In a recent posting here about heat stick alternatives for neck removal (my pair of foam cutting wands are enroute from Asia as we speak) there was a reference to Ted Woodford and his videos.
I have been binge watching since then, and although I will always credit Dan Erlewine with sparking my interest in fixing/improving my own (and recently my friend's) guitars and giving me the knowledge and confidence to try things, I am adding to this base of knowledge with local Ontarian Ted Woodford's valuable video series.
To the point.
I have a Sigma SG5+ which is a Hummingbird style acoustic, and is my current favourite among the small herd I've acquired (flock of ducks, school of fish, xxxxx of guitars?, embarassment? waste?).
When I acquired it, the electronics had been removed and a cardboard (yep, cardboard) shim had been put under the saddle to bring it roughly back to height after the removal of the pickup strip that had sat beneath it.
I had an old saddle that roughly fit, and went ahead for months with that.
In one of Ted Woodfords videos (and I am struggling to recall which one specifically as they are all so instructionally rich and varied) he showed a method for intonating saddles more specifically than just copying the rough 'intonated saddle' pattern that seemed typical: E-G single slope toward the sound hole, B closer to bridge pins and e closest to sound hole.
Here is the method Ted demonstrated;
1. Roughly square/flatten the bottom of the saddle blank and get the length and width set so it fits the bridge (snug but not tight, i.e. doesn't fall out if you turn the guitar upside down, but cannot lift the guitar by the pulling on the saddle)
2. Arc the saddle top to the correct radius (e.g. 15" radius)
3. Adjust the action height to suit your preferences, by removing material from the saddle bottom
4. Here is the brilliant part:
a. insert the roughed in saddle (arced to radius, but the top is still flat 'front to back') and bring all strings to pitch
b. roughly mark the spacing of the strings on the top of the saddle, six lines running from front to back, this helped me with filing later
c. raise the E string (pull hard or detune momentarily) and place an old B string between the saddle and the E, this suspends the e at a very specific point on the top of the saddle, this helper B string should be perpendicular to the E string on the guitar and run along the length of the saddle (but only running underneath the string you are determining the intonation point for)
d. check pitch on E string, and move the B string, that is now between E and the saddle, either toward the front edge or back edge of the saddle, and check the intonation at various positions of the B until the intonation is correct.
e. you can mark this point directly on the saddle or make a diagram and mark roughly the position of the intonation point between the front and back of the saddle top in the diagram
f. remove helper B string and repeat steps c/d/e above on the remaining five strings (ADGBe)
g. remove the saddle from the guitar
h. use your marks on the saddle (string position along the length and front to back position where your helper B string positioning supported the correct intonation point) or transcribe from your diagram to the top of the saddle. This will show where you should remove no height, but file a slope away from this point. Which direction to put the slope on depends on where the mark is in the thickness of the saddle (if it's in the middle, a shallow slope away towards the front and another toward the back of the saddle). Don't remove any material from the top of the saddle at the intonation point, and leave a narrow strip at this point full height (a 64th?)
The pattern of intonation points for the Sigma saddle I did yesterday deviates significantly from the standard pattern found on an off the shelf 'intonated saddle'. But today the intonation still seems spot on.
I watch a lot of YouTube, and Ted's videos are among the most informative and entertaining I have found...he is a Canadian National Treasure.
Mark , i agree , i am an experienced luthier but i still learn from Ted . I am impressed by his use of hand tools and shooting boards .