Verbatim from my post immediately preceding the one you quoted:
====Since the maximum baluster spacing is often set by code (don't want
children to get there heads caught between balusters), that makes a
good start point for laying out the pattern.
1. Choose the spacing you want, "D", less than or equal to the code
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.