MIMF

Last weekend I saw a double bass with a removable neck made by Charlie Chadwick. It's a conversion of a Shen plywood bass. Now I have a solid wood bass, not terribly expensive but better than plywood, in good condition. I don't imagine the Shen bass would compete with it. It's disadvantage is that it's 4/4 so rather difficult to transport. I'm quite happy to have the neck as a separate piece to carry or I could find a custom case, so I don't need to put it inside the bass like the Chadwick design.
I wondered if anyone has any experience of detachable bass necks? Is there any hardware available off the shelf? I'm not averse to having some metal in there and fixings showing if tastefully done.

While I'm asking questions, how do you go about removing a perfectly well glued double bass neck?

While I'm asking questions, how do you go about removing a perfectly well glued double bass neck?

In my opinion, the answer here is "you don't- you leave it alone!"

I am a guitar guy, and not a violin-family luthier at all but I just thought after I read this, that I'd throw my opinion out there. If I had a decent bass, I wouldn't try to fool around or experiment with it...I'd get a plywood one and try that. Messing with a good instrument is asking for trouble and regrets.

You might try contacting Matthew Tucker at Bresque Basses
http://bresque.studio205.net.au/double-basses.html

He has done conversions of this sort very successfully, and will show one at the ISB competitions this summer.

He features exactly what you are asking, and the neck has a separate case. All can be assembled or dis-assembled in about ten minutes, if I remember correctly. He will do custom transformations, or tell you how it is done. Good guy all around.

Chet Bishop

Chet,

I checked out this Tucker guy...

He's an amazing bass builder - using alternative woods, designs and finishes. (a man after my own heart)

Even though my practice has not ever had anything to do with making basses, I've repaired my fair share, and find them fascinating (from a distance) they're so darned BIG compared to a fiddle. I can't imagine what making them is like - repairing them is more than enough for me...

And don't overlook his last name - that's a big clue to his competence!

Thanks for posting that link!

ct

If you want to see a really neat restoration project, Matthew posted lots of details over here: http://www.anzlf.com/viewtopic.php?f=1&t=2414

Well, as suggested I've got another bass to work on. Again all solid wood but in a bit of a state, unglued round both C bouts and a well cracked top.
I got the top off to discover that a previous "repairer" had used white wood glue for most everything so I've had lots of cleaning up to do and lots of splinters to steam off the top of the ribs. Looks like I'm going to learn a lot of skills before this plays again, including crack repair and re-edging.

Today I wrestled the neck off with lots of steam and wriggling. It was fixed by a parallel dovetail from top to bottom. There was an existing break in the heel from an original joint. At the moment I have left the bottom third of the heel attached to the button.

I have looked at many removable neck designs but am unsure which is best. I worry about the forces involved. The simplest seem to rely on a close fitting joint and one bolt. That bolt would need to be low down on the heel I think, so what should I do about the break? Remove the last third of the heel and reglue it to the neck is easy but does it then need reinforcing? With a thick dowel?

Or should I go for a solution that involves more metal? Maybe that would allow for action adjustment at the neck.

Comments and suggestions please.

I would heartily recommend the Chuck Traeger book http://www.amazon.com/Setup-Repair-Doub ... 1892210061
as he will give you all the knowledge you need to fix this bass. Cheap at twice the price.

Yes, I've got it. Partly that's what makes me concerned about the neck joint, he's very clear that all parts of the bass are vibrating and I don't think a substandard joint will help that.

If you are going to make the neck joint detachable then you have more things to consider, but if you are going to repair it to a sturdy traditional condition I would NOT use a dowel, but use a spline in the heel to reinforce the entire length of the heel.

Thanks, that's useful knowledge. The issue then is that a fixing bolt would go through the spline taking away much of its strength. What sort of dimensions are you thinking of for the spline?

I've thought a bit more and think I may have a solution. As I need to square off the dovetail on the heel I was thinking of a triangular insert each side, but I could also achieve this and avoid weakening a single spline with the bolt if I put a spline each side with the bolt passing between them. Carefully opening out and squaring up the mortice in the tail block to match.

Would maple be a good choice for the splines? I think it needs to be a hard wood to take the wear and tear when it is assembled and dissassembled. Grain direction should be up and down the heel I take it?

Do you think similar inserts in the sides of the mortise would be a good idea?

Why do you need to square off the dovetail and mortice ?
I do removable necks on guitars and generally use the typical curved profile heel found on classical guitars, but fitted into a mortice similar to what a violin would use. I use 1 bolt, low on the heel, and a couple of alignment pins higher up. I bore a hole part way through the back of the heel, and inset a metal spline with a hole bored through it for the bolt to pass through and bear against. The head of the bolt (cap screw) is countersunk into the heel and is removable with an allen wrench. It makes a less conspicuous, easily accessed removable neck. It would also lend itself to being changed back if that later become desirable.