I don't recall seeing a decent SG plan anywhere.
But don't let that stop you.
There are only two ways to get plans. Either the manufacturer or someone who has carefully
measured a guitar and made a plan.
impossible to get your hands on Gibson plans. But there are an awful lot of SG's out
there. Get your hands on one, take it apart, and make accurate tracings and take accurate
measurements and make your own drawings.
Get a roll of cheap lining wallpaper,
a decent flat surface to work on, some decent straight edges and rulers, a thickness
caliper, and a decent set square to start with.
Shapes can be traced, angles
can be measured direct or calculated with basic maths, scale lengths are easily found
online, you can buy templates for fret locations, find tables online, or calculate them
from 1st principles with a simple spreadsheet.
And before you say that it's
too much work or the tools are too expensive. All the tools you need to make a drawing
will be useful or essential in building, and the knowledge you gain from making your own
drawing will save you hours when you start making your SG. It's not unreasonable to
suggest that a good drawing is like making a prototype without have to spend the hours
woodworking and buying the woods and hardware. And if a drawing goes wrong it's a lot
cheaper to tear it up and start again.
Making a drawing requires the same
skills as marking out your wood for cutting. If you can't draw it, you can't make it;
because ultimately you will have to mark out and measure that accurately to build it
anyway. If you get the drawing right first time, great. But if you are really lucky you'll
need 3 or 4 attempts to get it right, and in the process you'll have a much better
understanding when you start building.
Where a plan might be most helpful is in
working out the neck join, but there's no reason why you can't get a Les Paul plan like this
And a final word of
caution. Whether you buy, make, or adapt, a plan; be prepared to adapt it to accommodate
the hardware you choose.
When the going gets weird, the Weird turn Pro.