when Snap to Grid is enabled, the gridsize is 20, and you can adjust it, as shown below:
<abs contexttype="opengear" gridsize="5" id="_top" style=""/>

Here is a before picture (gridsize="20"):

Here is an after picture (gridsize="5"):

For other users who may view this post, you can enable snap to grid by right-clicking on the background and checking Snap to grid. This is shown in the before and after pictures.
Hope this helps,
Kayla
#DashBoard