{"id":73418,"date":"2025-01-17T15:55:45","date_gmt":"2025-01-17T20:55:45","guid":{"rendered":"https:\/\/pappp.net\/?p=73418"},"modified":"2025-01-17T15:55:45","modified_gmt":"2025-01-17T20:55:45","slug":"a-goofy-3d-printer-setup","status":"publish","type":"post","link":"https:\/\/pappp.net\/?p=73418","title":{"rendered":"A Goofy 3D Printer Setup"},"content":{"rendered":"\n

TL;DR: I converted my Anycubic Linear Kossel to Klipper.
Using a hacked Chromebook as the host, which is great and I recommend hacking surplus education market Chromebooks for many of hobby projects usually done with an SBC.
Running in containers as a docker-compose project, which works but is dumb and wasteful.
Next I’m going to try to do some systematic performance experiments to it, but that’s for a later post.
Details below.<\/p>\n\n\n\n\n\n\n\n

I wanted to play with Klipper<\/a> (a hybrid control stack that uses a relatively generic firmware on the printer uC for IO only, and does parsing and motion planning etc. on a host computer) and the nice modern fluidd<\/a> web front-end for it, with my little old Anycubic Linear Kossel<\/a> which is known-supported<\/a>. This was brought about partly by having some un-allocated time for a change, partly by seeing some neat Klipper-based projects, and partly because the aging craptop I’d been using as an OctoPrint server finally finished dying.

I grabbed the older of the used Chromebooks I have around – a Dell Chromebook 11 3189, flashed with a UEFI payload and running normal Arch Linux which I was last playing with Hyprland on – to use as the host part, not just because I already had it, but because this stack is designed to run on a little SBC, and it is my conviction that education market surplus Chromebooks are cheaper, better, easier, and more ecologically sound than SBCs and the associated pile of expensive add-ons for like 90% of tasks people get them for. I’m even using the built-in webcam as the monitoring camera by …sticking the whole laptop on an empty box so it lines up.<\/p>\n\n\n\n

\"A<\/figure>\n\n\n\n

I started setting it up, downloaded the klipper package out of the Arch repos, built a firmware image and flashed the Trigorilla board’s Atmega2560 over to Klipper, and loaded up Lukas’ sample config. Then I realized that while Arch has Klipper (with some nicely opinionated packaging choices since upstream is a little goofy) and Fluidd in the repos … the Moonraker<\/a> API package required for them to talk to each other isn’t packaged (?!) There is only a moonraker-git in the AUR, so I assume at one point it was packaged and something breaking happened, but I haven’t investigated.

Instead of doing the reasonable thing and just building the Moonraker AUR package or installing a better supported OS on the computer, I saw this prind<\/a> project that runs the whole stack out of a pile of docker containers. Since that seemed easy and likely to offer desirable stability\/portability guarantees, I decided to use setting that up as an excuse to refresh on dealing with docker and docker compose.

I generally view containers as 90% “adding an extra layer of complexity to isolate badly designed, un-deployable software,” but that’s kind of what we’re doing here, so it seemed reasonable(-ish), and It’s good to check in on container-land once every once and a while since they’ve become so common.

The only special thing I had to do (which is mentioned way down in the prind README) is cause the printer’s serial device to be assigned GID 20 – which on debian-likes is “dialout” and on Arch is fortunately unused by default, and likewise make whatever webcam I want to use get GID 44 – “video” on debian-likes, also unused by default on Arch. That this is how permissions work through the container boundary is rancid<\/em>.

That’s straightforward with a couple udev rules on the host like:<\/p>\n\n\n\n

=== \/etc\/udev\/rules.d\/71-kossel.rules ====\n#prind's debian-derived container wants the serial device to belong to dialout with gid=20\nACTION==\"add\",SUBSYSTEM==\"tty\",ATTRS{idVendor}==\"10c4\",ATTRS{idProduct}==\"ea60\",GROUP=\"20\"\n# And cameras need GID=44\nACTION==\"add\",SUBSYSTEM==\"video4linux\",ATTRS{idVendor}==\"1415\",ATTRS{idProduct}==\"2000\",GROUP=\"44\"<\/code><\/pre>\n\n\n\n

… And with that done it just works. Did the automatic probe calibration, automatic Delta calibration, automatic PID calibration, edited my PrusaSlicer profile to output Klipper-dialect gcode, and printed a part.<\/p>\n\n\n\n
It’s not noticeably better (or worse) quality or faster than it was with the Marlin build I had on there – which is not surprising since I sliced with essentially the same profile – but it does sound different with the different control regime.

I have a suitable “Mellow Fly” ADXL345+ RP2040 accelerometer board, and I’ve already rigged up an adapter to mount it to the effector, so I can start figuring out how to push it and\/or start studying if any stiffening tricks are worthwhile – one of the main reasons for this project is I’d like to systematically try some schemes for stiffening a kossel. 

Now I have 5 containers running, totaling something like 2.5GB, to deploy like 25MB of software, which is absurd.  It’s all running on a slightly hacked Chromebook, which is not as absurd as it sounds. 
As is often the case with appliance-like computers and\/or sophisticated deployments, I should have just installed Debian and the packages I wanted to deploy on the bare hardware, and not looked at as other-than-appliance again for 5 years, instead of touching the complexity fetishist junk, but it’s good enough to play with for now. 
<\/p>\n","protected":false},"excerpt":{"rendered":"
TL;DR: I converted my Anycubic Linear Kossel to Klipper. Using a hacked Chromebook as the host, which is great and I recommend hacking surplus education market Chromebooks for many of hobby projects usually done with an SBC. Running in containers … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4,8,37,1],"tags":[],"class_list":["post-73418","post","type-post","status-publish","format-standard","hentry","category-computers","category-diy","category-electronics","category-general"],"_links":{"self":[{"href":"https:\/\/pappp.net\/index.php?rest_route=\/wp\/v2\/posts\/73418","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pappp.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/pappp.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/pappp.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/pappp.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=73418"}],"version-history":[{"count":0,"href":"https:\/\/pappp.net\/index.php?rest_route=\/wp\/v2\/posts\/73418\/revisions"}],"wp:attachment":[{"href":"https:\/\/pappp.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=73418"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pappp.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=73418"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pappp.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=73418"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}