1. Please take 30 seconds to register your free account to remove most ads, post topics, make friends, earn reward points at our store, and more!  

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

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


  1. MPU

    MPU

    Sep 21, 2004
    Valkeala Finland
    Contact Bruce Johnson for a truss rod that leaves no air gaps in the neck. I like those rods a lot, they really make a difference to the feel and sound of the neck.
     
  2. papasteack

    papasteack

    Oct 11, 2012
    Last edited: Jul 24, 2018
  3. rwkeating

    rwkeating

    Oct 1, 2014
    Chicago
    none
    Just my 2 cents, but I think it is a big mistake to not use an adjustable truss rod.
     
  4. GentProvocateur

    GentProvocateur Supporting Member

    Jul 3, 2014
    Nashville, TN
    .
    Yeah, reading more about things like linear thermal expansion, I think an aluminum bar taking up half or more of the neck might not be a great idea. Really curious about using carbon fiber TOW plus epoxy in addition to a truss rod.

    Not sure if it needs one or two truss rods though. My current six string, which has 16.5 spacing, a thinner neck and 34" scale, has two dual action truss rods.

    Given that this is 36"-32" and 15mm spacing I'm thinking one truss rod and two carbon fiber reinforcements.
     
    BritFunk likes this.
  5. GentProvocateur

    GentProvocateur Supporting Member

    Jul 3, 2014
    Nashville, TN
    I wrote Bruce at his work email so we'll see. In the meantime I'm doing some plotting in anticipation of the steel cutting tomorrow morning. Luckily I have some help:

    IMG_6236.JPG


    One thing I'm exited to try is the arm rest angle and belly cut - the cool thing about having steel sheet sides and back is the ability to heat them up and bend them - so no carving necessary! Just really hot temperatures and lots of grinding
     
  6. Will_White

    Will_White

    Jul 1, 2011
    Salem, OR
    How thick of steel are you planning on using? I used 1/16" for the sides and bent everything by hand. On my steel bass. I would be weary of weight steel gets heavy fast without a top only a control cavity mine went from about a 4lb neck through too about a 15lb finished instrument.
     
  7. GentProvocateur

    GentProvocateur Supporting Member

    Jul 3, 2014
    Nashville, TN
    the sheet I'm trying it with first is 14 gauge - so 5/64. Sounds like you were using 16 gauge, which I was considering. I'm a terrible judge of weight so after the pieces are cut tomorrow I'll weigh them. The 6 single string tuning bridges are 600 grams, or 1.31 lbs (without screws). No idea about pickups yet, but there will be two of them.

    Still deciding between a darker center block like mahogany or going the swamp ash or basswood route. Point of clarification though - there aren't any wood wings. The only place wood shows through is in the top horn. So there's a lot of hollow space. Depending on how things go tomorrow though I may be redoing things on 16 gauge though.
     
    MPU, Matt Liebenau and Will_White like this.
  8. Reedt2000

    Reedt2000 Supporting Member

    Apr 26, 2017
    Central New Jersey
    I get the feeling this is either gonna be brilliance at the highest level or painful trainwreck...

    Either way I'm in! Can't wait to see how it plays out :thumbsup:
     
  9. Will_White

    Will_White

    Jul 1, 2011
    Salem, OR
    That sounds allot like how I did mine. I don't have a good picture of it finished but here's a picture (thumbnail) of the outer frame. If you want to see more of how I did mine you can look at my thread Winter 2017 Build-Off: Basso-Cello
    20171113_205852.jpg
     
    GentProvocateur likes this.
  10. GentProvocateur

    GentProvocateur Supporting Member

    Jul 3, 2014
    Nashville, TN
    Tried free-cutting the 14 gauge with the plasma cutter. It worked ok but I decided to redo it after I make a more precise template out of 1/4" MDF. I could laser cut it but that would be a lot more money and I sorta feel like it would be cheating ;)
    IMG_6241.JPG

    1 lb 11.4 oz
    IMG_6242.JPG

    I think I'll use 14 gauge for the back and 16 gauge for the front - keeps the weight closer to my center of gravity.

    Given the cutouts for the pickups it's becoming imminent that I decide pickups today. Unfortunately there's nothing out there that is grabbing my interest for combination of geometry, prices nd tone. My favorite pickup right now is essentially a lundgren m8 made for 6 string bass. Getting a calibrated set of those would be stupid expensive though ($500+).

    I don't really like the sound of Lace Alumatones but they're readily available, would fit, would offset the weight of the sheet metal, and the look would go soooo well together. Edit - yeah, after re listening to clips i just can't get along with them
     
    Last edited: Jul 25, 2018
    gscroggin likes this.
  11. Will_White

    Will_White

    Jul 1, 2011
    Salem, OR
    Delano makes some Oval pickups, that might fit the aesthetic better. And there's always the option to make a wooden pickup cover for a standard pickup.
     
    GentProvocateur likes this.
  12. GentProvocateur

    GentProvocateur Supporting Member

    Jul 3, 2014
    Nashville, TN
    Not really a fan of the oval delanos ", and it throws off the 1-3-5 design elements.

    On another note - I made a template from mdf and usin it to cut didn't turn out much better than just free handing it.
     
    Will_White likes this.
  13. Will_White

    Will_White

    Jul 1, 2011
    Salem, OR
    My advice for the plasma cutter is to cut off of the line and get familiar with a die grinder or dremel and files to get it to where you want it, I use one everyday at work and I still have to go in with a die grinder to get things to fit right. There's also no shame in getting it CNC cut. I'm working on a prototype aluminum bass and for future builds I'm planning on getting the top and backs laser cut.
     
  14. GentProvocateur

    GentProvocateur Supporting Member

    Jul 3, 2014
    Nashville, TN
    It's looking more and more likely that I might do the cnc/laser route. So much money though. And I really like the challenge.

    You read my mind with cutting off lines and then using a grinder
     
  15. Bruce Johnson

    Bruce Johnson Commercial User

    Feb 4, 2011
    Fillmore, CA
    Professional Luthier
    Cats make great french curves. You lay them down on the workpiece and position them in line with the known apexes. They will naturally form into a fair curve. Quickly run a pencil around the outside as the curve forms, then a light scratch on the neck before it changes shape.

    Hello Grayson;

    Thanks for writing! I'm sorry that I didn't get a chance to answer you before, either here or to the e-mail you sent me. Too many threads, too little time....Your project is interesting.

    About the neck structure, I agree with what the other guys are saying. Yes, you need a truss rod in the neck, to make the relief adjustable. For a six-string neck, a single truss rod down the middle is fine. You can add carbon fiber or aluminum bars or TOW reinforcements if you like, but they really aren't necessary. The neck that you are describing here shouldn't have any real structural problems.

    Making a strong, stable neck is all about making a good wood structure. Make up a 3-piece or 5-piece laminate, with all the strips cut and arranged so they have no internal stresses, minimal runout, and the rings are arranged in a symmetrical opposing pattern. The basics.

    No need for my special truss rod here. It's extra work and complication to install, and you have so many other interesting things going on with this project, that you wouldn't notice the subtle advantages. Use one of the commercial double-acting double-rod truss rods. They are simple to install and will do the job for you. Just beware of the really cheap ones.
     
  16. GentProvocateur

    GentProvocateur Supporting Member

    Jul 3, 2014
    Nashville, TN
    Ha! Noted. When my partner was working from home for a while we took to calling him Mr. Secretary for his love of helping with paperwork - laying on it, biting and ripping it, etc.

    Many thanks for the response! It'll definitely simplify things to have just a single, shallow truss rod. I'll likely still use reinforcements of some sort to offset the asymmetrical neck a-la Strandberg.
     
  17. GentProvocateur

    GentProvocateur Supporting Member

    Jul 3, 2014
    Nashville, TN
    Update:
    Tuners and nuts came yesterday. Technology for Musicians. A little more expensive than MERA, but they shipped in four days - four days! - and they look great.
    IMG_6256.JPG

    Got the steel cap cut last night. Next up - grind a bunch, straighten out the straight edges and make the curves more pretty. Then create the back and sides, weld it together using MIG, then a bunch more grinding. Depending on my work schedule it'll either be Wednesday or Thursday. After measuring the tuners against my template I changed the steel cap design to two pieces. There was just a thin strip between the bridge pickup and the bridge tuners to begin with so it wasn't a huge change.

    IMG_6257.JPG

    Going to get the body wood tomorrow. [CONTENT WARNING: TONEWOOD DISCUSSION] Sorta torn between basswood, African mahogany, and ash. I'm thinking the steel cap/back will provide upper content, so the mahogany or basswood could balance it out. I'm digging the lightness of basswood also, given the steel and bridge tuners. Not sure how I'll finish the basswood on the upper horn though. Alder is another possibility.

    There's a part of me that wants to put ash into this for the percussiveness, low end, and good looks but it would definitely increase the weight and the high end might be too much - then again, I could just roll off the tone. FYI I'm putting passive electronics in this.

    My current bass is mahogany and while it would probably sound fine I'm interested in trying a different wood.
     
    Last edited: Jul 31, 2018
    BritFunk and charlie monroe like this.
  18. Bruce Johnson

    Bruce Johnson Commercial User

    Feb 4, 2011
    Fillmore, CA
    Professional Luthier
    Remember, when you look at how the bass structure affects the tone on the strings, what matters is the overall stiffness of the entire structure. The sum total. If the whole thing is stiff and rigid, then having some chunks of soft wood in there isn't going to do anything to warm up the tone. From what I'm seeing of your design, those steel plates are going to completely overwhelm anything the wood could do. The body is going to act and sound like a steel box. Unless you do something to make the plates floating, what wood you use won't make any difference at all.
     
  19. Those look a lot like Mera tuners. I used Mera on my last build, man they took a long time to get here.
     
    GentProvocateur likes this.
  20. GentProvocateur

    GentProvocateur Supporting Member

    Jul 3, 2014
    Nashville, TN
    Yeah, they're really similar. t4m tuners are more but it still blow my mind that they arrived in four days from Italy. The extra cost was definitely worth the expedited shipping and immediate availability
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.