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View Full Version : My first build complete, and hopefully learn some lessons.



mikeyb2
03-26-2016, 07:37 AM
I made quite a few mistakes with this, my first uke build. I continued to finish it so that I would make all the mistakes on the same build and learn from them. Some observations. There are a couple of things I'm not sure how to correct in my next build. Maybe you could help. I used a 15' radius dish to shape the back and braces, but the radius seems to have flattened out somewhat. It seemed ok when I first glued the braces up, using a homemade go bar deck with the back sat in the dish.
Secondly. the top has dipped slightly and when looking side on, the positions of the fan braces can be seen over the lower bout. Maybe I went too thin with the top, I don't know.
Overall, I'm quite pleased though, it sounds ok, plays ok and the intonations pretty good8972089721897228972389724.

Beau Hannam Ukuleles
03-26-2016, 07:49 AM
Looks nice. Congrats
Personally, id make:
1- the bridge a tad thinner, (my tenor bridges are 7/8" x 4")- the difference of 1/8" in thickness is noticeable.
2- the heel radius smaller
3- the heel cap smaller

DotBot
03-26-2016, 10:56 AM
I used a 15' radius dish to shape the back and braces, but the radius seems to have flattened out somewhat. It seemed ok when I first glued the braces up, using a homemade go bar deck with the back sat in the dish.
Secondly. the top has dipped slightly and when looking side on, the positions of the fan braces can be seen over the lower bout. Maybe I went too thin with the top, I don't know.

Hi Mikey,

Well done! Finishing your first build is a great accomplishment. As a novice myself, and having experienced similar issues with radius decreasing or top sinking, keeping an eye on humidity when gluing up these parts is crucial.

If your work space is at the mercy of the elements it can be frustrating to wait until the humidity is favorable but it's worth the wait. If you search this forum, no doubt you will find lots of good advice about this from the experts.

Cheers,
Aaron

Allen
03-26-2016, 11:02 AM
The back flattening out is most likely due to variation in relative humidity from when it was braced to when it was attached to the body. Being drier or more humid will change the shape of any part that has been cross braced. Careful control of humidity is crucial, or at the very least be aware and have a build schedule that takes it into account.

The sound board dip if not too severe can be a good thing. You actually want a tiny bit of belly behind the bridge and this will tend to cause the area in front of the bridge to dip. Telegraphing of the braces through the sound board if slight is ok too. On thin tops you will certainly see this. It's also common to see this happen when the humidity swings a fair bit from when the box was first closed up.

mikeyb2
03-26-2016, 01:42 PM
Thanks everyone, I suspected humidity might have caused a problem, but just how much variation causes this problem?. I've built this over the last few months here in the UK, autumn through winter when the humidity is low with not too much variation. Temperature may have been an issue, as my workshop is my open garage which has been very cold at times, and when I needed to glue anything, if the temperature was below 10c(Titebond) , it was taken into the house.
I'm still not quite sure what to do about humidity in the future. My next build will be over the coming spring/summer months when the humidity will be higher, but the temperature will be high enough to glue in the garage.
Oh and Beau, I agree with your point about the bridge, thanks for the input.
Mike

PhilUSAFRet
03-26-2016, 03:38 PM
Not helpful, but I think it's a great looking first build. If everyone could build a "perfect" instrument on their first try, luthiers would quickly go out of business.

sequoia
03-26-2016, 04:42 PM
For a first build, this a very tasty looking instrument. You should be proud. Good job... I notice that you might not be totally satisfied with the sound (sounds ok, plays ok and the intonations pretty good). Give it time. These things need a little time to adjust and settle in. Also, your subjective ear to sound is maybe not realistic. Give it a couple of weeks... One thing you don't specify is the thickness of your top and back in real dimensions. That would be helpful. As Allen and others have pointed out, small amounts of witnessing and unevenness is to be expected. This might not be a problem with overbuilt instruments (little tanks) which is why the low-end manufacturer's ukes sound so bad. They don't witness or move ever. Or at least not until the warranty expires.

mikeyb2
03-26-2016, 11:12 PM
For a first build, this a very tasty looking instrument. You should be proud. Good job... I notice that you might not be totally satisfied with the sound (sounds ok, plays ok and the intonations pretty good). Give it time. These things need a little time to adjust and settle in. Also, your subjective ear to sound is maybe not realistic. Give it a couple of weeks... One thing you don't specify is the thickness of your top and back in real dimensions. That would be helpful. As Allen and others have pointed out, small amounts of witnessing and unevenness is to be expected. This might not be a problem with overbuilt instruments (little tanks) which is why the low-end manufacturer's ukes sound so bad. They don't witness or move ever. Or at least not until the warranty expires.
Thanks. My thoughts on the sound are mainly based on my inexperience with ukuleles, and inability to appreciate the finer sonic qualities of various ukes.(I'm not a player but I've learnt some basic chords recently.) It does sound good to me, but what would I know? The only one I can compare it with is a Kamoa maple tenor which I bought used as a reference in building. The Kamao is louder but mine has a sweeter tone.
When I was thicknessing the top and back, I was aiming for 1.8 top and 2 for back, but after final sanding with a ROS, in reality I seem to remember they ended at a shade less than 1.7 for the top and 1.9 back. Mike

kohanmike
03-27-2016, 04:45 AM
Very nice, good work. (BTW, when you get ready to post the photos, be sure to hit a couple of carriage returns so the photos don't whack out the spacing of the paragraph. You can edit your post and add the carriage returns anytime.)

ProfChris
03-27-2016, 08:08 AM
Humidity changes much more in the UK than you'd think, and in an open garage you will get the benefit of every change!

My suggestion is to build yourself a hygrometer - two thin strips of veneer glued together with the grain at 90 degrees. Mount this on a board so the strip can curl, and you can put pencil marks on the board to show where it has curled to. Then, every time you look at it, mark where the end of the strip is. After a few weeks it will have curled back and forth across the likely range of humidity. Work out which is the dry side (that will be the cross-grain side) and only do bracing or box closing when the pointer is towards that side. That's good enough for UK conditions (though not Arizona, say).

mikeyb2
03-27-2016, 09:18 AM
Humidity changes much more in the UK than you'd think, and in an open garage you will get the benefit of every change!

My suggestion is to build yourself a hygrometer - two thin strips of veneer glued together with the grain at 90 degrees. Mount this on a board so the strip can curl, and you can put pencil marks on the board to show where it has curled to. Then, every time you look at it, mark where the end of the strip is. After a few weeks it will have curled back and forth across the likely range of humidity. Work out which is the dry side (that will be the cross-grain side) and only do bracing or box closing when the pointer is towards that side. That's good enough for UK conditions (though not Arizona, say).
That's just the king of advice I was looking for, although I'm not entirely sure what this would look like. Do you have picture showing the idea and size? That would be a great help. Thanks Mike. In the meantime I'll google it.

sequoia
03-27-2016, 05:59 PM
but after final sanding with a ROS, in reality I seem to remember they ended at a shade less than 1.7 for the top and 1.9 back. Mike

I don't think this is so much a humidity issue as a top and back thickness issue. I don't do millimeter dimensions (ignorant American), but your dimensions work out to less than 1/16th of an inch or 0.062 or less which is on the hairy edge of being too thin thus the witnessing etc. This is not necessarily a bad thing acoustically, but from a structural point of view... potentially problematic. It is a fine line.

ksquine
03-28-2016, 06:51 AM
If you still want to build another one.....you didn't learn your lesson :p

mikeyb2
03-28-2016, 12:44 PM
If you still want to build another one.....you didn't learn your lesson :p
many a true word..........................