Kohei Fujii Guitars

Kohei Fujii Guitars

Sunday, January 29, 2012

Neck shaping

     I installed fret wires on to the MD and the SSJ necks. Then, I finished a neck shaping work for the MD neck. I learned a neck shaping method form master guitar builder of Taku Sakashita. His method is quite logical. First step is making a square-shaped neck that has final neck thickness at first fret and the 10-th fret. In my steel strings guitar, I have 19-mm thickness at 1-st fret and 21mm thickness at 10-th fret. 2nd step is making a trapezoid shape. Top and bottom sizes on the trapezoid are depending on the final neck shape. Final step is making a curved neck cross section. This method is able to create very precise neck straightness. Actuary, hand neck shaping needs a serious training to create a precise straightness for the neck shaping. Common issue is a bell bottom jeans like neck shape. You night be able to see a poor neck that has a suspended bridge like neck straightness. Taku's method helps a lot to achieve pretty precise neck shape. His method has many hidden techniques those I am not able to tell here. Those techniques make an amazingly comfortable neck shape. Factory built computer shaping machine is not able to create a super comfortable neck like we have been making.
      I also finished a bridge making. This is my signature low profile bridge. I really like super thin wings those minimize bridge weight. This bridge material is Madagascar rose wood.
     Remaining work on the MD model is a final sanding. SSJ model needs a neck shaping and final sanding. Now, my construction projects are approaching to the final stage.

Sunday, January 22, 2012

Neck install

Both of MD and SSJ 12-string are neck installed. After install the neck, a guitar need a finger board final leveling. I have been using a low angle block plane and a scraping plane for the final leveling. Scraping plane enables almost perfect surface with minimum effort. This is a real time saver for me. Now, both of guitars have perfectly leveled finger board.


Saturday, January 21, 2012

Neck making (Veneer and finger board)

Neck making is almost done except neck shaping. I installed head plate veneers for top and back. Top material is Brazilian rose wood. Back material is Ebony. I also installed finger board. MD model is Ebony and the 12-strings SSJ is Brazilian rosewood. These necks need finger board radiusing, fret board install, and neck shaping.

Sunday, January 8, 2012

Neck joint

   I finished neck install and alignment.Neck installing alignments (string height angle and strings angle) are a time consuming process. I select the string height angle based on my own adjusting method. The method is that extended plane from the neck surface touches to the bridge location. This makes perfect saddle height on the bridge. I have been using a home made straight edge as shown in the first picture. In this case, height at the bridge location is exactly same as the finger board template thickness of 5.5mm.    After I finish the neck installing alignment, I make a cavity for the neck joint. Above the 14th-fret, my finger board has solid wood block which improves high position tonal quality. This block also works as a solid connection block between neck and body. Without using any mechanical screw joint between finger board and the body, my guitar has a quite solid joint between finger board above 14th fret and the body. I also finished a neck extension install at 14th fret.
   Last two photos show that my neck string angle is not on the straight line of the guitar center. My neck has slight offset towered 1-st string. My neck's extended center line is 2mm offset from the guitar's body center at the bottom. This makes approximately 0.8mm-offset at the 14th fret. So, my finger board has more margins from the edge to 1st string at higher position. Without using this offsetting technique, a player might experience a string falling problem when he or she plays 1-st string at high position. This problem is more serious on the Nylon strings guitar, because of lower string tension.

Sunday, January 1, 2012

Neck joint

A happy new year to you. I made more progress on MD and SSJ projects. Neck joint work to the body has been done. My guitar has been using the bolt on joint technique. My guitars do not use any glue joint on the neck attachment, and the neck is removable without using gluing.
Both MD and SSJ bodies are already finished the sanding work for back and sides.