How to Calculate neck taper angle

Google 'table saw taper jig'. I've seen several vaiations in woodworking magazines & books- it's a common operation for guys making table or chair legs. To calcualte the angle, I'd suggest drawing it full size on a piece of MDF.

 

I use wooden templates and a router table to shape the final profile of my necks. you can see the stack of templates in the background of this image



all the best,

R

 

I always make templates for my necks using printouts from fretfind (see sticky faq). But unlike rodent I do not include the headstock. Another different thing I do is use the templates just for maeking the taper on the blank. I then use a straight piece of MDF with some jig clamps to hold the neck and copy the MDFs straight edge on the taper line. But I first go at it with the bandsaw to less than 1/8 from the line.

 

I know a couple guys who use a similar method to Wilser (Brian Ristola comes immediately to mind)

I did forget to mention that I use a bandsaw to trim the outline to less than 1/8" prior to detailing at the router table ... but it is a three step process for me, as I have an intermediate step when I thickness the headstock and install the transition radius with a sanding jig at an oscilating drum sander, and then apply the fretboard radius with a swing jig on a horizontal belt sander. Once my headstock is properly thicknessed and the fretboard radius applied, then I take the neck to the router table

and depending on the wood species and/or figuring at the heel, I just may use the drum sander to finish detail the half oval heel profile instead of routing it with a flush trim bit ... I don't want to chance any tear out so close to being completed

all the best,

R

 

Hey. Are you building neck through or bolt on/set? And are you using laminates? If you are using lams, I detailed a method on my thread '6 String Fretless has begun!', that requires only one cut to be made with the table saw, and if there is any compound error, it will be symmetrical...
I can't remember if I explained perfectly on my thread, so give me a pm if you need a better explaination.
Note, this method will mean that for the headstock, you'll have to glue on extra bits after creating the central piece, which is what I'll be doing, but I don't reckon that's too hard...

 

Hey Will,
Your method seems to work fine as your bass is turning out very nice. But it would require that 1) you have a finely tuned tablesaw with a blade that leaves a ready to glue surface and 2) gluing up ears to the headstock. The first can be accomplished but for the second one, I prefer a headstock with no ears.

 

you could just draw out a fullscale model on some paper to save time

 

FWIW I like to leave ~1/16 or so outside the final taper, and I don't take it down to finished dimensions until the (finish-tapered) fretboard is glued on.

 

Sorry Rodent, you said Brian Ristola, The only Luthier by that name I know of is from Bestbassgear.com. Is he on this forum, maybe I can check out his work? Thanks man.

 

Here's a link.

http://www.ristolainstruments.com/index.htm

 

I base everything from the centerline, but I make necks 2 ways dependant on whether it is a set-neck or a bolt-on. For the bolt-on, I use an MDF template which includes the complete headstock shape. On the set-neck basses, I do the body centerblock and the neck and the center of the headstock all with one long tapered MDF template. This keeps the centerline of the neck centered with the body wings and the headstock "cheeks". Instead of a router, I use a shaper table with a spiral cutter. Before I had the shaper, I would get it close on a band saw and bring it down to final with a jointer/planer. That method does not, however, work on the bolt-ons.

 

As far as the actual measurement of the neck, here is one sure-fire and easy method that is one of my personal favorites. A nut of 45mm has a centerline of 22.5mm. Measure in 5mm from the outside edge for the center position of your B string. The difference between the centerline and the center of B is 17.5mm. Now find the difference between center and B @ the bridge. This is 40mm. Now you know the angular excursion of B from center, a total of 22.5mm change over scale length. Multiply this number by .75 to find the excursion of B @ the 24th fret, or 16.875mm. Add this to the distance of B from the nut (17.5mm)to find the distance of B from the centerline @ the 24th fret, or 34.375mm. To find the neck width, add 6mm back to this figure. Thus the neck will be 40.375mm @ the 24th fret from centerline to the B string edge. Repeat for the C string side, but start with 4mm from the edge, and add 5mm to the 24th fret. Skipping the calc, it is 39.625mm from centerline to the C string edge. Adding the two together, you have a total neck width of exactly 80mm at the 24th fret. Cheers!