Help! Challenge: Fretboard Generation

michael_flynn102

Hey! I'm trying to generate a guitar fretboard based off of configuration parameters, and I'm having a hard time figuring out the best way to go about it.

The challenge is that I need to essentially perform a function on each instance of a linear pattern to determine the distance to the next instance, instead of setting just one distance between each instance.

So far I have successfully used FeatureScript to generate the distances I need, but I'm not sure the best way to implement these distances, as I would LIKE for the end result to work with any number of frets entered and then generate a fretboard with that many frets. This is complicated by the fact that the face of the fretboard is a drafted curve, so just copying an object in a straight line won't really work as the angles won't be perfect.

I have this feature script to generate the variables I can use to manually put in each fret in the proper location, but ideally I'd like to write FeatureScript to generate all of the frets.

annotation { "Feature Type Name" : "Generate Fret Spacing Variables" }
export const addMyFunctions = defineFeature(function(context is Context, id is Id, definition is map)
    precondition
    {
        annotation { "Name" : "String Length" }
        isLength(definition.stringLength, LENGTH_BOUNDS);
        
        annotation { "Name" : "Fret Count" }
        isInteger(definition.fretCount, POSITIVE_COUNT_BOUNDS);
    }
    {
        var c = definition.stringLength;
        
        for (var i = 1; i <= definition.fretCount; i += 1)
        {
            var p = c;
            c = c / 1.059463;
            setVariable(context, "BL" ~ i, c);
            setVariable(context, "OL" ~ i, p - c);
            setVariable(context, "NL" ~ i, definition.stringLength - c);
        }
        
        setVariable(context, "NeckLength", definition.stringLength - c);
    });

In the above code, the prefixes mean:

• NL: Nut Length (Distance from top of string to fret)
• BL: Bridge Length (Distance from bottom of string to fret)
• OL: Offset Length (Distance from previous fret to this fret)

Here is my project, versioned V0.3 at time of writing: https://cad.onshape.com/documents/39121782acf88719d61983ae/w/4d7fdf89d456b54d1055a07d/e/5162cd4f7ed9efedfdb77ad6

The best idea I currently have is to try to split the neck at the set distances, and then insert a sketch circle at the top / front most position in each chunk and sweep it across the top edge, and then merge all the chunks back together. But I would love some other suggestions.

Thanks in advance!

NeilCooke

I wouldn't use variables at all. Do it all in the feature. You can select (or create) the fretboard and either select a modelled fret or even better, create the fret in the feature then use opPattern to create the others.

jelte_steur814

Do you really want to create a feature for this? it could be done with incrementing variables.

@GregBrown explains well in this video how to.

for #i, you could use my increment variable feature as well.

in this case it doesn't make much of a difference, but it would

https://www.youtube.com/watch?v=fNJlNqdtnzU

martin_kopplow

I didn't know about this little trick with the iterations before. Great find! I did that manually for a bass build I have under way, but I believe a FS that incorporates the steps would still be a nice thing.

MichaelPascoe

Nice feature @jelte_steur814! I had tried to come up with ways to make variable feature patterns easier for users but never quite was able to. This simplifies it really well.