6 string fanned fret headless-steel, wood, and negative space

Discussion in 'Luthier's Corner' started by BunchyMutt, Jul 9, 2018.

  1. BunchyMutt

    BunchyMutt Supporting Member

    Jul 3, 2014
    EDIT: The purpose of this thread went in a direction different from the original post below. Skip to post #11 for start of the build thread.

    I'm welding together what I guess could be described as a steel cello. The strings are solid steel bars ranging from the thickness of a guitar string to half an inch thick. Notes will be produced via a double bass bow.

    I'm trying to calculate the Scale Length if I know the Gauge and the Desired Note/Octave. Are there calculators or charts out there that could help?

    Many thanks
    Last edited: Jul 13, 2018
  2. Kallium strings have a good one on their website. Used it many time for weird scale length ramblings and plans!
  3. mark5009


    Feb 17, 2018
    Sydney, Oz
    Paul Beier has a calculator that'll do what you want

    Beier Fret and String Calculator | Beier Lute Software

    To quote:

    • Handles any type of solid string material such as gut, nylon and carbon, but also copper, brass, etc., and also includes Savarez and Pyramid, Kürschner and Aquila over-wound string catalogues.
    • Calculates the string equation based on string length, frequency, diameter, density and tension with the possibility of input from any part of the equation.
    GentProvocateur and Will_White like this.
  4. Beej


    Feb 10, 2007
    Vancouver Island
    Okay, I'll say it. PICS! Please show us some pics! :D
  5. mark5009


    Feb 17, 2018
    Sydney, Oz
  6. BunchyMutt

    BunchyMutt Supporting Member

    Jul 3, 2014
    GAH! darn exe files not compatible on Macs! I'll have to convert it before I'm sure, but it sounds promising:thumbsup:
  7. mark5009


    Feb 17, 2018
    Sydney, Oz
    Same here. vmware is your friend :)
    GentProvocateur likes this.
  8. ixlramp

    ixlramp Guest

    Jan 25, 2005
    No string tension calculator will be usable because they only work for strings with relatively insignificant stiffness, that is, nothing stiffer than a .024 plain steel. Your oscillators are solid bars that are so much stiffer they will vibrate in a different way because the restorative force is now caused by a combination of tension and significant stiffness.

    There may be calculators for metallophone bars but those are not under tension and are flat bars.
  9. charlie monroe

    charlie monroe Gold Supporting Member

    Feb 14, 2011
    Buffalo, NY
    It has been 4 days since @Beej requested pics.

    Don't test our patience, we can be a surly bunch when blown off :D
    GentProvocateur, SlingBlader and Beej like this.
  10. BunchyMutt

    BunchyMutt Supporting Member

    Jul 3, 2014
    Yeah, things got a little intense after I wrote and it went in a radically different direction - so giving an update was daunting.

    The night of my OP I whipped this out in 20 minutes:


    Quick and dirty. Just to see if rolled steel rod could be an alternative to string or gut. There are many examples of rod/sheet metal being used for sound but none that I could find that could be controlled in a harmonically consistent and predictable way. There are instruments like Marilyn Donadt's "The Wing", waterphones, Mega Marvin, or Bob Rutman's Steel Cello ensemble, but none of the bowing of the rod is easily controlled like bowing something under tension (I now know after experimentation).

    I could easily get notes out of the rods, but it was essentially the same idea as playing harmonics - bowing at different areas on the rod produced a different note. Playable, but not exactly what I wanted. Or maybe I just realized that the nature of the rolled rod prevented doing something radically different from what had been done before.

    So I scrapped the whole idea and decided to start on a different luthier project I've kicked around for a while. I have access to a great shop for the next month, I'm only working a part time job so I figure now's as good of a time as any to do something out of my skill level :)

    I've edited the thread title and OP to reflect this :)

    NEW PROJECT: 6 string bass
    Try a number of techniques that are new to me, including:
    - fanned fret
    - headless
    - use a combination of wood and sheet metal for the body
    - potentially a neck sans truss rod, instead using a 7075 aluminum hex bar that's cut in half lengthwise running the length of the neck.
    - hexagonal neck instead of curved, with a twist sort of like strandberg guitars. Shopping for quotes to see whether making the rod tapered (1.5" at the heel to 1" a the nut) would be cost prohibitive

    Lots of techniques from Rick Toone that I want to try for bass :D

    Here's a rough sketch:

    Neck will be 5pc maple with a bubinga center stripe. Rosewood fretboard. Alder and sheet metal body.

    My main bass for years has been a 6 string, 16.5mm, 34" and it's comfy for the most part so I'm staying close to that. Not sure about fretwire. I'm intrigued to try the Dingwall route of 18% hard nickel silver, but I'm also more familiar with medium, so we'll see.

    16mm at the bridge, 54 at the nut. 36"-33" scale. Very low curvature fret radius. 400mmR or more.

    Ok, that's it for now. I'll keep this build thread updated
  11. BunchyMutt

    BunchyMutt Supporting Member

    Jul 3, 2014
    That's essentially what I found in practice. It launched me on a path of might as well simplify and use traditional string, tuners, and a bridge, and if I do that I might as well build a sheet metal fretboard and just make a steel EUB. And if I do, that's not too far from just building a bass, so I might as well go all out and do a fanned fret, headless, 6-string bass because now's as good as any.

    The classic 'get complex by simplifying' design method:laugh:
    Last edited: Jul 13, 2018
  12. BunchyMutt

    BunchyMutt Supporting Member

    Jul 3, 2014
    Thanks for the push :thumbsup:
    BritFunk and charlie monroe like this.
  13. BunchyMutt

    BunchyMutt Supporting Member

    Jul 3, 2014
    For tuning systems I was initially thinking going the traditional with tuners at the headstock, especially since it would be less expensive than the headless route, but after pricing everything out the headless systems wouldn't be that much more expensive.

    Single string bridges ($20 each) + Gotoh res-o-lites ($147): ~ $267

    Single string bridges ($20 each) + hipshot ultralites ($168): ~$288

    ABM headless systems for fanned fret instruments are out of my price range. Six single string bridge tuners ($330) plus the headless nuts ($96.7) = $426

    There are two companies out of Europe (both in Italy I believe) that make single bridge tuners and nuts.

    Technology for Musicians (T4M)
    €35 per bridge tuner (6) + €15 per single string nut + €25 for shipping = €328 = $379.5

    $40 per tuner (6) + $90 for 6 headless nuts + free shipping = $330

    Unfortunately there's about a 1.5 month lead time for the MERAs while the T4Ms could ship immediately.
  14. BunchyMutt

    BunchyMutt Supporting Member

    Jul 3, 2014
  15. BunchyMutt

    BunchyMutt Supporting Member

    Jul 3, 2014
    After mapping out the nut, 12th, and 24th fret I decided to change the scale change from 36-33 to 36-32 with a 1.5" difference at the nut and a 2.5 difference at the bridge.

    I did this so that the angle of the frets at the heel (a) follow the angle of the wrist more naturally and (b) balance out the nut's fan.
    BritFunk and Will_White like this.
  16. BunchyMutt

    BunchyMutt Supporting Member

    Jul 3, 2014
    Quick updates - I was hoping to get to the metal fabrication shop at the MN College of Art and Design tonight but it'll have to wait till Wednesday or Thursday. Going to use the plasma cutter to make the sheet metal top and back.

    I got the maple and bubinga for the neck. I was hoping that Youngbloods in Mpls would have quartersawn maple for the center but it's a no go, so instead it's a 5 piece hard maple-bubinga-hard maple-bubinga-hard maple. All planed for glueing.

    I also found a pair of scrap aluminum bars that would make excellent neck and fretboard cauls. Looking forward to taping them up and giving them a spin.

    I started tweaking the design and playing more with negative space and odd numbers. I'm plotting out a lifesize 2D model tonight.
    I'm having trouble finding pickups put so it goes.

    Question for you all - one of the many experiments I'm working with on this build is going sans trussed in favor of five sided aluminum 7075 (the aircraft grade stuff) running underneath the fretboard. 1" or 3/4" wide at the headstock and 1.5" at the heel. 1/2" deep the entire length. I was originally thinking a semicircular bar, but the angles of the hex shape would help prevent twisting more me thinks.

    What epoxies + hardeners do you recommend for wood to aluminum applications? For west system I know the basic is the 105 - but I'm not sure about hardeners. Thoughts?
  17. Beej


    Feb 10, 2007
    Vancouver Island
    Watching with interest and seems like you're off to a good start. :) Just a thought on the trussrod - they are really installed to give the neck some adjustability. Making it stiff and flat can be good, but adjustability is also there for a good reason... :D
  18. BunchyMutt

    BunchyMutt Supporting Member

    Jul 3, 2014
    Thanks! I'm looking forward to it too.

    Yeah, I've been waffling about whether to go the tried and tested truss rod route (pun intended) or go for the single aluminum hex bar. On one hand, the truss rod option is significantly less expensive, about the same weight, and has the adjustability but I'd need to backtrack and figure out what to install, how to install, and then order parts.

    On the other, I'm really intrigued by the sonic and structural changes that might result from having a single aluminum hex bar creating a 'solid' neck without air gaps (such as increased attack 'quickness', sustain, and bass response). But it's more expensive and would require the services of a fabricator to get precise machining on the aluminum bar.
    franksidebottom likes this.