DIY Musical Instruments

Awesome! Show us some pictures! I've been in the early design stages of experimenting with a lightweight thumb piano using street sweeper bristles as the tines.

I just completed my first G Strumstick of hard Maple. 11.3 oz wood only, with about 3 oz in the metal pegs. I have 5 more in production. I am looking at wooden violin tuning pegs to reduce that weight and cost, but have just started considering options for reducing the body weight. Using a 24" scale length, my instrument is 31" overall, so I would also like to get it shorter. I love their simplicity, and how they sound with a harmonica.

Bert

You asked so here they are:

Wow Peter, you weren't kidding, these are beautiful. I would second the violin (or flamenco) tuning pegs. We're not talking much weight, and also tuning is more difficult/ touchy. If you or Bert decide to go with the tuning pegs, buy some glycerine soap and use that plus a little chalk (very little) to lube the pegs up and they will be much less finicky.

A few questions for Peter:

-What kind of woods did you use?

-What is the estimated thickness of the soundboard? Back and sides? Neck?

-Did you place any fan bracing on the underside of the soundboard?

-What difference, if any, do you notice between the two models? I can see your sound hole is not placed in the same location on both for one.

-What's the string action look like?

-Have you considered a Spanish guitar style bridge? Are your bridges solid wood or did you put bone at the apex?

I think you'll be pleasantly surprised by increasing the soundbox volume in your new dulcimer.

Bert, if you want to save some weight at the expense of putting a few dents/nicks in the neck wood, go with a conifer. Oak is overkill in my opinion, and while it probably won't make much difference, the conifers will provide better resonance qualities. Doug fir, sitka spruce, and Spanish Cedar are 3 that come to mind that would have more than adequate strength, no warping, but indeed a good deal softer.

Thanks for sharing Peter, now we just need an audio sample ;)

Here is a photo of my maple strum stick, and 3 more I am building. They are pretty fun, and my kids love to play them. I have not focused on tone quality yet. I am not finding much useful info on designing a sound box (depth, size, shape & hole sizing), as I would like to alter mine as well. Anyone know where to find that info?

-What kind of woods did you use?

The first one was red oak and 1/8" microlite ply. Not sure what the ply is but it is light and soft. Something I read said it was poplar, but it doesn't look or feel like it. Looks more like basswood to me.

The second one is poplar with an aspen sound board and a micro-lite ply back.

The new one is left over poplar and microlite ply.

Thus far the wood has been from Lowes and the hobby store for the ply. I may buy better wood in more attractive species as I get better at the process.

-What is the estimated thickness of the soundboard? Back and sides? Neck?

soundboard and back 1/8" on all
neck about 1"x1" or a bit less for the first two and about 0.9"x0.6" for the newest one

-Did you place any fan bracing on the underside of the soundboard?

No

-What difference, if any, do you notice between the two models? I can see your sound hole is not placed in the same location on both for one.

Yes the second one (round butt) has a bigger sound box and is more mellow. The aspen sound board may also have something to do with that.

-What's the string action look like?

I experimented and it wound up being fairly low.

-Have you considered a Spanish guitar style bridge? Are your bridges solid wood or did you put bone at the apex?

No and no. The bridges are just red oak.

Its not a focused answer to your question, but if you don't already know of this classic check it out:

http://www.amazon.com/Musical-Instrument-Design-Practical-Information/dp/1884365086/ref=tmm_pap_title_0?ie=UTF8&qid=1393460943&sr=8-1

It has a lot of what you want (Chap. 8: "Resonator and Radiators"), plus a lot more. If you are interested in the topic informally you may love this book. I sure do. Its basically written with the obsessed hobbyist in mind, and has a lot sketches and diagrams. His website had a ton of info last time I checked, as well as some designs for DIY instruments the like of which have never been seen before:

http://windworld.com/bart/invented-instruments/

Hope this helps a little.

I have taken and played homemade Shakuhachi and native American flutes on backpacking trips in the past. Very playable versions of both can be made cheaply out of PVC pipe from the hardware store if desired. They are nice because they have no moving parts. It would be amusing if you could multitask them in some way, perhaps as a tarp support or as a pot holder of some type. Then your unique designs might come close to rivaling some of Hopkins' weird ones. :-) Be sure to check out the pictures and recordings of the one listed – some of them are pretty cool. There are a lot of stringer instruments in there as well that could give you some ideas.

The drones and chanter sound are actually not too bad, although the playing leaves something to be desired (playing begins at 2:30):

http://www.youtube.com/watch?v=eVNhQHq2E1E

Terrible vid – totally awesome DIY instrument! Also, I like to be left alone if possible, and bagpipes might just do the trick in clearing out the area!

Wow, I never known strumstick. Very interesting! Thanks

Thanks for the replies to those questions Pete.

Very cool Bert, what kind of tuning peg setup is that on the lower one. They appear to work at a right angle, whereas my flamenco guitars just go straight down. I don't have experience building these sort of packable instruments but y'alls pics have definitely wet the appetite, but I'd say that the soundhole is a bit small relative to the soundbox size on these instruments. Because the soundbox is so narrow where you have the soundhole placed you could experiment with oval-shaped openings. There are guitar makers who take this approach. I would also consider making the depth of the neck less, I think a half inch would be sufficient (especially with the hardwoods you are using). IMO, and in the opinion of a lot of other more accomplished guitar makers, the soundboard is the most important piece of the guitar. By using bracing and a stiffer wood (ie. Sitka spruce) you can make the soundboard even thinner and therefore achieve greater resonance/sound quality and responsiveness. However, luthiery in the flamenco/classical guitar world is highly conservative and you won't find many people experimenting/thinking outside the box in terms of different soundbox sizes and shapes. Concert guitars are more voluminous, whereas flamenco guitar (which are relatively shallow) are less so. I would think a smaller soundbox volume would be positively correlated with reduced sustain but that also has to do with more minimal fan bracing under the soundboard. This is all getting far more technical than the intended use and expectation of a packable guitar though so take it for what it's worth.

Thanks for the inspiration guys and hopefully I'll have the time and money to put something together myself in the near future.

The parts came and I put it together. It came in at 7.8 ounces, right on target. I put steel strings on it and am playing around with different tunings. I did not care for the originally planned -G-C tuning, but it sounds pretty good tuned lower.

BTW: After getting the geared ukulele pegs, I found them to be pretty light (0.7 oz. each). I think they are worth the extra weight for the convenience of being geared. The total weight of the instrument came in at what I consider a satisfactory weight (7.8 oz.).

If I really was aggressive in trimming weight I could either get the weight down a little more or maybe make a three string version about the same weight.

Nathan,
Any pictures yet?

Well, the two string, less than 8 ounce, stick dulcimer has been done for a while and I am ready to report the results. It is a mixed success. On the good side the weight came out as expected and the sound is lovely, to my ear at least. On the bad side I find that I am more limited and less happy with two strings than I expected.

I feel limited enough that I decided to build a three string version. Not positive what the weight will come out to, but the bare instrument with no tuners, strings, or bridge is 6.2 ounces (the same as the 2 string one did in the same state). With the added string and tuner it will probably come in between 8.5 and 9 ounces. It has a smaller, but sturdier sound box so I expect less volume, but also less fragility.

My latest three string one came in at a little less than 9 ounces and is built pretty sturdy to take some abuse. My first impression was kind of luke warm, but after some tweaks I am really starting to like it. Initially the sound hole was not well located and maybe a bit too small. Also the action was kind of high and the string spacing a bit narrow.

I added two smaller sound holes and made a new nut and bridge and it is now a joy to play. I am extremely pleased with it and plan to take it on my mountain biking and backpacking trips this year.

I have watched my gear weight really closely on most items and eliminated a lot of things entirely. As a result I feel like I can splurge a little and take a fly rod and musical instrument and still have a reasonable base weight (probably 12-13 pounds depending on last minute changes). I know that on the JMT last year the fly rod added immensely to my enjoyment of the trip and I was still packing lighter than anyone I met other than a few runners or speed hikers seeking to break a record.

I decided that I didn't like playing the two string one much and thought that it might have a wide enough neck to accommodate three strings. So I took the geared tuners off, plugged the holes and re-drilled it for three friction ukulele tuning pegs. I built a new tail stock and strung it with ukulele strings. I weighed it and was surprised that it was actually lighter at 7.2 ounces. It sounds and plays nice too.

I got the book, Musical Instrument Design, and enjoyed it a lot. It gave good information on the effects of radiator surfaces and resonator cavities, but little guidance on how to optimize these. Also, not much info on sizing of sound holes.

I wanted to try a few new ideas, and this weekend completed a lightweight strumstick. I used Alder, for its light weight. I gave it a hollow neck (1/8" wall thickness), to decrease weight. I shortened the Scale length from 24" to 18", so I could get the overall length down to 24" for better fit in my backpack. I made blackwood tuning pegs, like a violin. And finally, I offset the body, with an angled end to give my arm a better place to rest on the instrument. The result weighed in at 134g (4.7oz).

The alder was great for everything but the fretboard – needs to be a harder wood, which would increase the weight slightly. A better sound board – like spruce might be an improvement without much weight difference. The hollow neck saved almost 50% in weight, and yet was strong enough. I get more neck flex than the solid maple, but both flex, affecting tuning somewhat. The profile feel in my hand was identical.
The shorter scale length makes the instruments tone less desirable, particularly the heavy string, but is still very good. The shorter length makes the fret placement more sensitive as well. At 24" it is still a bit tall for my pack, but feels very small in my hands, and so light, it takes more thought to keep it steady while playing. I am frustrated with the 4" required for the tuning pegs, and plan to try another alternative, using zither pins in the neck to remove that length. I would love to reduce the 2" base to bridge distance as well, but the bridge needs to transmit the vibration to a sensitive point in the sound board to get good amplification, so I don't know how to do that.
The wood tuning pegs are about 2g each, vs zither pins at 5g, and the geared guitar tuners at 27g each. However, they are much more difficult in use, requiring a tuning tool, and they have some stick/slip issues.
The offset body helps in handling, but required more steps and time to make. The resonator size is similar on the two instruments, and has a similar sound, though the alder is not as bright.
I don't see getting the weight down much, if at all, in an all wood design. Perhaps carbon fiber…
It has been fun to learn to play. Now I am wanting to make a 4-string, fully fretted ultralight guitar, for better chord playing.

Bert, I am impressed at the weight you achieved. I bet it sounds pretty good as well. Alder is a decent sound board wood, so I'd be surprised if there was much improvement if you go to spruce, but if you do, let us know how it works out.

You have inspired me to have another go at a trail instrument after I finish the full sized and weight mountain dulcimer I am currently working on.

By the way I was surprised how well microlite ply from the hobby shop worked out as a sound board when I tried it.