The Last Bass Outpost
Gear Discussion Forums => Bill's Shop: Projects, Mods & Repairs => Topic started by: drbassman on March 08, 2010, 05:33:18 AM
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Hi Guys! I've been working on some projects that will need scratch necks built and I was mulling over neck angle. I've been experimenting with 14-15 degrees which give a really nice pull on the strings and you never need string trees and the like (which I hate messing with). Weren't some of the Gibson basses 7 degrees or so? Do you have a preference regarding headstock angle? Just curious............
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I personally don't know, but Warmoth uses 13 degrees:
http://www.warmoth.com/Bass/Necks/Bass13Necks.aspx
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13 degrees is a good angle. Thanks for posting that.
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Back in the 60s Gibsons were usually 17 degrees. The 90s Les Paul basses were 10 degrees and I never heard of any problems with that low an angle. I remember reading that some Ricks have been 8 degrees, but less than that and you get into string tree territory pretty quick.
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Back in the 60s Gibsons were usually 17 degrees. The 90s Les Paul basses were 10 degrees and I never heard of any problems with that low an angle. I remember reading that some Ricks have been 8 degrees, but less than that and you get into string tree territory pretty quick.
Thanks Dave. I think the 8 degree Ric neck sounds familiar. I've had good luck with 15 degrees and probably will just stick with that. I'm building a jig so I can crank out that angle routinely.
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I was thinking 13 degrees also.
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For bass I use 10 degrees which I believe is the optimal angle for a bass headstock in a non-scarf neck. If you're doing a scarf joint I think you could do a greater angle, but for a one piece neck I would not go over 13 degrees though.
Back in the 60s Gibsons were usually 17 degrees. The 90s Les Paul basses were 10 degrees and I never heard of any problems with that low an angle. I remember reading that some Ricks have been 8 degrees, but less than that and you get into string tree territory pretty quick.
If that's true then maybe that's why so many Gibson basses from that era have broken headstocks. Too much grain run-out could have made the headstocks not strong enough to withstand the string pull of bass strings.
Back in the 60s Rickenbacker basses didn't have any angle at all, they were flat, and only by the early 70's they started to add a little bit of angle until they've got settle for 4,5 degrees in the late 70's and stay that way up until the late 90's when they changed to the current 7,5 degrees.
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Makes sense Daniel. I always use a scarf joint, much easier with the tools I have on hand.
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are scarf joints stronger than one piece neck depending on the angle?
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are scarf joints stronger than one piece neck depending on the angle?
The strength of a scarf joint is amazing, assuming it's glued properly and the surfaces mate up as they should. A one piece neck, as Daniel mentioned, will be weaker as the angle increases because the grain run out at the angle makes it so. There is no grain run out on a scarf joint. He point about Gibsons is illustrative.
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I'll have to disagree with you there. Bill. There's less short grain runout but it's not eliminated. You'd have to do a very long scarf on a short headstock to accomplish that and still keep enough headstock angle, and even then it wouldn't be eliminated because the angled grain is on one piece, not both.
Here's something I copied long ago at a forum I can't remember, it's from an acoustic guitar maker named Grant Goltz:
Now, the theoretical 3,000 psi strength of a glue joint in a scarf needs to be looked at in the proper context. Scarf joints are very common in boat building. I use them all the time. That is how one builds 16 foot long boats out of 8 foot long plywood. To get near the strength of a solid length of wood, the scarf joint needs to be cut at an 8 to 1 angle to minimize the end grain gluing effect. In other words, a scarf joining 1 inch wood needs to be 8 inches long, or on my 3/16" thick boat plywood it needs to be 1 1/2" long. So a 1/2" thick peghead should have a 4" long scarf, but that would only give a 7 1/2 degree peghead angle. At a more typical 15 degree angle, you only get a 2" long glue joint, or a 4 to 1 scarf. Compound that by the fact that the angle is all on one piece, effectively doubling the end grain effect (so do you have an effective 2 to 1 scarf?). In any case, no way in the world are you going to get anything approaching a 3,000 psi joint. Actually, on boatbuilding scarf joints, we would never trust the strength of woodworking glue (ignoring for the moment the non-waterproof fact). Such joints are always glued with marine epoxy, which does actually have strength in the glue.
So, what is the likely bottom line? Obviously both construction methods have been used with success on thousands of guitars. Thus both appear to have adequate strength under normal circumstances. I would be willing to bet that there is not a whole lot of difference in the actual strength of the two. So which is better? I guess, as my Dad used to say "six of one and a half a dozen of the other". Happy building.
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Hard to argue that. For me, scarfs are the easiest to make. As equipment changes, I might go the other route. Either way, I wouldn't be afraid of using either form.
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Of course Gibsons have a particular problem, and that's probably due as much to the low shear strength of mahogany as it is to the 17 degree headstock angle. But the Les Paul guitar aficionados don't like the less severe angles.
I've also seen breakages and glue line failures in scarf joints. No way is perfect, you do your best and try not to let some drunk knock it off a stand.
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Like most things in life, anything can break.
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I've also seen breakages and glue line failures in scarf joints. No way is perfect, you do your best and try not to let some drunk knock it off a stand.
I guess that's the bottom line. Don't let someone drop it on the floor.
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OK, I settled on 15 degrees and made a jig for cutting necks. Just for comparison, I measured the neck angle on my Hofner project and it's 15 degrees. So I thought, what the heck, works for me.
I made the jig from scraps and some ply I had laying around the shop. For a couple bucks, I got a guide rail from Sears that fits the track in my table saw. Neat!
Over the summer I might build another one with a rotating piece so I can dial in any angle I want. This will work great for 90% of my bass projects.
(http://i2.photobucket.com/albums/y16/drbassman/Misc%20Stuff/100_2946.jpg)
(http://i2.photobucket.com/albums/y16/drbassman/Misc%20Stuff/100_2947.jpg)
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As always looking good !
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Thanks Scott! I'm really getting into making jigs and such so I can turn things out quickly in the future.