Official Luthiers Forum!

I need the 'gangs' thoughts on harp guitars. I hear they're pretty tough/time consuming 'monsters'. I've seen postings where the builder says "I built one and that's it!"

So, what I'm looking for is the 'general' consensous, positive or negative, on building harp guitars. I like challenges and these seem awfully challenging but would like to know what y'all have to say about them too.

Thanks in advance!
Michael

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Michael Anthony

"Life's short. Play guitar!"

I'll let you know in a few months

I did build a harp ukulele, and it was a lot of fun. Definitely more to think about than a regular guitar, but the actual difficulty added depends largely on how you build your regular guitars. If you're big on moulds and jigs and dishes and power tooling batches of identical parts, then it'll probably be a lot more work than you're used to. But if you're more into freeform/lots of variety from instrument to instrument, then it's just moderately more work.

I'm just about finished with the design on mine, so I'll get a thread going in Doc-U-Build and post the plan for your perusal, hopefully tomorrow.

I have built two 20 string harp guitars and have obtained wood for 6 more. The first one I built was the hardest instrument I have ever built and I said....
NEVER AGAIN!!
Then I built another. I got interested in Harp guitars through my fascination with the HG's by Gibson. I think they are the most beautiful instruments on the planet. I bought and restored an extremely rare 1906 Gibson R. It took me 3 years.

This pic is a sample of the condition of the Gibson HG.



This is a pic of the finished Gibson and the first HG I built (I am keeping them)



This is HG number two (SOLD)



The most fun for me are the inlays





Michael

Beautiful guitars Michael. Question: When you build a harp guitar where the extension of the body for the bass harp strings joins the head of the neck for the six non-harp strings, how do you join the neck to the body? Off hand, I can't see any way of doing it other than integrating the neck to the body at the time the sides are built and I think that would be tricky for getting the perfect angle on the neck. Also, neck re-sets would be tough (impossible?). Am I missing something?

Pat

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There are three kinds of people:

Those that make things happen,
those that watch things happen,
and those that wondered what happened.

Hi,

I just finished my first harp guitar. Uh, the building was a big chalence, BUT I love it, it is so much fun to play it. I am SURE I will build some more;)
Go on and make yourself a dream harp guitar.

Link to my harp guitar pictures: http://fotoalbum.ee/photos/eestibloke/sets/1340250

Thanks,

Kristjan

I've built a couple of harp guitars. In both cases I worked on a solera, as it was the best way I could think of to keep the string alignments right. One of these days I'm going to build some more.

Anyone have any cad ( dwg/dxf.... vector) drawings of harp guitars - ukulele that they would be willing for us to use to make acrylic templates. ( I personally don't like all the designs.. so it would have to be something that appealed to me..... balanced, symmetrical to some extent)

We would gladly build a set of templates for whoever shared a set of drawings if these are the ones we decide to produce...... ( may have to do this from scratch...... ) We have had some request for both guitar and ukulele.

Blessings,

Kevin

Well, I got into guitar building to be able to own one. I will say they are very challenging to build. But when you love something, you don't care. I have built two. Several more are scheduled. If u are into a challenge, then this is for you. You can order the Dyer Harp plan set from Gregg Miner over at Harpguitars.net. Check out the many build logs.

Mike

Pat.. What you said is all correct. I use a bolt on tenonless neck to get all the angles right. Once everything is perfect, I bolt and glue the neck to the main body then glue the bass arm to the neck extension and finish gluing the partly attached bindings. I installed truss rods in the HGs but the neck is so firmly held in place that no neck reset will ever be necessary.







This is a Sullivan/Elliot style HG and the plans for it are also available from Gregg. If you go with bronze basses instead of the original Nylon basses (as I did) you will need to use a different bracing pattern. The altered bracing pattern takes me 20 hours to complete. You can find it in "American Lutherie Number" 99 (Fall 2009)

Alan... I enjoyed you talk during the Luthiers section at Harp Guitar Gathering #9 and your harp guitar is magnificent!

Mike O... I have followed your HG work and your purfling and other Dyer building tips will be very helpful to others making that style HG.

Kristjan... Your cutaway Dyer style looks beautiful. Really nice work!

Michael

Michael, your workmanship is stunning. I see you are using bone bridge pins to nut the bass strings. I've done that too, it's historically correct, but I'm not a fan. I'm looking at metal options. I want something stronger.

Mike

I just finished up the plan for mine:

Asymmetrical, yet balanced. Bridge is centered, unlike those Dyers where it's practically touching the perimeter. Not vector, but should be fairly easy to trace it if you like it. Although you'll have to do it yourself since I don't really want an acrylic template myself (paper takes less storage space). This has 7 bass strings which are fairly tightly spaced (so I can reach all 13 at once with my monster hands), but you could cut it to 6 strings like most harp guitars have and then they'd be spaced out more.

And here's the plan for my steel string harp ukulele too, although I ended up changing the headstock to get the tuners spaced out enough to use pegs, rather than my initial plan of Grovers.


Copy, modify, do whatever you want with 'em I'm not territorial on my designs... but do change the visual details like the headstock crest and logo inlay, so as not to be confusing.

Beautiful build and restoration Michael. I have a rough sketch that I would like to try after I get a few builds done.


Sent from right here.

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Stephen

There sure are a lot of Mike's around here! Lol!

Michael Anthony, I would be lying if I said you can do this with minimal frustration. Everything about a harp guitar will challenge you and your skills. Jigs, molds, etc. I actually built my first with a Jet 10-20 sander. (!!) It has lots of built in errors. I have one that Michael is referring to with regards to the purfling waiting to be fitted with a neck (it has few errors!!). All I can say is if you have the passion for it, ask lots of questions, view lots of build logs (not sure how many are here on OLF) over at harpguitars.net. There are a couple of guys here that post over there as well.

Mike

I think through building a harp a lot, and I always wonder how builders arrive at the correct top thickness and bracing. Of course there are plans available for some designs. But there are many variations in number of strings, and the way they are mounted over the top. The easy way would just be to overbuild. But I imagine some of the experts have some scheme to come up with a good sounding top thickness / bracing.

On my harp guitars I cheated: I did not have the usual top extension up the harp arm. That made the top into a 'normal' guitar top, more or less, and you can figure out the thickness and bracing for it in the normal way.

The first one, which I call a 'true' harp guitar, has the harp string pulling upward (or, in this case, downward) on their soundboard, which is perpendicular to the normal guitar soundboard. The harp strings run across the guitar top, being stopped at a bridge along the bottom edge of the lower bout, and the tuners are on a 'sponson' attached to the wide tail block. There is a post from the neck block to the tail block to support the tension of the harp strings, and the upper end of the harp soundboard is attached to the guitar headstock at the top. I know this is confusing, but there is a picture of the beast in the latest American Lutherie, and there was also a back page layout in 'Acoustic Guitar' a couple of years ago, and they will make it plain. On that guitar the soundboard only took the 'normal' guitar string load, and was simply designed and 'tuned' like a normal guitar.

My second one was a bit less unconventional, except for the fact that soundboard did not extend up the arm, as I said. In that case, the harp strings are attached at the guitar bridge in the normal manner, with their tuners at the top. Given the larger string load on the top I made it thicker than I would or a six-string guitar, and more like a 12-string. The bracing is also heavier. Ghe basic idea there is to use the 'cube rule'.

We like to make tops as thin as we can, so they'll be light enough to be easy to drive with the minimal horsepower of plucked strings. What sets the lower limit on the thickness is the stiffness of the top, which has to resist the torque of the bridge over the long term. That torque is a product of string tension and the height of the strings off the top at the saddle. Given the tension and height, it should be possible to calculate how thick you'll need to make the top.

If you assume that all of the top wood you use is 'the same', then all you need to do is keep track of the guitars that worked, and how thick you made the tops, and you can figure out how thick to go for something different, provided you don't change things like the outline or body length too much. You just use the 'cube rule', which says the the stiffness of the top varies as the cube of the thickness, and ditto for brace height. If you used a top that was .100" thick with braces .5" tall for a successful six string, and you're making a harp of the same basic size and shape from the same wood, then you just need to know the string tension. Suppose it's doubled: then the thickness for the harp top, and the bracing height, would be thicker by a factor of the cube root of 2, or 1.26. I know it doesn't seem like much, but it works.

This assumed that the wood was 'the same', which it never is. To be really sure you need to measure the 'Young's modulus' of the wood to correct for the differences. It's not all that hard, but I won't get into it now. You can also make use of an interesting property of soft woods, which is that the Young's modulus for bending along the grain is proportional to the density. Two pieces of softwood with the same density will have the same stiffness at a given thickness (within pretty close limits), no matter what species you use. Just keep track of the density, and use the cube rule to help you copy something that already worked.