All posts by Windell Oskay

About Windell Oskay

Co-founder of Evil Mad Scientist Laboratories.

The AxiDraw CLI and Python API

Following the release of our new AxiDraw software this week, we are pleased to announce the release of two additional software components that greatly extend the capability of the machine.

The AxiDraw software is now available in two alternate versions that may be helpful for developers or for anyone who would like to control the machine programmatically rather than through Inkscape: A stand-alone command-line interface (CLI) tool, as well as a full-featured Python library.

The AxiDraw CLI

The first new tool is the AxiDraw CLI,  a command-line API to drive the AxiDraw outside of Inkscape. Like the Inkscape-based software, its primary function is to plot SVG files. However, it is a stand-alone utility that can be driven from within shell scripts and other environments that make use of shell commands.

Once installed, plotting a file can be as simple as executing the following command:

axicli filename.svg

There are, of course, a breadth of different modes and configuration parameters available. We have written detailed descriptions of each of these options in our comprehensive API documentation. The CLI also supports the use of configuration files to quickly switch between different sets of parameters.

Since most common scripting and programming environments allow one to call shell commands like this, that allows the AxiDraw to be used directly within a wide variety of frameworks.


The Python API

The second new tool is the AxiDraw Python API. The AxiDraw CLI is written within Python, and we have both exposed and expanded upon that nucleus to create a flexible and powerful Python module, complete with its own comprehensive documentation.

Just like the CLI, the Python API can plot SVG documents; it can both read SVG files and accept strings containing SVG data.

It also has features that are not available within Inkscape or the CLI: It supports direct interactive XY control. You can use absolute or relative moveto/lineto type commands to control the AxiDraw from within your own programs. This is particularly useful for a wide variety of potential AxiDraw applications that are not writing or drawing, but otherwise making use of the AxiDraw as a low-cost motion control platform.

Hershey Text v 3.0

Some years ago we wrote a neat little Inkscape extension called Hershey Text. Hershey text could take a little bit of text that you would type and render it into stroke fonts, also known as engraving fonts.

We are very pleased this week to release an all-new version of Hershey Text, written from scratch, and far more useful, capable, and extensible. We have a comprehensive user guide for it as well.

Hershey Text v 3.0 will be bundled into future versions of Inkscape, but it’s also included with the new AxiDraw software and available on its own for download today.

Continue reading Hershey Text v 3.0

New AxiDraw Software v 2.5

We’re pleased to announce the release of the latest version of the AxiDraw software, 2.5. which includes a number of frequently-requested features that we’ve been working on over the last year.

An expanded user guide

Perhaps foremost, we have updated and greatly expanded the PDF AxiDraw user guide, which covers how to use the AxiDraw, including every part of the software. In addition to sections that go over the new features, we have thoroughly revised the rest, including a larger and clearer section on getting started.

A new SVG optimization tool

In normal use, the AxiDraw software plots elements in the same order that they occur in the file. However, depending on how your file was generated, that may not be the most efficient way to do things. If the order of the elements in the file is poor enough, the plot time can actually be dominated not by writing and drawing time, but by pen-up movements (illustrated here in red) between objects.

We’ve written a new SVG ordering utility, that can sorting of objects in an SVG document, re-ordering them as needed to reduce pen-up travel. It’s also a layer-aware and group-aware sorting tool, that can process a full document and reorder elements on each layer of the document and either respect or break apart other groups in your document. This tool is available in two versions: An individual Inkscape extension as well as an integrated version that you can use automatically within the AxiDraw software.

Better support for using multiple machines

The new AxiDraw software supports assigning names to individual AxiDraw units over USB, which you can use as semi-permanent labels when printing to a particular machine. You can also now plot to a specific AxiDraw, or simultaneously plot the same document to a number of connected machines.

A new version of Hershey Text

This release includes an all-new version of Hershey Text, our software for creating stroke-based text within Inkscape. You can about the new features in our blog post announcing it.

And more!

Amongst other improvements in the new software are the following:

  • Updated to use Inkscape 0.92
  • Paths in the document are now clipped gracefully and precisely at the boundaries of both the artboard (drawing canvas) and machine travel.
  • Supports more SVG object and layout types natively
  • Faster plotting on paths with very high vertex density
  • Online version check added
  • Improves behavior of Hatch Fill extension
  • Bug fixes galore

We recommend this new version to all AxiDraw users; you can download it for Mac, Windows, or Linux, following our guide here.

Evil Mad Scientist Valentines: 2019 Edition

2019 valentines

Today we are releasing our newest set of “Download and Print” cards for Valentine’s day. This is our seventh year, and seventh set of cards. The 2013 set had six equation-heavy cards, the 2014 set was a set of six symbol-heavy cards, and the 2015 set included love, hearts, and arrows. The 2016 set featured Pluto’s cold heart, and the perfect card for your robotic expression of love. In 2017 we featured atomic orbitals, exponential growth, and an epsilon delta declaration of love. The 2018 set featured normal force, stable equilibriums, and something about RPN calculators.

This year’s set features geometry, division by zero, batteries, a nod to quantum chromodynamics, and two very bad puns. (Sorry not sorry.)

Be my Valentine. Any other choice would be irrational.

To the extent that it is important that romance is rational, this is an extremely romantic card.

Roses are red, some quarks are blue. The strong nuclear force is what attracts me to you.

A proton or neutron is made up of three quarks, but its mass turns out to be dominated by chromodynamic binding energy, not the mass of those quarks. Corollary: By weight, humans are almost entirely binding energy.

Unlike most Valentine’s cards, which neglect the vast majority of your potential paramour, this card will let them know that you appreciate more than a tiny fraction of them.

It's hard to define home much I like you. But we should.

I tried to compute my love for you but my calculator gave me an error.

You get me all charged up.

Like a LiPo battery charged at the proper rate so that it does not explode.

You must have taken my electron, because I've got my ion you.

You had better be positive before you give this card to someone.

2019 valentines

You can download the full set here, which includes all 42 designs from all seven years (PDF, 1.8 MB).

As usual, print them out on (or otherwise affix to) card stock, personalize, and [some steps omitted] enjoy the resulting lifelong romance.

Linkdump: November 2018

Linkdump: September 2018

The AxiDraw SE/A3

AxiDraw SE/A3

We’re very pleased to introduce a new member of the AxiDraw family: the special edition AxiDraw SE/A3. This new model joins our existing models including the AxiDraw V3 and AxiDraw V3/A3.

Like the AxiDraw V3/A3, the AxiDraw SE/A3 has an XY travel suitable for use paper up to 11×17″/A3 size. However, in place of the central extrusion that makes up the body of that machine, the AxiDraw SE/A3 has a central beam that is CNC machined from a solid billet of 6061-T6 aluminum, and then anodized to a sleek black finish.

This heavy, rigid structure — it’s a solid block of metal! — provides dramatically better straightness and stiffness, even compared to the already-stiff AxiDraw V3/A3. This design adds mass exactly where you want it: to the non-moving base that forms the X-axis of the machine. In order to keep the weight light where it matters, the moving Y-axis of the AxiDraw SE/A3 uses the same stiff and light custom aluminum extrusion that we use on the AxiDraw V3/A3.

We made a video showing off the SE/A3, and how it’s made:

The AxiDraw SE/A3 is available to order now at the Evil Mad Scientist shop.

Two New Accessories for AxiDraw

We’ve just added two new accessories for the AxiDraw V3.

XL Pen Clip

The first of them, shown above, is the XL Pen Clip — something that we’ve had a number of requests for. The pen holder on the AxiDraw normally fits pens and other instruments up to 5/8″ (16 mm) in diameter. However, this new XL pen clip can hold instruments up to 1″ (25.4 mm) in diameter.

That is to say, it can hold things like this freaking huge marker:

huge pen

The second new accessory is a little more subtle: an Italic Pen Adapter that gives the AxiDraw a “right handed” grip on pens.

Italic Pen Adapter Italic Pen Adapter
Italic Pen Adapter Italic Pen Adapter

It’s a little bracket of anodized aluminum, with captured screws and threaded inserts, which rotates the AxiDraw pen clip 45° out from the X-axis of the AxiDraw. This angle can give a slightly more “natural” look to certain types of handwriting-like plotting.

Italic Pen Adapter

And of course, it’s ideal for use with various types of blunt-tipped pens, including chisel-point felt tip pens as well as pens with stub and italic nibs.

Both the XL Pen Clip and the Italic Pen Adapter are in stock at the Evil Mad Scientist shop. They join the Rigid End Effector and Tripod Mount on our AxiDraw Accessories page.

Linkdump: July 2018

SMT LED sitting on mirror to show directional marking on component underside