Seeking some advise on Deb Suran's HD plans

[ken axe]

Hi this is my first post here. I have been wanting to build a Hammered dulcimer for a few years and now find that I have the time to not only build one, but learn how to play it. I have read the posts in the library and have decided to build an instrument according to Deb's plans (GAL #39), but will make it larger (15/14 or 17/18). I would like to ask Deb some questions but it appears that she is no longer posting here. Is there a way I can reach her?

[Jim McConkey]

Deb still stops in occasionally. Search for one of her posts and send her a private message. I will move this discussion shortly to Other Strings, where it will get more visibility.

[ken axe]

Thank you!

[Charlie Schultz]

Hi Ken,
You can look in our library here for posts from Dave Kern and Deb discussing the same kind of modification (it's about 1/4 way down the list).

http://www.mimf.com/old-lib/hamdul3.htm

[ken axe]

Thanks Charlie. I have read that post but was considering going in a slightly different direction and wanted to run it past her just to make sure I wasn't going to end up with a folding HD

[Nicholas Blanton]

You are wise, to ponder the possibility of, not so much a folding HD, but a non-functioning HD. Deb's plan had kind of short string lengths OK for a small instrument, but if you simply added courses to make it bigger, with more bass, keeping the angles of the box the same, you would have the lowest strings on the treble bridge too short. The rule for simple strings is that the length doubles with every octave, and that's why harps, pianos and harpsichords have a curve, because the string lengths increase quickly. A HD has straight sides, and so there is a compromise as to where to put the shorter strings, where to put the longer strings, where to change to copper alloys, where to go to wound strings.

If you want to save a bit of time, in experimenting, you can measure the string lengths of some 16/15 instruments you already like, and build your box around those lengths.

[ken axe]

Nicholas, thank you very much for chiming in on this tread. I am humbled that a builder of you reputation would take the time to help out a newbie like myself. I am primarily a guitar player so I have some understanding of how string length and strings gauge works. However, I have virtually no experience with the HD. Here in California even in the rich Folk/Irish/Celtic area of Sonora, there is no place to play any HD, let alone compare several. I have discovered a local HD player who plays in a Celtic band and will get the chance to meet her next weekend (God willing).

The reason I am considering a larger instrument is that I am worship leader and many of the songs we use are in D G and A. D and G are no problem with a standard 15/14, but that will only take me to A below Middle C and two octave range (with a bit of a jump to reach the top G#) in the Key of A. What I was considering is going to a 17/17 starting with A, E and B and ending with the C#, G#(for the key of A), D. Do you think this is good idea, or am I way over-thinking this?

BTW I will be taking Deb's plan and use the dimensions beginning with the D, G#, and C# courses and increase the dimensions on the big end as I go to the lower courses. I also realize that this may still require wound strings for a good tone (floppy strings sound...well floppy)

[Nicholas Blanton]

It likely won't work very well to simply extend the instrument, keeping the same angles, etc. because those treble strings will be too short. And you can't use wound strings on a treble bridge- they will sound funny, and the friction over the top of the bridge will make it very hard, even impossible, to keep both sides tuned, and one side or the other will soon get loose windings and start buzzing. You will need to go to brass or phosphor bronze wire. I don't have Deb's plan on file, but it was short-scaled enough that I think you could lengthen the bottom strings a little, use copper alloys for them, and you would not have to worry about the steel strings above suddenly being too long. How long is the E4 on the treble bridge in her plan?

I am not quite sure what you mean by "starting with A,E and B and ending with the C#, G# , D". A 15/14 will begin with a D#/G# course at the bottom of the treble bridge. The typical way to augment that is to add three courses below, C#/F#, B/E, and A#/D#. Some years back you would find a lot of experimentation with condensed tuning schemes, and one of them might be to replace those three with two, C#/F natural and A#/D#, since the B/E course and F# are duplicate notes found elsewhere on the instrument . Did you have something like this in mind?

[ken axe]

I see what you mean about wound strings but I have seen several makers who use them across the treble bridge. I have not yet purchased Deb's plans so I cannot tell you what the length of the E4 is in her plan.

What I had in mind was to extend the bass bridge from the D by adding C#, B, A and the treble from the D#/G# by adding C#/F#, B/E. That would give me a 17/17 with the same note pattern all the way through except for the upper G# for the A scale (which could be dealt with by offsetting the bridge on that course).

Are there plans out there you would recommend that would be better suited to this? I have no problem with drafting up changes, but I thought that Deb's plan had the basic structure to build a lighter, more resonant instrument.

[Nicholas Blanton]

The plans - and books- that I have seen so far have been for instruments of 15 courses or less. I think this is in part because the older instruments were small- when Deb and I started building people played 12/11"s, and Chet Parker, one of the old guys, had a one-bridge instrument of I think 10 courses. The other reason is that it's harder to work up a bigger instrument that works well all over.

I am pretty sure Deb's has a 1/4" unstressed softwood- I think cedar-soundboard. I would suggest you bump that up to 3/8", that will give you more mellow bass response and reduce the distortion of the top. Don't make the rails thicker, instead making the whole instrument a little deeper- even 1/8"- will make it stronger, too, and that's a good thing, with an unstressed soundboard. Look at some other 18 courses instruments that seem to work for you- maybe Dusty Strings'- and use their string lengths as a guide. And you might go ahead and build two instrument boxes, leave the soundboard off one, finish the other, and if it does wacky stuff, incorporate what you have learned into the second one...and stuff the first into the woodstove on a cold night. Naturally, don't use precious tropical woods, even if they'll burn longer...

[ken axe]

Nicholas, I discovered your website and found the tuning chart for you Extended Range.

What I had in mind was taking out the highest courses of both bridges and the lowest course on the treble bridge as well as eliminating the extra bridges. that would leave me with a 17/17 tuned like this.
D6 - G#5 C#5
*C6 - F5 Bb4*
B5 - E5 A4
A5 - D5 G4
*G5 - C5 F4*
F#5 - B4 E4
E5 - A4 D4
*D5 - G4 C4*
C#5 - F#4 B3
B4 - E4 A3
*A4 - D4 G3*
G#4 - C#4 F#3
F#4 - B3 E3
*E4 - A3 D3*
D#4 - G#3 C#3
C#4 - F#3 B2
*B3 - E3 A2*

(this doesn't render well on the forum but hopefully you will get it)

If you are using Rizzetta's model (which I assume you are) that would mean that you are using a .025 PB string of about 44" across the treble (B3/E3) bridge and a .032 wound string of around 36" for the A2. Does that sound about right?

Deb's plans are for a stressed soundboard of 1/4" cedar with a 1/4 plywood back. I was thinking of going with 1/4" ply (High quality Baltic birch) front and back and going 1/2" deeper for strength and better bottom end tone. I recognize that this will not produce a light weight instrument but to be honest it can't weigh that much more than my twin-neck acoustic (and I won't have to hold it with a neck strap while playing).

The only thing I am not real sure on is using the ply top. I am really wishing I had not sold the thickness sander I built with the lathe when I moved a while back. If I can find someone who can get that done for me here I will use Cedar or redwood for the top.

Am I missing anything obvious here?

[Nicholas Blanton]

Sorry to have not come back to this sooner.
Yes, the total length of the B3/E3 course is about 44", but the A2 is shortened a bit from the Rizzetta scaling, to 30", using a .042" wound string with a .018" core. As you may have noticed, you have quite a lot of flexibility with wound strings, since you can change core and windings to get something that will stay in tune at a lot of different lengths.

1/2" more depth would give you quite a bit more rigidity to the frame. You could do the back from Birch ply, but 3/8" would be better than 1/4". For the top, you really should try to get something a bit better than 1/4" birch ply. It will tend to distort under the compression load of the strings unless very thoroughly braced, and when that thoroughly braced it won't sound very good. Even thoroughly-dried tulip poplar would work better. But cedar would be best. And really, you should not need a thickness sander to deal with cedar, the stuff practically planes itself, with a good sharp handplane.

.

[ken axe]

Thanks Nicholas, I purchased the plans from GAL and have the coin to purchase the wood (though I may have to wait a bit to get the hardware). The building will begin as soon as I get my shop moved into the new place (couple of weeks). I'll let you know if I have more questions, and post my progress here.

[ken axe]

Well it took longer than I thought it would to get all the pieces together to start this but I got it done. You can see the build thread here.