Construction failures

A couple questions..

1. What do you think is the most common failure in a uke as a result of construction?

2. Are certain failures more common in certain styles of instruments?

3. What do you think is the appropriate period of time, under tension, that you can say an instrument, or a component, hasn't failed? For example, "the top has held up over X amount of time so I feel comfortable not using a bridge patch."

Anyone have any more? I think some of this goes back to the discussion about copying first and experimenting later. At what point can a builder gain confidence in his procedure?

The most common failure......Failure to cure Ukulele Building Syndrome. I just keep wanting to build more and more

ksquine said:

The most common failure......Failure to cure Ukulele Building Syndrome. I just keep wanting to build more and more

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Is that abbreviated UBS

thistle3585 said:

A couple questions..

1. What do you think is the most common failure in a uke as a result of construction?

2. Are certain failures more common in certain styles of instruments?

3. What do you think is the appropriate period of time, under tension, that you can say an instrument, or a component, hasn't failed? For example, "the top has held up over X amount of time so I feel comfortable not using a bridge patch."

Anyone have any more? I think some of this goes back to the discussion about copying first and experimenting later. At what point can a builder gain confidence in his procedure?

Click to expand...

I think top of the list has to be bridge separation from the sound board. Behind that has to be sound board buckling and further down the list, neck separation from the body.
Suspect tension from strings so tenors first with sopranos being most forgiving but also would depend on just how crappy the build.
As I think about your third question and first from a consumer point of view, my expectation is that it will last forever (guitar or ukulele or a piece of furniture). So your absolutely right when you say start out with proven methods. There might be a way to accelerate time by increasing the tension and subjecting an instrument to temp and humidity changes but I don't know what that is or who would know. So, sadly the bottom line has to be, you look around see what has worked and take a chance. Building without a bridge plate increases the focus of stress to the sound board and/or the bridge. You have to ask is the sound that much improved to take that chance? Or, does the builder increase the sound board thickness to compensate for lack of bridge plate? More food for thought than an answer.

To the failures mentioned by Fred I would add a bowed neck, and a crack in the back (under extreme heat). We've also had a bridge separation (also under in extreme heat).

Any failure due to high heat or extreme humidity changes are not construction failures they are owner abuse. I have done a lot of guitar repairs and various other stringed instruments and overwhelmingly they are necessary because of owner actions. The few that were construction failures were due to three things. Most often a poor choice of wood, either too weak, too soft or unstable. Second, a poor choice of glue, allowing parts under tension to creep. And third, a poor fit between parts, most often between the bridge and the top. I have seen cheap tuners fail but not yet on a uke. I haven't seen enough ukes to give an opinion on question 2. As to question 3, it shouldn't fail ever but realistically if it hasn't failed in a year it will probably never fail.

After inspecting a lot of Ukes including my own pathetic efforts..I've come to the conclusion that the most common construction failure is in measurement...Neck angles way off with bridges off set or saddles way too high etc:..Bridges in the wrong place = (bad intonation) ...sound boards (tops) too thick or too thin..Frets not parallel (skewiff)..Tuning peg's out of line..marker dots off ctr...Rosettes not concentric to sound hole..and thats just my uke's...some of the others are worse

Those aren't failures, those are features!
"Yes, the intonation is uniquely eclectic. People are intrigued by it."

This isn't a failure, but its a common mistake i see a lot of people make...........Dont use fancy or expensive woods on your first few instruments. If you dont have the chops as a builder, its kind of a waste. Save the good stuff for later.

Jake Maclay
http://www.hiveukuleles.com/

Plywood body. You could play tennis with it and it probably wouldn't break, but it's still a failure. On guitars it's always the neck at the headstock from falling over... I dunno, I have a 30's harmony and the only thing coming loose on it is the plastic b/w rosette.

Eclectic intonation lol... I guess mine is probably eclectic too..