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PostPosted: Mon Aug 26, 2024 4:35 pm 
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Koa
Koa

Joined: Thu Jan 11, 2018 9:19 am
Posts: 530
Location: St. Charles MO
First name: Karl
Last Name: Borum
State: MO
Zip/Postal Code: 63303
Country: United States
Focus: Build
Status: Amateur
This is a long story about guitar drawings, templates and specifications, and how important it is to have them, up front, if you ever plan on moving into building (and obtaining templates, jigs and fixtures) from scratch. Experienced builders already know this, I will guarantee that!

Six years ago I bought three SM Dreadnaught Kits, when East Indian Rosewood started to become scarce. As I was building these kits, I also started to tool up for building scratch guitars, the end goal.

  • I got LMI 25.4” dreadnaught templates (LMI neck template dimensions didn’t exactly match the drawing).
  • I got LMI 25.4” dreadnaught plans (LMI neck dimensions did not match the LMI neck template).
  • The SM 25.4” scale Dread kit came with “drawings” (that did not include various views and dimensions critical for building a guitar from scratch (neck, bridge, sides).
  • The SM kit also came with an assembly book that included some dimensions, some of those did not match the drawings. THe actual parts were the tie breaker.
  • Bought fret slotting template for SM 25.4” (which is engraved with “25.34 scale, commonly referred to as 25.4”). This metal fret cutting jig did not match the LMI neck template or scale of the LMI plans (of course it wouldn’t).


The SM plan/ drawing was actually for a 25.34” scale length (plan had this dimension correct, but different than stated in the book). The drawings did not include many views and dimensions critical for building a guitar from scratch (neck, bridge, sides).
THe LMI plan was a dead-nuts 25.4 scale (this made the scales, fret spacing, nut position different between SM and LMI; enough that it mattered). It also meant that the LMI neck template was not correct for a 25.34” scale- or the SM fret cutting template. Side dimensions were absent as well, so I had to buy an LMI side template (nothing I had specified the dimensions of an unbent side).

  • SM wooden bridge peg hole spacing did not match the drawing.
  • Neither of those plans have neck shape dimensions.
  • The SM 1953 D-28 neck shaft shape template is for a vintage baseball bat, not appropriate for me or most players with smaller hands/ fingers.

So I do have it all sorted out. I wanted to UNDERSTAND the dimensions and options before I started the scratch build, so I started measuring. Thats when I discovered these discrepancies. I now have several sets of corrected and modified drawings (correct and red-lined the ones I have).

I had to:
  • Commit to an exact scale length (25.34"), which matches the slotting jig I have.
  • Commit to a bridge pin spacing/ neck taper (2 1/8” Bridge pin spacing),
  • make a bridge template from one that met the dimensional / stle requirements
  • Figure out how to compensate for the LMI 25.4” neck template, until I make my own.
  • Commit to a neck shape and cast neck shaft shape templates from my J-45 neck.

I’ve agonized over countless hours of measuring 6 guitars, multiple sets of plans and numerous of the shelf parts, to arrive at dimensions and geometry suitable and complete for building a scratch guitar. Even from like-models, guitar to guitar, there were variations. I don’t know if there is one single plan that has everything- I will never know.

Wanted to throw that out there for others that may be planning a foray into guitar building after a kit or two. You need a good set of plans from the beginning (a good teacher/ class wouldn't hurt either). SM kit and drawing was sparce (and I'm being kind) in the build-from-scratch space, and they don’t sell much in the way of templates (neck, side, headstock, bridge) that match their dreadnaught kit. LMI plans required you to buy a separate side cutting template. You will be buying arts and measuring them to make your some of your own drawings and templates, based on YOUR design criteria. And you will need to make “DD” sure that the scale length of EVERYTHING is exactly matching/ harmonious, before you start cutting $$$ wood.

Not sorry that I ran into such a dimensional/ specification mess. It helped me understand the geometry options, how they interplay, and allowed me to design them to my expectations and tastes. Good luck on your build whether it is a kit or a scratch build. Neither will be as easy as you thought they would be, but the journey will be immensely satisfying.

_________________
Measure Twice,

Karl Borum



These users thanked the author Kbore for the post (total 4): Durero (Wed Aug 28, 2024 11:05 pm) • rbuddy (Wed Aug 28, 2024 7:58 am) • bcombs510 (Wed Aug 28, 2024 6:14 am) • Hesh (Wed Aug 28, 2024 5:36 am)
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PostPosted: Wed Aug 28, 2024 5:36 am 
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Old Growth Brazilian Rosewood
Old Growth Brazilian Rosewood
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Joined: Fri Nov 02, 2007 9:49 am
Posts: 13390
Location: Ann Arbor, Michigan
First name: Hesh
Last Name: Breakstone
City: Ann Arbor
State: Michigan
Country: United States
Status: Professional
Thanks Karl good stuff.



These users thanked the author Hesh for the post: Kbore (Wed Aug 28, 2024 12:08 pm)
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