7 String Falcate Flamenco

[jeffhigh]

EIR/ Englemann
Now ready for neck fitting

[kiwigeo]

Nice looking gat Jeff. Have you done any sound spectrum analysis of the free plate top/back and closed up box?

[jeffhigh]

Not Yet,
I dont see a lot of worth in free plate, I'll do the box when it's finish sanded, but I found on the last two that the frequency changed when I added the neck and in a major way when I added the bridge.
I don't use a bridgeplate on nylons so it is still pretty loose until the bridge goes on.

[Trevor Gore]

Love that height-adjustable work bench!

[jeffhigh]

I reckon it's saved MY back in the 15 years I've had it

[charangohabsburg]

[...], but I found on the last two that the frequency changed when I added the neck [...]

That sounds interesting to me. Which frequency did change? And how (+ how much?) did it change? The neck as "side mass"?

[jeffhigh]

Yeah. neck as side mass, dropped the top around 2Hz. I know Trevor has said that was not his experience, but with my body shape etc, it did it in a measurable and repeatable manner.

[charangohabsburg]

Yeah. neck as side mass, dropped the top around 2Hz. I know Trevor has said that was not his experience, but with my body shape etc, it did it in a measurable and repeatable manner.

I imagine that if one can measure a difference of the fundamental top frequency or not might depend on the stiffness difference of the body structure with and without attached neck. If there is a big enough stiffness difference (stiffer with neck attached) this might eliminate the neck's "side mass effect" on the top fundamental frequency.
That's just my conjecture, of course.

[jeffhigh]

That may very well be
My design uses a cantilevered fretboard extension so it adds no stiffness to the top only mass

[jeffhigh]

Walnut bridge with 2 layers of CF

Currently at 12.5 grams(without saddle) and with a bit more sanding remaining

21 hole tieblock

[Dominic]

Hey Jeff, is that american walnut or Qld? Pretty light so far. And longer saddle area. I like 21 holes, so much neater not having the string wrap over the tie block.
Look forward to the finished thing.
Cheers
Dom

[jeffhigh]

American black walnut, cant stand the smell of the QLD plus it is quite heavy.
This stuff doesn't smell great but not totally disgusting.
Yes, longer saddle section for the 7 string but I only added 5mm to the total length

French polishing the body now

[kiwigeo]

All looking good there Jeff. Looking forward to seeing the finished instrument.

[Dominic]

Hey Jeff, I saw a vid on youtube of your on-the-fly adjustable guitar neck. (That is your guitar isn't it?) Have you put up any pics of how it works? Does your heel move in a recess in the headblock or do you just let there be a gap? And what is your pivot point?

I have been doing raised fingerboards with one bolt on my classicals so I am only a few details away from making it adjustable. But I have not yet resolved in my head a design that I am happy to put on both a non-cutaway and a cutaway. I might have to do two different designs.
Cheers
Dom

[jeffhigh]

Pretty simple Dom
My neck is cut off 5mm longer than the joining fret at the appropriate angle
The neckblock has a 6mm insert about midway down on the inside face.
After the body is closed and the fretboard fitted to the neck ,I shim the neck to the right height, I insert a sharpened bolt from the inside of the body and use that to scribe the end of the neck.
I drill a 6mm hole through the heel at an appropriate angle (on a platform on my lathe bed)
I mount the neck to the body with a bolt/strapbutton and scribe for the pocket which I cut a little undersize and creep up on a good fit
The pocket is 6mm deep and the pivot is just a strip of 3x1mm CF glued to the top edge.
Have not done a cutaway, I think Craig did.

[Dominic]

Thanks Jeff, one more thing, how much room do you need at the bottom of the heel to go from a low action to a high action. It wouldn't be much. 1 to 5 ratio or so?
For a cutaway I want a nice smooth joint where the hand goes. So I could deal with a small gap for a high action and no gap for a low action but I don't want any overlap like I've seen on some Doolins. I've been tossing up ideas in my head for months about how to design it so I can execute it well. I'm at the stage where i need to do some mock ups so I was interested in different approaches .
And your vid was really cool.
Cheers
Dom

[jeffhigh]

Thanks Jeff, one more thing, how much room do you need at the bottom of the heel to go from a low action to a high action. It wouldn't be much. 1 to 5 ratio or so?
For a cutaway I want a nice smooth joint where the hand goes. So I could deal with a small gap for a high action and no gap for a low action but I don't want any overlap like I've seen on some Doolins. I've been tossing up ideas in my head for months about how to design it so I can execute it well. I'm at the stage where i need to do some mock ups so I was interested in different approaches .
And your vid was really cool.
Cheers
Dom

You are only talking a mm or so from high to low. If I get the neck angle right just that 1mm elevation at the pivot is enough to give plenty of range.
I have not done a cutaway yet, and have not come to any conclusions about how I would do it.
Like you I would prefer to have a smooth transition from neck to cutaway, so I am interested to see what you come up with.

[Dominic]

Thanks Jeff, once I have my ideas resolved I'll mock it up and post the results. My problem is that once I get motivated I want to do all the projects I have been thinking about and I have already committed myself to finish my bass, make a couple of CS356's and do these clones with all the jigs making. Surprisingly everything is moving forward but this neck joint is a priority so I can imagine dropping everything else once the inspiration strikes.
Cheers
Dom

[jeffhigh]

Vacuum clamping the bridge with HHG

[jeffhigh]

40 minutes later, all cleaned up

[jeffhigh]

The T(1,1)2 went up around 10 HZ to 189 with the bridge glued on
I'm expecting that with the added mass of the saddle, golpeador, strings, neck (side mass) and the effect of bringing down the back frequency, I will approach 180

[kiwigeo]

Any chance of a look at the full spectrum Jeff?

[jeffhigh]

Ok lets try this
At the moment, its 87, 189, 265

[jeffhigh]

Strung up for setup and tuning of resonances.
Then probably bind the soundhole and a bit of finish touchup.

[kiwigeo]

Looking good there Jeff...