New Model Mandolin: 8

 My "New Model" mandolin (as I'm currently calling it) has now been completed. I'm incredibly happy with the final outcome and looking forward to building the next one! Here is the last video in the series and below that a whole batch of photos for you.

Cheers Gary

New Model Mandolin: 7

Well, this is another long video but so, so much to get through!

The bridge is made and I have brief chat about its design, the strings go on and I show you how I set-up my mandolins. And finally……..the New Model Mandolin gets to sing its first notes!

So, cuppa at the ready and off we go.

Cheers Gary

Making Paul’s neck blank

I thought that I’d show you how I put a neck blank together- although this one is for Paul’s Standard Plus mandolin, the general process is the same for any of the instruments that I make.

We start with some basic woodwork- I don’t have (or want!) a large band-saw or planer machine, so it’s down to traditional, hand skills to true up this piece of maple.

Once the maple is flat and square, the rough profile is cut-out and prepared for laminating with some rosewood veneers and a thicker piece of pau ferro.

Another piece of maple (from the same board) is prepared for the head- my bench-top band-saw is just about at its limit here!

The head is glued on- I always use a spliced head joint.

Once the head is on, two slots are routed for the carbon-fibre strips that I like to use to stiffen the neck. With CF epoxied in place, the head overlay can be glued on- this is a precious piece of beautiful chocolate brown Brazilian rosewood. It does look good enough to eat!

Next the head can be shaped and the tuner holes drilled- you also have to counter-bore the holes to take the bushes.

The head can then be inlaid with my N logo; Paul has chosen abalone for his.

And after quite a few hours work, we have the finished neck blank…..

You can also see that on the back of the head, I’ve partially carved the volute and, those tuners are some very nice handmade Robsons.

Nomenclature

I recently posted on the Mandolin Café forum that I was making a “tenor and octave”.  As Mandolin Café members are mainly USA based, this caused some confusion, as Shaw said, England and America are two countries separated by a common language!

In the UK the tenor mandola is the instrument which is tuned to a fifth below the mandolin, in the same relationship as that of the viola to the violin but in USA it’s simply called a mandola. It makes perfect sense to me just to call it a mandola, why use two words when one describes it accurately.

And of course many in the UK call the octave mandolin (USA) an octave mandola, which doesn’t make much sense as it’s tuned an octave below a mandolin and not a mandola!  D’oh!

This got me thinking about the naming of my instruments; so below is Adrian’s mandola with all the construction work complete.

Some thoughts on mandolin design

For most of the mandolin players, that I come into contact with, the sound that an instrument produces is paramount. As a professional luthier, I always try to build the best constructed and most aesthetically pleasing instrument that I can, but that all counts for very little unless the tone is there too.

We know from the law of conservation of energy, that energy cannot be created or destroyed but is transformed from one type to another. Essentially a mandolin (or any other acoustic instrument for that matter) has to transform the kinetic energy of the musician’s hand into sound energy. That transformation has to be done as efficiently as possible to get the maximum sound out of the instrument.

So you pluck the string, it vibrates (kinetic energy) and you want the maximum amount of this energy transferred into the soundboard.

The job of the bridge is to hold the strings in the correct position relative to the rest of the instrument (for string spacing, action, intonation) and to make the soundboard vibrate.

A bridge needs to be as light as possible, so that the minimum amount of energy is used in moving the bridge itself. However, it has to be strong enough to support the strings and wide enough at its base to be stable. I make my bridges without any metal height adjusters; I feel that any mechanism that cuts the bridge into two parts must interfere with the bridge’s efficiency. Admittedly, I use a removable bone saddle to aid the adjustment of the action, but that saddle is firmly embedded within a deep slot and the bone saddle helps with acoustic impedance matching- metal to bone to ebony to spruce.

My bridge actually looks like a bridge! It makes contact with the soundboard only at the two ends- the central portion is removed; this reduces mass and lessens any restriction of the soundboard’s vibrations. However, by reducing the area of contact, you increase the pressure at the points of contact with the soundboard, which in my opinion, allows the transfer of energy to be more efficient. The feet of the bridge are not in some random position- they rest on the bracing which is designed to support the downward force and to help transmit energy across the soundboard.

The break angle at the bridge is also critical- the greater the angle the greater the downward force. However, if the bridge is pressing down too much on the soundboard, it will choke it- you know yourself, if you press down on the soundboard you will dampen the instrument (a good argument for armrests). The break angle is governed by the angle of the neck relative to the soundboard and is not just a function of the bridge.

The tailpiece should be a rigid anchor for the strings, so that energy is not absorbed by it; my theory is that any of the available energy will follow the path of least resistance and that path should be into the soundboard via the bridge.

The tailpiece must be a minimum length. If the length of the string between the bridge and the tailpiece is too great, you get this part of the string vibrating in sympathy and that’s wasting our precious input energy. You’ll notice that on some mandolins that have the anchor point of the strings close to the tail block, they will have harmonic suppressors fitted to the strings, behind the bridge.

I like to think that the body of the mandolin is like a loud speaker; the soundboard is the equivalent to the paper cone and that the back and sides are the metal chassis. Therefore, the back and sides should be rigid so that they don’t absorb energy from the soundboard. I also like the inner surfaces to be extremely smooth so they act as a reflector.

Having stated some of my design ideas; you should appreciate why I use French polish as my finish of choice. French polish is a very light surface coating and as such will have a minimal damping effect on the soundboard.

Well there’s is my two pennies worth- hope that you found that of interest.

Project X

 Project X? Not because it’s top secret but because I’m still thinking of a suitable name! I’m adding a new model to my range of mandolins that will sit between my Standard and Twin-point. Essentially, it will be the same shape as the Standard but will have more of the fancy detailing that my twin-point has; this should give me something for everyone!So the first one is under-way. Red spruce soundboard with a rosewood herringbone rosette.

The back and sides will be Indian rosewood and you can see below, that the rim is complete.

The neck......

.....I’m using wenge on this one. It’s quite an interesting wood to work, not for the faint-hearted- very sharp, low angle planes are required.

This mandolin will have all the nice touches, such as an inlaid head and handmade tailpiece.

So I’ve been thinking about the name, model 3? Model A? I even thought of calling it the Italian for pear- pera but that looks like a typo! Something for me to ponder!

This mandolin doesn’t have a home yet so if you’re interested, email me via my website.