Official Luthiers Forum!

Hi I originally posted this in the other JRHall thread on shortening necks with a scarf joint - but thought mabye it would get more attention as its own thread..

I was reading the JRH shortening thread with some interest, because at a swap meet I bought a John Watkins LP style semi hollowbody that was EIRosewood capped and mahog backed, routed for soapbar pu's and 2 tone/vol controls
and came with a 1pc mahog neck - however when I approached the project it became abundantly clear that it was not the proper neck for the project
The bridge and saddle locations were already drilled out for a 24 3/4" scale, which was fine with me as I wanted this scale anyhow... being sausaged fingered... but it precluded the option of adjusting scale wise,,, but anyhow>
Like I said I wanted a proper LP scale -
Now after alot of head scratching, contemplation, adjusting and reconfiguring adding zerofrets recalculating etc
I came to realize that I would have to remove about 1 1/2" of the neck to configure it in a trad 24 3/4" config.
Id like to use this neck - I could simply build one - but why bother if I have an easily salvageable prefab?
Now I saw the JRHall method and while helpful to some, it doesnt really interest me in that Id like to avoid the visible scarf on the neck.... this may end up being a gift and Id like it to be spiff
Im interested in the bridle joint and researched a pile of different bridle joint options -
(bridle joint sounds like something your wife would smoke on your wedding night ) and I see a few ways to possibly do this - however -

What would be your recomendations experienced builders???,,, please enlighten me? -

I really value the wisdom of those hoary with age,,,
And Id like to do this right.... any photos or completish/detailed descriptions would be really appreciated!
Thanks so Much in advance
Cheers
Charlie
PS before anyone asks me to simply contact John, and ask to have a proper neck sold to me or have one built - I did that and it wasnt possible/feasible unfortunately

Really ???
No-one has a specfic way theyd like to share on creating this joint?

Its OK Ive already sort of decided how Id like to mabye accomplish this anyhow,
Im planning on creating a modified bridle in a V configuration... with a volute which is already there...Im planning on making the V notch fit in in a sort of tenon fit into the headstock receptacle, and the actual v joint will not show through the bottom, as it will only extend mabye just over 5/8" or so thick, just to extend past the truss rod slot (depthwise) which is already routed into the neck.
This is what I ascertained would be the best joint because the neck is already rounded and its easier to create a proper joint fit into the headstock...
Only the butt joint that is below the V will show through, however this seems to be the best way to ensure a larger gluing surface I think... The v joint will be covered with the headpplate,,
Im surprised no-one else has chimed in....If anyone else has a better suggestion Im all ears.... Thanks again in advance
Cheers
Charlie

Kinda sounds like more work than making a new neck...

Is the neck glued to the body? Am i understanding it right, you have a body and neck, not attached, and you think they are not matched properly scale wize?

Maybe make a new neck to work with the scale length you want for this guitar, and use the old neck on a different project. Thats probably what i would do anyways.

If the neck is glued in, and everything is set up to work with a longer scale, i would just use the easily doable scale. A joint like that is quite tweaky, and you only have one shot to get it perfect.

Sorry for the confused reply, i am not sure i fully understand what you have to work with.

_________________
Jordan Aceto
Ithaca, NY

jordan aceto
unfortunately its a one piece neck, CNCed and fairly complete...in terms of it being finished almost..
I should just use it on another project perhaps, mabye a piccolo bass or a longscale, baritone something or other
However I could use the experience making the joint fit, and if it is ruined - it wouldnt be the end of the world....
Cheers
Charlie

If you want to do it, have at it! Sorry for sounding discouraging, and good luck.

_________________
Jordan Aceto
Ithaca, NY

Hi Charlie,
I just saw your post. Tomorrow I will try to post some pics and information on how I would do it using a table saw.

Clay

Hi Charlie,
I took some pics and will try to explain things as best I can. Here is the joint we want to cut. On the right is the neck as it comes off the table saw. In the middle is the joint apart and to the left the neck and peghead together.

I usually build these things from scratch, so my procedure for that is a little different than the one for shortening necks.
To shorten the neck the first thing we need to do is cut off the peghead. We can do this with a backsaw, tablesaw or chopsaw - anything that will give us a nice smooth cut 90 degrees to the face of the peghead.

After the peghead is removed the neck shaft needs to be marked where it will be shortened to. Typically to go from 14 to 12 fret this will be about 1 3/8 inches. Depending on the angle of the peghead and the size of the volute, the volute will extend past the shaft an additional length. To account for this you need to glue a small bit of wood onto the back of the neck. I used a block plane to make a flat spot on the neck to add this bit of wood and allowed the wood to extend past the neck about 5/8ths of an inch. My peghead angle is 11 degrees.
The jig is a homemade tenoning jig and is shimmed out using scraps of wood to place it at the proper distance.
To make the first cut the tablesaw blade is angled to 11 degrees and raised up 2 inches (1 3/8 +5/8 from above). The jig is shimmed until it just touches the saw blade.

The neck is stood on end, clamped to the jig and run through the saw.

The next cut steps back the thickness of the peghead."Shims" are removed from the jig to bring the neck into position. I usually mark this line on the neck and visually check my alignment with the saw blade.

For the third cut the blade is set back to vertical and the cut is aligned so it will intersect the top of the second cut. This forms the "birds mouth" that will mate with the top and bottom of the peghead.

The next step is to remove wood from the sides and back to begin forming the volute and the angled portion that fits into the peghead ramp. I used a dovetail saw and a chisel, but i'm sure it can be done a number of different ways.

To cut the ramp in the peghead I use a simple router jig. I am showing the top and bottom of two jigs (11 and 14 degrees) to show how the peghead fits into a recess in the bottom and the router rides on the top. I use a top bearing bit with the jig.

Here is a picture of the joint slightly apart. As it is moved into position it tightens up. If it is still a loose fit whenit "bottoms out" the ramp end can be trimmed to tighten things up.

Here is the joint assembled but not glued and carved to shape. I usually carve the volute before I glue things up using a sacrificial peghead to take the scars from carving. A better craftsman may not need to do this.
To anyone trying this joint for the first time I would recommend using scrap to work out the final geometries of your setup and to discover the pitfalls I have unintentionally failed to mention.

In the above photo you can make out the small bit of wood added for the volute. This was a scrap from the shop floor and glued with superglue for this quick demo. If this was carefully selected and glued it would be much less conspicuous.
Below is a picture of a finished guitar using this joint. I find it to be a nice solution to fitting a peghead to the neck shaft and when combined with a glued on block heel a very economical method for making necks,

Clay
Thats Exactly what I had in mind!!!
Well actually what I had in mind was a more simplified version of that - this looks alot better - with more surface area for gluing than I had in mind.
Thanks a ton - thats an extremely concise and complete description!
You Rock friend!
Cheers
Charlie

Hi Charlie,
You are certainly quite welcome.
One thing I failed to mention is that when the peghead overlay is glued on four gluing surfaces are present, and it is a very strong joint.