Redhead Mandolins

I was really enjoying the Superman/Lex Luthier metaphor, but I have to mix it up here.

If Lloyd Loar was more divine
than Superman, say, a god, then Roger Siminoff would be a major
prophet/disciple.

Siminoff has written several books about building instruments
and improving acoustical properties of those instruments, and cites
Loar quite often. Although his reverence for Loar is apparent, I
give him much credit for continuing to consider other theories and
modifications for improving acoustics. He has an excellent website
with invaluble reading and resources for the aspiring mandolin maker,
and runs a camp in which attendees build their own F-5’s. On the
page is a compelling biography of Lloyd Loar.   Roger is
quick to make the point that Loar is not a luthier,  but a scientist
and industrialist and designer, and has had to defend that position publicly to Loar’s many devotees. But Loar’s workbench, pictured here, Is that of a craftsman as well, and closely mimics the chaotic nature of mine, which gives me hope.
(this pic is from Siminoff website, and the key to the letters and
arrows can be found there.

The Siminoff website front page is
here..

Roger Siminoff seems like a
terrific guy, and very knowledgeable.   I have two of his books, and refer to them often.  His “Luthier’s Handbook” will take you as deep into the acoustic properties of every feature of the instrument as you would likely care to go. If I have one beef with him it is that in his luthier camps he takes a strict machinist’s approach
to construction. He has created many fantastic jigs, templates and
fixtures that make the construction of an F-5 simple and straight
forward.

The construction of an F-5 is anything
but simple, and the construction of some of the jigs and fixtures
requires as much skill as building the instrument, at least in terms
of tolerances, etc.

So I’m curious how many of the
campers actually go home and build more instruments. For many,
that’s likely not even a goal, they just want to own and play an instrument that they can proudly claim to have built themselves.
But the process seems to me to be like touring the GM plant,
operating the assembly machinery at each station, and then being able
to go home and build a Chevy in your garage.

To be fair, Roger also hosts a
workshop in building fixtures and jigs, and if I wanted to learn
about making instruments, that’s where my money would go first.

My initial efforts at building were undisciplined and jig free. Once you decide to make more than 1 or 2, those templates and jigs are critical, especially if you want
to make your next one look like your last one. So far, I’m relying
more on templates than jigs. Most importantly, you need to determine
which features you want to duplicate exactly before you put the time
and effort into building a jig.

Quick Tip:  I’ve found the easiest way
to create a template from a full sized blueprint is to secure
colored tissue paper to the drawing and carefully trace the part you
want to template.    Carefully cut out the shape. Then I use 3M
spray adhesive to apply the tissue paper directly to a piece of 1/4”
birch ply,  This adhesive gives you time to smooth out the tissue
before it sets up.  Then I cut out on the bandsaw and smooth the
edges.  Check against the original before using.

For instance, Roger has constructed
jigs for creating his modification of the neck to body joint, the
most critical and vulnerable joint in any stringed instrument. In
the factory setting, this joint is typically a tapered dovetail as
pictured:

Many luthiers have duplicated the
joint for the reason that it is typical of factory made guitars of
the highest quality. But Roger is on the money in deciding that the
joint is flawed, and his background in instrument repair no doubt
convinced him of that. The neck portion of the dovetail is weak
because of the orientation of the grain, and in the picture above, if
you look closely, you can see that it has been modified by gluing a
strip whose grain runs perpendicular to the grain of the neck. This
is like a flying buttress to me, an architectural afterthought to
compensate for faulty design.  Roger’s modification is to keep the V shape and eliminate the dovetail, securing the joint by pinning it with dowels.

When I made that first mandolin 10
years ago for my wife, Judy, I eliminated that joint by making the
neck and the headblock out of one piece, or rather, 5 pieces
laminated to be one piece. On the mandola that I made 8 years later,
I did the same thing, and all the benefits, structural and acoustic,
of having a tight, solid joint there are only increased by doing
this. The neck can never move in relation to the body, which is
ideal. It would be impractical to build a guitar like this in an
assembly line setting, where the finished neck is attached to the
(often differently) finished body. The drawback is that there is no
way to adjust the neck if necessary down the road, but this is not
much of a problem with the short neck we’re talking about. You could
never do this with a guitar, where the neck will likely have to be
adjusted at some point in its life.

The top of the A style mandos I’m
making lately are curved, and I like to finish the carving and
planing before fitting the neck. The ideal angle of the neck to body
joint is 6 degrees, but if slightly too much wood was removed, you
can make 5 &1/2 work. So it’s become necessary to abandon the
notion of a integral neck, and find the right joint to get the most
dependable results.

After a bit of research, I found
William Cumpiano’s hardware-based neck joint, that uses
the type of hardware that comes with your Ikea furniture. His page
is here.
It’s secure, strong and fairly easy, and unlike the pinned joint
that Siminoff uses, which is fine for parts machined to perfect
tolerances, you have a little bit of adjustment. I’ve used it a few
times, and I can really torque it down tight, unlike alternative
hardware based (bolt on, i.e.) joints.

On the mandocello I recently built, I
used a combination of Roger’s modified V joint and the knockdown
hardware. The V just gives a little more “meat” to the
tenon, which I don’t feel is needed on mandolins, but the cello has a
longer neck(guitar length) and I felt anything I could do to make it
stronger was worth it. I also added a truss rod to that neck,
non-adjustable 3/8” from
Stewart-MacDonald.

So far that neck shows no deflection,
and I expect it never will, since besides the truss rod, I did a 3
piece glue-up of mahogany-rosewood-mahogany.

I’ll be posting pics of that cello in
the next day or so.

Regards, Lex