Double changer idea

[mac639]

I've built pull/release, all pull, and double changer guitars. My favourite is the double changer, but it is significantly more complicated to make. The beauty of it in my mind anyway is the total lack of any undesireable interaction between the raising and the lowering of the same string, especially when there are more than one raise or lower.
I got this idea about 3:00 AM in the night last night (this is when I wake up most nights lately)....must be a 74 thing! Anyway, got up and scribbled some drawings and made a test board up today. It does work really good, and not too hard to make, way better and easier than what I've been making before. Of course it's for a keyless guitar which is not everybody's cup of tea. If you look at the pictures it's a 24-1/4" scale. I also thought now's a good time to try running the string through the finger rather than pins or slots etc. I don't see a problem with doing that either. I tried different strings on the test board all the way from .010 to a .50 which is on there in the picture. Spring tension is adjustable but seems to be adequate for anything I tried. The basic tuning is with the bolt that sticks up and the piece it's attached to doesn't move at all when tuning. It's 3 raises and 3 lowers, fine tuning done with the regular nylon nuts. I have this butternut body made up but it's only 29" long so had to "invent" a tuning system that would fit on the space I had left at the far end (about 2-1/2"). This will be a Zane King E6/9 tuning guitar and has a total of 24 pulls. A bit much for an all pull 10 string but I think this design will work out better all around.
Thanks for looking at my hair brained stuff all the time, and I really would like any comments ar suggestions any of you might have on how I could maybe do it different or whatever...
Rotten day here....non stop March rain, melting all the snow and making nasty ice for us old guys to fall on!
Cheers,
Mac

[Jim Smith]

The double changer idea has been around since at least the 70s. One company that made them was called Bossan, I think. It's a good idea though, and I'm surprised that it hasn't caught on more.

[mac639]

Hi Jim... yes I've made I think 8 or 10 double changer guitars, but they all have been keyed guitars. If you look at my site http://www.mkguitars.com the two guitars that are "sold" are both double changer ones. Although they work fine it's a lot more work to make and also is a bit of a pain to feed the string down under the roller before going to the tuning machine head. As far as keyless goes, it takes a bit of time to accept that there are no traditional machine heads, but in fact the keyless tuning works fine and is easy to tune and stays there with no backlash etc.
Thanks,
Mac

[azureskys]

Hi mac , i also thought about your idea there (similar) but never did do anything as of yet , looks like there might be alot of possibilities there keep us posted as to any progress you make , you are a briiliant man and a creative dynamo, God bless ya buddy. Russ

[Bent]

That's how simple it can be eh? Mac, you're a fine thinker. That number 74 means nothing.
So you tune the open string with the long screw on the lower finger - right?
Are you providing for grooving for the strings? I mean just like on the grooved rollers.
And here I am struggling with trying to balance a regular all pull changer. Hm...

[mac639]

Bent... yes I'm thinking of grooving the lowering fingers. Not sure how I could do that accurately. It's not like I could put them on the lathe since they're not round. Maybe I'll get a brainwave at 3:00 AM tonight! Maybe as an alternative just make the finger tops progressively smaller (lower) on top???

Thanks,
Mac

[LushPyle]

Mac - I really like your idea. Very simple integration of the keyless tuner. I just might "borrow" your idea if you don't mind! This is an elegantly simple design and I give it a "10" for conceptual excellence! By the way I really dont think you need to groove the lower finger. Just my opinion. Ed Packard got away without grooving the finger on his "Beast" guitar which would seem to need it a lot more than your design.

[Bent]

I was thinking something like a cutting disk for the mill..ground at a 60 deg angle and plunge it to the correct depth for each string size.
Do it on the little thingy that holds the string. You could even incorporate a roller into the little thingy.

[LushPyle]

Bent I see now you are talking about indexing the string height like gauged rollers. I did not make the connection before. I cant blame it on 74 but I can still blame it on the 60s!

[mac639]

I don't much like the idea of grooving the lowering fingers. The guitars that I've built with that sort of finger at the nut end (even though it was a different shape) had amazing sustain. I think I'll leave well enough alone without grooving but I'm going to adjust the heights of the individual strings by adjusting the height of the actual finger relative to each other, so the tops of the strings will be level all the way across. It may take a bit of dickin' around to do it when I round the tops of the fingers.
Mac