How 'bout this?

[musicofanatic]

I'm not wild about the five string (I've made a four and a five, and prefer the former), but I like the idea of extending the range on the low end. I think on my next one I'd like to increase the scale length to extends the G down to E, adding 3 more frets. Think Pete Seeger. I like the possibility of a slightly larger inst., too, hopefully decreasing the number of times I hear, "What is that, an electric ukulele?".
How does this sound conceptually? Lemme know whatcha think.
This one will be a semi-hollow, fitted with the old Gibson "Charlie Christian" mandolin p.u. I recently acquired.

[London Al]

I think your idea is well worth exploring. Would you just use a mandola \ octave mandolin scale length for the fretboard or do the maths and work out your own?
I build solid electric mandolins and I know how annoying the ukelele comments can be.
Any keen woodworker can copy an F5, and good luck to all the talented folks doin just that.
I think where you are going is more interesting than just making reproduction antiques.
AL

And as my old friend D.Wayne Love says "The meek aint gonna inherit **** "

[Joel Glassman]

I'd suggest trying strings on a capo'd electric guitar. See
if you can tune them to the notes you want at the scale you
want. This may save you creating an unplayable instrument...

[mandofiddle]

Ron Oates already does something similar to this. He calls it a Baritone elctric mandolin. I believe it has 3 extra frets. It's between a mandolin and a mandola tuningwise I believe.

[Lee]

Different scale lengths will exemplify different areas of the harmonic series. This is why, all other things being equal, a Stratocaster will always sound uniquely different than a Les paul. Because the scale lengths are different. You can do a heck of a lot of scientific learnin' about sclae length theory, or it might be quicker to build a few and see what happens. Schwab does quite well with the 14.5" scale length.