Hammering Out Some Neck/top Angle Qs Before Building

[IPA or death]

In the last few days, I've searched on the subject of neck angle and matching top angle on a carved top guitar. I have found a couple of things that didn't jive with each other.

One question I have is this: Does the neck angle carved onto the top of the guitar start at the end of the fretboard, or just past the neck pickup cavity?

Also, am I right in saying that the second angle on the top (pickup angle) is carved from the neck angle line to the bridge? Or is it just in front of the bridge, so the bridge sits on a dead flat area with the tailpeice?

Another Q: On the jigs used to carve the neck angle (Setch's comes to mind), are the beams that the router rides on connected to keep them from splitting apart and dropping the router? Is the best method for using said jig to move from up toward the bridge back, then slide the bars sideways and repeat?

Thanks for any advice you can give.

Greg

[rhoads56]

you must draw it out. there is no other answer.

[biliousfrog]

Sorry to dig up this thread but this seems like a good place to ask this question.

I've been going over the carve top tutorial, searching the forums & google, reading through MYOEG & drawing everything out full scale but something is puzzling me. In Setch's tutorial he planes a pickup plane from the neck angle to the bridge. How does that work? I nearly get it then I just get puzzled again.

I've drawn out everything full scale & got my neck angle. I plane the angle into the body...now, how can I plane a further angle from there to the bridge without affecting the height & placement of the neck? I'm sorry if I'm being stupid but I can't seem to get it to work on paper. I was going to just leave the pickup plane out but it would be good to understand why & how.

[rhoads56]

build what you have drawn. nothing more, nothing less. dont add an angle just because someone else did, use an angle because thats how it worked on paper.

[Setch]

I plane the angle into the body...now, how can I plane a further angle from there to the bridge without affecting the height & placement of the neck? I'm sorry if I'm being stupid but I can't seem to get it to work on paper. I was going to just leave the pickup plane out but it would be good to understand why & how.

When you plane the 'pickup plane' you only plane the area between the bridge and the end of the fretboard. The neck angle is left untouched, and the bridge mounting postion is also untouched. All you are doing is creating a flat area between the bridge and the neck to mount your pickups on.

[biliousfrog]

Yeah, I've read that over & over but what I don't get is why or how there's any wood to plane away. As an example, look at Perry's neck angle diagram:

There's no extra wood between the neck angle & the bridge that can be removed. The only way that there could be is if the neck is moved forward & that would throw out any calculations for neck angle & scale length. Do you see why this is confusing? As Perry said, if it works on paper then go with that but I like to see how others work & hopefully learn from it. I don't want to just accept what I'm told without understanding why.

I wonder how many others have read the neck angle & carve top tutorials & also got confused...maybe nobody.

[erikbojerik]

Frog, part of the problem is that the drawing you have is for a flat-topped body, not a carve top. Think about it...if you take a cross-section down the centerline of a carve top, it will not look like that. The drawing that Perry sent you is a schematic to help you understand what goes into calculating a neck angle to begin with.

Starting from there, you need to draw out the arch and contours of the carve on that body, including the area between the bridge and the heel, then it will become clear. Basically, what you will get is that the area between the end of the fretboard and the bridge will be flatter than you have it drawn for the flat-top, the area underneath the bridge will drop off starting somewhere around the bridge pickup, then there will be a larger curved drop-off from the bridge to the tail.

In a Les Paul (for example), the only parts of the entire top that are truly flat is the part underneath the end of the fretboard, and a very small area underneath the bridge. To construct the neck angle, the top of the arch where the bridge sits is left pretty flat (the area of flatness is left up to you) so it is left at full body thickness, and only the area underneath the fretboard is planed to the proper neck angle. Then (AFTER you've routed out your neck pocket/mortise and pickup cavities...) you carve the transition between these two flat areas.

Edited April 27, 2007 by erikbojerik

[Mattia]

What Erik said.

On my carved tops, I start by angle the top from the bridge to the neck joint area, flat at first, generally stays that way around the pickups (sometimes I carve it rounder, like a Les Paul, sometimes I don't), and that plane becomes the 'flat' reference plane for working out the neck angle, NOT the glue line between body and top. Drawing it all out helps make sense of things, and it all depends on how you carve your top.

[biliousfrog]

I've kinda got it now I think. I just redrew it full scale using far more reference lines than I would expect & I seem to have something that supports what you've said. Here's an example of how I worked it out (not to scale )

Does that seem right? Because of the neck angle + the carve angle I'm getting an angle of 7 degrees which seems really steep...especially as my last one was only 3.

[Setch]

Almost there, but not quite. That approach may work for a DC single cut, or a design where the binding can vary in height, but it aint going to cut it on a LP. If you look at you final drawing, the fretboard would be sitting below the binding, well into the mahogany below.

You first step is correct, but the next step is to calculate neck angle. You consider the top of the binding to be the 'face' of the guitar, and consider the thickness of the carve as part of your bridge, so the bridge height you use is bridge + carvetop - fretboard thickness. Mark this on you drawing, then draw a straight line connecting the top of the binding to the bridge height mark. This is you neck angle. Then, it's as simple as plaing a straight surface bewteen the bridge and the end of the fretboard.

[biliousfrog]

Yes, I think that's probably closer to what I drew full scale than the diagram I knocked up above. On the blue singlecut that I'm working on the top curve actually points further forwards than the neck join HERE so I tried to make sure that the transition from full thickness to binding ended at the furthest forward point. Because of the angled neck join it makes cross section drawings a lot more complicated but I think I have it now.

Thanks for all the help.