Small (very) acoustic archtop design questions
-
- Posts: 6
- Joined: Wed Nov 27, 2019 4:11 pm
- Location: Ucluelet, BC
Small (very) acoustic archtop design questions
Hello!
I'm embarking on building myself a small acoustic archtop guitar, out of necessity.
I was an avid guitar player until about 5 years ago, when I had major reconstructive surgery on my right shoulder.
Since then I haven't been able to play guitar for more than a few minutes without causing days of pain.
I play a lot of clawhammer banjo though, using 11" and 12" pots (noting that the 11" feel more comfortable), tucked under my right arm, with the neck extending out from (not across) my body.
I've been playing a bit more guitar lately, having found that my 16" lower bout 3" depth (at the tail, not counting the top/bottom plates) archtop guitar is slightly more comfortable than my various flattops.
So my big idea is to try to build a 13.5" bout archtop (ala Gibson L1), trying to keep it as thin as possible (even thinner than 3" if possible) while also maintaining an interesting, big sound.
This is probably impossible, but I'd like to try as I'm running out of other options and thinner electrified instruments don't work for our genre of music.
Does anyone have any ideas/suggestions how to proceed?
I've selected some nice flamed maple for the back, and a sitka spruce top.
I've been thinking about building a guitar who's depth tapers from the tail (shallower -- 2") to the neck (deeper, 4"). I've never seen this before, but I am curious if it might work, given that most flattops are built with the opposite taper. Is this a terrible idea?
I'm also considering building the vertical wedge in it (manzer style), although I think the tail->neck taper is more what I need for comfort.
Sorry for the long-winded post, and thanks in advance
I'm embarking on building myself a small acoustic archtop guitar, out of necessity.
I was an avid guitar player until about 5 years ago, when I had major reconstructive surgery on my right shoulder.
Since then I haven't been able to play guitar for more than a few minutes without causing days of pain.
I play a lot of clawhammer banjo though, using 11" and 12" pots (noting that the 11" feel more comfortable), tucked under my right arm, with the neck extending out from (not across) my body.
I've been playing a bit more guitar lately, having found that my 16" lower bout 3" depth (at the tail, not counting the top/bottom plates) archtop guitar is slightly more comfortable than my various flattops.
So my big idea is to try to build a 13.5" bout archtop (ala Gibson L1), trying to keep it as thin as possible (even thinner than 3" if possible) while also maintaining an interesting, big sound.
This is probably impossible, but I'd like to try as I'm running out of other options and thinner electrified instruments don't work for our genre of music.
Does anyone have any ideas/suggestions how to proceed?
I've selected some nice flamed maple for the back, and a sitka spruce top.
I've been thinking about building a guitar who's depth tapers from the tail (shallower -- 2") to the neck (deeper, 4"). I've never seen this before, but I am curious if it might work, given that most flattops are built with the opposite taper. Is this a terrible idea?
I'm also considering building the vertical wedge in it (manzer style), although I think the tail->neck taper is more what I need for comfort.
Sorry for the long-winded post, and thanks in advance
-
- Posts: 236
- Joined: Wed Feb 08, 2012 8:12 pm
- Location: Murphy NC
- Contact:
Re: Small (very) acoustic archtop design questions
My GOM plan is essentially a 14.5" wide and 2.5" side depth archtop guitar. I built to a 23.5" scale length. So far I have completed two octave mandolins (8 strings, 4 courses) and one guitar. The guitar uses the 23.5" scale length and a standard 1.680" nut width. Has a great sound and plenty of volume even with the smaller size.
The plan is available on MIMF with the proceeds benefiting the site, so no financial interest for me. Hope this gives you some ideas.
The plan is available on MIMF with the proceeds benefiting the site, so no financial interest for me. Hope this gives you some ideas.
- Barry Daniels
- Posts: 3191
- Joined: Thu Jan 05, 2012 10:58 am
- Location: The Woodlands, Texas
Re: Small (very) acoustic archtop design questions
I wouldn't be so quick to dismiss the Manzer wedge. It was designed to address the issue you described. And it does not reduce the interior volume of the body, which can't be said for your initial solution.
MIMF Staff
-
- Posts: 169
- Joined: Tue May 21, 2019 8:58 pm
- Location: SW Oregon
Re: Small (very) acoustic archtop design questions
Art Overholtzer, in his book on classical guitar making from the 1960’s, states that he built his guitars with a reverse taper as you describe (though the dimensions differ). As I recall, he was after a megaphone effect; didn't credit himself with this innovation, but said other makers were doing this also.james inkster wrote:
I've been thinking about building a guitar who's depth tapers from the tail (shallower -- 2") to the neck (deeper, 4"). I've never seen this before, but I am curious if it might work, given that most flattops are built with the opposite taper. Is this a terrible idea?
I have two guitars on the bench now that incorporate the feature. For now I'm going with it not being a terrible idea.
My experience after 26 acoustic guitars is that I like the overall sound of a thinner body. And, of course the ergonomics.
-
- Posts: 1266
- Joined: Sun Jan 15, 2012 1:11 pm
Re: Small (very) acoustic archtop design questions
The 'Manzer' wedge (actually patented by Smith) is probably just what you need. 1" of sideways taper (make the treble side 1/2" deeper and the bass side 1/2" shallower), is the equivalent of reducing the width of the lower bout by 1", more or less. It's easy to do, too.
My most recent archtop was based reasonably closely on a Gibson Lloyd Loar from the 20s, and was intended for acoustic use. It seems to have been successful; at leas the customer likes it. I used the 'full' style of arch that Gibson uses, although not as extreme, and 'parallel' bracing rather than the X that I have been using. The F-holes are also quite narrow, which helps keep the 'main air' resonant pitch down ti a more 'normal' guitar like range. It is 17" across the lower bout, and you'll want to go smaller, but I'd stick with those main lines of features.
You may also want to reduce the thickness of the plates from the usual, to drop the resonant pitches somewhat. If you do, use a lower arch height in proportion: too high makes the sound 'harsh' with light graduations. I've made two arch top classical guitars, on a 16" platform, with tops that were 'reverse graduated': 3mm thick over all with a thinner area down the center line in the middle. I used a 15 mm arch height as measured off the table: 12 mm up from the low point at the edges, and 'curtate cycloid' cross arches. There has been no problem with the top sinking under string load, ; just juggle your neck overstand and bridge height to get the break angle down to a minimum of about 6 degrees.
My most recent archtop was based reasonably closely on a Gibson Lloyd Loar from the 20s, and was intended for acoustic use. It seems to have been successful; at leas the customer likes it. I used the 'full' style of arch that Gibson uses, although not as extreme, and 'parallel' bracing rather than the X that I have been using. The F-holes are also quite narrow, which helps keep the 'main air' resonant pitch down ti a more 'normal' guitar like range. It is 17" across the lower bout, and you'll want to go smaller, but I'd stick with those main lines of features.
You may also want to reduce the thickness of the plates from the usual, to drop the resonant pitches somewhat. If you do, use a lower arch height in proportion: too high makes the sound 'harsh' with light graduations. I've made two arch top classical guitars, on a 16" platform, with tops that were 'reverse graduated': 3mm thick over all with a thinner area down the center line in the middle. I used a 15 mm arch height as measured off the table: 12 mm up from the low point at the edges, and 'curtate cycloid' cross arches. There has been no problem with the top sinking under string load, ; just juggle your neck overstand and bridge height to get the break angle down to a minimum of about 6 degrees.
-
- Posts: 6
- Joined: Wed Nov 27, 2019 4:11 pm
- Location: Ucluelet, BC
Re: Small (very) acoustic archtop design questions
Wow, thanks for all the great replies.
I will definitely not discount the wedge, as I know it was designed for shoulder issues (though not necessarily the same shoulder issues..). I had previously done some tests trying to emulate how the wedge would feel using my flattops and it didn't seem to help much.
The key for me seems to be a shall tail.
However, that's also the reason I'm lately drawn to the archtop -- the tail is naturally shallower, building up to the arch, which i find quite comfortable.
I'm sure I'll have many more questions, thanks for the help.
I will definitely not discount the wedge, as I know it was designed for shoulder issues (though not necessarily the same shoulder issues..). I had previously done some tests trying to emulate how the wedge would feel using my flattops and it didn't seem to help much.
The key for me seems to be a shall tail.
However, that's also the reason I'm lately drawn to the archtop -- the tail is naturally shallower, building up to the arch, which i find quite comfortable.
I'm sure I'll have many more questions, thanks for the help.
-
- Posts: 6
- Joined: Wed Nov 27, 2019 4:11 pm
- Location: Ucluelet, BC
Re: Small (very) acoustic archtop design questions
Hi Mike, where on the site do I find your plans?Mike Conner wrote:My GOM plan is essentially a 14.5" wide and 2.5" side depth archtop guitar. I built to a 23.5" scale length. So far I have completed two octave mandolins (8 strings, 4 courses) and one guitar. The guitar uses the 23.5" scale length and a standard 1.680" nut width. Has a great sound and plenty of volume even with the smaller size.
The plan is available on MIMF with the proceeds benefiting the site, so no financial interest for me. Hope this gives you some ideas.
- Barry Daniels
- Posts: 3191
- Joined: Thu Jan 05, 2012 10:58 am
- Location: The Woodlands, Texas
Re: Small (very) acoustic archtop design questions
Just remember that even though the archtop tail is rather thin, the distance from the high points on the top and the back is not any thinner than a dreadnaught due to the arched plates.
MIMF Staff
-
- Posts: 6
- Joined: Wed Nov 27, 2019 4:11 pm
- Location: Ucluelet, BC
Re: Small (very) acoustic archtop design questions
Yup, for sure.Barry Daniels wrote:Just remember that even though the archtop tail is rather thin, the distance from the high points on the top and the back is not any thinner than a dreadnaught due to the arched plates.
But to get my point, grab an archtop guitar with a ~3" tail height and place your hand at the bridge. Take a look at the angle of your shoulder.
Do likewise with a dreadnaught (4"+).
For me, although neither feels wonderful, that extra angle makes a world of difference on my shoulder...
- Barry Daniels
- Posts: 3191
- Joined: Thu Jan 05, 2012 10:58 am
- Location: The Woodlands, Texas
Re: Small (very) acoustic archtop design questions
An archtop has a 3" tail but the back and top arches add another inch and one half for a total of 4-1/2" and the bridge adds another 3/4". But I am not trying to be argumentative. If the thin archtop works for you then go for it.
MIMF Staff
-
- Posts: 6
- Joined: Wed Nov 27, 2019 4:11 pm
- Location: Ucluelet, BC
Re: Small (very) acoustic archtop design questions
Yes, I really do understand that (I have an archtop guitar ) and I can assure you that the one hurts much more for me than the other.Barry Daniels wrote:An archtop has a 3" tail but the back and top arches add another inch and one half for a total of 4-1/2" and the bridge adds another 3/4". But I am not trying to be argumentative. If the thin archtop works for you then go for it.
Did you try draping your arm over a dreadnaught and then over an archtop to see the difference in arm angle?
- Barry Daniels
- Posts: 3191
- Joined: Thu Jan 05, 2012 10:58 am
- Location: The Woodlands, Texas
Re: Small (very) acoustic archtop design questions
Yeah, you are probably right. The arm contacts the edge of the guitar and an archtop definitely has a lower edge. Sorry. I wasn't looking at it that way.
MIMF Staff
-
- Posts: 236
- Joined: Wed Feb 08, 2012 8:12 pm
- Location: Murphy NC
- Contact:
Re: Small (very) acoustic archtop design questions
James: The link is available at a couple of places from the Board Index. The plans are here:james inkster wrote:Hi Mike, where on the site do I find your plans?Mike Conner wrote:My GOM plan is essentially a 14.5" wide and 2.5" side depth archtop guitar. I built to a 23.5" scale length. So far I have completed two octave mandolins (8 strings, 4 courses) and one guitar. The guitar uses the 23.5" scale length and a standard 1.680" nut width. Has a great sound and plenty of volume even with the smaller size.
The plan is available on MIMF with the proceeds benefiting the site, so no financial interest for me. Hope this gives you some ideas.
https://www.mimf.com//phpbb/viewtopic.php?f=15&t=1465
I also have posted a Archtop Build Journal on MIMF, found under the Detailed Builds/Tutorials section, here:
https://www.mimf.com//phpbb/viewtopic.php?f=59&t=4668
Hoping you will share your build process details with curious folks like me!
-
- Posts: 1266
- Joined: Sun Jan 15, 2012 1:11 pm
Re: Small (very) acoustic archtop design questions
The arm angle is the whole point about the wedge, of course. The depth of the box along the center line is the same as always, and so is the box volume, it's just easier to reach around it.
-
- Posts: 180
- Joined: Mon Dec 18, 2017 3:08 pm
Re: Small (very) acoustic archtop design questions
I made this parlor-size acoustic archtop. Lower bout is 13.75." Side depth is standard 3". It has a cedar top and sapelle back & sides. The top has a relatively low arch (about 5/8" from bottom to top), and I used parallel bracing. It's quite loud and has a nice snappy sound. It would work fine for acoustic music jamming. So I think what you have in mind is definitely workable.
-
- Posts: 6
- Joined: Wed Nov 27, 2019 4:11 pm
- Location: Ucluelet, BC
Re: Small (very) acoustic archtop design questions
Great, thanks again for all the feedback folks.
I'm sure I'll have lots more questions soon
I'm sure I'll have lots more questions soon