Official Luthiers Forum!

I just made some radius sanding dishes and when I measured the results I ended up with
a 13' radius and the other is 23'.....

I was just wondering if anyone can see any problems associated with these radii as far as the guitar is concerned.....and wonder if these are to extreme and to what effect it would have on the sound.....??

cheers and thanks for any advice...
Grant

Mine are 15 and 28. One of the UK guys uses a 12, but I don't remember if it is Colin or Dave.

Ron

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OLD MAN formerly (and formally) known as:

Ron Wisdom

Somewhere in the middle of Arkansas......

Mine are now 16 and 28, but I built my first kit with a 12 foot back, and didn't experience any issues at all, and it sounds great. I know a fairly well respected builder who uses 12 regularly...so I think you'd be fine.

As for 23 on the top, I'll let some of the sages weigh in on that one. That feels a little tight to me, but I don't know.

Bill

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Eagles may soar, but weasels don't get sucked into jet engines.

[QUOTE=old man] Mine are 15 and 28. One of the UK guys uses a 12, but I don't remember if it is Colin or Dave.

Ron[/QUOTE]

I use a 10' radius on my backs and a 13' radius for my tops.

You'll be fine with those radii. If you were building a guitar with 16" lower bout width, and were to measure the difference in height the edge of the lower bout will be compared with the centre for a 23' radius top and then for a 28' radius top, then the difference between the two is just over 1/64". Not a lot!

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Dave White
De Faoite Stringed Instruments
". . . the one thing a machine just can't do is give you character and personalities and sometimes that comes with flaws, but it always comes with humanity" Monty Don talking about hand weaving, "Mastercrafts", Weaving, BBC March 2010

[QUOTE=Dave White]

I use a 10' radius on my backs and a 13' radius for my tops.
[/QUOTE]



Dave, if you go much tighter, you'll be playing a cylinder.

Ron

_________________
OLD MAN formerly (and formally) known as:

Ron Wisdom

Somewhere in the middle of Arkansas......

Dave, you might try just joining the top and back at the edges and not using sides at all.

Ron

_________________
OLD MAN formerly (and formally) known as:

Ron Wisdom

Somewhere in the middle of Arkansas......

thanks guys......
i should have added that it is an OM size body

[QUOTE=old man] Dave, you might try just joining the top and back at the edges and not using sides at all.

Ron[/QUOTE]

Ron,

Cool idea. All I have to do is build with a 2.7' radius top and back and I won't need any sides - and only one routing to do for binding too Do you think hide glue would be best to join the top and back due to it's acoustic superiority

_________________
Dave White
De Faoite Stringed Instruments
". . . the one thing a machine just can't do is give you character and personalities and sometimes that comes with flaws, but it always comes with humanity" Monty Don talking about hand weaving, "Mastercrafts", Weaving, BBC March 2010

After reading through the archives I am going to re-do the dishes.....
I'm more concerned with the 23' dish for the face as far as the fretboard extension, neck angle .
I also don't want the face to be so stiff that it looses bass and is brighter.....
So I think I'll re-rout the 23' dish to 15' and make a fresh one for 28' face......
thanks

[QUOTE=Dave White] [QUOTE=old man] Dave, you might try just joining the top and back at the edges and not using sides at all.

Ron[/QUOTE]

Ron,

Cool idea. All I have to do is build with a 2.7' radius top and back and I won't need any sides - and only one routing to do for binding too Do you think hide glue would be best to join the top and back due to it's acoustic superiority [/QUOTE]



I don't use hide glue, so I don't know the answer. 2.7 radius would be killer, Dave. Make a prototype for us. Probably have to use staves like a lute back. Do that on top and back, wow.

Ron

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OLD MAN formerly (and formally) known as:

Ron Wisdom

Somewhere in the middle of Arkansas......

Dave don't need no stinkin sides !





     Lawrence of Australia

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CRAIG LAWRENCE of AUSTRALIA
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[QUOTE=gratay] After reading through the archives I am going to re-do the dishes.....
I'm more concerned with the 23' dish for the face as far as the fretboard extension, neck angle .
I also don't want the face to be so stiff that it looses bass and is brighter.....
So I think I'll re-rout the 23' dish to 15' and make a fresh one for 28' face......
thanks[/QUOTE]

Grant,

I can see your issues with neck-angle and as I use a free-floating fretboard extension this is not an issue for me. However. I do wonder where the idea that if you build tops with "significant" arches you lose bass and the guitar becomes bright. There are so many other variables and design options that are available to a builder that means you can get the sound you are looking for.

Also the pull of the strings on the top "domes" it up through time as well and you don't hear the bass disappear during this process. I'd love to hear from Olsen owners and those that have played his guitars - I've only seen one here in the UK and that was before I was into building - as to how the top looks after a year or so. Is it flat as he first built it or does it have a dome?

_________________
Dave White
De Faoite Stringed Instruments
". . . the one thing a machine just can't do is give you character and personalities and sometimes that comes with flaws, but it always comes with humanity" Monty Don talking about hand weaving, "Mastercrafts", Weaving, BBC March 2010

[QUOTE=old man] [QUOTE=Dave White] [QUOTE=old man] Dave, you might try just joining the top and back at the edges and not using sides at all.

Ron[/QUOTE]

Ron,

Cool idea. All I have to do is build with a 2.7' radius top and back and I won't need any sides - and only one routing to do for binding too Do you think hide glue would be best to join the top and back due to it's acoustic superiority [/QUOTE]



I don't use hide glue, so I don't know the answer. 2.7 radius would be killer, Dave. Make a prototype for us. Probably have to use staves like a lute back. Do that on top and back, wow.

Ron[/QUOTE]


Hmmmmm ......

_________________
Dave White
De Faoite Stringed Instruments
". . . the one thing a machine just can't do is give you character and personalities and sometimes that comes with flaws, but it always comes with humanity" Monty Don talking about hand weaving, "Mastercrafts", Weaving, BBC March 2010

[QUOTE=Dave White] [QUOTE=gratay] After reading through the archives I am going to re-do the dishes.....
I'm more concerned with the 23' dish for the face as far as the fretboard extension, neck angle .
I also don't want the face to be so stiff that it looses bass and is brighter.....
So I think I'll re-rout the 23' dish to 15' and make a fresh one for 28' face......
thanks[/QUOTE]

Grant,

I can see your issues with neck-angle and as I use a free-floating fretboard extension this is not an issue for me. However. I do wonder where the idea that if you build tops with "significant" arches you lose bass and the guitar becomes bright. There are so many other variables and design options that are available to a builder that means you can get the sound you are looking for.

Also the pull of the strings on the top "domes" it up through time as well and you don't hear the bass disappear during this process. I'd love to hear from Olsen owners and those that have played his guitars - I've only seen one here in the UK and that was before I was into building - as to how the top looks after a year or so. Is it flat as he first built it or does it have a dome?[/QUOTE]
Its just a thought I had .....possibly not true because like you said there is so many other variables....
but my thought was that if you have a more significant arch could mean a stiffer face.....and possibly wouldn't be as free to vibrate....hence I'm thinking that may result in a brighter sound with possibly less sustain...
but having said that maybe a stiffer face could be braced lighter to counteract that....
I don't know if that is true or not? like I said just a thought..

But I have rectified the dishes and now have 15' and 28' and if I have to make anymore it will be to soon....