#1
EDIT: HOLY SHIT these pics are giant, sorry.

First of all, I got this idea from sevenstring.org. I wish I could claim it as my own, because it's fairly cool. For those who are interested, here is my illustrated chronicle.

WARNING: Crappy phone pictures.

I bought a cheap-ass 12 string acoustic/electric from Amazon. Other than two broken strings, and the fact that I hate the way 12-strings feel, it came in fine, perfectly playable condition:



Also, the tuners turn like a square wheel. But they work and that's all that matters.

I bought a blank Micarta nut and saddle from StewMac to swap them out. After some investigation, it turned out that the saddle the guitar came with didn't actually have grooves cut in it, the strings just sat there. So I kept the original saddle and only used the new nut. Busted out the old hacksaw and sandpaper to shape that bitch. Here it is all marked up:



Micarta dust is nasty so I opened the windows, wore the best mask I could get together at the time, and kept the nut moist with a wet towel in a (fruitless?) attempt to make the dust sink faster. I still choked on it bunch of times. It's ok, I love cancer. Next time I'll shell out the extra dollar or two for real bone.



So I glued the nut on. Then I sanded the scuffs from the strings off the saddle, cut some new grooves, and put a paper space under it to crudely raise the action a touch before gluing it back on. Strung the bitch up through 7 of the old peg holes and...

Fretting it on the first fret changed the pitch almost a step in a half. Turns out I had measured like a real jive turkey and the nut was super-tall. So I sanded it down again, re measured and re-cut my slots, and re-strung it.

BAM:



Came out surprisingly good, given how little effort I put in. I eyeballed a lot of stuff, and got really impatient toward the end because it was 2:00 AM and I still hadn't started my homework yet. The A string buzzes a tiny bit, barely perceptible, and the D string buzzes more perceptibly. In both cases it's because I filed the slot down too much. I'll grab some wood filler or something (any recommendations on something more effective?) and patch that up. Also the string spacing looks great at the nut, but at the bridge the high strings are kind of weirdly close. Fingerpicking is a bit difficult. But it sounds sludgy as dicks distorted, and doesn't feed back nearly as much as you'd expect. Clean, it produces some smooth jazzy tones. It's unamplified response is decent too. The lows have acceptable clarity and sustain. Overall I'm happy with it.

At some point I'd like to make a sort of hardtail or archtop style bridge for it, and maybe remake the nut if I can't fix what I already made, as well as remove the excess tuners and wood from the headstock. I'll probably shape the headstock into a mandolin body-style curly thing, and use the tuners on a cigar box banjo.

Anyway, I enjoyed playing Dr. Frankenstein, so I'd be happy to answer questions/take abuse regarding this monster. I'll probably post a soundclip later tonight.
Last edited by FrauVfromPoB at Apr 12, 2013,
#2
You should pull the bridge pins out and fill the pin holes.
Then mark out 7 points that are equal spaces and do the same for the bridge.
Re-drill the pin holes and you have a nice looking 7 String that has proper spacing. I can't imagine that it plays too good right now because of this issue.

Killer Idea. I think I might try it on a cheap 12 string, maybe a rouge from MF.
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#3
Certainly an interesting idea! I once saw an acoustic 8 string bass that had been converted to a 5 string - the owner had made quite a shoddy job of it, but it was shockingly nice to play and sounded brilliant.

Other than the odd string spacing at the bridge it looks fantastic. I have no idea how easy Robbgnarly's idea is, but it might be worth looking into at some point. The headstock might look a little out of place too, but in a cool kind of ''This is what I started with, and this is what I have now'' sort of a way!
I deeply regret the 6661 in my username. Siiiigh. Damn you, 14 year old me, you edgy little bastard.
#4
Quote by Robbgnarly
You should pull the bridge pins out and fill the pin holes.
Then mark out 7 points that are equal spaces and do the same for the bridge.
Re-drill the pin holes and you have a nice looking 7 String that has proper spacing. I can't imagine that it plays too good right now because of this issue.

Killer Idea. I think I might try it on a cheap 12 string, maybe a rouge from MF.


It plays pretty OK, actually. It doesn't affect the intonation or anything. The spacing is noticeable, but it only takes a second to accommodate for it. This whole thing's more proof-of-concept than anything. I'll be sprucing it up as I get the opportunity. In the ss.org thread that I got the idea from, the guy had taken a chunk of rosewood and shaped it down to what basically amounted to a hardtail bridge. Using the existing bridge to support a new 7 string saddle, he glued the new hardtail in behind the old bridge and just filled the peg holes and left it. It looked quite nice. I was considering doing that, though your idea sounds more cost effective.