Loar Neck Set

[toabetterworld]

Hello,

This is my first post on the forum. I am a violinmaker by trade, but the main instrument I play is the mandolin. After dealing with my sub-par mandolin for too long, I have decided to make one for myself. I am going to make an F-5. There are a few places where I don't know how to proceed.

I have the F-5 mandolin plans from elderly instruments which I am working from. It says that the "top surface of the neck is shifted approx. 1/32'' toward body scroll, producing an asymmetrical heel joint. Centerline of the fingerboard typically intersects the the body centerline between the points of the 'ff' holes."
It also says that the "lateral centerline between the 'ff' holes is slightly oblique to body centerline, positioning one 'ff' hole slightly closer to the neck joint."

Do you set your necks this way?

The dovetail neck joint on a mandolin is already more complicated than the violin necks I am used to, but if this is the way to do it I want to do it right.

Thanks very much for your help.

Michael Doran
www.doranviolins.com

[Spruce]

Do you set your necks this way?

Hi Michael...

Welcome to the Cafe....

OK, it's my impression that not that many folks are anal enough to do it this way...
That's my impression from looking at the finished instruments, and I could be (and often am), wrong....

That being said, I think it's one of the more important "tells" to getting the F5 design "right"...

You might want to spend a day (ha ha) and read this thread....

Lots of good info in there on the Loar details....

Here's a pic of that offset dovetail:



This is obviously off an F4, but you get the idea....

Luck!

[sunburst]

As Bruce says, if you want to build an F5 (Loar) copy that will take a hard look for an expert to tell it's not a mint real one, go ahead and do the neck set "wrong" (I'm still convinced that Gibson's tooling was 'off' a little and that's why the dovetail is offset, but what do I know), but you'll find that many modern builders (including me) use a center line that is in the center, and it works fine.

[Jim Hilburn]

Bruce, is there a story to the picture? Looks like some exploritory holes to determine the trussrod depth.

[Gail Hester]

Do you set your necks this way?

Yes, I think it's an important detail if you are trying to copy/recreate the Loar era designs and I am.

[Spruce]

Bruce, is there a story to the picture? Looks like some exploritory holes to determine the trussrod depth.

I probably robbed it from these pages....
Someone will hopefully chime in....

[Bill Halsey]

Michael, welcome to the Cafe!

Here's a link, and another one, to an old thread on this subject of the neck (fingerboard) offset on the F-5, including my take on it.

[HoGo]

Michael,
the neck geometry doesn't need to be that way unless you want to do a "bench" copy of Loar era mandolin, pretty much like "correct" placement of the pins vs. purflings&centerlin on Strad or del Gesu model violin. If you want to simplify the design, just forgetthe body centerline and use the neck centerline for the whole instrument and place dovetail there too. The f-holes were typically rotated a bit so they better 'fit' the neck centerline then the body centerline.
Bruce, the pic is from Darryl W (he drilled the holes to determine t/r position), and I drew the lines, I believe, I posted a pic of that neck placed over my drawings in one of the old long forgotten threads.

[Darryl Wolfe]

That's an F4 neck I have, and yes those are exploratory holes