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View Full Version : Few questions from experienced mando builder, first time uke builder.



fscott
03-31-2018, 10:50 AM
So trying to see what techniques I can bring over from my mando building . I'd assume some may be overbuilding, but alas, need some guidance... And I'll just use this thread if/when I have some new questions.

I am building a tenor size mando, and want to use the highest tension tuning and/or string. I don't know all the details about strings yet. Very new to the uke.


1. I am thinking of doing a dovetail joint like I do on mandos, or in the least, a straight tenon joint with dowels to hold it in place. Are either of these options something that can be done?

2. If doing a dt joint or dowel joint mentioned above, what size should the head block be? Right now I'm thinking mahogany at 60mm wide and about 25mm deep. Is this big enough or too big?

3. Tail block size?

4. Finally, tap tuning AFTER the soundboard is glued to the rim. I do some tap tuning with the mando after top has been glued, and it works out well. Not sure if there is a guideline that you builders use to determine the top stiffness. I also some deflection tuning but that jig is built for mandos obviously. Just looking for some thoughts on whether you guys have tried tapping the tops when youre close to final.

That's all I can think of for now. I've got the rim already glued up and my top and back sanded down to about .100" which I know they will have to go thinner. Walnut back/sides with douglas fir top.

sequoia
03-31-2018, 02:11 PM
1) Either join method will work fine.
2) I make my neck blocks 50 mm wide.
3) My tailblock is 1 3/4 inch wide.
4) I'll leave the black magic of tap tuning to some one else.

None of these dimensions is very critical and can vary widely. Good luck!

fscott
03-31-2018, 11:19 PM
Thanks.

I see youre headblock as 50mm wide, what depth would you recommend it to be if I use a dovetail joint?

5) I plan on doing a 14 fret neck, with the higher tuning. Does this change the standard 3 fan bracing I see on plans?

greenscoe
04-01-2018, 12:21 AM
None of these dimensions are exact: different makers will have their own ideas. Many cheap Chinese ukes have very small neck blocks, whilst some makers will use quite massive neck blocks. Few makers use the tapered dovetail joint, I think the commonest joint may be the bolted joint. Some will use a tenon, a biscuit joint or use a dowel. Some will simply use a butt joint. The upper bout/neck interface may be flat or curved: if curved this adds to the complexity of making the joint.

I normally use the tapered dovetail joint: the link shows this joint which is 0.5" (12mm) deep to answer your question.

http://forum.ukuleleunderground.com/showthread.php?132194-Necking

It's the same story with fans. Tall or low, wide or narrow, whether parallel or tapered.... take your pick. Each maker finds their own solution. If you have a plan as a basis for your build and you think greater tension needs beefier fans, then you could modify slightly. An overstrutted soundboard is likely to favour the treble side.

I dont think many do much tap tuning. After a few builds you get an idea about the sound and feel of a soundboard.

As a first build, whatever you do, its unlikely you'll produce a masterpiece, so view it as a learning exercise. I constantly recommend that new builders spend time reading old posts on this forum and watching classical guitar and uke videos on YouTube to see the many, many approaches to making an instrument.

I am a hobby maker with about 25 instrument builds to date, tenor ukes form the largest category.

fscott
04-01-2018, 02:03 AM
I appreciate that reply greenacres. I have watched a ton of uke building videos, slides, etc.. And the fact that there are so many variations in building is what makes it even more confusing. Mando building has far less "options".

Like you say, I dont have any experience on the forces and tension that a uke experiences, so I'm clueless on how to build it without some guidance. I see instrument building as an exercise in offsetting the forces with the least amount of wood possible.

Uke Don
04-01-2018, 04:43 AM
A tenor uke has about 40 lbs of total string tension, a fraction of a mando. So the type of neck joint is less critical in a uke build.

fscott
04-01-2018, 04:05 PM
6) I am doing a 20' or 25' radius top and back with traditional 3 brace fan with the 2 transverse braces above and below soundhole. Do all braces get the radiused profile on their bottom (glued side)? I was thinking of the two outside fan braces.. I guess they are pointing to the "center" of the top so they receive the same radius bottom as the other braces..?

sequoia
04-01-2018, 05:04 PM
Thanks.

I see youre headblock as 50mm wide, what depth would you recommend it to be if I use a dovetail joint?

5) I plan on doing a 14 fret neck, with the higher tuning. Does this change the standard 3 fan bracing I see on plans?

My neck block is 2 7/16 inches tall and my tail block is 2 5/8 tall so that there is a 3/32 difference giving the sides just a little less than a 1/4 inch taper over 12 inches. I strongly believe (which I have absolutely no evidence) that a tapered body is important to the sound.... I don't believe the dimensions of your neck block has anything to do with what type of neck join you choose to use.

No, the standard 14th to the body has nothing to do with your bracing plan. A three fan brace system is an old standard for tenors. As far as radiousing your top, be aware that this opens a lot of gumption traps for construction. I would recommend just doing a flat top for a first build.

What I will say is, don't over think this thing too much. We are just building ukuleles here and not Atlas rocket boosters. You will find that whatever you do, the resulting product will sound pretty much like an... ukulele. And yes, like Greenscoe says, it is just a first build and is ultimately a learning experience. Try not to obsess too much over the esoteric details. Just build the dang thang and let the chips fall where they may. Good luck!

greenscoe
04-01-2018, 09:02 PM
6) I am doing a 20' or 25' radius top and back with traditional 3 brace fan with the 2 transverse braces above and below soundhole. Do all braces get the radiused profile on their bottom (glued side)? I was thinking of the two outside fan braces.. I guess they are pointing to the "center" of the top so they receive the same radius bottom as the other braces..?

I think many (especially hobby builders) will use a flat top and this is how I have made most (not all) of my tenors. Using a radius top builds in some tension. This combats the tendency for bridge rotation where the soundboard dips ahead of the bridge and bows behind the bridge. Many pro builders would also say it makes their instruments sound better.

20/25' is OK for a top, 12 or 15' would be a more appropriate radius for the back.

If you do radius the top, the transverse brace below the soundhole can be profiled on the glue side. The fans (and a bridge patch, if you are using one) are not usually profiled on the glue side (this may depend on what bracing system you use). The radius dish/solera used for the construction together with clamping of the fans on a go-bar deck is normally all thats required to build in the radius to the top. Be aware that the radius may be reduced if/when the fans are subsequently pared down.

fscott
04-01-2018, 11:03 PM
Thanks to both replies above. I'm glad you mentioned radiusing on the lower transverse brace, that makes sense to me. I have a go bar deck so it should come in handy.

I fully get the 1st build phenomenon. I'm more interested in grasping the build process fully rather than trying to build a great tone. The tone comes from many builds.

The fact that there are so many ways to build a uke is what makes it interesting.