neck alignment

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tonyturley

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I bolted the rough cut neck on my baritone ukulele body yesterday to check alignment. Apparently, despite using a body mold, the heel face of the body is not perfectly square to the centerline. The neck fits tightly, and the plane of the fretboard is flat, as I expected. However, when I run a long ruler along the fretboard centerline, it is not perfectly aligned. Sighting down the neck toward the soundhole, I cannot detect the discrepancy, but it's there.

I would leave it, but it's going to make my bridge out of square with the bridge plate. Besides just living with it, I see two other options:

1. Floss the neck heel, but that will make the 14th fret not square with the body join, and that would bug me to no end.

2. Sand the mating surface of the body to bring the neck into alignment, but that seems fraught with the possibility of really messing up.

Any thoughts or suggestions out there? Stuff like this drives me crazy. I never can seem to get through a build without some sort of error.
 
When I built a StewMac tenor uke years ago, I was surprised at all the precision that was required. Despite being careful, the neck is not perfectly aligned with the body. It's not something anyone would notice without examinging it, and I have no problem living with it. It's a strictly aesthetic thing. Looking at this picture, it seems as though the bridge is at an angle, but it isn't. Just an optical illusion - angle of the camera.

1.jpg
 
Thanks for the feedback, Jerry. I had the same thing happen when I built my first uke, also a StewMac tenor kit. The discrepancy was minor, and you could only tell with a ruler. I have had some builds where the neck came out dead-on, but it seems to be hard to replicate, at least for me.
 
tonyturley said:
Thanks for the feedback, Jerry. I had the same thing happen when I built my first uke, also a StewMac tenor kit. The discrepancy was minor, and you could only tell with a ruler. I have had some builds where the neck came out dead-on, but it seems to be hard to replicate, at least for me.
Click to expand...

Obviously, there is a problem with the StewMac kit. ;)
 
Ideally, the center line of the neck should be exactly in line with the center line of the body (sound board). Then, the strings should pass over the sound hole spaced equidistantly, and the bridge will be positioned dead center.

OK - that is stating the obvious, but the important word in that statement is, "ideally".

If, as you say, leaving it as it is will put the bridge significantly out of line with the position of the bridge plate, I would not consider that acceptable. Remember that moving the center line of the bridge over by 1/16" will offset the bridge by 1/8" relative to the sides of the sound board (and the bridge plate).

For me, there is no alternative but to work on the neck/body fit until it is as good as you can get it. It may take a lot of time and effort but that's what instrument making involves.

It is rare, in my experience, to get this exactly right. The bridge often has to be slightly offset. Provided the offset is not obvious, and the strings do not look wrong as they pass over the sound hole, and - very importantly - the strings are not close to the edges of the fret board, then you can breathe a sigh of relief.

How much offset is acceptable? That's up to you. I only build sopranos. There is very little room for error.

Fingers crossed,

John Colter
 
Use a wide neck blank to start with. ..Just work on the joint end first before the rest of the neck is profiled, when you get near enough...Then draw the neck centre line and adjust the shape of the neck to suit.
 
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Timbuck said:
Use a wide neck blank to start with. ..Just work on the joint end first before the rest of the neck is profiled, when you get near enough...Then draw the neck centre line and adjust the shape of the neck to suit.
Click to expand...

Ah, you must have done this before. ;)
 
This may help

 
Question: You do not say exactly in inches or millimetres how much the misalignment is. This is important as it is a question of degree. A very slight misalignment can be okay because as you say, you can compensate with slight bridge misalignment. As we all know, error increases over distance. I tolerate nothing more than a couple millimetres over 23 inches on a tenor. and spot on is best because of potential structural issues down the line.

To fix, I sand both the neck AND the body to align. Eventually you can dial it in. But don't touch the edges of the neck heal at your peril or you can create an unsightly gap. Go slow, be patient and it will eventually get perfect alignment. Note that the calculated position of the nut placement on the peghead may change depending on how much meat you have to remove.

Yes, Ken's method is spot on. I also get the neck to body join near perfect on the rough neck blank before starting anything. Getting it right then will save a lot of fiddling later down the line. Not only side to side alignment but also up and down for the proper finished neck angle.
 
I read about a Guy who claimed he did the perfect build..from resawing all the way up to final construction, everything went well and he couldnt believe his luck...Then after the uke was sold on the internet, he decided to give it a final polish on the buffing wheel before he packaged it for the customer....During that final polish he caught the edge of the uke on the buffing wheel and it pulled out of his hands and flew across the workshop with disastrous results. :wallbash::wallbash::wallbash:
 
As it happens I’m putting a soprano together at the moment...this is the stage where I check the alignment with a 2ft rule I use the hole at the rule end on the centre line of the lower bout, then check for equidistance all the way up the neck...this one is acceptable.::)
44EA0B3E-9AED-4CDC-B707-EC8D14C5674F by Ken Timms.. *EDIT * Ok so it's an 18" rule.:eek:
 
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Thanks for all the replies. The heel/body fit is gapless, top to bottom and side to side. I don't want to mess that up. I'm going to look at it again before I proceed. I'm going to do some mock stringing and see how everything looks.
 
After tapering the neck and fretboard, and carving/sanding the neck to shape, I bolted everything together and checked again. The difference is 2.5 mm at the tail end of a 30" instrument. I don't like it, and it's not ideal, but the neck and soundboard are co-planar and the heel fit to the body is tight top to bottom. The string placement over the soundhole isn't noticeable, so I'm just going to leave it and use it as a learning lesson. I'm not planning on using that body mold again, so I'm just going to toss it.
 
Hi Tony,
I had that neck, bridge alignment disaster happen on my first builds a couple of times too many. Drove me insane so I threw all my insanity into a master plan mold, solera Mcgyver thingamajig and came up with an indexed jig thing to build around the centerline for all sizes. Here’s a couple of pics. A little overkill but what the heck, it works for me.

D0060B9C-474B-4DE9-AEB3-69B1872BD8C9.jpg
E6BB9121-F462-47F7-B315-6B51BCBD9503.jpg
 
Dougbias said:
Hi Tony,
I had that neck, bridge alignment disaster happen on my first builds a couple of times too many. Drove me insane so I threw all my insanity into a master plan mold, solera Mcgyver thingamajig and came up with an indexed jig thing to build around the centerline for all sizes. Here’s a couple of pics. A little overkill but what the heck, it works for me.
Click to expand...
Thanks for the pics, Doug. Looks like a nice solution.
 
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