Question about building order (octave mando)

**belbein** · Jun-26-2012, 11:06am

I'm about 1/3 of the way through with my build of an Octave mandolin from a kit. The instructions say that I should glue on both front and back plates before working on the neck blank (shaping, fretboard, etc.). Then I'm supposed to attach the neck to the built-on block. It's a bolt-on neck, by the way.

BUT ... my hand is not going to fit through the oval sound hole to bolt the neck on, or take it off.

So, I'm thinking: WITHOUT gluing on the top, I'll remove the neck, roughly shape it, (everything up through shaping, fretting, dots, and attaching the fretboard), then I'll 4re-attach the neck, then glue on the top, and then go on from there.

Is there a problem with this?

**Mike Black** · Jun-26-2012, 11:18am

With bolt on necks you can use a long wrench through the endpin. Weld an allen wrench to the end of a long T shaped shaft.

**TijnBerends** · Jun-26-2012, 11:40am

With all three instruments I built, I glued on the neck first, then the top and back plates. That way, I could make sure everything as perfectly aligned too.

**belbein** · Jun-26-2012, 12:13pm

Wouldn't that make the end-pin hole, like, 1/2 inch in diameter?

**dunwell** · Jun-26-2012, 2:03pm

Originally Posted by belbein

Wouldn't that make the end-pin hole, like, 1/2 inch in diameter?

Close, but not really. I made mine the size of the hole I drill before reaming (5/16, 3/8" can't remember just now). You can sort of see the tool in use HERE The thing in the f-hole is an LED flashlight with a goosneck.
Ah, found another better shot HERE.

It is just a piece of drill rod that I end drilled to take the proper sized allen wrench piece. I use a ball-end allen, that makes it easier to get it into the bolt heads. I also cross drilled and tapped it for a set screw. I then used a grinder to make a notch/slot in the allen wrench below where the set screw goes in. This holds the allen to make sure it can't accidently pull out and let the setscrew be a bit recessed. The other end I threaded 1/4-20 and spun on a t-handle thing.

Alan D.

**Rick Lindstrom** · Jun-26-2012, 2:30pm

You can't really be sure that you have the proper neck angle until the neck block is securely attached to both the front and back plates, and the neck has been adjusted accordingly. It doesn't take much to throw things out of whack if the neck block moves even a tiny bit.

Just my opinion, of course.

Rick

**belbein** · Jun-26-2012, 2:35pm

Originally Posted by dunwell

You can sort of see the tool in use HERE The thing in the f-hole is an LED flashlight with a goosneck.

OK, that reminded me waaaaay too much of something I need to schedule with my internist. Talk about "pucker."

**belbein** · Jun-26-2012, 2:39pm

Originally Posted by Rick Lindstrom

You can't really be sure that you have the proper neck angle until the neck block is securely attached to both the front and back plates, and the neck has been adjusted accordingly. It doesn't take much to throw things out of whack if the neck block moves even a tiny bit.

I'm not sure what you mean. By "neck block" do you mean the block that has the mortise in it for the tennon in the neck? In any case, I'm having a hard time understanding the bottom line. Are you saying that I should leave the neck on and glue on the top plate, or take the neck off and figure out how to attach the neck after I glue the top plate?

**dunwell** · Jun-26-2012, 2:41pm

Updated and added another photo that shows it in use from the back side (so to speak)

**dunwell** · Jun-26-2012, 2:48pm

Originally Posted by Rick Lindstrom

You can't really be sure that you have the proper neck angle until the neck block is securely attached to both the front and back plates, and the neck has been adjusted accordingly. It doesn't take much to throw things out of whack if the neck block moves even a tiny bit.

Just my opinion, of course.

Rick

Rick, you are right of course with a glue on neck. But with a bolt on not so sure. I set my neck angle with the top glued to the ribs, that having been done in the form. So it gets locked pretty good right there. Then I fit the neck to body really close with the back off. Then the neck comes off and the back gets glued, again in the form, so the body is really locked at that point. Now I can come back and tweak the neck angle if necessary when I bolt it on, but so far that hasn't been necessary. See what I'm getting at? Just different ways of going at it.

Alna D.

**belbein** · Jun-26-2012, 2:55pm

Originally Posted by dunwell

Then I fit the neck to body really close with the back off. ... tweak the neck angle if necessary when I bolt it on,

I want to be sure I'm understanding you. So when you say "fit the neck close," you mean make sure that your mortise and tennon are really tight. And when you say "tweak" the angle, you mean shimming if necessary. Right?

**belbein** · Jun-26-2012, 2:57pm

Originally Posted by dunwell

Ah, found another better shot .

OK. Thanks. Now I got it. Of course, now I'm wondering if my one-screw neck should be two screws, since that would allow me to adjust the angle after I close up the corpse.

**dunwell** · Jun-26-2012, 3:22pm

Originally Posted by belbein

OK. Thanks. Now I got it. Of course, now I'm wondering if my one-screw neck should be two screws, since that would allow me to adjust the angle after I close up the corpse.

It is actually kind of a tough question with something as small as a mando. One screw set just below the center line would probably be enough once it is strung up. If you are using thread in anchors then one is probably all you should use since two are going to use up a lot of "meat" in the heel. With my design with a vertical rod into the heel then it doesn't matter how many times I drill and thread the rod. The fit of the heel butt to the body still determines the neck set, there isn't much wiggle there so it still has to be really right. You don't adjust the back angle at all with the bolts, they just hold it in place. It does have some side to side where it can rotate around the radius of the body, thus my dorking around with being fussy about getting it centered just so. Once I snug the screws even a little though it grabs on and doesn't move. Once the finish is on it really locks in place when you snug it up.

Alan D.

**dunwell** · Jun-26-2012, 3:30pm

Originally Posted by belbein

I want to be sure I'm understanding you. So when you say "fit the neck close," you mean make sure that your mortise and tennon are really tight. And when you say "tweak" the angle, you mean shimming if necessary. Right?

Ahh, no mortise and tenon. I use a straight up butt joint. So by fit close I mean fit the curvature of the heel butt to the body so that it wedges snug and has the proper back angle. If I need to tweak the back angle that is done by re-shaping the butt of the heel. That can get nasty though once the fretboard and extension are in place, I have not needed to do that so far. But in that case, yes, I'd probably do it by making a piece of tapered maple veneer to insert. With my bolt on bouzouki setup I actually just make an obvious shim of contrasting wood and sand the taper onto that, but there the head block is flat so that works well. With the rounded mandolin setup it doesn't.

Alan D.

**belbein** · Jun-26-2012, 4:16pm

OK, so given all that, and given that my mortise and tenon fit as tight as ... well, tight. Is there any reason that I have to futz around with taking the neck off to glue on the top, and then gluing on the top and then re-futzing with the neck through that little sound hole or the [twinge] "back side"? If there is, I'll do it. If not, I'd just as soon avoid it.