3D Printer Workbench Work Proposal

Problem Statement

Designing 3D printer variants with pre-designed OSE parts and modules in FreeCAD is time-consuming and cumbersome.

Solution

Develop a FreeCAD workbench to streamline the design of 3D printer variants using pre-designed OSE parts and modules.

Proposal

General Requirements

• Support OSE Linux and FreeCAD 16
  • If we can support 18 while not at the expense of 16, then great.
• Keep file size of parts low. See File Simplification for details.
• See further details in proposal.

Phase 1

FreeCAD macro for changing the lengths of Universal Axis objects

• Creates a FeaturePython object or Scripted object allowing users to interact with object at a high-level and modify custom properties like Length.
• Additional properties can be added to this object in a later phase:
  • Axis Orientation
    • X, Y, Z
  • Motor Orientation / Position
    • Left or Right
  • Belt Catcher Orientation - because in practice, we never end up following a convention and correct this with how we plug in wires into the controller. It is faster to change wires than to modify axis during the build.
    • Up or down
  • Rod size
    • 8mm, 1”, 2” Leave out the 2 inch - as this is not simple Intensive Scalability of 8 mm version. Do this as at a later stage of the project - first stage restricted to 8 mm
    • For the 1" axis, please use the same design as found on the D3D Mega v19.12 - but we can only use the Z axis to remain compatible with the existing D3D Pro components. We will need other mounting corner pieces for larger versions of the 3D printer. But the hybrid 8 mm - 1" version appears relevant as it allows a large bed to be used, allowing for max 2' 3D printers, but they can be very tall because the Z is strong. The vertical Z bed is important to enable future high temperature chambers.

Phase 2

FreeCAD workbench for assembling multiple Universal Axis objects together

• Initialize workbench repository and codebase
• Add buttons to generate objects for designing 3D Printer:
  1. Universal X Axis
  2. Universal Y Axis
  3. Universal Z Axis
  4. Extruder
  5. Heated bed - a box either 8x8" - 2" tall - or larger/smaller, 2" tall, just like you see in the picture at D3D Pro
• Generate these objects parametrically and programmatically in Python

Phase 3

Add Frame button to Workbench

• Why start with frame as opposed to considering D3D Universal configurations first?
  • D3D pro configurations have more axes, are more tedious to resize, and will benefit more greatly from automation.
• Generates frame from FCStd file in repository
• Assume X YY ZZ configuration to start
  • Clicking Universal Y Axis button will generate 2 objects with default placements
  • Allow different configurations at a later phase (e.g. 4 Z axes for > 12” beds or 2 X axes)
• Attach Axes to frame when clicked
• Assume static and fixed frame size
  • Allow resizing frame at a later phase
• Assume cubic frame shape
  • Allow rectangular shapes in a later phase
• Determine if it makes sense to allow resizing axes individually when attached to cubic frame

Next Steps

Assess progress, determine next steps, and plan next three sprints:

• Enhance Universal Axis object with additional properties
• Design and develop interaction between frame and axes when resizing frame
• Explore workbench interactions when designing D3D Universal configurations (self-supporting 3 axes)

Execution

The above proposal is planned to be carried out over the course of three 2-week sprints.

Each sprint will culminate in a sprint demo consisting of a video recording posted on G Roques Log with an email sent to relevant stakeholders ensuring project meets goals.

Sprint Planning

Sprint 1 (Mon 1/27/19 - Sun 2/9/19)

• FreeCAD macro for changing the lengths of Universal Axis objects
  • Initialize macro repository and codebase
  • Creates new document
  • Creates a FeaturePython object or Scripted object from UniversalAxisSimple.FCStd file within repository allowing users to interact with object at a high-level and modify custom properties like Length.

Sprint 2 (Mon 2/10/19 - Sun 2/23/19)

• FreeCAD workbench for assembling multiple Universal Axis objects together
  • Initialize workbench repository and codebase
  • Add 3 buttons to generate Universal Axis objects in different orientations:
    • 1) Universal X Axis 2) Universal Y Axis 3) Universal Z Axis
    • Defaults placement to origin

Sprint 3 (Mon 2/24/19 - Sun 3/8/19)

• Add Frame button to Workbench
  • Assume X YY ZZ configuration to start
  • Clicking Universal Y Axis button will generate 2 objects with default placements
  • Attach Axes to frame when clicked
  • Assume static and fixed frame size
  • Assume cubic frame shape
  • Determine if it makes sense to allow resizing axes individually when attached to cubic frame

Phase 2 (Second 90 day iteration)

TODO: Need to reorganize this page, and section.

• Goal: Increase replicability of work accomplished in phase 1 (first 90 day iteration)

Deliverables

• Add more unit tests, documentation, and valuable refactors to existing ose-3d-printer-workbench.
  • Increased documentation on existing patterns
  • Library or framework of code containing encapsulating functionality common to all OSE workbenches (will be within ose-3d-printer-workbench, but designed to be ported out into a separate repo and project later)

• ose-workbench-generator using a project scaffolding tool like cookiecutter or yeoman to quickly generate new workbenches with requisite files and structure needed to reduce barrier to entry.

Stretch Goals: YouTube tutorial video series on FreeCAD Workbench Python Programming.

Existing Work

There was a similar effort around late 2017 to early-to-mid 2018 by Steven Kaiser and Ruslan Krenzler with the D3D Workbench and Piping Workbench.

The D3D workbench was merely a start, and it so far has a frame only, but made of PVC pipe, which is not our main branch of development. Though, it's useful for anyone wanting to build with PVC.

This proposal is for a new branch of development related to the idea of a OSE 3D Printer FreeCAD workbench starting in early 2019.

Links

• 3D Printer Workbench 2020