neural
starting to spend too much on rocks
Member since November 2019
Posts: 132
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Post by neural on May 3, 2021 21:12:52 GMT -5
So, obsidian comes in some pretty large sizes, and while I was tinkering with the trim plate on my slab saw I had an idea which...the slab saw wouldn't necessarily be able to accomplish directly, but I might be able to do it with some filing. I want to make an Obsidian Lithophone. The 3D image below is a mock up I did in Blender. Essentially, you take a large-ish block of Obsidian (or other structurally homogenous stone) and cut several "vanes" into the single piece. You then trim them to different lengths so that when struck with a mallet they produce a tone that matches a given scale (i.e. C major). Ideally, I'd like to make one that is around 14" or so tall. I *believe* that with the trim plate on my LS-14 I could make the initial cuts without a problem, but where I'm stuck is how to get the cuts down near the base of the piece to be nearly horizontal with the surface it would be set on. Having any form of strong peak deep within the cut might result in muddying the sound or just overall unsatisfactory sound quality. I would need to do a bit of fine level filing anyway to get the tones right, so my question, to start, would be whether or not it's possible to get a file that is roughly the width of the 14" blade (which is something around 2mm) that is also around 6" in length (not including the handle). If not a file of that type, what other methods might I look into in order to level off the inside area of the cuts at the base?  (note: this image is a very very very rough representation. Getting the notes to sound properly will probably result in the vanes and overall appearance being totally different) |
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Post by hummingbirdstones on May 3, 2021 21:48:24 GMT -5
Cool idea. Looks like it would be a lot of work. 
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neural
starting to spend too much on rocks
Member since November 2019
Posts: 132
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Post by neural on May 3, 2021 21:55:44 GMT -5
Cool idea. Looks like it would be a lot of work. 
That might do the trick. It's an odd project, but I like metal, stone, and music. Windchimes and such tend to be overdone with metal, so I thought it would be interesting to make a Lithophone.  |
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pizzano
Cave Dweller 
Member since February 2018
Posts: 1,390
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Post by pizzano on May 3, 2021 23:40:40 GMT -5
Cool idea. Looks like it would be a lot of work.
That might do the trick. It's an odd project, but I like metal, stone, and music. Windchimes and such tend to be overdone with metal, so I thought it would be interesting to make a Lithophone. Like the idea....... I've actually been around Marimba's (stone Xylophone) made from a "slate" and constructed from Mexican stone (Jorge Santana's percussionist had a couple)........but never a "wind chime" abstract made from a "glass" composition like Obsidian. Also have owned a few "slate" type chimes, that were very well tuned (chromatic scale of C4-C6), that the band traveled with, but didn't take well to the travel........I'm sure the precise cut "tuning" will be an adventure worth following...! |
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Post by fernwood on May 4, 2021 4:04:13 GMT -5
Looking forward to seeing how this project develops.
I love the concept.
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RWA3006
Cave Dweller
Member since March 2009
Posts: 4,640 
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Post by RWA3006 on May 11, 2021 18:32:40 GMT -5
A mini drag saw could be made to finish the cuts. A mini wire saw would work also. Both are relatively easy to build.
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JR8675309
freely admits to licking rocks
Member since August 2019
Posts: 807
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Post by JR8675309 on Jul 24, 2021 9:56:25 GMT -5
Cool idea. Looks like it would be a lot of work.
That might do the trick. It's an odd project, but I like metal, stone, and music. Windchimes and such tend to be overdone with metal, so I thought it would be interesting to make a Lithophone. "I like metal, stone and music"... grabbing popcorn, I can't wait to see how this turns out. Don't keep us in the dark |
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Post by Pat on Jul 24, 2021 10:46:00 GMT -5
Interesting. jamesp the engineering would be fun. The result would be pretty. |
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,607
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Post by jamesp on Jul 27, 2021 11:22:46 GMT -5
Interesting. jamesp the engineering would be fun. The result would be pretty. I suppose sawing deep grooves in a single brick of obsidian would probably take a low vibration saw like a jeweler's saw as hummingbirdstones mentioned. The LS-14 may do the job with a very straight blade and good lubrication. I saw slabs off of my 2"x6"x12" cast glass bricks using a high speed 12" tile saw with lots of water to dull the vibration. Sawing a 6 inch long X 2 inch slab say 1/4" thick off of these glass bricks without breaking the slab takes a very straight blade at 4000 rpm with a lot of water being sprayed while sawing. The diamonds in the blade even have to be finer, like a glass blade instead of a tile blade. Otherwise the vibration impacts of the coarser diamonds in a tile blade tends to break the slabs before the entire 6 inch long cut is made. I needed the slab to be a whole 6 inches for knappers to make spearheads out of theses slabs. When sawing glass for a lithophone as neural is proposing likely ups the chances for one of the sections to break off. A precision jewelers saw with fine diamonds and a slow feed is probably going to do the trick IMO. Also, the glass or obsidian has to be virtually fracture free - i.e. very solid. Slabs/bricks: www.flickr.com/photos/67205364@N06/sets/72157712150466066www.flickr.com/photos/67205364@N06/sets/72157706002257634I did start out with an 18" lapidary saw filled with water to cut glass bricks but the water and alkalinity rusted the saw heavily. The glass ruined saw oil quickly so I used water. Canned the slow cutting lapidary saw and went to a high speed powerful tile saw for more production since the slabs were selling well. I will say that glass glue(a form of super glue) generates one of the strongest known bonds when gluing flat plates of glass together. neural - I would cut my slabs to you desired octave/harmonic length and glue them together clamped. Perhaps using thinner window glass for the spacers. Cut the spacers to size with a plain glass cutter. Or use microscope glass slides. Cool project. Fine circular diamond blades with 60-80-100 grit diamonds leave edge chips at cut visible on this sandwiched sawn brick. Coarser blades with 30-40-50 grit diamonds are much more aggressive cutting leaving yet bigger edge chips but create vibration that breaks the slab.  6 inch spear point knapped from 6" x 2" slab 1/4" thick.  |
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