www.FretlessBass.com

Okay guys, I don't actually play fretless bass, but rather regular fretted/limited guitar. I am interested in beginning to luthe my own instruments, and my friend and I wish to work on a fretless bass project. So far we have decided on a through-neck design (5 part laminate, cliché purpleheart stripes, etc) and I have a few questions. Taking into consideration that a fretless bass (obviously) has no frets, and that the through neck structure should be quite strong, will it require a truss rod? The problem that concerns me with a no truss instrument is not so much the issues with strength or bowing of the neck, it's just that I don't know how much (if any) relief a fretless bass neck requires. Assuming that the neck stays straight (I still plan to include 2 strengthening beams), the only problem that I can foresee is that the neck requires relief to compensate for the fact that the amplitude of the string vibrations are greater in the middle. Put simply, will the strings bottom out on the fingerboard board? I was also wondering someone could help me with the following queries: how high should the strings be off the fingerboard at the nut? Should the strings be parallel to the fingerboard (if not, is there a desirable angle / comparative height between nut and bridge)? What is a good radius for a fingerboard? Can you recommend any woods for the body? Should I aim for brighter or warmer woods?

Search other posts on this site for answers to these questions.

Ok well thanks, but really I only found this (yes, I looked over the WHOLE board). http://fretlessbass.com/viewtopic.php?t=32 This is good in terms of adjustment of a truss rod, but it doesn't answer my question about the necessity of a truss rod. If anyone has any other advice, or even if some one could just do a few measurements for me (string height from fingerboard at nut, and at end of fingerboard (specify ~roughly~ what that is in fret-number-terms)) and that'd be great. And just descriptions of the woods and the resulting sounds would be really helpful. So far I think maple and purpleheart neck-through, but body I have no idea.

Stringed instrument neck relief is a balance between string tension, neck strength, the amount of relief you desire, and preloading of the neck (in the case of non-truss rod necks), or opposing stress imparted by a tension rod.

If you are never going to change string gauge or tension, then a neck without a rod will work fine provided you have enough experience to build the neck with the desired amount of preloading to achieve your target relief in the first place. If your calculations are off, or the woods have strength greater or less than you predicted then the final relief will not be what you anticipated. Some accommodation can be had in re-work by shaving the neck until it is thinner (and weaker) to arrive at your target relief. On the other hand, if you have too much relief you may take off the fingerboard and replace it with a thicker, stronger one. Another approach would be to remove the fingerboard, load (bend) the neck to the preload condition you need and plane it flat in this new state. It may also be possible to re-glue the existing fingerboard while the neck is preloaded (bent) and rely on the strength of the glue to keep the neck in the relief condition you need, then plane the fingerboard.

Luthiers (I am not a luthier) may have some better advice and techniques to share. Since non-truss rod necks are commonly found in violins it might be a good idea to consult a violin maker. How to plane a fingerboard while the neck is loaded with the proper amount of tension would be a good question to ask.

This link in FretlessBass.com may help. http://fretlessbass.com/viewtopic.php?t=127

This post explains about non-truss rod axes such as Modulus and includes measurements. http://fretlessbass.com/viewtopic.php?t=35

You will also find posts regarding the advantage/disadvantage of neck-through versus bolt on design.

As far as tonewoods go, that is a personal preference that your customer should relate to you. Some discussion on tonewoods is also on this board.

Radius is another personal/player preference, generally wider necks get greater (flatter) radius. It requires an unusually thick slab of raw fingerboard to make a wide fingerboard with a small radius. You might want to consider a variable radius fingerboard that will fit on the available fingerboard slab.

Good luck with your fretless project, I hope it is a success.

Hey man, that's awesome :) thanks heaps.

I am not at all an experienced luthier so loading the neck would be a luck kind of deal, and I'll be changing the tuning too, I imagine. So truss-rod seems like a definite for a first time project. I am building for myself and another for my friend, both of us really have no idea on which woods to use. I assume fretless basses would benefit from brighter woods, but it will still need to be able to carry the middle and lower registers. I'm pretty fixed on the neck through design, but I'll check out that link none the less. So a typical "greater" radius would be 12"? I really have no idea. Compound radius as not really plausible as I will be making my radius with a curved sanding block.

That's heaps of resources there, thanks again man.

Any one who gives this a read, feel free to quickly jot down the woods and neck construction of your fretless and what tones you get out of it.

Cheers \m/