Working Backwards

First, a quick announcement. Openings in my classes for this year are almost gone but there are a few spots left to anyone who doesn't want to wait until next year.
I will be at the Connecticut Valley School of Woodworking teaching the Continuous Armchair
Friday – Sunday April 11 – 13 & May 9 - 11  There are only a couple of spots open here.

And I have three classes this summer here in Sterling MA
June 23-28 Fan Back Side Chair

July 21-26 Balloon back Side Chair

August 11-16  Continuous Armchair (chairmaking experience required)
Each of these classes has a couple of openings, please contact me for more information


Hopefully you have seen the posts and videos that I did regarding my sightline rule. The sightline rule is basically a chairmakers framing square that eliminates the need to use trig tables or elaborate graphics to transform rake and splay into sightlines and resultant angles. If you didn't see them, check out this post ,or this one, or visit my youtube channel to see videos on the sightline rule.

Anyway, I've found one more handy way to use the sightline rule, which is to take an already existing pattern and derive the rake and splay from it. This is very handy if you want to use the same angles or change angles on an existing pattern and don't know the rake and splay. Here is an example

So there it is, rake of 17 degrees and splay of 16.5. Of course, if you knew this info first, you could simply follow the drawings in reverse to get the sightline and resultant.
It was a slap on the forehead when this one dawned on me. I still have the pdf's available if anyone wants the printout, email me at peter@petergalbertchairmaker.com