High action question

Posted by Steve Banks on February 3, 2010 at 6:31pm

You CBG veterans are probably sick of this question, so forgive me: I've made a 4 string CBG using a straight, dry piece of 1X3 red oak for the neck.  I hand planed to the approximate shape of the neck on an electric guitar we have.  The fret scale is 25"; the neck passes all the way through the box and the strings anchor in the tail of the piece where it exits the box.  One mistake I know I've made was to shape the piece all the way down it's length rather than leaving it 1X3 where it is concealed by the box.  Lost some strength there.  It turned out to be a pretty instrument, and it holds an open D tuning nicely.  When I tune it though, the neck flexes to the extent that the action at the 12th fret is nearly a centimeter off the neck.  I'm using medium gauge Elixir strings.  It plays great with a slide, but I am disappointed not to be able to fret notes very well up the neck.  Any recommendations for how to avoid this circumstance on my next CBG..?  Or any thoughts on a remedy with this one..?  Thanks for your thoughts..

 

-Steve

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Replies

  • Wes "I'm Baaaaack" Yates March 18, 2010 at 6:42am
    Huzza! I have some pics and plans on my blog if you need more info.

    Here

    -WY

    Dave Breault said:
    One thing you might try on your next build is to laminate you neck stock so that you get more of a quarter sawn effect. Or if you can track some down use solid quarter sawn oak. If you are not familiar with the difference in the properties of quarter sawn versus flat sawn think of it like a piece of paper. If you hold out the paper on the flat it flops down, if you try to hold it on edge it has no downward deflection.
  • Craig Winkelmann March 17, 2010 at 6:55pm
    You might just have to tune down a half step.
    I use this as a guide: http://www.strothers.com/string_choice.htm

    When I build guitar necks I like hard maple, birdseye, flame and the like. Quarter sawn wood keeps it's shape nicely. Typically, depending on your tensioning, thinner necks need truss rods moreso than do thick necks. I don't know the construction of you neck, but, if your box has the room you could remove it an glue on a 1/4" fingerboard to help fortify the thing.
  • Steve Banks March 9, 2010 at 6:50pm
    I am familiar with quarter sawn lumber, but never gave that a thought. That would make a world of difference. Thanks for the tip. -Steve

    Dave Breault said:
    One thing you might try on your next build is to laminate you neck stock so that you get more of a quarter sawn effect. Or if you can track some down use solid quarter sawn oak. If you are not familiar with the difference in the properties of quarter sawn versus flat sawn think of it like a piece of paper. If you hold out the paper on the flat it flops down, if you try to hold it on edge it has no downward deflection.
  • Steve Banks March 9, 2010 at 6:47pm
    Wow... Very informative response; thank you. As far as I knew the oak I bought was kiln dried and ready to go. I did dress it down considerably to make the neck approximate the dimensions of one of my electric guitars, and that probably made it too weak without some sort of truss rod... Getting better at this as I go, though. Again, thank you for your thoughtful posting. -Steve

    Mark aka. Junk Box Instruments said:
    I'm surprised you got that much of a bow but it's difficult to say without more info. I don't know the engineering properties of red oak so I suppose it might be significantly different from the timbers I've used (sapele, maple and English oak). Was it seasoned timber or was it relatively freshly felled? If it wasn't seasoned then it'll be softer and more likley to flex (it'll also be liable to warp or bend over time as it dries out). I don't know what the standard practice is for construction lumber in the USA but I'm guessing it won't be seasoned in the way that would be the case for wood destined for higher precision uses such as quality furniture. Try to find properly seasoned wood.

    (Incidentally, in the UK it seems we have different building practices because all you can normally find in DIY shops or builders merchants over here are various types of pine and similar softwood - which is useless. I generally scrounge deals on hardwood offcuts from helpful local furniture makers and joinery firms).

    You might also consider using a different section. If I understand correctly, the actual dimensions of a piece of 1x3 are 3⁄4 in × 21⁄2 in (19 mm × 64 mm), which I reckon might be on the shallow side for a four-stringer. The depth dimension is quite important if you want a neck that doesn't flex too much. So maybe you ought to start with 2x2 or 2x3.
    (I'm not sure why you've used a piece that wide. I'm guessing maybe you've cut it away so you only use the full width for the headstock and have a narrower width for the main part of the neck...if not, then you've got a pretty wide neck there...64mm is wider than my standard 6-string jumbo acoustic)

    All I can say for sure is that, using well seasoned hardwoods, I've made necks with a depth dimension of 25mm and a width of 38mm and the amount of bow has been zero or hardly visible, even when quite heavily strung.

    I agree with Fergus's observation that it's easier to get a good action if you have a slight "break" angle on the neck (ie. the fingerboard and the top of the body aren't in the same plane but instead are at a slight angle). To see an example look at a Gibson Les Paul or a similar shaped guitar. It means you can have a reasonably high bridge (and sufficient clearance for pickups or for certain picking styles) while also having a decently low action on the higher frets (I learned this the hard way while trying to adjust the action on one of my early builds). But, I very much prefer a thru-neck design for strength and sound properties, so I achieve the angle by cutting away wood from the top of the "heel" end of the neck.
  • Dave Breault March 8, 2010 at 2:54pm
    One thing you might try on your next build is to laminate you neck stock so that you get more of a quarter sawn effect. Or if you can track some down use solid quarter sawn oak. If you are not familiar with the difference in the properties of quarter sawn versus flat sawn think of it like a piece of paper. If you hold out the paper on the flat it flops down, if you try to hold it on edge it has no downward deflection.
  • Mark March 8, 2010 at 10:45am
    I'm surprised you got that much of a bow but it's difficult to say without more info. I don't know the engineering properties of red oak so I suppose it might be significantly different from the timbers I've used (sapele, maple and English oak). Was it seasoned timber or was it relatively freshly felled? If it wasn't seasoned then it'll be softer and more likley to flex (it'll also be liable to warp or bend over time as it dries out). I don't know what the standard practice is for construction lumber in the USA but I'm guessing it won't be seasoned in the way that would be the case for wood destined for higher precision uses such as quality furniture. Try to find properly seasoned wood.

    (Incidentally, in the UK it seems we have different building practices because all you can normally find in DIY shops or builders merchants over here are various types of pine and similar softwood - which is useless. I generally scrounge deals on hardwood offcuts from helpful local furniture makers and joinery firms).

    You might also consider using a different section. If I understand correctly, the actual dimensions of a piece of 1x3 are 3⁄4 in × 21⁄2 in (19 mm × 64 mm), which I reckon might be on the shallow side for a four-stringer. The depth dimension is quite important if you want a neck that doesn't flex too much. So maybe you ought to start with 2x2 or 2x3.
    (I'm not sure why you've used a piece that wide. I'm guessing maybe you've cut it away so you only use the full width for the headstock and have a narrower width for the main part of the neck...if not, then you've got a pretty wide neck there...64mm is wider than my standard 6-string jumbo acoustic)

    All I can say for sure is that, using well seasoned hardwoods, I've made necks with a depth dimension of 25mm and a width of 38mm and the amount of bow has been zero or hardly visible, even when quite heavily strung.

    I agree with Fergus's observation that it's easier to get a good action if you have a slight "break" angle on the neck (ie. the fingerboard and the top of the body aren't in the same plane but instead are at a slight angle). To see an example look at a Gibson Les Paul or a similar shaped guitar. It means you can have a reasonably high bridge (and sufficient clearance for pickups or for certain picking styles) while also having a decently low action on the higher frets (I learned this the hard way while trying to adjust the action on one of my early builds). But, I very much prefer a thru-neck design for strength and sound properties, so I achieve the angle by cutting away wood from the top of the "heel" end of the neck.
  • Steve Banks February 4, 2010 at 5:52pm
    That's an interesting thought. I'll try it on the next one. I have a bolt-on neck attempt underway at the moment. The other thing I thought I might do is look for a length of oak that has a slight deflection in it already, so that string tension might straighten it out rather than bow it upward. Thanks for your ideas. -Steve
    Fergus Morris said:
    I am by no means a 'veteran' builder but have experienced problems like this. If the neck is actually bowing, then maybe you need to use lighter strings.... To get really good action I find it is best to make sure the neck sits at a slight angle pointing down from the box (ie, not at a right angle), my favourite way to do this is to make a bolt on neck that screws in inside the box and wedge something like a bit of plastic card or leather under one end so the neck is angled, like in this picture:

    153081775?profile=original

    My latest CBG project was actually revisiting an old "thru-neck" cbg i made and making it bolt on like this for better action. Some people like higher action for playing slide playing, but I tend to like to be able to do both. As I said, I am not at all an expert and there may be a simpler solution. Knowing how to get good action with a through neck is something I would like to know!
  • Fergus Morris February 4, 2010 at 1:24pm
    I am by no means a 'veteran' builder but have experienced problems like this. If the neck is actually bowing, then maybe you need to use lighter strings.... To get really good action I find it is best to make sure the neck sits at a slight angle pointing down from the box (ie, not at a right angle), my favourite way to do this is to make a bolt on neck that screws in inside the box and wedge something like a bit of plastic card or leather under one end so the neck is angled, like in this picture:

    153081775?profile=original

    My latest CBG project was actually revisiting an old "thru-neck" cbg i made and making it bolt on like this for better action. Some people like higher action for playing slide playing, but I tend to like to be able to do both. As I said, I am not at all an expert and there may be a simpler solution. Knowing how to get good action with a through neck is something I would like to know!
This reply was deleted.