DONE!

Ok strung this up tonight and it sounds pretty good, decent volume and good sustain... IMHO.. I did end up making the low C pair and Octave pair, we will see if I change that in the future.. Not sure if the action is still a bit high but going to play it for a bit and  see..

Getting Very Close

So the finish is done a satin sort of French Polish, not too shiny, I like it.. The tuners are on a nut & Saddle are made and tonight I glued on the bridge... Should be making music with this Mandocello pretty soon..

I think at least for the start I'm going to string it up with the C string pair as an Octave pair its easy to change if I don't like it.. But harder to go the other direction...

French Polish so far my favourite finish

Front view

Back view

Tuners front

Tuners back

The only way I could set the intonation was to actually string it up
with a temporary tailpiece and just fiddle with the bridge position...
actually 2mm of compensation came out pretty close

Gluing on the bridge

Pore Filling

I'm still not 100% sure I personally like a pore filled instrument but it is pretty much the standard for instrument building these days..

Typically I use z-poxy to pore fill & it works well enough. For this instrument it left it a bit heavier than I have in the past in the hopes of getting a better French polish on top of it.. We will see how that works..

Now on to the French polish...

Intonation & Bridge position

So intonation, a bit of a black art to say the least, how do you get it right? I have some ideas for 6 string guitars pretty much based on the work done by others and some trial & error but for a fanned-fret Mandocello I have no idea how to calculate that.. But luckily there is a low tech way to do this..

I take no credit for this method, I saw Dan Erlewine doing this in a guitar bridge replacement video.. Basically you make a temporary tailpiece to allow you to string up the guitar and just adjust the bridge by trial & error until the instrument play in tune up and down the fretboard.. Not really a fast process but it works.. So that is what I did.

Of course once I am finished French polishing I'll have to do it again to get the final bridge placement before I drill  holes etc but this was good practice any way and now that the bridge position is masked off I can start finishing. First z-poxy pore filling, then some sanding & on to French Polish....

Attaching the Neck & Fretboard

Things are moving along and really starting to look like an instrument now, the neck & fretboard are attached to the body (bolt on mortise & tenon joint) and the next step is to carve the neck.

The bridge is also made but will not be permanently attached until after finishing the Mandocello..

More MandoCello Design - Strings

There are several reasons you might make a guitar a multi scale or fanned fret instrument, one is to make the instrument more ergonomic and playable the other is to allow for better string tension on the bass strings, which is my reason.

Since a MandoCello uses relatively large strings on the low C (0.070-0.074”) getting enough string tension at the shorter scale length I want to use (24.75”) is problematic so to help I’m hoping to do a fanned fret design with the treble side (A₃) being 24.75” and the bass side (C₂) being 26.25”.

Unfortunately going to a fanned fret or multi-scale design changes the design of the entire instrument as the saddle, bridge and nut all now need to move around and this effects the brace position.

My first consideration is getting the fingerboard properly designed and picking the strings. Choosing strings is an art in and of itself, there are many options and types to consider. I’ve looked at several types and since I want to do a pin bridge I need ball end strings. So after much thought and a bit of a guess work I’ve settled on stainless round wound strings for everything but the A string which still might be plain steel.

Next the string gauge needs to be determined. Ideally all strings should have the same tension or a slight increase in tension as you go lower in pitch, at least that is what I am aiming for and that tension needs to be high enough so the strings are not “floppy” and low enough so the instrument can be built with reasonable bracing so that it continues to be responsive.

So after some fiddling with an on line calculator (http://www.surveyor.com/guitar/stringtension.html) I’ve ended up with the following, C₂-0.068; G₂-0.046; D₃-0.030; A₃-0.018 which give 24 to 25# tension per string  slightly increasing as they go lower. So around 200# total string tension which is say about what an extra light strung 12 string would be, I think.

Now I need to design/modify the top bracing to accommodate the new bridge location.

Thinking about MandoCello Design

So I'm busy this summer with things other than lutherie, but it is on my mind, things like tonewood and the odd part purchase and trying to design a new Workbench and tool box addition.

In Addition to that I've been thinking about the conundrum of trying to make a MandoCello in a scale length short enough for me to play comfortably and yet long enough for the low C to not be too floppy. Frankly the two requirements are not really compatible.. So How to solve this??

Well it came to me the other day when I was reading a post on multi-scale classical guitars! Make it multi-scale or as some people call it fanned-fret.. Not sure why this did not come to my mind before, perhaps because I have no real idea how to design a multi-scale fingerboard...

Time for some serious reading.. need to figure out the two scale lengths and then where the 90 degree fret will be, I thinking 24.75 and 26.75 or maybe 27 inches for the scales and maybe the 5th fret for the 90 degree fret but that is all wild guesses right now...

I'll probably have to tweak the the X brave a bit too to account for the bridge angle...

Here is a phot of a multi-scale guitar made by Mike Doolin http://www.doolinguitars.com