Marz Guitar Design Workbench

What is Marz Guitar Design Workbench

This is a custom FreeCAD Workbench for Electric Guitar/Bass Parametric Design. It allows you to create Fretboards, Necks, Nuts, ... based on a common set of parameters.

Features

This is a work in progress project, this is the list of the currently implemented features. Theay are working but need more testing.

• Fretboard

  • Compound Radius
  • Multi Scale
  • Zero Fret
  • Perpendicular Fret setting
  • Fret nipping
  • Margins
  • Thicikness
  • String distance
  • Customizable Fret Wire (for accurate slots)
  • Custom Inalys

• Neck

  • Neck Profiles
  • Thickness (start-end)
  • Smooth transitions to Headstock and Heel
  • Set-In, Bolt-On, Through Join
  • Tenon
  • Neck break angle
  • Top offset
  • Truss-Rod Channel

• Headstock

  • Dimensions
  • Transition
  • Volute
  • Flat/Angled
  • Custom shape
  • Pockets/Holes

• Bridge

  • String distance
  • Compensation

• Nut

  • Dimensions
  • Position

• Body

  • Top/Back Dimensions
  • Neck pocket
  • Custom Shape
  • Pockets/Holes

Planned Features

• Nut

  • 3d Object

• Other

  • Provide better options for transition curves
  • Create a Neck Profile repository

Documentation

Just add objects (Instrument, Fretboard, Neck, Body, etc...) from the toolbar and change parameters. All the parameters are on the Root Instrument Object.

The Wiki contains some useful documents: Wiki

Requirements

• FreeCAD v0.19+ (link)

Notes

• This project was designed for 0.19.x, so 0.18.x support is very experimental but it works most of the time.
• The user experience in 0.19.x is significantly better.
• Windows users may experience some issues in v0.19.x

Install

Automatic Install

The recommended way to install this workbench is through the FreeCAD Addon Manager.

Manual Install

Bugs

If you find problems, please report the issue here in Github. I will try to fix/respond not too late.

Background

I initially made a web based Marz Designer, it is still active at: https://marzguitars.com/marz-designer/ and it is very practical for quick calculations and references, but it is 2D and lacks some features like ZeroFret support.

I decided to go to the next level and make it 3D, so I started this project and work on this in my free time. This is a work in progress thing.

FreeCAD extensions are coded in Python, Python is not my preferred language, so maybe there are some non pythonic patterns in my code but I did my best.

This is also my first FreeCAD extension, so it involved a lot of googling, and forum reading. FreeCAD documentation is minimal so I have learned most of the things reading other extensions and the forum.

My Web based project was written in javascript using THREE.js library, and in order to port my existing code quickly, I ported the THREE.js Vector2 class. (I added the credits in the file) At some point in future I will refactor all the code to use FreeCAD's Vector class exclusively.

Multicore multiprocessing in Python

In order to make the code more performant, I coded it to be multithreaded, but python threads runs all on the same core, so they are not suitable for CPU bound tasks, so I used QT Treads to overcome this limitation. The code itself is very clean and reusable and could be a good library for other FreeCAD extensions.

Cache Management

Some 3D Boolean operations are very slow, so I used an aggressive cache strategy to avoid recreation of expensive objects. Thanks to Python's Decorators, it was not too difficult, but I plan to change this strategy to something more reactive based on a dependency graph.

General note on code

I started this project porting my existing javascript code, some things still needs to be refactored properly.