I would like to enter custom parameters for a pot core.  Everything seems pretty clear, but when I enter the bobbin width BW, I see the value for 'effective bobbin width' BWE below changes to number of primary layers L * BW.  What does that mean?  Does that affect the actual bobbin I need? The effective bobbin width (BWE) is a term used to fit a wire into an even number of layers (L), given a certain bobbin width (BW). As a user of the spreadsheet, you have to enter only the bobbin width and PIXls will fit the wire in the given number of layers (L)

Also, how does PI Expert know what the maximum height is for the bobbin?  Do I have to give it a bobbin part number it recognizes?  How do I know the windings will fit in my pot core? PIXls does not have the capability to perform a vertical fit. What that means is that PIXls cannot tell you if all the layers will necessarily fit in the bobbin you have selected. 

Thanks for any help!