Adding Extension Wood To Extend Scale Length?

[lukeo]

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Edited February 19, 2011 by lukeo

[another doug]

That neck is a 34" scale length. Moving the bridge farther from the nut will only make it impossible to intonate.

You would only be able to change the scale length by moving the bridge if you had a fretless neck (preferably with no lines or dots).

[dpm99]

Or you'd need to remove the fretboard and replace it with a 38" scale fretboard.

[jammy]

The place you have to add length for a job like that is behind the nut.

Buy a bolt on construction bass and make a 28" (or as close as you can) scale neck for it by, in effect, adding frets behind the nut.

[lukeo]

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Edited February 19, 2011 by lukeo

[Mickguard]

Oh I definitely plan on ordering the neck fretless with no lines or side dots. I am just wondering construction wise would the extension piece hold on after being glued from 3 sides?

First, you ought to let us know if you're understanding the concept of scale length.... just adding wood at the end of the fretboard doesn't change the scale length. That is determined by the distance between the nut and the bridge saddles. All you'd be doing by adding the extra bit of fretboard would be adding the possibility to reach higher notes.

Got that? Hey, just checking.

Anyway, I don't see a problem with gluing an extra bit of fretboard onto the end bit there.

And there's no reason why you have to stick to a throughneck design, you could easily convert that to a set in or bolt on. I don't really see the point of adding more wood to the end of the through neck, if that's what you're suggesting. Unless you just like the look of a through neck? A scarf joint would do that easily.

[lukeo]

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Edited February 19, 2011 by lukeo

[joshvegas]

I understand the concept of scale length. No, I'm not talking about adding wood onto the end of the fretboard. I'm talking about adding a 6" x 2.4" x 1.68" piece onto the very end of the carvin neck-thru neck. So the bridge would be put onto that piece, and saddles to nut I'd have 38". I was talking about just glueing it on flat, didn't think of making a joint there.

I just really like the neck-thru design so I'd prefer that over a bolt on, and I'm gonna do a few of these before I attempt a glued in set neck.

thanks for recomending the scarf joint. I looked it up in "Martrin Koch, building electric guitars" and he does it a few different ways. I'm just starting to collect my tools now, what would you say is the best way to make a scarf joint?

why not justtreat the trhough neck as a very very long neck tennon? any way even if you do what you are suggesting are you not going to have a very short fingerboard?

And why 38? I don't think I could even play that with my tiny arms!

Edited November 20, 2008 by joshvegas

[foil1more]

Isn't 38 about the length of an upright bass?

[lukeo]

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Edited February 19, 2011 by lukeo

[Mickguard]

Have a search through the forum, there's tons of great info about scarf joints here. Usually in relation to the headstock, but same principle. As you figured out, you can't get a good joint from gluing endgrain.

I actually think the project is a pretty cool one. Are you planning to play it as an upright too?

You oughtn't rule out extending the fretboard, while you're at it. It wouldn't be that difficult to do, and you can hide the joint with a bit of inlay. The only issue I suppose would be getting a matching board that gets wide enough.

[avdekan]

Its possible, But you'll have to do a good job fitting the wood piece in there.

I think that simply taking a rectangle chunk out of the neck through end, going through the entire thickness of the bass is probably not such a good idea, since the two surfaces that go alongside the neck will probably be subjected to "crawling" due to string tension, and the remaining surface would be end-grain to end grain contact (weak).

I would suggest increasing the gluing surface with some sort of a "step" like a rabbet joint, or simply not to go all the way through in order to provide a gluing surface thats flat to the direction of the string pull.

Also, you will not have a bridge pickup since you are moving the bridge away from the pickups, and routing the piece of wood you are adding would severely weaken it.

hope it helps.

B

[j. pierce]

What are you going to do for a bridge? If you use a standard bass bridge on a neck scale 4 inches longer than normal, but with a neck originally constructed for a conventional electric bass scale length, I'd imagine the string taper is going to be kind of messed up, and you could end up with a significant amount of extra fretboard overhang at the higher positions.

Could probably be solved easily enough by making your own bridge with saddles, or using a supplier like Hipshot that offers some variations on string spacing, but worth mentioning.

[lukeo]

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Edited February 19, 2011 by lukeo