Journeyman Wood Butcher
Join Date: Feb 2008
Location: Central Illinois
don't overthink the issue....try this:
6 posts, each 1.5 inches....that will mean 7 spaces.
That will mean (using your figures) that you subtract 9.0 inches (for the sum of the 6 posts) from your opening of 35.43 inches, leaving you
Divide this by the number of spaces- 7 (the number of spaces between the existing posts and all the new posts). This yields 3.77 inches.
Call it 3.75, and no one will be the wiser, to make it easy to measure and lay out.
Scribe yourself some pencil lines, starting at one end, from the existing post, 3.75, then 1.5, then 3.75, then 1.5...and so on until you're all laid out.
Hope this helps....