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Carbon Fiber Violin


Johnmasters
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I suspect it will stop a 9mm bullet but would not be playable after. One of these days I will test the limits of what it will take and put it up on YouTube with a Definite "do not try at home"

At last, a fiddle designed for those late-night roadhouse gigs! You might have a serious marketing gimmick there.

Stuart, this is most impressive, creating your own material & all. Alternative materials are certainly the future, and we need all the experimentation we can get.

A thought: have you tried various pickups & piezo bridges on this? E-violins tend to be thin & strident, so a "tubby" acoustic might morph into a fine electric.

Also, try recording it fairly close. (much closer than one would normally mic a fiddle) Many times, an instrument that sounds bad "out front" records like a dream. (and vice-versa) As you experiment with design & materials, you might stumble upon a fine specialty-instrument.

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What do you think of the shape and feel of it. If you were blindfolded and handed #9 would you guess it was not wood? How is the setup? I could stand to take a class or 20 on setup.

Since you asked, I'll list a few things I think might be off from "standard":

Neck is too thick... by about 3 mm. I measured 21.5 - 24, and Johnson/Courtnall specify 18.5 - 20.5

Neck stop length is 127, should be 130

Body stop length is 191, should be 195... combined with short neck stop, this gives a string 7 mm shorter than normal. The bridge might be 2 mm forward of the nicks, but I didn't mess with it.

Overstand is ~10 mm, should be 6 - 6.5

String clearance over fingerboard is between 5.5 and 5.75 mm on all strings; J/C specifies 4.75 G, 3.75 E. So it's high, and especially high on the E.

String clearance at the nut looks high to me... but I've been accused of making mine too low.

Fingerboard has significant waviness to it, so relationship between string clearance and actual playability is uncertain. It would definitely be difficult very high up on the fingerboard, but I don't go there.

I think the short vibrating string length compensates some for the high action; it's not that difficult to play.

The sound is definitely not like the sound of wood violins... at least, ones made of the usual spruce/maple. So, if blindfolded, I would be able to tell that it is different. However, I'm not sure if I could tell if it was composite or some other non-standard wood. Perhaps if I played a lot of composite and oddwood fiddles, I would be more able to distinguish between them.

And, as usual, the difference is far more pronounced to the player, and not so much to a listener (I listened to a recording of my playing, and the impression is quite different).

Power and projection tests will be upcoming.

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Again thank you Don!! The string length should be 330 from nut edge to bridge. It has gone through several hands so adjustments may have been made and or shifts in shipping. I have a feeling the neck is starting to warp up and is causing the string heights to be high above the fingerboard. The resin I used for that one was not satisfactory and I have changed to harder and higher temperature resistant resin. I did use a very cheap VSO to make the molds so some of the problems are inherent in the existing molds.

I am working on new molds designed on a strad scan that I have converted into 3D CAD. I just have to find someone to machine new molds. O and the time and money too. :) But I am still learning more and more from each one I make and try to correct any mistakes I can.

The neck is my bad. I thought I had gotten it down to 17mm but guess I got in a hurry and missed that detail, same for the overstand. I need to get the local Luthier to carve a nice fingerboard for me so I can make a mold of it. I attempted to carve a fingerboard and have been using that mold. I have since found out that my dish is way to far south and my molding technique is still a work in progress.

Look forward to learning other things I need to improve. I learn from my mistakes at least most of the time.

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I am working on new molds designed on a strad scan that I have converted into 3D CAD. I just have to find someone to machine new molds.

Would you share what program you use for the 3D Cad and how you managed to take a Strad (CT?) scan into that?

Nice to know in case a more natural model FEA could be done at some time.

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Anders,

I am using the laser scans from the luthier's library. Take all the measurements and lots of work with autocad 11 3D. I have built up the body but have not even thought about doing the neck.

A Coworker has a 3D mapping arm and is going to map the 1/2 and 3/4 size bodies and necks for me. If I can find someone local that has a fantastic violin I will try to work something out to get that mapped with the arm.

Allan,

I have thought about adding pickups. I will be seeing a guy this coming January that is working on an ultra small pickup I can embed in the sound post and or the carbon fiber bridge. I would love to put a wireless system in it too. All sorts of things I want to do. :-) , just a matter of time and money.

I do appreciate all the information I have gathered reading on this forum. Great bunch of people on here.

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I took this CF fiddle to an old-time fiddling contest last weekend (I took 2nd, and my band took 1st :)... using my #4 fiddle ) and tried it out in some of the jam sessions. As I expected, the lack of high frequency output made it unable to cut through the clatter, except for one or two notes that corresponded to a strong resonance... then it kindof honked. A fiddler friend of mine who tried it commented that it was hard to tune (not in the mechanical sense, as it has those geared tuners), which I attribute also to the lack of overtones. It's harder to tune to low frequencies.

This morning I switched the CF bridge for the wood one, and moved the bridge to get 330mm active string length. Here's a before/after spectral comparison:

post-25192-1286813110_thumb.jpg

The resonances generally shifted upward in frequency slightly, and there's a little more energy in the 2000 - 4000 Hz area. Sounds a bit brighter... but still mostly the same character. I noted that the CF bridge weighed 4.1g vs 2.5 for the wood one. Additionally, the CF bridge is uniform thickness, which gives even more of its mass up by the strings... probably a noticable muting effect.

My interest in this testing was to see how material properties affect sound. A test sample of one item is not much, but the preliminary conclusion is that density, weight, and the related "radiation ratio" actually do matter, particularly for high frequency response. CF is a great material, but in solid form it is vastly heavier than spruce. Perhaps with a 2mm foam or honeycomb core and very thin unidirectional face skins, power and projection of spruce could be achieved or exceeded.

Stuart,

I don't really know what your goals are with this project, so I don't want to be too discouraging. If you're doing this for fun, OK. If you intend to make this into a profitable business venture, I hope you take a realistic look at the market and pricepoint; I think it's a very tough sell.

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I noted that the CF bridge weighed 4.1g vs 2.5 for the wood one. Additionally, the CF bridge is uniform thickness, which gives even more of its mass up by the strings... probably a noticable muting effect.

Interesting post there Don. 2,5 grams for a bridge is still pretty heavy and sort of a mute. I guess the bridge is high?

I think common top shop bridges usually weigh in below 2g.

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My end goal is to make rental units that kids can't break. Not looking to knock wood off the block. :-)

Having a fiddle that will take any climate or just about any abuse you can dish out is not all bad.

Stay tuned, I will keep tinkering with the materials and layer patterns. Who know what I might find. Or I could just waste a lot of money and time. Won't know till I am done.

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  • 3 weeks later...

Not sure if this worth anything but there are a number of carbon fiber guitar manufacturers/luthiers. They have been around for probably two decades so there's a long track record. The company that produced the most 'woody' sounding guitars (really indiscernible in tone from real wood) is the now defunct Composite Acoustics. They really are excellent instruments if one is looking for a durable wood sound. They used KEVLAR layers to dampen some of the CF's harmonic series to get a more wood like tone. Not sure if there's application here but thought I'd mention it because they are so successsful.

Josh

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