Who am I?

Gina Häußge aka foosel

• Fun fact: the ß is pronounced like an S
  (there is no B there, really!)
• Creator & maintainer of OctoPrint
  and mostly sole developer
• Passionate coder 👩‍💻
• Former IT Consultant & Software Architect
• Owner of a 3d printer since late 2012
  (help, they keep multiplying!)

Why did I create OctoPrint?

First printer acquired in November 2012

• Obviously wanted my desk back
• Rough idea how to solve this:
  • Web interface
  • Server installed on a headless Raspberry Pi
    (had just come out that year)
  • Put printer in spare (bath) room
  • Remotely monitor full print via WLAN

• Problem: existing solutions treated printer as write-only
  • Connect
  • Upload a file
  • Hope that it prints
• I didn't trust that at all, no feedback
• Wanted to at least
  • track temperature
  • track progress
  • ideally provide webcam view

How hard can it be?

• Sat down & built first version over Christmas 2012
• Published my little pet project, figured "I'm done"
• People started messaging me about it
• Then it took over my life
• And now I've been working on it for the past six years
  (Honestly I'm still unsure how this all happened...)
• Learned a ton

Challenge #1

No proper protocol specification

The "protocol"

• Organically grown dialect of GCODE
• GCODE:
  • (standardized) programming language for CNCs from the 1950s
  • plain text file format
  • nothing about sending messages over serial
  • no error correction
• Communication protocol stuff hacked on top

The "protocol"

• More or less accurate general documentation in the RepRap wiki
  • Living document
  • Anyone can edit it
  • No governing body
• Marlin (mainline) specific documentation on marlinfw.org 👍
• General problem with both:
  • No test suite or reference implementation
  • In general no definition of command responses

Result

• New firmwares or forks with
  • New commands that have incompatible meaning elsewhere
  • Common functionality in a slightly different or outright broken way
• Example: possible (simplified) temperature reports

  
  ok T:20.3/0 B:20.2/0                      ; Marlin & Repetier, single extruder
  ok T:20.4/0 T0:20.3/0 T1:20.4/0 B:20.2/0  ; Marlin & Repetier, multi extruder, 
                                            ;   T1 active
  ok T:20.3/0 T1:20.4/0 B:20.2/0            ; Smoothieware, multi extruder
  T:20.3/0 B:20.2/0                         ; autoreport or blocking heatup
  T:20.3/0                                  ; autoreport or blocking heatup
  T:20.3                                    ; blocking heatup?
  ok ==T:20.3 /0 ==B:20.2 /0                ; Creality CR-X 🤨
  echo: T20.3 /0.0 B:20.2/ 0.0ok            ; Lerdge S 🤦‍♀️
  								

Consequence

• Regularly need to read firmware source of forks
• These days increasingly difficult (China...)
• Last resort: Logs from & close collaboration w/ users
• Have to draw a line somewhere w/rt broken firmware
• Attempt to standardize: Strong resistance 🤷‍♀️

Please scream at your vendors if they break widely supported behaviour and not at me, I'm on your side 😉

Challenge #2

Fragmented firmware landscape

Fragmentation left and right

• Most users rarely update their printer firmware
  • if they even can!
• Vendors fork and never merge from upstream again

Result

• Ancient bugs still present in current printers
  I still get tickets regularly caused by bugs in Marlin forks I fixed six years ago
  • Missing oks
  • Translated serial messages
  • Broken resend requests
  • etc
• Takes ages for new features to propagate
  If they propagate at all
  • E.g. busy protocol
  • E.g. capability reports

Consequence

• OctoPrint has to accommodate firmware
  • from today
  • from 7 years ago
  • and from anything in between
• Next to no way to differentiate between those
  • Marlin V1; Sprinter/grbl mashup for gen6
  • Author: (default)
• ➡ Complex code to handle printer communication

Please update your printer's firmware regularly - and ideally run the mainline version, not an (outdated) vendor fork 😉

Challenge #3

Plugins require backwards compatibility

Plugins in OctoPrint

• Since OctoPrint 1.2.0 (~2015)
• Users can easily add or modify functionality
• Currently over 160 plugins registered on the repository
• Advantage: Easier to customize OctoPrint to your specific workflow
  • Not everyone wants every feature
  • Just pick what you need
• Advantage: Bundled plugins are also easier to maintain
• Disadvantage: Easy fixes turn into backwards compatibility nightmares

Result

• Typo in API? Plugin might depend on that name.
• Order of events on subsystem? Plugin might depend on the order.
• Third party dependency version? Plugin might depend on it.
• Python 3 compatibility? Plugin might not be Python 3 ready.
• ➡ Have to think of consequences all the time

Consequence

• Need to be very careful with every single change
• Breaking backwards compatibility = breaking established plugins
• Breaking established plugins = unhappy users 😕
• Sometimes means bending over backwards to solve a trivial issue

Please be patient if a seemingly trivial change appears to take ages 🙂

Challenge #4

Supporting the masses

Consumer mentality vs DIY enthusiasts

• Early days: Huge overlap between owners & DIY enthusiasts
  • Tinker happy
  • Happy to google around for a solution
  • Capable of fixing stuff themselves
• These days: Lots and lots of consumers
  • Printers are marketed as plug-n-play but aren't
  • Many owners never had to tinker before
  • OctoPrint might be their first interaction w/ Open Source

Result

• Lots of development/OSS inexperienced users
  • Constant need to ask for logs & more info that "it doesn't work"
  • Tricky to explain some things, e.g. why proprietary printer won't work
    and can't "quickly be added"
• Sometimes expectation to get support on par with huge multinational company
• Sometimes hostile reaction when told inconvenient truths

Consequence

• Huge support overhead
  • Hours per week of fielding questions
  • Repetitive
• Often very frustrating experience
• ➡ Established community forum
  • Central place for support, questions, sharing
  • Not just me anymore, everyone can help to help
  • Seems to work best so far

Please help each other with questions and problems 🙂

Challenge #5

Funding

This has become a job

• Project size way way past pet project level:
  • Maintenance
  • New development
  • Community management
  • Support
  • etc
• Full time job and then some
  A lot of people think I'm a multi person company 😋

Consequence

• Turned part time in 2013 (own cost)
• Turned full time in 2014 (single sponsor)
• Turned crowdfunded via Patreon in April 2016
• It works 😲
  but is also really scary
• Huge thanks to the community! 😍

If you like OctoPrint, consider supporting my work on it 🤗