Official Luthiers Forum!
http://www.luthiersforum.com/forum/

Top radius and neck alignment
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=27453
Page 1 of 1

Author:  Mark Ewing [ Tue May 18, 2010 8:44 pm ]
Post subject:  Top radius and neck alignment

Just finished 2&3 doing 4,5,&6 now. I can't get my head around the geomentry of top radius and neck alignment. (No 2 had the dreaded 14th fret hump. What a pain.) I include the top of the heel block when I radius the top at 28r. But then I brace the top in the upper bought flat for the fret board extention. This sounds wrong to me. Can someone help me figure this out?

Author:  Rene [ Tue May 18, 2010 9:11 pm ]
Post subject:  Re: Top radius and neck alignment

Have you seen Hesh's "Flattening the Upper Bout" in the Fixture, Video, and Picture Tutorials?

René

Author:  Barry Daniels [ Wed May 19, 2010 7:42 am ]
Post subject:  Re: Top radius and neck alignment

You got a hump because your head block was radiused (sticking up on the inside edge) but your top's upper bout was flat. As Rene suggested, flatten the rims in the upper bout area before gluing on the top.

Author:  TonyKarol [ Wed May 19, 2010 8:56 am ]
Post subject:  Re: Top radius and neck alignment

Or simply radius both ... works for me ...

Author:  Laurent Brondel [ Wed May 19, 2010 9:26 am ]
Post subject:  Re: Top radius and neck alignment

There are two schools on this:

- use a flat UTB and flatten the upper bout of the rim
- use a radiused UTB that will go on the radiused rim, and flatten the area of the top where the FB will be glued afterwards.

I use a 3rd method for cylindrical plates, which is to use a radiused UTB, but flattened on 3" in the middle. The neck block (and upper foot) is also flat. That allows me to keep the top full thickness there.

The most important, with any method, is to carefully take into account your FB and bridge thicknesses (and how much the top may rise with string tension), and work the necessary angle at the neck block for a healthy saddle height and action, and no 12th or 14th fret hump.

Author:  Haans [ Wed May 19, 2010 9:47 am ]
Post subject:  Re: Top radius and neck alignment

+1 for cylindrical tops. Mine's 15' and works perfectly...

Author:  Edward Taylor [ Wed May 19, 2010 9:59 am ]
Post subject:  Re: Top radius and neck alignment

What is the advantage of a cylindrical top over a dome? Do you have cylindrical dishes for gluing or just radius the braces?

Or is that a whole n'other thread...

Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/