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..

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...

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