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PostPosted: Sun Mar 26, 2006 3:37 am 
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Koa
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By the way I really like your end graft. I might just steal that for one of mine.

Al


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PostPosted: Sun Mar 26, 2006 6:46 am 
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Koa
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Thanks so much guys for all the help and advise. I will take some additional photos tonight and post but I am on the road all next weeks so I will have to put it aside for now. Probably better off to get away from it for awhile anyway and think it through.

When I lay the straightedge across the neck (without the fretboard) it lands a little high off the soundboard but part of this is due to the way it is hitting the soundboard near the front of the soundhole. Now my instinct tells me if I shave the neck toward the fretboard I will close the angle, making the straight edge touch the soundboard at the bridge area - but that will only worsen the gap at the body between the neck and the fretboard. That is what is confusing me.

Either way, I am thinking I need to get the neck right first and then deal with the fingerboard, and gap.

Hesh, that pic of the neck design that extends over the soundboard was one consideration. Appreciate you finding that. I was actually thinking of building a neck using that approach. Might be the way to go but will try working through with this one first.

I am still not sure how I ended up this way. I have always used a radius dish to sand the rim and never any real problem. On my last build (prior to this one) I reversed the dish and sanded a reverse dip at the neck area. Found this approach on one of the OLF discussions and it worked out good. When doing this one, one of the brain cells must have gone bad and I forgot to do it again.

Also wondering if maybe I grabbed the wrong dish and used the 15' radius dish used for my backs. Don't think so but how else could I have this issue after building 20 some guitars to this point.

In any case, you guys have given me some real encouragement because the other night I was ready to make a clock out of this build and hang it on the wall of shame!!

OK, back to work around the house - will post some additional pictures tonight.

Thanks again to all.





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PostPosted: Sun Mar 26, 2006 7:30 am 
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Koa
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OK, here are some more pics and description of issue at hand:



The above picture shows angle where straight edge is resting on soundboard



In the above shot, the straight edge is resting on neck. You can see that the soundhole area is actually distorting the actual angle. If the soundhole were flat, the straight edge would be closer to the soundboard where the bridge is located.



Above: this is a view with the bridge in place and the straight edge resting on top of the bridge



Another shot of the neck bolted on and flush with the soundboard. Straight edge resting on the soundboard near the bridge area.

Now as I said before, it looks like I have to raise the headstock or front of the neck by shaving the top of the heal closest to the soundboard which will improve the neck angle but worsen the gap in the fretboard.

Also, I clamped the fretboard alone to the top and run the stright edge from the bridge across the fret board and this confirms a pretty good gap between the front of the body and the fretboard, but also then a gap between the fretboard and the neck.

Hope this helps clarify.


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PostPosted: Sun Mar 26, 2006 9:47 am 
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Wow, Rich, something does seem odd here. If you've done 20 guitars, you have more experience than me and Hesh put together.

Thanks for the complements Hesh. I always lay out my builds in Autocad (I have a very funny story to tell about this some othertime). To me, it helps eliminate the posiblilty of problems. But this works for me, and maybe not for everyone else.

Here's a little reminder tutorial for those that may find it usefull.

So, I will draw out the front and tail edge of the body, than draw a straight line between them.



Next I draw in the 25' radius (I don't use this buy there are many that do so I will encorporate it)



Notice that it is at the very center of the body and that the gap between the "flat" line of the top and the curve is 5/32" which is greater than Rich's 1/8"+/- gap.

So now we take the neck layout. The red line represents our 25.4 scale at the top of the frets.



And we lay it out on the body which is sanded to 25' radius.



And of course we have our gap just like Rich's



Now we set the neck by shaving the heel.



And here is the angle we need to trim off the heal (Look familiar anyone)



Now here is the height at the bridge that we are looking for, maybe even a bit low (by about 1/32")



So this shows why 25' radius has been used to set the neck for a 3/8" bridge height.

Hope this helps someone, it helped me remember just by doing this.

Cheers All.

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PostPosted: Sun Mar 26, 2006 10:50 am 
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Koa
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You da man Rod. You must be an engineer??? I see your point and understand it. In this case, if I shave the base are of the heel I think my height off the soundboard will be much higher than the bridge. Also seems like I will get a significant slope on the fret board from the 14th fret to the end of the board with as much as I would have to remove. Let's see what the others think as well. I am going to print your cad drawings and keep them for future reference. Excellent!!

Thanks so much


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PostPosted: Sun Mar 26, 2006 11:19 am 
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You could shim the underside of the f/b as has been mentioned and then add 1/16" to the bottom of your bridge...

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PostPosted: Sun Mar 26, 2006 3:27 pm 
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Brazilian Rosewood
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Wow, thank you Rod and Hesh, this thread was so great, i saved everything! That was Hard Rock Lutherie! You guys speak a language i really understand!

Good luck in fixing this Rich, now you got all the input you need!


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PostPosted: Sun Mar 26, 2006 4:27 pm 
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Hesh, that is a very cool looking bridge you have on that guitar.



Do you have any more pics of it?

Oh is that a 14-1/2 fret joint you got going there? Starting something new eh?

Rod True38803.0677893519

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PostPosted: Sun Mar 26, 2006 4:43 pm 
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Well Rich, the only thing else I can think of is a humidity issue there.

You may have to go with the wedge design to get over that hump at the top of the soundhole. But what will happen with the gap between the fret board and the neck?

Keep us posted.Rod True38803.0772106481

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PostPosted: Sun Mar 26, 2006 5:06 pm 
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[QUOTE=rich altieri]


In the above shot, the straight edge is resting on neck. You can see that the soundhole area is actually distorting the actual angle. If the soundhole were flat, the straight edge would be closer to the soundboard where the bridge is located.[/QUOTE]

So there is a gap between the straight edge and the neck and soundboard here yes?

[QUOTE=Rich Altieri]

Above: this is a view with the bridge in place and the straight edge resting on top of the bridge



Another shot of the neck bolted on and flush with the soundboard. Straight edge resting on the soundboard near the bridge area.

Now as I said before, it looks like I have to raise the headstock or front of the neck by shaving the top of the heal closest to the soundboard which will improve the neck angle but worsen the gap in the fretboard.[/QUOTE]

So if you did this, would you have to push the neck up (ie: drill new bolt holes in the head block) than add the wedge under the fretboard? That seems like the way to go.

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PostPosted: Sun Mar 26, 2006 8:10 pm 
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Koa
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Think I would have a combination. First, get the neck angle right and then taper the fretboatd to match. My current thinking. Off for Toronoto on business and looking fwd to next weekend to get this resolved.

In the mean time, thanks to all for your feedback and advise


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PostPosted: Sun Mar 26, 2006 9:52 pm 
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Brazilian Rosewood
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If you were not that shy Hesh, i'd say start a new thread and show pics and specs of every build you did, so far they all look amazing to me. Perhaps it'd be nice to have a library of builds from our members !


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PostPosted: Sun Mar 26, 2006 10:59 pm 
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Rod's wonderful CAD drawing confirms mathematically what I have been doing now for years - I use a 28 foot bowl, radius the upper transverse brace and block, then set the neck so that the FB lies flat on the top (after flattening the top area under the FB slightly - it doesnt take much at all witha 28 ft radius). The results of this now allows for a 5/16 bridge height, a decent ammount of saddle showing (about 1/8 inch) to get excellent action (5 to 5.5 64ths high to low).

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PostPosted: Mon Mar 27, 2006 12:05 am 
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Well, for those who haven't seen it...this is my first guitar...I built freehand, without a mold or anything to keep it straight...looks okay to me tho...


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PostPosted: Mon Mar 27, 2006 12:26 am 
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Nice bearclaw there Larry.

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PostPosted: Mon Mar 27, 2006 12:28 am 
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Brazilian Rosewood
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Larry, we want specs please, must have some twisted sound!


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PostPosted: Mon Mar 27, 2006 12:33 am 
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THis is why I end the dome at the start of the upper bout. In other words after the waist and straight tangent leading to the upper bout I sand the rim flat. and the upper transvers brace and transverse gtaft are flat bottom not radiused. I still have to prperly fit the neck for correct back angle.

Cheer up though after the fix all will be good as gold


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PostPosted: Mon Mar 27, 2006 12:34 am 
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Koa
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Rich,
   Even with a radical neck angle cut into the heel cheeks to allow the fingerboard tongue to lay on that top surface, your approach would be completely off at the bridge ebing much higher than is necessary or possible to use. It's clearly obvious by the photos that your top kerfing is cut to a much smaller radius than it should be. With the typical 25 foot radius, your drop at that end would be closer to 1/32" or even 1/16" at an extreme.

    It's more of a body problem than a neck problem. The angle of the intersection between the the top and the sides where the neck meetsthe body is just as important to maintain as the actual neck angle. I've seen alot of folks lay a straight edge on the surface of the top where the fingerboard tongue will be glued or bolted down to measure the approach of the surface and to be sure that they have about 1/16" clearance between the straight edge and the top where the bridge will be. That's only part of what needs to be built into the guitar and monitored during construction and especially during the sanding of the rim to the appropriate radius for the top to be installed onto.

   If your pressure applied in the sanding dish favors the neck or the butt end of the body while taking off material, you will be affecting the final structure and the angles at which the top will intersect the sids at both ends. I'm building a fixture now that will lower the rim into my sanding dish aty a controlled rate and at consistent and predetermined angles that will be adjustable. It will resemble that rim sanding machine that Martin uses in some ways, but will have some unique features that will be proprietary to my piece.

   I hadn't read all posts in this thread so if I've repeated some of the comments made by others, I apologize.

I hope it works out for you,
Kevin Gallagher/Omega Guitars


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PostPosted: Mon Mar 27, 2006 1:44 am 
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Koa
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[QUOTE=L. Presnall] Well, for those who haven't seen it...this is my first guitar...I built freehand, without a mold or anything to keep it straight...looks okay to me tho...

[/QUOTE]

That's a riot - exactly what I am fearful of with this build. Hope it doesnt come out this way. Great sense of humor!!!!


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PostPosted: Mon Mar 27, 2006 1:48 am 
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Koa
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[QUOTE=Kevin Gallagher] Rich,
   Even with a radical neck angle cut into the heel cheeks to allow the fingerboard tongue to lay on that top surface, your approach would be completely off at the bridge ebing much higher than is necessary or possible to use. It's clearly obvious by the photos that your top kerfing is cut to a much smaller radius than it should be. With the typical 25 foot radius, your drop at that end would be closer to 1/32" or even 1/16" at an extreme.

    It's more of a body problem than a neck problem. The angle of the intersection between the the top and the sides where the neck meetsthe body is just as important to maintain as the actual neck angle. I've seen alot of folks lay a straight edge on the surface of the top where the fingerboard tongue will be glued or bolted down to measure the approach of the surface and to be sure that they have about 1/16" clearance between the straight edge and the top where the bridge will be. That's only part of what needs to be built into the guitar and monitored during construction and especially during the sanding of the rim to the appropriate radius for the top to be installed onto.

   If your pressure applied in the sanding dish favors the neck or the butt end of the body while taking off material, you will be affecting the final structure and the angles at which the top will intersect the sids at both ends. I'm building a fixture now that will lower the rim into my sanding dish aty a controlled rate and at consistent and predetermined angles that will be adjustable. It will resemble that rim sanding machine that Martin uses in some ways, but will have some unique features that will be proprietary to my piece.

   I hadn't read all posts in this thread so if I've repeated some of the comments made by others, I apologize.

I hope it works out for you,
Kevin Gallagher/Omega Guitars[/QUOTE]


That's exactly what I think happened. You are right on. Would you redo the soundboard if you were me or would you try and adjust the neck?? Based on your feedback, I am thinking I might just cut my losses and try to remove the soundboard and then redo the rim. Of course I will probably destroy the soundboard in the process so thinking I might make a nice clock from this one (just joking)


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PostPosted: Mon Mar 27, 2006 1:51 am 
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If you do decide to pull the top Rich, you could always save it for a smaller body guitar like a 000.

All is never lost.

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