[Jer7440]

Hey! I finally am back to work on this project! I was able to do some work on the neck this weekend. (I copied this post from a post I just made over on Project Guitar.com

First thing I ran into was a problem The angle of my scarf joint was 2 deg more than my cad model. To fix this I set the neck up at the correct angle and milled the face of the headstock flat.
angle fix

While I had the neck at this angle anyway, I decided to cut the shape of the head stock
headstock shape

Then I set the neck blank up in the flat postion and cut the truss rod channel and I drilled two 1/8" locator holes that will locate the fretboard. The holes are drilled at the 12th fret marker postion and will be covered by the inlay.
Locator holes and truss rod channel

Next I made a steel jig to hold the neck when I flip it over to cut the back side. The jig is a piece of 1.5 x 1.5 inch cold roll steel. On the top of the jig I milled a 1/8" tall "key" that fits into the trussrod slot of the neck. This jig give me the location for the rest of my operations.
neck jig

The next step was to taper the neck blank
Neck blank tapered

This was as far as I got on Sat night.

This morning I came to work early and started the carving process. Here is the neck about 1/2 carved.



Hopefully will have finished pics this afternoon.

[lakeside]

nice work looks good

[Jer7440]

It's finished! -_- Here are some pics.

Back of neck

front of neck

volute

heel



I'm not completely happy with the heel (mostly because my 3D cad sucks), but i'll sand it up and smooth it out and it will do for this time around

[sdantonio]

If you look at the Benedetto book (archtop jazz guitars) he doesn't use a scarf joint. Just cuts 3 to 5 side profiles, glues them up into a laminate stack and then carves the neck and headstock from there

[Jer7440]

By using the scarf joint you avoid having end grain runout on the face of the head stock. I'm sure if Benedetto is doing it, it works and it works well. I just didn't have the material to pursue that kind of a build up.

[sdantonio]

I know all about endgrain runout (especially in the places where it can be most detrimental). Actually he buys cheep slabcut maply for the necks. Cuts out the side profile. Then when their laminated you end up with nicely quartered wood with the growth rings going in the right direction. In the end this actually cuts the material cost way down for future instruments you may wish to build.

I agree with you though that making a scarf joint eliminates the runout problem and actually makes for a stronger neck joint. I used to use them myself. But he claims he has never had a problem with either strength or runout. He also uses .7mm veneer on the front and back of the head which covers any runout so it isn't seen by the customer.

The only thing I wouldn't use this for is on a classical guitar.

This is the file I ment to attach earlier for my profile for a archtop neck.

[sdantonio]

Very nice work BTW, I don't remember if I said that yet

[Jer7440]

Next time around I may try the layered method. It would be pretty easy to throw the boards in the mill and cut out the contours.

Thanks for the compliments

[luthier]

The neck looks great. You may want to consider a locating pin in the truss rod channel down towards the nut end of the neck. 3 pins will be more reliable than 2 next to each other. The glue tends to be slippery when you glue on the fingerboard, and clamping pressure may cause it to move out of alignment. I do something similar, only I use finish nails with their heads cut off. I'm starting my first parlor guitar and I'm using up some left over scrap from other guitar projects. I just glued up a stacked heel for a bolt on mahogany neck with a scarfed on peghead.

[Jer7440]

Luthier,

Thanks for the tip :cheers: I'll give that a try next time around.

On another note, I just got done joining some quilted maple for the carved top on this guitar. Hope to cut that at some point over the long holiday weekend.

[Mcgyver]

that looks great, nice work. I've always wondered how the frets are laid out - hopefully you'll get up with the description & pics as it moves along. I know just the tiniest bit of music theory, ie Pythagorean vs tempered scales, and had always thought it must be one very difficult task to lay the frets out accurately. Or maybe its more forgiving than I'm thinking? either way, I'd guess cnc makes the job a lot easier.

[Jer7440]

Honestly, I bought my fretboard with the slots precut from Stewart- Mac Donald. If you search online there are several different fret spacing calculators available. You typically enter your scale length (distance from the nut to the bridge), and the number of frets you want, and the calculator will spit out the exact distance between each fret.

[sdantonio]

I have found the most accurate wat to make a fingerboard (at least for me) is the tablesaw and a .024 kerf blade (available from either stewmac or lmii, I forget which, and actually they buy them from a company in Rhode Island).

Stewmac has a fretscale calculator on their site that is free to use.

Look at their stainless steel fret scales for this application, you can make essentially the same thing from aluminum. Lay them out and use the CNC to cut them and then run off all your fingerboards on the table saw.

[luthier]

McGyver,
The frets are laid out using some fairly simple math. It is called the rule of 18. You take the scale length and divide by 17.817 if I recall. 17.817 is some math constant. The resulting number is the distance from the nut to the first fret. Then you subtract that calculated distance from the scale length and repeat with the resulting new number. This continues for the number of frets you want to calculate. There are fret calculators online where you plug in the number and the computer does the math for you.

[guitarattack]

Could you provide some info on the endmill you used to route this neck? Brand and flutes/size would be helpful.

Thanks for the help,
John

[Jer7440]

Hey John,

I used a few different end mills on this neck. All of the endmills were solid carbide, 4 flute (I had no particular reason for the 4 flute, it was just what I had.). For most of the roughing work I used a 5/8" dia. straight endmill. For routing the headstock shape, I used a 3/8" straight endmill. Finally for the carving of the back of the neck I used a 1/2" Ballnose carbide endmill.

Again, I used these becaused they are what I had around. I have no idea what brand they are. They were just cheapies. In the future I hope to get a 1" dia. ballnose to use for my carving. I will probably just get HSS as carbide cost about 5Xs as much in this size range.

[guitarattack]

Thanks for the quick response...appreciate the help. Good luck on the guitar.

John

[Drakkn]

are you guys making necks with a straight drop in trus rod - if so which truss rod are you using

[luthier]

Stewart McDonald's Hot Rod ( 2 way) is easy to use. I've also used there Gibson style rod with no problems.

[Jer7440]

Stew Mac hot rod here as well.