Yamaha JR2 guitar to octave mandolin ???

[kkmm]

Have anyone converted a Yamaha JR2 (21.5" scale length) to octave mandolin ?
I just got one of these and start ordering parts for the conversion process.
I have done 3 conversions to 3 guitars, one is 25.5", two are 23/5" scale length. Too hard for me to play. I hope 21.5" is easier for me to play.
I appreciated advises that apply to this particular guitar (which string set to use, tailpiece or simply bridge holes, etc...)

[bbcee]

Hi kkmm,
I thought hard about doing one of those JR2's, but at the time they weren't available in Spain, and I wound up getting an already converted Pluckthun waldzither instead, which I love. I am going to do a student-size electric guitar conversion this spring, but with a bolt-on neck, it's an easy mod.

Graham McDonald, among others, has an easy to use string tension calculator on his site. That will give you a good idea what string gauges you need to shoot for.

Keep us posted of your progress! It doesn't exist without (lots of) pictures!

[oinkstrings]

Have anyone converted a Yamaha JR2 (21.5" scale length) to octave mandolin ?
I just got one of these and start ordering parts for the conversion process.
I have done 3 conversions to 3 guitars, one is 25.5", two are 23/5" scale length. Too hard for me to play. I hope 21.5" is easier for me to play.
I appreciated advises that apply to this particular guitar (which string set to use, tailpiece or simply bridge holes, etc...)

Just about to start one. I just finished a Mitchell MDJ 10 conversion. It is the same scale length as the Yamaha but I strung it as a mandola, ADGC. I've done a few conversions but this is my favorite one to date. ( I think the solid top helps.)
# 1 advise, thin the neck down. I've been pulling the fret board off, thinning it down, then thinning the neck down to match the board width. The Mitchell is around a 34 mm nut, 44 mm at the 12th fret and 44 mm string width at the saddle. I believe those are from a 23 inch scale so you could go a little smaller but I like the room.
The Mitchel is strung with Martin Retros, 11,14,23,34, but again that's in ADGC.
If I stick with the Mandola tuning on the Yamaha I may just try a set of D'Addario EJ70's on it. They are phosphor bronze, .011,.015,.024, and .038. Which seem right for this tuning. ( Also, I have a BUNCH of sets so, what the heck.)
If I drop to the EADG OM tuning, well, I'll let you know what I come up with.
I have been filling the peg hole, Gluing a matching wood laminate over the head stock and bridge and re drilling just 4 peg holes. ( 2 strings each.) I like the look, and it's cheap.
I'm with you on the search for a shorter scale length. I've done several 23 inch tenors, one 23 inch OM and the 21.5 inch Mitchell. The Mitchell is WAY easier for melodies. I'm actually thinking of cutting the Yamaha down to a 20 inch scale, we'll see.
Either way, I'll keep you posted.

[fox]

You can try my bridge method if you remember how I got 8 strings into 6 holes?

[oinkstrings]

Actually. Fox, I was very much considering your method. Simpler and looks great. Just wasn't sure I had enough real estate between the pins and the saddle on this little bridge. I think I will try it. Nothing to loose. If I get in trouble I can always go back to my last method. little harm done.
Working on the other end first. I'll update you when I get to the South side of things.

[kkmm]

Parts I ordered finally arrived (mandolin tuning hardware, tailpiece, string set).
I went thru routines to plug holes, drill new ones at head stock, installed tuners.
Tailpiece is a piece of cake to install, only 3 small screws to hold it in place.
Only when I install the strings, then I discover one of the tuning shaft (for the G string) has NO HOLE in it !!!
Oh well, I will report this to the eBay seller.
For now, the G bass string is single string instead of double.
Here are some pictures.



The work is not completely done yet, I strung it just to hear how it sounds. There are more cosmetic works to be done and work at the nut as well as the saddle to get good intonation.
For now, I tune is 1/2 step below GDAE and put a capo at fret#1.

[kkmm]

I contacted the eBay seller and he will ship me the replacement part for G/D strings.
Once it arrives, I will remove the tuning hardware and put on a veneer on the headstock to make it look good.

[fox]

I bet it sounds great but I can't help thinking it would sound much better with more pressure on the bridge.