Archtop Ukulele

[rgarcia26]

Hi Guys this is the first time that I posting on this forum, I got to tell you that I got a huge admiration for the talent displaying here...

Ok lets get down to the point...
This is my first building project I am working on customizing an Grizzly Ukulele kit, and I'm making it an archtop Ukulele, I am doing this because I want to build a Archtop guitar and I want some practice before.
I got a question about the design that I made (See the PDF file)! Are the baces ok? and what do you think about the F-holes???
thank you your help is appreciate

PS Here some progress that I made today

[graham mcdonald]

A couple of points to think about. There is not very much tension on four nylon uke strings, and so not much energy to drive the soundboard. I suspect you will need to carve the soundboard quite thin, and perhaps not need any braces at all. The other thing is that the bridges on archtop instruments are usually at the high point of the arch, somewhere around the middle, rather more forward than a normal uke bridge position. To get the bridge on your uke somewhere more towards the middle of the soundboard would then require a longer neck, with more frets before the body join.

In any case, welcome to the forum. You will doubtless get lots of useful advice

cheers

graham

[Patrick Hanna]

I can only offer some general advice--and perhaps a resource. First of all, archtop instruments don't work like flat tops. Archtops use floating bridges and tailpieces. Flat tops (like most ukes) use tied or pinned bridges. Having said that, it looks to me like your arch might be a little high relative to the general scale of your top. It could be a trick of the raking light in your photos, but I think I am seeing a very high arch. This is no problem as long as you haven't hollowed out the underside yet. I would reduce the arch if it were mine. I don't have a specific height to tell you, but I think I'd aim for something about 1/2-inch at the most. Then I'd hollow the underside of the top. As to the resource: John D'Angelico (a legendary arch top guitar builder) made an archtop uke, and it is well photographed in the book "Acquired of the Angels". No dimensions given, but you can visualize approximates just by looking at the photos. I expect you can find a photo of this instrument with a Google search.

Now, having said all that, Mr. McDonald knows a heckuva lot more about building instruments than I do, He has responded to my own posts, and his advice was much appreciated. I ALWAYS listen to someone with that sort of experience and knowledge. So, follow Mr. McDonald's advice first, and then think about mine second. Press on, and learn.

It might be a ripper! If not, just use your acquired experience and jump in a build another one. Each one will be better.

Patrick

[graham mcdonald]

Patrick spotted something that I overlooked, the arching height. I would agree that a 1/2" - 12-13mm arching height would be enough, and remember that is the total height of the soundboard, from the gluing surface on the bottom to the highest outside point, not the internal height.

I also spotted a typo in my own post: it should read "carve the soundboard quite thin" I would suggest carving to 4mm thick in the middle, down to 2.5mm in the recurve and out to 4mm at the edges. You may need to go even thinner to get it to work. That is entirely guesswork on my part, keeping in mind the string tension. Aim for a bridge height of 12-13mm as well. If you haven't already done it, draw a side profile of the whole instrument where you can draw the longitudinal arch of the soundboard, the bridge and neck angle.

cheers

[rgarcia26]

Patrick spotted something that I overlooked, the arching height. I would agree that a 1/2" - 12-13mm arching height would be enough, and remember that is the total height of the soundboard, from the gluing surface on the bottom to the highest outside point, not the internal height.

I also spotted a typo in my own post: it should read "carve the soundboard quite thin" I would suggest carving to 4mm thick in the middle, down to 2.5mm in the recurve and out to 4mm at the edges. You may need to go even thinner to get it to work. That is entirely guesswork on my part, keeping in mind the string tension. Aim for a bridge height of 12-13mm as well. If you haven't already done it, draw a side profile of the whole instrument where you can draw the longitudinal arch of the soundboard, the bridge and neck angle.

cheers

Thank you for your answer, I did not carved the inside. The top its about .75” (19mm) high from top to bottom; what I will do is to lower the arch to 12mm and located the apex of the curve where my bridge is going to be.

I do plan to use an floating bridge w a tail piece. (I am following an archtop design as you can see)

But it got a question Mr. McDonald… you recommend 4mm thick in the middle and edges, and about 2.5mm in the in the Recurve? How I know where exactly in the middle?

I got an idea based in your suggestion, I will do a longitudinal drawing of the instrument showing the top plate thickness, and I will show it to you to see what you think
Thank you so much for tacking the time to help me Ruben

[rgarcia26]

I can only offer some general advice--and perhaps a resource. First of all, archtop instruments don't work like flat tops. Archtops use floating bridges and tailpieces. Flat tops (like most ukes) use tied or pinned bridges. Having said that, it looks to me like your arch might be a little high relative to the general scale of your top. It could be a trick of the raking light in your photos, but I think I am seeing a very high arch. This is no problem as long as you haven't hollowed out the underside yet. I would reduce the arch if it were mine. I don't have a specific height to tell you, but I think I'd aim for something about 1/2-inch at the most. Then I'd hollow the underside of the top. As to the resource: John D'Angelico (a legendary arch top guitar builder) made an archtop uke, and it is well photographed in the book "Acquired of the Angels". No dimensions given, but you can visualize approximates just by looking at the photos. I expect you can find a photo of this instrument with a Google search.

Now, having said all that, Mr. McDonald knows a heckuva lot more about building instruments than I do, He has responded to my own posts, and his advice was much appreciated. I ALWAYS listen to someone with that sort of experience and knowledge. So, follow Mr. McDonald's advice first, and then think about mine second. Press on, and learn.

It might be a ripper! If not, just use your acquired experience and jump in a build another one. Each one will be better.

Patrick

I did not carve the inside of the plate, and I do agree it’s too tall, I will get it down to about 12mm… thank you for pointing that out
Another little problem that I am having its that the curve is not perfect, its hard to remove material from one side and then make it symmetrical

[Allen]

HI, and welcome to the forum.

There have been lot's of arch top uke builds posted on the Ukulele Underground forum, and Brad Donaldson in particular is the most knowledgeable luthier I'm aware of on building them. He posted plans for several styles a year or so back and invited people to post their builds to his plans. He's very helpful to any and all that ask questions.

[graham mcdonald]

hello Ruben,

My suggestions for thickness are mildly educated guesswork, and Brad Donaldson, as Allen suggests, will be more likely to give a better idea of how to carve a uke archtop. The maximum thickness is not just a single spot under the bridge, but more an area a little smaller than the palm of your hand and then reducing in thickness to the recurve which I would put about 15mm in from the edge in the upper and lower bouts and 10mm in the waist. The final recurve thickness should be 40% thinner than the middle. Don't start carving the inside until you have got the outside as perfect as you can, as all the thicknesses are referenced from the outside carving. Carving symmetrically can be tricky. I used arching templates for the first few mandolins I carved, and I still use them for fiddle soundboards. They are not hard to generate. This evening I will post a diagram of how I create them for mandolins, which you should be able to adapt to ukes.

BTW, no-one calls me Mr McDonald...

cheers

graham

[rgarcia26]

HI, and welcome to the forum.

There have been lot's of arch top uke builds posted on the Ukulele Underground forum, and Brad Donaldson in particular is the most knowledgeable luthier I'm aware of on building them. He posted plans for several styles a year or so back and invited people to post their builds to his plans. He's very helpful to any and all that ask questions.

Thank you I registering for Ukulele underground

[rgarcia26]

hello Ruben,

My suggestions for thickness are mildly educated guesswork, and Brad Donaldson, as Allen suggests, will be more likely to give a better idea of how to carve a uke archtop. The maximum thickness is not just a single spot under the bridge, but more an area a little smaller than the palm of your hand and then reducing in thickness to the recurve which I would put about 15mm in from the edge in the upper and lower bouts and 10mm in the waist. The final recurve thickness should be 40% thinner than the middle. Don't start carving the inside until you have got the outside as perfect as you can, as all the thicknesses are referenced from the outside carving. Carving symmetrically can be tricky. I used arching templates for the first few mandolins I carved, and I still use them for fiddle soundboards. They are not hard to generate. This evening I will post a diagram of how I create them for mandolins, which you should be able to adapt to ukes.

BTW, no-one calls me Mr McDonald...

cheers

graham

That is very helpfull, I am looking forward to see ur diagrams.....

[Kim]

Some really helpful advice and direction in this thread, thanks to all for the effort

BTW welcome to the ANZLF Ruben.

A suggestion. Rather than relying upon something as impersonal as a user name, you can add your name to your signature line from the "User Control Panel" (top right of your screen) so it will display automatically with each post you make. This is certainly not a requirement but it is more in line with the informal shed talk we all seem to enjoy around here.

Cheers

Kim

[rgarcia26]

Some really helpful advice and direction in this thread, thanks to all for the effort

BTW welcome to the ANZLF Ruben.

A suggestion. Rather than relying upon something as impersonal as a user name, you can add your name to your signature line from the "User Control Panel" (top right of your screen) so it will display automatically with each post you make. This is certainly not a requirement but it is more in line with the informal shed talk we all seem to enjoy around here.

Cheers

I did not know about that thanks for pointing it out Kim.....
I got to tell u all I am new as a member but I have being following this forum for like two years... But I did not have anything to add until few days ago, I am glad for your help

[graham mcdonald]

Here is a diagram of how I make arching templates.
1. Draw a half body outline
2. Draw in a longitudinal arch
3. Draw in the transverse arches (as many as you want) using the longitudinal arch as the starting height for each one
4. Use the transverse arches to work out contour lines for the initial carving (it is a matter of just measuring where particular heights are and joining the dots.
5. Make a copy and cut out the various templates. When carving it can be easier to use half width rather than full width templates, though a full length one for the longitudinal template is needed.

For arching shapes find a curcate cycloid calcualtor on line and this will give you a good start for the arching shapes. Though Stradivarius didn't know about curtate cycloids his arching shapes are pretty close to those curves.

Ignore the 20mm and 8mm measuremnts, That was drawn for an Irish bouzouki, but you should get the idea

cheers

graham

[rgarcia26]

Here is a diagram of how I make arching templates.
1. Draw a half body outline
2. Draw in a longitudinal arch
3. Draw in the transverse arches (as many as you want) using the longitudinal arch as the starting height for each one
4. Use the transverse arches to work out contour lines for the initial carving (it is a matter of just measuring where particular heights are and joining the dots.
5. Make a copy and cut out the various templates. When carving it can be easier to use half width rather than full width templates, though a full length one for the longitudinal template is needed.

For arching shapes find a curcate cycloid calcualtor on line and this will give you a good start for the arching shapes. Though Stradivarius didn't know about curtate cycloids his arching shapes are pretty close to those curves.

Ignore the 20mm and 8mm measuremnts, That was drawn for an Irish bouzouki, but you should get the idea

cheers

graham

Thank you Graham it does help me a lot, I am working on the curcate cycloid calculator, I am using the one on Mottola website. I got a good idea of what is doing but not 100%. I will input the data into my autocad to see what is going on.

[rgarcia26]

I hope i am not too far out to fix my top

[charangohabsburg]

I hope i am not too far out to fix my top

Hi Ruben,

If you think you went too far with removing material from this top, why not save it for smaller archie uke (cutting off the offending surplus on the lower bout periphery - small and tiny instruments are soooooo cool! ) and go for a new top on this one?
I think that such a small piece of spruce is just not worth a lot of headache (although I never would throw it away, I'm such a nickel nurser ).

[rgarcia26]

I hope i am not too far out to fix my top

Hi Ruben,

If you think you went too far with removing material from this top, why not save it for smaller archie uke (cutting off the offending surplus on the lower bout periphery - small and tiny instruments are soooooo cool! ) and go for a new top on this one?
I think that such a small piece of spruce is just not worth a lot of headache (although I never would throw it away, I'm such a nickel nurser ).

Your right, even when I spend 4 hours carving that top its a small piece Lol (may be because its my the fisrt time)... however I bought the spruce when I was living in atlanta there where a really nice guy who got tons of tonewood on this business, here in S.florida other that lumber yards, I havent see anything good.
well i dont know yet and the whole point its to gain experience

[Allen]

You can also almost use all of the other soft wood species you can get in North America. I've seen them built with Western Red Cedar, several different species of pine, Douglas Fir etc. Well you get the idea. There has got to be something in the local building centre that would work.

[rgarcia26]

You can also almost use all of the other soft wood species you can get in North America. I've seen them built with Western Red Cedar, several different species of pine, Douglas Fir etc. Well you get the idea. There has got to be something in the local building centre that would work.

Construction grade pine?, few month ago I found some 2x8 super nice, quartersaw! it was a little softer that normal pine and lighter, very nice to work with. if you take ur time you can find nice lumber even from the big box store. I wonder if that piece of pine can make a nice instrument!!!
But any ways I found some suppliers of nice wood like 50 milles away not many spruce around but I can try other options like you said

[rgarcia26]

Ps I have to apologize for my writing, I bed I am hard to understand what I am saying; the truth is that I am not US native I in fact from Latin America Venenzuela if you want to know… English is my second language

[charangohabsburg]

As fas as I know there have been made guitar tops and archie tops from virtually every kind of pine available. Without ever having done such a thing I'd say go ahead!

Ps I have to apologize for my writing, I bet I am hard to understand what I am saying; the truth is that I am not US native [...]

Don't worry, I bet that Aussies and Kiwis are also hard to understand, most of them are also not US native!

[...] I in fact from Latin America Venezuela if you want to know… English is my second language

English is also not my first language.

Of course I wanted to know where you are from... I know a Bolivian whose name is also Rubén García (con tildes).

Cheers,

[Allen]

No worries Ruben. English is a second language to many Kiwis I've met.

Did you see Peter Coombe's Radiata Pine Mandolin?

There's some inspiration for you.

[rgarcia26]

Here is a diagram of how I make arching templates.
1. Draw a half body outline
2. Draw in a longitudinal arch
3. Draw in the transverse arches (as many as you want) using the longitudinal arch as the starting height for each one
4. Use the transverse arches to work out contour lines for the initial carving (it is a matter of just measuring where particular heights are and joining the dots.
5. Make a copy and cut out the various templates. When carving it can be easier to use half width rather than full width templates, though a full length one for the longitudinal template is needed.

For arching shapes find a curcate cycloid calcualtor on line and this will give you a good start for the arching shapes. Though Stradivarius didn't know about curtate cycloids his arching shapes are pretty close to those curves.

Ignore the 20mm and 8mm measuremnts, That was drawn for an Irish bouzouki, but you should get the idea

cheers

graham

So I when yesterday home after work and I put the measurements into the curcate cycloid Java calculator, and then he gave some instructions on how to convert the coordinates to an .DXF file for autocad use…but then I ran into trouble, my autocad (ver 2005) said that the file did not have any layer define, so that the end of my tale and discard the drawing… I guess I can always crab a piece of paper like in the old days, or input the coordinates into my A-CAD by hand, it just will take me a little longer to complete the task. I am inspired now! I am going try one more time

[rgarcia26]

As fas as I know there have been made guitar tops and archie tops from virtually every kind of pine available. Without ever having done such a thing I'd say go ahead!

Ps I have to apologize for my writing, I bet I am hard to understand what I am saying; the truth is that I am not US native [...]

Don't worry, I bet that Aussies and Kiwis are also hard to understand, most of them are also not US native!

[...] I in fact from Latin America Venezuela if you want to know… English is my second language

English is also not my first language.

Of course I wanted to know where you are from... I know a Bolivian whose name is also Rubén García (con tildes).

Cheers,

I will check my local Home Depot, pine is super cheap but its hard to find a knot free one, like I did before... well its suck a small piece that it can be done for sure... A little concern its the humidity content in the lumber, I made ones a bed using that pine and expand at least ½” or more, well again it’s a small piece wont have that much movement, and its very good for practicing

I am glad it doesn’t bother you guys my broken English,

I never being in Bolivia I heard its beautiful over there

[rgarcia26]

No worries Ruben. English is a second language to many Kiwis I've met.

Did you see Peter Coombe's Radiata Pine Mandolin?

There's some inspiration for you.

Thank you
It really can by done…. 

PS that guitar bracing its out of this planed!!!