Post 28: STARTING A NEW INSTRUMENT

    I have not quite finished the last post and will update it later with pictures of the finished instrument.

    But I want to share the new project first.

   I have been wanting for a while to build a smaller instrument for a change. The violin is a little too high-pitched for my taste, so I thought I would design a 5 or 6 strings viola with the additional strings on the low side. I started thinking about a unique design using of course aluminum and brass and sketching in my notebook. After a few attempts I did not like, I finally came up with a simple design I liked a lot. This is the rough sketch of the concept:

   The structural part is a 1/4" thick curvy aluminum spine to which is attached a split wooden fingerboard(1/2 on each side of the spine). The strings are stretched and roughly tuned using dulcimer pins tuners at the neck, and there are slightly larger brass versions of the standard cello fine tuners on the tailpiece. The bridge is triangular with a slot that fits on the spine and a built-in piezo stick like the new cello bridge.

I started a scale drawing with tentative shapes, geometry, and dimension:

After a few days mulling, it evolved into this:

  

       I am particularly pleased with the spine design, the holes being both decorative and purposeful,  the final weight being a big concern. I had to make the instrument as light as possible without compromising the rigidity. Here are some details of the tailpiece, bridge and neck:

  After a while, the blueprint got messy and I needed to make minor changes, so I started a new one with corrections:

         It's time to start building this thing. First, I had to carve out a small space in my cramped studio:

       First, I cut the basic spine shape out of a piece of 1/4" aluminum:

        Then I used Forstner bits to drill the holes. 

       Next, I made a sample fine tuner out of alu and brass:

     The tailpiece was cut out of the same piece of 5/16" thick 2" aluminum tubing I made the neck of the 12 strings bass lap of. I had a hard time flattening it to the proper curvature and drilling the hole. I also made more fine tuners. 

      Next, I roughly cut the two wooden sides out of Guatemalan caoba, a lightweight mahogany. The wood not being thick enough, I had to glue a piece on each side to accomodate the wider part of the fingerboard:

         I cut them in a wedge shape on the bandsaw and used two threaded rods to attach them to the aluminum spine:

    I cut the large slot for the preamp and started shaping the wood on the belt sander. I cut a separate piece for the fingerboard and roughly shaped its curve too. I will take measurements of †he neck of LaDonna's viola when she comes by with it and figure out how to modify it to accomodate 6 strings instead of 4:

POST 27: REPAIRING THE 12 STRING BASS

When testing the 12 string bass with a musician friend,  I caught my feet in the audio cable and yanked the guitar to the floor. It was seriously busted up. The tension of the strings caused the wood at the end of the neck to split. I was so upset I put it up and have not touched it for years.

But then the other day, my musician friend, who has been playing the cello and the long bass for a couple of years asked if I would repair it, and I decided to not only repair it but improve it and finish it up. 

The first thing is to replace the split wood, after cutting out the bad part at the location the 5th (future) fret:

That way, the splice will be for all practical purposes invisible once I set the small 1 mm fret markers:

I happened to have a piece of human bone, out of which I cut ten 3/8" dots which I set into the wood:

Now, the biggest challenge is to redesign the brass headstock so it holds the strings with set screws without cutting them, and is firmly attached to the aluminum neck with screws instead of to the wood. In order to drill and tap the holes for the screws, I will make it in two parts, with 2 "wings" to assemble them:

The bottom will be cut out of the same 3/4" solid brass stock as the original, the top plate out of 1.4" stock. That will be A JOB!

Post 26: Finishing up the Lap Steel

    Since my fingertips are numb and my right hand is beginning to lose its dexterity too, I better finish up all the instruments before it gets worse. The  small screws give me a hard time

   The lap steel was functional, but still lacking frets, in need of improvements to the bridge and the nut, as well as some cosmetic work. I took the cheap round wound strings off, as they will be replaced by better smooth flat wound strings that will be much less noisy with the slide. I marked the fret positions as accurately as I could, doing my measurements four separate times and using the average of the four.

   I had never set frets before, but it was easy enough once I got the right saw. I already had a razor-thin saw and an old blunt wider one. I ordered a fretting saw and made a (much too) big miter box. To keep the fretboard straight in the miter box, I taped at each end of the ebony fretboard a dowel cut to the width of the box. I used the thin saw to score a shallow mark at each fret and checked my measurements a second dime. The fretboard is about 3/16" thick and the small brass frets about 3/32", so I marked a line on the saw blade at about 1/8" and cut the 24 fret slots. Ebony is very hard, and the slots cut with the "fret saw" turned out to be too narrow. Luckily, my old worn-out saw was perfect to score them to the proper width. I  cut each fret to size, set them with a few blows from a plastic mallet, and filed the ends smooth one by one, polishing ebony and brass as I went with fine steel wool. 

   I finally drilled shallow 1/4" holes to inset abalone markers.

   The fretboard turned out well and looks really good. These very small mandolin frets are only going to be used as guides for the position of the steel slide.

   Next, I refined the rough cut ebony bridge, adding a few curves and polishing it. Finally, I drilled 3 big holes and filled two with aluminum rods. I drilled four smaller holes and inset four brass rods:

  I put the whole thing back together after rubbing the aluminum body with a soft 3M pad. 

Post 25: Temporarily Sidetracked by a new Harmonica!

    I am still working on the bass, but I received a new harmonica from Germany a few days ago that got me into something. Basically, I found out a week or so ago that Seydel, the only old-time harmonica manufacturer left in Germany, and the only maker of steel reed harmonicas had come up with an instrument that could be re-tuned at will from Major to Natural Minor, Harmonic Minor, or even some odd tunings, using magnets:

     Since I prefer the Minor tunings, it seemed like a really interesting design that would allow me to experiment. It wasn't cheap, German-made harmonicas are more expensive than Chinese made harmonicas with a German name like Hohner, but I got excited and ordered it. It came all the way from Germany in two days. Honestly, I was a little disappointed at first, I suppose because I am not used to steel reeds. The sound is colder to my ear than the warm sound of brass reed, and there seem to be fewer harmonics. It's harder to play and take some getting used to. Also, I was not overly impressed with the tuning system. It does work, but the magnets affect the sound quality and are hard to adjust precisely, especially on the draw reeds. The whole thing seemed a little flimsy. I considered sending it back, but there was in the user sheet an interesting footnote saying:

     "The inspiration for designing the ALL MINOR HARMONICA came from Jim Antaki's Turboslide harmonica (>www.turboharp.com) where little magnets were used to alter the pitch of stainless steel reeds for the first time."

     So of course, I checked out the website mentioned:  TURBOHARP.COM

     And that's how I discovered that a guy named Jim Antaki was actually the "inventor" and had patented the magnet idea. I am not sure what the relationship is with Seydel, maybe they pay him a fee to use his idea, or maybe they made a deal since he uses Seydel Harmonica as a base for the "Turboharps" he sells.

    In any case, there are all kinds of interesting things on his website, including detailed drawings of his tuning mechanism, which is different from Seydel's. He mounts his magnets on the plate next to the reed and slides them over towards the reed. The magnets can be adjusted a bit vertically with an X-wrench :

    Seydel on the other hand has the magnets attached to the cover plates, and slides them diagonally over the reed. I felt like I would like to play with the idea too, and decided to keep that harmonica. Of course, I immediately took it apart to see exactly how it worked, and it is actually pretty simple: a magnetic field close to the reed slows down its vibration, and flattens the pitch about a halftone, allowing minor tunings. The magnet slides closer to the tip of the reed diagonally, and the player just tunes to a flat by ear with the sliders:

      As I said above, it does work, but frankly not all that well, especially on the bottom draw reeds, presumably because they are on the same side of the reed plate. Could I possibly take off with the idea and do better? I do like challenges after all! 

   

Post 24: Making the 12 Strings Bass 3

    After some tests on the backside of the 2x4, I gave up the idea of drilling holes larger than 1/2". But I placed them close together and staggered in 3 rows. I cut out most of the back, leaving just 3 crossties. I have a piece of 1/8" padouk that will make a nice lightweight cover plate. 

    I quite like the final result:

      It turned out easier than I thought to drill 6 holes through the body into the neck. I have temporary screws holding the thing together, that will be replaced by 4"+ through threaded rods with brass acorn nuts. 

      I ordered some brass/gold pickup covers, and some steel pick up plates. They were of course way too shiny for my taste. It actually took a lot of sanding to remove multiple layers of gold, nickel, and copper plating. Also, the brass covers were too small for my pickups, so I had to stretch them a bit and sand the plastic on the sides of the pickups to make them fit, but they came out looking great.

      To make the bridge adjustable in height, I made a 1/4" aluminum plate and fitted (barely) two of my 1/4" knurled brass screws. Two rod-piezo pickups will go between the aluminum plate and the brass bridge. 

     Time to assemble things and see if everything fits as planned. Final assembly with the nut in place and the strings tight will tell, but it seems that the bridge will probably need very little adjustment for the strings to be at the proper height above the fingerboard and the big frets I will be using. I might actually make the nut adjustable too. 

      The acoustic guitar PreampEqualizer is a tight fit at the end of the 2x4, which will be cut with the matching curve. The pots will get large knurled aluminum knobs. I am well pleased with the look:

         Now, putting the strings on this thing turned out to be quite a challenge, as both the anchor block for the strings at the head and the tuning system at the bridge gave me problems. I finally got all strings on and tuned to test it, and it works fine, but I am going to have to do some more work on both. 

       At first, I only used two M3 screws to attach the brass strip holding the tuning screws to a slanted aluminum base, and they were pulled by the tension of the 12 strings, so I had to modify it and use four screws with washers and nuts.  After full assembly and stringing, I could see the slanted plate was too narrow and too slanted, and I will replace it with one that supports the 12 small brass string holders.

       At the other end, my hard steel tightening screws ended up breaking a number of strings, and I had to use small pieces of brass rod as fillers and spacers.  They had to be tightened very hard, and some threads stripped. I rethreaded bigger, but that doesn't look so good.  Also, I never managed to get out the small drill bit I broke in there and had to drill another hole next to it. The entire brass anchor block system needs to be redesigned and modified to be gentler on the strings. I should probably add a cover to hide the ends of the strings;  unless of course  I just snip them really short.

Post 23: Making the 12 Strings Bass 2

   Well, I had a (maybe) better idea. I have laying around a couple of long aluminum 2x4's I used in the construction of my house 20 years ago. They are very thick and very rigid, but also very rough from construction use (and abuse). It's OK though, I don't mind a few "scars" left from a hard life after I sand and polish them as best I can. 

    So I cut notches in the neck for the two pickups and bent it. I then cut a piece 20 " or so, and notched it to fit one end of my long neck. It took quite a while to get that properly fitted, as the walls of the 2x4 are 1/4" thick. The neck will be attached with six 4.5" long through 1/4" bolts and brass spacers.

        That chunk of metal is heavy and needs to be tightened while keeping its rigidity. I could drill a bunch of large holes on the side and back, but that would be very time consuming, and I am not sure the result would be satisfactory. So I chose instead to cut most of the backside out leaving just three half-inch wide ties. It can be covered with a lightweight aluminum plate. The top needs a cutout for the pots and jack plate. The sides could still possibly be drilled, but with a bunch of smaller holes. The largest drill I have is 1", and I will just have to try and see if I can drill neat enough holes.

Post 22: Making the 12 Strings Bass

         After sanding and polishing, the neck blank looks really good:

      I made the bridge out of solid brass. It's not really easy to "machine" an entire brass bridge without machines. I just cut the 10 pieces on the band-saw,  sanded them to size and shape on the belt sander, and assembled with M3 socket screws. 

      Next, I made the tuners using long M3 screws. 

       Last but not least in terms of difficulty, I made a brass anchor block for the strings to attach to the end of the neck. I broke a drill bit deep in the block on one of the first holes. I found a solution to remove it on the internet, which is apparently an old trick of watch and clockmakers. Dropping  the brass block in a very hot saturated solution of alum, and let it bubble until the steel is completely dissolved:

     I put the whole thing together as a mock-up to see how it would work. The two humbucker soap bar pickups will need to be embedded deep into the "neck", and it will have to be extended 6" or so to fit the pots and jack assembly. In order for the bridge to fit and the tuners to do their job pulling the strings down on the bridge at a sufficient angle, it will have to be bent :

    The cut is so deep there will be just an inch or so of aluminum left, so it will need to be re-enforced somehow at the bent. The best solution seems to be if it can be found, to use a foot long section of 1/4"' thick 2 1/2" aluminum pipe that will wrap tightly around the neck and be attached to it with two large bolts on each side of the bent. It would make the "body of the bass 1/2" wider, just about enough to accommodate the bridge, tuner, and pickup full width:

Post 21: Starting to think about the 12 Strings Bass

     I just ordered some black Bass Tuners, some black Guitar Tuners, a set of flat wound bass strings, two sets of flat wound guitar strings, and two soap bar humbucker pickups. I am pretty much out of large aluminum pieces, so I am going to go by the Metal SuperMarket to check prices and see what is available on their scrap pile at a discount. The length of the shortest string will determine the length of the neck. For the guitar to be playable, I need the shape of the neck to be similar to a regular wooden neck, not just be plain square or round aluminum tubing. An option might be two side by side round tubes with a wide flat piece on top for the fingerboard and another narrow one under to place the thumb. I tried different arrangements, then realized I actually had a piece of 2" aluminum pipe with thick 1/4 " thick walls and an outside diameter of about 2 3/8". Now, that's about what the neck is supposed to be at it's widest on most 12 strings basses, narrowing to a tad less than 2" at the nut. If I cut that tubing at a slant, it would be just about perfect. It could be filled with a half-round piece of wood to create the fingerboard.

    So I sliced the pipe lengthwise on the bandsaw, sanded it even, and cut a piece of padouk I am going to carve to fit inside:

     The carving was difficult, and I ended up wasting some wood, but I finally got it to fit well enough, and used plenty of epoxy to attach the wood to the aluminum. I camped it tightly overnight:

     Then, looking at some 12 strings bass on the internet, I ran into the image of a few brass adjustable bridge/tuner set up that doesn't use standard tuners with a knob, but something similar to what I did on that first "homemade guitar" I built when I was a kid using bicycle spokes as tuners.  This is even more basic actually, and I think I could design and make something similar that would look a little slicker...

   I went to the hardware store to look at socket screws and figured out I would need M3 Metric 3 mm screws, some long for the tuners, and some short ones for other adjustments and assembly. So I ordered an assortment of long ones and an assortment of short ones with nuts and wrench:

      

    I worked out the basic dimensions from the photograph above:

Post 20: How about a Single String Stainless Steel Stick Bass(Model #SSSSSB!)

As always looking to use stuff I already had on hand and going for utter simplicity and minimalist design I modified the original design and ended up with something finished and functional before I even had time to post about the process. 

        Detail of the tuner, made of a 1" thick circular piece of solid brass (leftover from outfitting my bobber years ago) that slides over the stainless steel tubing, a stainless steel flange normally used to install a coat hanging rod, a brass disk, and a 1/4-20 x 3" screw with a knurled brass  knob:

    Detail of the brass bridge (a section of a nonfunctioning brass punch) and its support/spacer(a stainless steel gear out of a gearbox):

    The plain black soap bar pickup is attached the long way with the two stainless steel adjusting screws it came with through the tubing. An extra nut raises the side closest to the bridge so it is in line with the string. The angle plug at the end of a black coiled electric guitar cable is simply fitted tight in a 1/4" hole(establishing the ground), and the red wire of the pickup is soldered to the end of the plug. Could not be simpler:

      The ball end of the string is threaded through the end of a copper plug that has been hammered into a cup, comes out through a hole in the stainless steel tube, and goes over a brass nut shaped like a lopsided ring:

      A wooden fingerboard was carved out of cedar, grooved to fit over the tube, and stained black to look like ebony(see image 1).  I may replace it with the real thing.

      A stainless steel lever with a black ball knob (out of an old tile cutter) is used for the pin, and slides in a series of metal tubes forced into the end of the stainless steel main tube.