odd guitar scale length

[Larry Schultz]

I am building a copy of my first classical guitar, a 1960's Goya G1, which has a 630 mm scale length. I seem to recall reading an article, probably in the GAL publication, about using existing fretting templates to generate new scale lengths, but I'll be darned if I can locate it now. Can anyone point me in the right direction? I am currently using a Stew-Mac template with 650 and 660mm scale lengths on it. I know I could calculate the fret distances using the formula found in Cumpiano/Natelson, among others, but my eyesight isn't what it used to be and I think I'd get better results using a CNC'd template if possible. Thanks for any help.

[Magnus Hultin]

Larry,

Your Goya is probably a G-10 (never heard of any G-1 model...).
These guitars were made by Levin in Gothenburg Sweden, and Levin used 630 mm scales for all steelstringed guitars and 650 mm for most classical, G-10 beeing one exception where they chose the short scale.

I have several Levin and Goya instruments with the 630 mm scale. I could measure one up for You if You think this will help, but I have a feeling that the 630 mm scale is pretty much the same as a normal 24,7 inch scale, and there must be templates for this?

/Magnus

[Larry Schultz]

Magnus,
Thank you for your reply. You are correct, the guitar is a G-10 (the lable is so faded that it's hard to read). There's no need for you to measure up one of your instruments; if I have to I can measure my own. I was hoping there was an easier, and probably more accurate, way of doing it (darn these tri-focal glasses!). I hadn't thought of checking on how close an "inch" template would be to a metric template, but I'll pursue that approach.

Larry

[Magnus Hultin]

Larry,

If You take 24,7 multiplied by 25,4 (one inch in mm) You get 627,4.
630 divided by 25,4 makes 24,8 inches. What length is a typical short scale?

Magnus

[Larry Schultz]

Hi Magnus,

What's a typical short scale? Good question! I see Stew-Mac sells templates for a 24.9" Martin scale, and a 24.75" scale for Gibson. Luthier's Merchantile sells a 24.5" template for "parlor" guitars. I don't think there is any standard for short scale guitars. Based on the above, I think the Gibson 24.75" scale is probably the one I'll go with, as .05" is an insignificant difference and probably much closer than I could measure myself anyway. This raises an interesting question of "compensation", i.e. moving the saddle back a couple of mm's to compensate for string stretch. What I mean is, could this guitar's scale, which measurers exactly 630mm from nut to saddle, actually be a 627.4mm scale with 2.6mm of compensation? I've read that shorter scale length instruments need more compensation than longer scale length instruments. Hmmmm. I don't know if there's any way to answer this.
Anyway, since you appear to be something of an expert on Levin/Goya guitars, I would appreciate it if you could look at your 630mm scale instruments and let me know how the neck is attached to the body. My Goya appears to have a single screw (nail?) deeply sunk into the neck block. I'm assuming that this is either a mortice-tenon joint or a dovetail joint with a screw/nail for added security. At any rate, the guitar I'm building has a "bolt-on" mortice -tenon joint, so this is just curiosity on my part.
Thanks again,

Larry

[Magnus Hultin]

I have never dismounted a G-10, but I am pretty shure it is a dovetail. What You see in Your neck block could simply be the hole most Levins and Goyas have through the neckblock into the joint.

If You check my thread in this forum on dismounting neck with hot airgun, there are pictures on a dismounted neck, which I bet is more ore less identical with the G-10. (The G-10 probably lacks the aluminum T-bar...)

On my flattops with 630 mm scale the neck is bolted, there are some pictures as reference in the thread on conversion from dovetail to bolt-on.

I have seen pictures on Goyas from around 1960, where the joint is combined mortise/tenon and bolts. I´ll see if I can find example pics.

[Larry Schultz]

Magnus,
Thank you so very much for all your help here. You are a true gentleman and scholar. I've also checked out your other contributions to this forum, and I especially liked the photos of using the heat gun/hairdryer to dismantle neck joints. It was very easy to see how this could work in a wide variety of situations.
I'll try to keep you and the rest of this forum up to date on my progress with the guitar I'm building and send in some pictures when it's done.
Thanks again,
Larry

[Magnus Hultin]

Larry,

The pictures I mentioned. A Goya M-24 froom late 50:s, this is the only one I have seen with this particular joint. There is a vertical steel rod placed vertical in the heel with threaded holes for the bolts. The bolt closest to the fretboard on these guitars is actually the trussrod.