Parametrix concepts

Parametrix presentation

Parametrix is a web-app to generate 2D designs.

Overview

The user of Parametrix gets:

• 2D
• web app
• programmatic
• parametrizable
• simulation included

The programmer of Parametrix design (a.k.a. Designix) gets an API with:

• circle, stroke and arc
• corner widening or rounding
• export to DXF, SVG
• compatible with FreeCAD
• lines and arcs ready for CAM tools ;)

The API provides options for rounding or widening corners of outlines. It’s useful for:

• good looking parts
• manufacturabilty
• improve mechanical strength

Programmatic CAD

Instead of using graphical tools like FreeCAD, Programmatic CAD is the process of generating CAD designs from software code. Below some benefits of this approach:

• designs managed by software development tools like git
• lightweight. Typically you need a text-editor and a small viewer
• complex parametrization are better solved by software
• repeated pattern are easier to implement and maintained
• curve from complex mathematical formula
• can be integrated in web-backend or software automation chain

CAD flow comparsion

Low-tech CAD pros:

• less computer demanding
• scalability of established designs cons:
• restricted to subset of 3D shapes
• complex 2D programmatic design

The constraints of part manufacturing and low-tech CAD shaping concept are similar. As consequences:

• low-tech CAD is good enough for mechanical parts
• too restrictive for esthetic/design parts

Extruded-2D-design is good enough for 90% of technical parts

Future tools around Parametrix

Web app

web app characteristics

• [+] security
• [+] ubiquity
• [+] no installation
• [+] OS agnostic
• [+] browser agnostic (web standards)
• [-] no file access
• [+] could be installed locally for offline usage
• [+] fast development of GUI
• [-] restricted to web protocols
• [-] restricted hardware access

native app characteristics

• [+] performance
• [+] multi-threading
• [+] many programming languages
• [+] compiled or interpreted
• [+] run with internet-off
• [-] OS dependent
• [-] complex development of GUI
• [+] any network protocol
• [+] access to hardware

In 2023 the eco-system for developing web-apps is mature.

• nodejs V18 is the first LTS with official support for ESM.
• SvelteKit is the first frontend framework that support ESM.

Electrical motors

Types of electrical motors

Controller of electrical motors

An optimal BLDC motor control enables:

• better dynamics
• no missing steps
• energy efficient
• backdrivable
• enable motor synchronization (CNC or multi-motor-joint)

The project SimpleFOC (Field Orientation Control) provides a solution for this problematic.

Embedded electronics

Embedded key technologies:

• Powerful microcontroller like STM32
• ROS2 maturity
• mROS: micro-ROS without agent
• Zephyr-OS, Tock-OS
• Ethernet 10BASE-T1S and 100BASE-T1
• SimpleFOC (Field Orientation Control)

Enable motor synchronization for:

• CNC
• robot
• mechanical joint with multi-motors

multi-motor joint

advantages of mechanical join with multi-motors

• [+] distributed efforts
• [+] spread thermic, better cooling
• [+] scalable
• [+] use standard high-tech/mid-range components
• [+] easier maintenance
• [+] easier manufacturing standardization
• [+] smoother control
• [+] no backlash
• [-] complex motor driver
• [+] distributed power
• [+] improve split between small standard high-tech and large low cost

Gimbal

Gimbal is a two axis mechanism for controlling pan and tilt orientation. It is used to stabilize and orientate camera (100g), as articulation of arm-bot (5kg) or to orientate solar panel (2000kg).

Advantages of heliostats (aka solar tracker):

• optimized radiation quantity
• ensure ray perpendicular to the panel
• enable more efficient photovoltaic micro-lense technology
• enable concentrators for solar thermic panel

Roadmap

• Parametrix
• gears
• gimbal
• heliostat