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Reso cone warning!

I just did my first build using a lightning reso cone from Gitty and at the end found I had a problem with intonation. I laid everything out first as I always do, used a 24" scale. I was very careful to measure twice and cut once for the hole to hold the cone. All done and string it up and something is not right, intonation is off. I used a medium action since I wanted to do both slide and finger notes, it is fully fretted. I know it will go a bit sharp if the action is too high. So , to get the intonation to be correct , I had to slide the discuit/ saddle back by a bit over 1/4", so now the biscuit is not centered on the cone "nipple" like it should be but teetering on the edge. I think I will make a new biscuit/saddle on an oval shape (maybe rectangle) and screw it to the cone so it does not tip off the edge of the "nipple". I've done resonators before but never one where moving the biscuit causes a problem. I guess the moral of the story is I needed to figure in some "compensation" in my calculation of where to mount the cone on the box for my scale length.

Anyone else run into this??

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Permalink Reply by ChickenboneJohn on November 18, 2017 at 11:00pm

Fretting a string can only sharpen a note, never flatten it, as you are deflecting the string from a straight path thus increasing the tension in the string..that's why when setting a bridge it will always be further away from the nut than the theoretical scale length.

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Permalink Reply by Taffy Evans on November 18, 2017 at 11:34pm

One can get a flat note, and I find it when I am setting customers guitars up. If you press on the string pushing it to the fingerboard, behind the fret,and set the intonation to that note, you can get a lower note if the string is pushed more softly and maybe stops at the fret, so not being stretched as far.

This is often experienced when setting intonation for other players, they all have different playing styles so setting spot on intonation can be tricky.

I have tested this by fretting a string whilst watching the tuner and rolling my finger behind the fret,I can make the note go flat and sharp, if I set it with a firm pressure on the string to start with.

So l have developed a method to over come this.
Cheers Taff

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Permalink Reply by Michael Fred Johnson on November 19, 2017 at 2:06am

Depending on the design of your git,could you relocate the fingerboard/nut away from the saddle using a bit of creative bodging?

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Permalink Reply by Bluesheart on November 19, 2017 at 2:32am

That is actually a really good idea and one I had not thought of. I could add 1/4" to the length of the through neck . I'm not sure if I would like it visually as I have the fretboard meeting up with the body right where I want it now but thanks for the food for thought! I think this is similar idea that another poster suggested, but they were talking, pre build. I had not thought of it as a retrofit.

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Permalink Reply by Richard Dean on November 19, 2017 at 2:36am

you can trim out the neck to box where they meet

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Permalink Reply by Michael Fred Johnson on November 20, 2017 at 12:14am

Make another fingerboard,you can always use this one on a future build.

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Permalink Reply by Bluesheart on November 20, 2017 at 11:29am

Fingerboard is glued on and fretted, fret spacing etc are fine. I'm going to go with the simplest solution, make a new biscuit with the slot cut off center.

Thank you all again for all the helpful suggestions!!

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Permalink Reply by CboxGypsy on December 6, 2017 at 5:23am

Before you move the resonator back check the break angle of the strings and adjust if necessary. I ran into this problem and moved the res back. Still had an issue. I ended using the neck on a different git and had the same problem. I finally discovered the break angle was all wrong eventually after slowing down and taking a closer look. Even if it isn't wrong, the angle of the strings can influence better intonation.

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Permalink Reply by Taffy Evans on December 6, 2017 at 9:35am

Hi, changing the break angle at the bridge and/or nut would have an effect on how the strings feel, soft or tight, and may tie in with what I mentioned on this thread earlier. The fact that finger pressure on strings when setting intonation can effect good intonation. Soft strings and soft/light tension may allow the string move more under finger pressure. Giving a false note against the harmonic.

Taff