neck angle's... again (Full Version)

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Gimar Yestra -> neck angle's... again (Oct. 20 2011 21:07:31)

I knoooow there have been 1000 topics about neck angles, none of wish refer to my build specs, so sorry guys, yet another neck angle topic :D

As far as my thinking goes, I won't need any angle, therefore im asking for a double check, just in case.

my top in compeltely flat, no dome whatsoever
fretboard is 5mm thick, that would be +- 6 mm including frets.
bridge will be 5 mm thick.

5 mm from the bridge + 3mm saddle height above the bridge makes 8mm string height over the top. With no neck angle this would make a action of 2 mm (wich might be too low).

Im assuming the top will tend to bulk up a bit under string tension, I have no idea how much obviously, and there will be a bunch of factors involved in the eventual dome. I don't expect to top to reach a final dome under string tension of more than 2 mm, no idea if this is realistic though.

If necesary I could always taper my fretboard slightly.

Realy curious what you guys think, will a flat top under tension will get a dome or not?, and howmuch dome I should expect.


EDIT: dont mind spelling please :D



Jim Kirby -> RE: neck angle's... again (Oct. 20 2011 23:46:47)

You are estimating a fretboard plus fret height of 6mm, and a bridge saddle height of 8mm? That would be 1mm of action at the 12th fret, I think, 1/2 of the 2mm extra at the saddle. I think you need some forward pitch to the neck, doming of the top, or tapering of the fretboard.



Gimar Yestra -> RE: neck angle's... again (Oct. 21 2011 0:00:46)

hmm that's a realy good call, I guess I forgot that the string at the nut won't be 2 mm high, therefore altering the action a bit. Thanks, very helpfull input!

I guess I'll make a 1:1 drawing of the situation to help visualise it for myself.

anyone have a comment of the doming of a flat top under tension??



Stephen Eden -> RE: neck angle's... again (Oct. 21 2011 8:22:27)

I always draw everything based on the measurements I either know or want. that way you can find out exactly what you need to do. Start with the string, the height you want form the sound board and the nut. Everything will come together easily :)



Anders Eliasson -> RE: neck angle's... again (Oct. 21 2011 8:29:40)

To much theory Gimar. The soundboard will dome a couple of mm, the neck will settle a mm etc. How much depends on your building and your bracing. And besides, nevermind the amount of correct calculations, the guitars are stubborn creatures and often do what they want to do and not what you want them to do., so a bit of correction on the fingerboard is pretty normal.
You wont need a lot of neckangle if building the soundboard flat but you will need something. (2 - 4mm at the nut)



Gimar Yestra -> RE: neck angle's... again (Oct. 21 2011 9:58:59)

thnx for all the input!



Sean -> RE: neck angle's... again (Oct. 21 2011 15:26:18)

Generally the flatter the top the more neck angle you need. I'm curious why you chose a bridge height of just 5mm, that's not a lot of wood for having 3mm of saddle sticking above it.



Gimar Yestra -> RE: neck angle's... again (Oct. 21 2011 16:13:40)

I havent made the bridge yet.
The 5 mm bridge was actually just to give it a number, might aswell be 6 or 7 mm, the final string height is more important to me at this point.



Stephen Eden -> RE: neck angle's... again (Oct. 21 2011 19:08:36)

Yeah the flatter the soundboard the more angle you need! although you could get away with a 4mm fingerboard if you wanted to stay flat. I would make the neck 20mm in the that case. A little extra to play with.

Wood is wood and it can be very naughty indeed as Anders says. I planed 3 fingerboards today and all of them needed slightly different attention despite all being made in the same way and the same jigs! you still cant just have any angle you want though



Gimar Yestra -> RE: neck angle's... again (Oct. 21 2011 19:26:21)

thnx for the input SEden!

I know wood has a mind of it's own, that's also why I deceided to just glue the back on, and try to get that little - neck angle, we'll see tomorrow how things turn out.

Since this is my first flamenco i'm just accepting things might not go as planned.
If the guitar turns out better than the 800 euro flamenco's I've playd im happy, also I learned a couple of things so far.



Andy Culpepper -> RE: neck angle's... again (Oct. 22 2011 2:40:36)

Your fingerboard probably should not be thicknessed to 5 mm right now. When you get the guitar assembled with whatever neck angle you decided on, use some blocks of wood to simulate various thicknesses of fingerboard + fret + action at both the nut and the 12th fret, and lay a straightedge long enough to extend from the nut to the bridge across the blocks. Measure what the string height will be and substitute different blocks in until you've found the fingerboard thickness/taper that will give you the correct height.
You have a lot of room to mess with the fingerboard.. say you're simulating a flat board of 5 mm and your string height is coming out at 12.5 mm or so, well, just make your FB tapered from 6.5 at the nut to 4.5 at the 12th fret and that will put your string height at 8. It might look slightly strange but the setup will be correct.
Don't assume any doming of the top that will raise the action. If anything a totally flat top will tend to go concave in front of the bridge. The neck will pull up a little but in my experience that usually only pulls the action up about .2 mm or so, and you just knock the saddle down a bit.



Anders Eliasson -> RE: neck angle's... again (Oct. 22 2011 8:00:22)

Hmmmmm Andy.... Do you think its acceptable to have a fingerboard which is 6,5mm at the nut and 4,5mm at the 12th fret????
It can be played, but it´ll show poor workmanship.



Gimar Yestra -> RE: neck angle's... again (Oct. 22 2011 11:10:22)

thnx andy!

i was thinking the same thing, you can get away with alot of things by tapering the fretboard, and honestly for my very first flamenco i wouldn't realy mind if it will turn out into a proper playable guitar.

I also with Anders though, I dont think it would make for a sale worthy guitar.

I have to say though, building a flamenco guitar definatly is something completely different from electrics, steelstring acoustic and archtops.. I realy have to re-think the order/strategy im working in for the next flamenco guitar I want to build.



Gimar Yestra -> RE: neck angle's... again (Oct. 22 2011 12:13:54)

hmm i guess it didnt work out exactly as I was hoping, i think i might need to build a new stronger solera, i think i bent the solera a bit while clamping the back.

right now i have a slight angle to wrong way... I already planed my fretboard to 5 mm a while ago, i currently dont have any other fretboard to use, so i quickly modified this fretboard since I wont be able to use this fretboard for any other guitars, so might aswell experiment with it.

I tapering it from 5 mm at the nut to about 3,5 at the very last fret, and this seems to give me a good 2,3 mm action (frets included) with a string height of 8,5 at the bridge.

It does look a bit odd but i think i can make it work this way, not realy happy about doing it this way, but this does make it a challenge for me for upcoming flamenco's I'm deffinatly going to building more in the future.



Andy Culpepper -> RE: neck angle's... again (Oct. 22 2011 14:11:03)

quote:

Hmmmmm Andy.... Do you think its acceptable to have a fingerboard which is 6,5mm at the nut and 4,5mm at the 12th fret????
It can be played, but it´ll show poor workmanship.


Definitely not for someone that knows what they are doing with flamenco guitars (my figerboards are not tapered more than .5 mm) BUT if he gets to that point and that's the only way to make the setup come out correct, then I think that's the really important thing.



Andy Culpepper -> RE: neck angle's... again (Oct. 22 2011 14:16:44)

quote:

I tapering it from 5 mm at the nut to about 3,5 at the very last fret, and this seems to give me a good 2,3 mm action (frets included) with a string height of 8,5 at the bridge.


That seems very thin to me, even at the nut (I'm usually 6 mm at the nut). Don't forget that the fingerboard is an important structural part of the neck..



Gimar Yestra -> RE: neck angle's... again (Oct. 22 2011 14:24:44)

@ Andy,

yeah it is thin, it seemd like anice thickness when i was working onit, I havent seen many flamenco guitars in real life (only 3 or 4) so i haven't had many references when it comes to stuff like that.

Im kinda thinking what to do now: just finish the guitar, learn from it and use what i learned for future guitars

or take off the back and redo the neck angle.

Im afraid I will damage things while taking the back off.
I have no idea if the top and back turned out to be ok, if the braces are worked properly etc, I know im in the range from inspecting a few proper flamenco guitars, but basically this entire guitar is a experiment.



Anders Eliasson -> RE: neck angle's... again (Oct. 22 2011 19:34:32)

quote:


I tapering it from 5 mm at the nut to about 3,5 at the very last fret, and this seems to give me a good 2,3 mm action (frets included) with a string height of 8,5 at the bridge.


Thats not to bad. A little thin, but I´ve seen famous spanish guitars with 4mm fingerboards and they worked well. Why should it actually be thicker? As long as you can install the frets. I hope it works well with strings on.



Jeff Highland -> RE: neck angle's... again (Oct. 22 2011 20:34:04)

This seems to come up very frequently
I have just written a spreadsheet to do the neck angle calcs
Anyone wants a copy pm me your email



Anders Eliasson -> RE: neck angle's... again (Oct. 25 2011 20:33:03)

The problem with calculations is that they never take into account that wood is wood and difficult to calculate and that even though you use the very same solera for 90 guitars, there´ll always be difference in neckangle. The more guitars you build, the better you get at conrtroling these diferences in output but it still cant be calculated.



Jeff Highland -> RE: neck angle's... again (Oct. 26 2011 9:19:34)

I agree Anders, the end result is going to depend on the flexibility and long term movement of the neck and the box.
But it is good to have a target that you are aiming for, and understand the consequences of the decisions you make on things like neck set, doming and fretboard thickness at nut and 12th.



Gimar Yestra -> RE: neck angle's... again (Oct. 26 2011 12:36:11)

I've been playing around for fun with your spreadsheet Jeff, i think its quite handy to help understand the neckangle issue, and eventhough I wouldnt rely on the outcome of calculations 100% I think it makes for a realy handy guideline for those who are not very familiar with building flamenco guitars.



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