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A new member introduction, saddle height question
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=47800		 Page 1 of 1
Author:  Jason King [ Fri May 20, 2016 9:04 pm ]
Post subject:  A new member introduction, saddle height question
Boy am I glad I found this place. Its a wealth of information! If only I'd found the forum a bit sooner.

I just finished my first guitar build. It's a maple and mesquite classical guitar with a douglas fir top. Not exactly the most orthodox woods, but it's what they had at the lumber yard for me to play around with. I figured I should stay away from the African Blackwood until I had a few guitars under my belt.

Here's a (not very good) photo:
Image

I'm wonderfully happy with the way she looks and sounds. Being a first guitar, there are about 300 mistakes here and there, but most folks don't notice them if I don't point them out.

On to the problem. I used a bolt on neck design loosely based on the Cumpiano book and made the mistake of setting the neck angle as if it were a steel string guitar. In retrospect this was an obvious no no, but hey, it's my first guitar. Suffice it to say that the neck angle is off a bit, and I need a very tall saddle height to fix things.

The picture above shows the first saddle, which was too low. I put a new saddle in to get the string action up to about 3mm at the 12th fret (for all strings). Sadly, in order to get up to 3mm at the 12th fret, my saddle sits about 17mm above the soundboard. It's high. It looks high, and it feels high.

All that said, since its my first guitar I expect little things like this. I overbuilt the top (because I was afraid to get too thin). So the top is about .09" at the edges, but bulges to about .12-.13 in the center. the bracing is a classical fan, but I didn't scallop the braces, they're still full height from Cumpiano's book.

So now for the question. Can I leave it like this without the top exploding on me in a couple weeks? The taller saddle sounds MUCH better than the lower saddle, not just a lack of buzzing, but the guitar is much louder and the high notes actually come out. I'm clearly no expert, but the high saddle has really opened up the sound. With the low saddle the whole thing sounded muffled. I don't mind an awkward looking high saddle for my first guitar, especially since it sounds so darn good. But I don't want to hurt my baby after I spent so much time on her.

I know the "right" thing to do is a neck reset, but again, if I'm not hurting anything I really like how she sounds.

Any thoughts are always appreciated. I'm happy to provide more pictures if needed. Thanks in advance.
Author:  WaddyThomson [ Fri May 20, 2016 9:51 pm ]
Post subject:  Re: A new member introduction, saddle height question
Your guitar looks great. I don't think you are going to have an explosion, but, as you know, the saddle is about 5 to 6 mm higher than it should be. The worst that might happen is the bridge might come loose from the excessive tipping force on the saddle. The thickness of the top and the full height braces will, most likely, keep the top from deforming too much. Play it till the bridge comes off, if it does. Build another, and work on your neck angle. Do you know what angle you used?
Author:  Jason King [ Fri May 20, 2016 10:30 pm ]
Post subject:  Re: A new member introduction, saddle height question
Thanks Waddy, that's good to know and good to hear.

Odd as it may seem, I don't know what my neck angle is. It started out at 90 degrees, and when I test fit the neck to the body, I used a straight edge on the fretboard (with frets installed) and the straight edge extended straight into the soundboard.

Using Cumpiano's method (which I'm sure is fairly standard for steel strings) I shaved the joint until the straight edge extended out 3/8" of an inch above the soundboard at the location where the saddle was.

This probably would have worked just fine for a steel string, but 3/8" is the height of my classical bridge. Once we get strings up to 3mm above the 12th fret, we're 6mm above the 3/8ths bridge. 3/8ths is just about 10 mm, so once we add the bridge height into the equation, 16-17 mm makes a lot of sense. I just wish I'd done the math earlier in the process.

Ah well, live and learn.

Thanks again.
Author:  WaddyThomson [ Fri May 20, 2016 11:10 pm ]
Post subject:  Re: A new member introduction, saddle height question
On a classical, the neck angle is the opposite of a steel string. Steel string has back angle on the neck, a classical has forward angle on the neck. You must have missed something in Coumpiano, as I'm sure he explained that somewhere. I didn't like his book, but I did read it twice. Very difficult to weed out the classical vs steel string details. Best Classical build book for general knowledge of classical construction, in my opinion, is "Making Master Guitars" by Roy Courtnall. Expensive, but a good book with some real plans in it. Undersized plans, but useable. Your mistake is probably not uncommon for first timers.
Author:  DennisK [ Sat May 21, 2016 12:13 am ]
Post subject:  Re: A new member introduction, saddle height question
At that soundboard thickness, I think the high saddle is a good thing. As long as the front edge of the saddle slot doesn't break off and the bridge stays glued, it should be fine.
Author:  Alan Carruth [ Sat May 21, 2016 7:42 am ]
Post subject:  Re: A new member introduction, saddle height question
Trevor Gore mentions that he gets good sound with no structural problems when the bridge rotates forward about two degrees under string tension. This depends on a bunch of things, with top thickness and bracing, string tension, and string height off the top being the main ones (along with the usual stuff, like the phase of the moon and the stock market...). Of course, with that sort of saddle height you do have a large torque load on the back edge of the bridge, and will need to keep an eye on it. Doug fir tends to be dense, and accordingly stiff along the grain, so you are probably not in trouble there. My experience with it suggests that it has low splitting resistance, and if the bridge starts to lift it could pull fibers from the top, or worse if the wood has any runout. The tall saddle probably also gives a high break angle, which raises the tipping force on the saddle, and could split out the front of the bridge. Angling the saddle back helps a lot with that, but it's probably late to correct that now. If you do need to replace the bridge at some point you could look to that, and use a wider (deeper along the line of pull) one to reduce the peeling stress at the back edge.
Author:  David Newton [ Sat May 21, 2016 8:30 am ]
Post subject:  Re: A new member introduction, saddle height question
As most have mentioned, it probably won't explode, just looks & feels funny when playing.
You said it is a bolt-on neck, why not reset the neck and remove & replace the bridge?
But go ahead and start another guitar.
Author:  david farmer [ Sat May 21, 2016 8:32 am ]
Post subject:  Re: A new member introduction, saddle height question
Welcome Jason.
I just wanted to second Waddy's book recommendation. If your going to keep building classical. " Making Master Guitars" I found beautifully straight forward and clear when I started. It also offers a useful overview of many of the great builders. My copy looks like I've had it in my back pocket all these 15+ years. Still useful to this day.
Author:  Wayne Brown [ Sat May 21, 2016 12:24 pm ]
Post subject:  Re: A new member introduction, saddle height question
+1 also on Waddy's book recommendation of "Making Master Guitars! Very helpful.
Author:  Clay S. [ Sat May 21, 2016 2:33 pm ]
Post subject:  Re: A new member introduction, saddle height question
For some reason the photo doesn't show up - only a circle with a minus sign in it.
Since it is your first you could play it until you complete your second, and then decide whether to redo it or not. If you decide to reset the neck and make a new bridge, then you might want to thin the soundboard some also. But for now enjoy your first.
Author:  Jason King [ Sat May 21, 2016 3:30 pm ]
Post subject:  Re: A new member introduction, saddle height question
Thanks everyone, I'll definitely check out the book recommendation. I'll keep the guitar as is for now, and maybe revisit the issue after my next guitar.
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