A method on drawing multiscale guitars

Discussion in 'Plans, Designs & Software' started by Jenious, Jun 23, 2013.

  1. Jenious

    Jenious Member

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    If anyone else has tried to import the .dxf from fret find into emachineshop you might have run into it not being properly scaled. At least I ran into this problem, and after messing with it for about a half hour, I said screw it and took a different approach for drawing out a multi-scale guitar. So I figured I’d make this thread for two reasons A). To help anyone else having this problem B). So people can check me work and find my mistakes.

    I won’t go into great detail on the program since there is already a great thread covering this for straight scale guitars here

    So to start off I still made my layout on fretfind, for this demo I’ll being making the layout parameters being:
    -26”/28” scale
    -perpendicular on the 8th fret
    - string spacing at nut: 2”
    -bridge spacing: 3.0625”
    This is what the measurements look like when entered in fretfind:
    [​IMG]

    Now fretfind spits out a bunch of X,Y coordinates, here’s the ones we’ll be using.
    [​IMG][/URL][/IMG]

    Using the measurement #1 in the pic above, the centerline is 27.00727, so we make a line that long, at 0.

    [​IMG]

    We can us the (X,Y) coordinates of strings 1 and 8 we can figure the angle of the nut and bridge using some trigonometry.

    IMPORTANT: Since we’re drawing the fingerboard horizontal instead of vertical like fretfind does, the x’s and y’s are flipped!

    Starting with the nut we take the first (x,y) coordinate of string 1, which in this case is (2.69325,0.80018) and flip it so we get (0.80018,2.69325). Then we do the same with the (x,y) coordinates of the 8th string and get (0.05996,0.69325).

    Next we take X 1st string - X 8th string and Y 1st string- Y 8th string which is:
    X=0.800180-0.05996
    Y=2.69325-0.69325
    and get X=0.74022, Y=2.

    From here we can draw a right triangle:

    [​IMG]

    By connecting the ends of the triangles you have your nut face, at the proper angle and length. (I was going to explain how to calculate the angle and the length of the nut, but I realized there’s no need if you draw the legs of the triangle and then connect them in emachineshop.)

    After drawing the line I copy and pasted it into the file where the center line is draw, then snapped the center of the nut, to the end of the center line.

    [​IMG]

    Then you go and do the exact same steps as above for the bridge and get something like this:
    [​IMG]

    Now connect the ends to get:

    [​IMG]

    Time to draw the outside of the fingerboard, which is really easy; just copy and paste the strings, make sure the copy is directly on top of the original string. Then using this tool, enter your overhang in the box and hit enter (that is important). So for the 8th string I have an overhang of .162”. So I enter that in the box, hit enter, make sure the string is selected and press up on the arrow key. Then do the same for the 1st string, but my overhang this time is .13, and as you guessed, we press down on the arrow key this time. Here’s the result:

    [​IMG]

    [​IMG]

    As you can see they don’t intersect, so some of the line will need to be extended. So just draw a line at the same angle as the one you’re extending. The length doesn’t really matter at this point since we’ll be cutting off the excess. So for the bridge we draw two lines at 292.37 deg, and snap them at the ends of the bridge like so:

    [​IMG]

    The bass edge of the fingerboard doesn’t intersect so extend that, and do the same for the nut so that they’re all intersecting. Again, make sure the angle of the lines you draw match the one you’re extending.

    [​IMG]

    Then using the intersect tool (ctrl+I) clean up the drawing. Now you have your outline.

    [​IMG]

    I'll cover how I drew the frets in a bit, right now it's dinner time.
     
  2. Adam

    Adam Well-Known Member

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    None of your pictures work for me... Photobucket can be so annoying...
     
  3. Jenious

    Jenious Member

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    yea I just fixed that, sorry about that, copied the wrong links hahaha
     
  4. Adam

    Adam Well-Known Member

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    Ugh trigonometry :lol:
     
  5. Jenious

    Jenious Member

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    Alright, time to add the frets, and get the nut to size.

    For the nut just copy and paste the line that marks the face of the nut, the doing the same thing we did for the edges of the finger board, move it to the right the desired distance.

    [​IMG]

    Again, extend the lines as needed, and trim as needed so you have your nut.
    Finally, the last thing I’m going to cover is laying out the frets since everything else will pretty much be the same as it was in heretics thread that I have linked at the beginning of this thread.

    For the frets make two lines and snap one at the intersection of the nut for the 8th string and one for the 1st string, the length doesn’t matter here but the angle should be 90 deg.

    [​IMG]

    Then adjust the x values to the position of the desired fret, I like to start with the 24, and work my way towards the nut. So in this case the line for the 8th string intersects at 27.37742”, using the stewmac fret calculator, you know the center of the 24th fret on a 28” scale falls 21” from the face of the nut. Meaning 27.37742”-21” will give us the x coordinate for the 24th fret for the 8th string; which is 6.37742" in this case. We repeat this again for the 1st string but this time it’s 26.63720" – 19.5” since the treble side is a 26” scale. The result will look like so. OR you can just do the same thing we did to layout the nut using that line shift tool instead of calculating each individual X location.

    [​IMG]


    [​IMG]

    If the line does not intersect the string just tack on a little extra length so it does.

    Next snap a line on of the intersections and then connect it to the other intersection. I’ve had trouble here where it doesn’t always select where the lines cross. The solution I have found is, if the intersection will not highlight, exit the line drawing tool, click one of the lines that make the intersection, then click on the other. After you have done this, usually you can now snap the end to the intersection using the line edit tool. Now you have your 24th fret.

    [​IMG]

    All you have to do now is extend it and trim again (you’re getting sick of hearing that arentcha?). Ta-da you have the center of your 24th fret marked.

    [​IMG]

    From here it’s just the tedious task of marking the rest of the frets if you decide to do so, and same with the strings. Like I said earlier, from here on out is pretty much the same as heretics thread so I feel no need to cover it.

    Hope this helped at least one person out.
     
    Purelojik likes this.
  6. Adam

    Adam Well-Known Member

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    Good tutorial :yesway: I noticed that about FretFind as well, the .dxf export is worthless. What I did was just get the angles from the nut and the bridge from the .dxf then starting fresh, no math :lol:
     
  7. Jenious

    Jenious Member

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    Yea I didn't think to just make the triangle in emachineshop until I made this thread. The first time I drew it, I did it by hand and did the whole tanX= opp./adj. thing.

    And who likes to do things the easy way? :rofl: (as i slowly die inside asking why i didn't think of that, and the thought of all the wasted time with calculating)
     

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