Official Luthiers Forum!

Owned and operated by Lance Kragenbrink
It is currently Tue Apr 29, 2025 4:33 pm


All times are UTC - 5 hours





Post new topic Reply to topic  [ 55 posts ]  Go to page 1, 2, 3  Next
Author Message
 Post subject:
PostPosted: Sat Mar 25, 2006 11:06 am 
Offline
Koa
Koa

Joined: Sun Sep 04, 2005 3:20 pm
Posts: 632
Location: United States
Think I messed up big time. Didn't realize it at the time but sanded the top rim with dish and assembled. I have a serious dip at the front where the neck attached. Put a square from the soundboard down the sides as the neck would attach and the dip is rougly 1/8". You can see from the pic what I am saying.

Wondering what to do??? Doesn't look like shaving the heel will fix this type of problem.



Top
 Profile  
 
 Post subject:
PostPosted: Sat Mar 25, 2006 11:09 am 
Offline
Koa
Koa

Joined: Thu Nov 10, 2005 12:43 pm
Posts: 1031
Location: United States
How is your neck angle compared to the bridge? This will determine how to fix it.

Al


Top
 Profile  
 
 Post subject:
PostPosted: Sat Mar 25, 2006 11:24 am 
Offline
Cocobolo
Cocobolo

Joined: Mon Jan 24, 2005 10:38 am
Posts: 133
You can relieve the underside of the fingerboard extension (sand out a wedge) which is not too hard if the board is not yet attached. I'm not sure you'll get all the relief you need, but it is a start.

Don't take too much or you'll sand through to the fret slots.

And as Al indicated, keep your eye on the trajectory at the bridge.



Top
 Profile  
 
 Post subject:
PostPosted: Sat Mar 25, 2006 11:33 am 
Offline
Contributing Member
Contributing Member

Joined: Mon Jan 03, 2005 7:46 am
Posts: 1315
Location: Branson, MO
First name: stan
Last Name: thomison
City: branson
State: mo
Zip/Postal Code: 65616
Country: united states
Focus: Build
Status: Professional
Did you sand or is the top where tongue lays flat?


Top
 Profile  
 
 Post subject:
PostPosted: Sat Mar 25, 2006 11:33 am 
Offline
Contributing Member
Contributing Member

Joined: Mon Jan 03, 2005 7:46 am
Posts: 1315
Location: Branson, MO
First name: stan
Last Name: thomison
City: branson
State: mo
Zip/Postal Code: 65616
Country: united states
Focus: Build
Status: Professional
don't think that is the problem but who knows


Top
 Profile  
 
 Post subject:
PostPosted: Sat Mar 25, 2006 11:46 am 
Offline
Koa
Koa

Joined: Thu Nov 10, 2005 12:43 pm
Posts: 1031
Location: United States
From the photo it looks like the neck angle is opposite of what it should be. Sort of like a neck in bad need of a reset. The fingerboard when clamped tight to the neck. and extended to the bridge area with a straight edge should measure about 3/8" above the body without frets. If you will check this then mabe we can find a way to fix it.

Al


Top
 Profile  
 
 Post subject:
PostPosted: Sat Mar 25, 2006 12:23 pm 
Offline
Koa
Koa

Joined: Thu Feb 17, 2005 3:38 pm
Posts: 1542
Location: United States
If the neck angle is ok then a wedge can me made or a combinations of thining the fretboard extension and wedge
john hall


Top
 Profile  
 
 Post subject:
PostPosted: Sat Mar 25, 2006 1:02 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Thu Feb 09, 2006 2:35 pm
Posts: 2951
Location: United States
First name: Joe
Last Name: Beaver
City: Lake Forest
State: California
Focus: Build
I doubt it is a neck angle problem at all. You just need more top under the fingerboard. The easiest way I can see for you to do that is glue a mahogony wedge (or maybe the same material as the fingerboard?) under the fingerboard. Shave it down to just replace the missing top and bonding wood, put the fingerboard back on and chock it up to experience.

Good luck. Joe Beaver38801.8780671296

_________________
Joe Beaver
Maker of Sawdust


Top
 Profile  
 
 Post subject:
PostPosted: Sat Mar 25, 2006 1:22 pm 
Offline
Koa
Koa

Joined: Sat Jan 15, 2005 7:24 am
Posts: 830
Location: United States
I agree with John Hall....
I would build a nice looking "Shimm" for that space when neck is set and you are happy with the action.
I have used a nice piece of Mahogany works nicely if done properly!!!
Good Luck Brother,
walter


Top
 Profile  
 
 Post subject:
PostPosted: Sat Mar 25, 2006 1:29 pm 
Offline
Koa
Koa

Joined: Sun Sep 04, 2005 3:20 pm
Posts: 632
Location: United States


This pic shows the drop with a square



With the fret board positioned as such, I can get a good neck angle. Looks like I will have to make a tapered fingerboard or glue up a piece of something under the fingerboard and the taper it to fit the neck at this angle. Or should I make another neck and taper the neck?

This makes me sick. The body came out flawless and has great tap tone to it. Here are a couple of shots. Mahogany back/sides, bearclaw top and rosewood bindings.









Top
 Profile  
 
 Post subject:
PostPosted: Sat Mar 25, 2006 1:54 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Tue Nov 29, 2005 11:44 am
Posts: 2186
Location: Newark, DE
First name: Jim
Last Name: Kirby
Focus: Build
Status: Amateur
Your second picture still doesn't show where a straightedge
placed on the flat surface of the neck would fall at the bridge location. This is crucial information. It looks like there is a definite problem, but its hard to tell how much could be taken care of by gowing with a higher neck angle and a slightlyh raised saddle.

Pretty box so far.

_________________
Jim Kirby
kirby@udel.edu


Top
 Profile  
 
 Post subject:
PostPosted: Sat Mar 25, 2006 2:01 pm 
Offline
Koa
Koa

Joined: Sun Sep 04, 2005 3:20 pm
Posts: 632
Location: United States
The straight edge falls perfect, just touching the bridge when the fretboard is positioned with the gap like in the picture. And with the fretboard held with a clamp at the first fret and also at the soundhole, it is level. That is what is leading me to think I could beef up the bottom of the fretboard and then taper it


Top
 Profile  
 
 Post subject:
PostPosted: Sat Mar 25, 2006 2:26 pm 
Offline
Koa
Koa

Joined: Thu Nov 10, 2005 12:43 pm
Posts: 1031
Location: United States
From the second picture, it's definately the neck angle. Just work the heel down, and the gap on the neck, and on the top will close.

AlA Peebels38801.9355092593


Top
 Profile  
 
 Post subject:
PostPosted: Sat Mar 25, 2006 3:32 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Tue Jan 04, 2005 10:03 am
Posts: 6680
Location: Abbotsford, BC Canada
I agree with Al and Hesh, looking at this picture



there doesn't appear to be any set to the neck. So take your square and place one edge on the fb surface of the neck and run the other end down the heal end (the edge that bares on the body). If this is 90* than you don't have any set to the neck. YOU NEED TO SET THE NECK.

Now, if you have set the neck, than you have to shim and taper the end of the fret board like John, Joe and Walter have said.

The other thing that make me think there is no set to the neck is that all guitars have a dip at the front like this



Just think if it were 90* to the side of the body and you have the neck set (All necks need to have to be set back in order for the action to work properly), than you would have a very large shim under the fretboard or one very distinct dip in the fretboard.

So.... I think you need to set the neck back and everything will work out just fine.

_________________
My Facebook Guitar Page

"There's really no wrong way, as long as the results are what's desired." Charles Fox

"We have to constantly remind ourselves what we're doing....No Luthier is putting a man on the moon!" Harry Fleishman

"Generosity is always different in the eye of the person who didn't receive anything, but who wanted some." Waddy Thomson


Top
 Profile  
 
 Post subject:
PostPosted: Sat Mar 25, 2006 3:37 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Tue Jan 04, 2005 10:03 am
Posts: 6680
Location: Abbotsford, BC Canada
Oh, one thing you might want to do is sand the radius out of the top, see in this picture how the top appears to curve from the front of the body to the top of the sound hole?



That same radius is runs the latteral direction of the top as well. Now, some folks make a nice little sander 25' radius convex ( to sand the bottom of the fret board. But I think it's easier to sand the top flat instead. There are several ways to make the front part of the top, we won't get into that here though.

_________________
My Facebook Guitar Page

"There's really no wrong way, as long as the results are what's desired." Charles Fox

"We have to constantly remind ourselves what we're doing....No Luthier is putting a man on the moon!" Harry Fleishman

"Generosity is always different in the eye of the person who didn't receive anything, but who wanted some." Waddy Thomson


Top
 Profile  
 
 Post subject:
PostPosted: Sat Mar 25, 2006 11:29 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Tue Nov 29, 2005 11:44 am
Posts: 2186
Location: Newark, DE
First name: Jim
Last Name: Kirby
Focus: Build
Status: Amateur
The neck may well have the proper set, it's just that the top is falling away so fast towards the neck block that we all can't see it.

I can't remember the builder(s?), but I've seen pictures in ads in places like Acoustic Guitar of bodies with tops that fall away rapidly towards the neck end, leaving a neck structure that stands way proud of the top. (Charles Fox?? I just can't remember. Isn't aging wonderful? ) If you pursued this approach, you could actually shim the neck joint (dovetail) or hike it up slightly northward (mortise and tenon) to bring the plane of the neck back level with the fretboard. Then, the remaining shim under the fingerboard extension could be of neck material, and you wouldn't need to taper the fretboard.

_________________
Jim Kirby
kirby@udel.edu


Top
 Profile  
 
 Post subject:
PostPosted: Sat Mar 25, 2006 11:55 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Sun Dec 25, 2005 6:32 am
Posts: 7774
Location: Canada
Rich, i'm no expert here but Hesh seems to have a point here, after looking at all the pics, it would make a lot of sense that the neck angle coupled with the strong radius of your top would have given you that kind of gap, FWIW. Anyway, good luck in fixin' this, keep us updated on how it goes!


Top
 Profile  
 
 Post subject:
PostPosted: Sun Mar 26, 2006 12:09 am 
Offline
Koa
Koa

Joined: Thu Feb 17, 2005 3:38 pm
Posts: 1542
Location: United States
   This looks like you will solve this problem Rich. Body looks killer. I think your angle may be off. Can post 2 pixs on from the nut to the bridge and one with a side shot from the nut to the saddle
john


Top
 Profile  
 
 Post subject:
PostPosted: Sun Mar 26, 2006 2:04 am 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Tue Jan 04, 2005 10:03 am
Posts: 6680
Location: Abbotsford, BC Canada
Remember, this is what rich said about the fret board,

[QUOTE=rich altieri]


With the fret board positioned as such, I can get a good neck angle.
[/QUOTE]

If this is the case, than don't be afraid to trim the heal of the neck to match this angle.

Here, to prove my point, I layed out a 25' radius in Autocad to show that 1/8" is not a large dip at the front of the body.



The green line is the radius, and the blue lines are the guitar body. So if you sanded the rims with the apex of the radius at the center point of the body, you get a 5/32" dip (this is on a 20" body length) and about a 1* taper. So I don't think you will have any problem setting the neck here.

_________________
My Facebook Guitar Page

"There's really no wrong way, as long as the results are what's desired." Charles Fox

"We have to constantly remind ourselves what we're doing....No Luthier is putting a man on the moon!" Harry Fleishman

"Generosity is always different in the eye of the person who didn't receive anything, but who wanted some." Waddy Thomson


Top
 Profile  
 
 Post subject:
PostPosted: Sun Mar 26, 2006 2:27 am 
Offline
Cocobolo
Cocobolo

Joined: Mon Jan 24, 2005 10:38 am
Posts: 133
I did exactly this same thing on my first guitar -- sanded the rims to a 25' radius then glued on the top. When the neck was set at the proper angle to the bridge, there is a considerable gap as Rod calculated and Rich's photo illustrates (I'm betting the neck set is fine).

If the fb is layed flat on the top and neck is set to match, the neck set will be too steep (Rod, I bet you can tell us how much too high) because a 25' radius yields too steep an angle.   

Having done this once, I now level the area above the soundhole flat (like Olson and others) to get the right angle before gluing on the top.

So this time, it would be easiest to follow John Hall's advice and make a wedge to fill the gap; I'd use wood that matches the fb.

Call it a design feature.



Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 55 posts ]  Go to page 1, 2, 3  Next

All times are UTC - 5 hours


Who is online

Users browsing this forum: No registered users and 19 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
Powered by phpBB® Forum Software © phpBB Group
phpBB customization services by 2by2host.com