Trying 1.75 mm Filament on the LulzBot TAZ 5

The LulzBot TAZ 5 User Manual has this mysterious section:

5.4 Using 1.75mm filament

Your LulzBot TAZ 3D printer is set up to use 3mm plastic filament by default and may be capable of printing 1.75mm filament with no hardware modification. While many of our advanced users are able to do so, your results may vary.

Since we wanted to use the remaining glow-in-the-dark filament, we decided to try our luck. So we changed the filament diameter to 1.75mm in Slic3r, and printed a few small objects. Everything went as expected, only the retraction moves didn’t work so well and the filament oozed out of the extruder nonetheless. But those strands can easily be cleaned up later, so we went on with some bigger objects. This was when the printer would reproducibly stop extruding after a few layers, and it seemed like the nozzle was clogged up. Investigation showed this beauty:

Apparently the filament was too thin to be directed into the hotend, so it decided to curl up in the space between the hobbed bolt and the upper entry of the nozzle instead. After all, the manual was right, our results really did vary.

2. CoderDojo im Stratum 0

CoderDojoBS - Kuchen (Foto: @CoderDojoBS)
CoderDojoBS - Kuchen (Foto: @CoderDojoBS)

Heute war es wieder soweit und 11 Kinder und Jugendliche trafen sich im Stratum 0 zum zweiten Braunschweiger CoderDojo. In nur drei Stunden wurden mit Scratch wieder viele Animationen, Spiele und Geräusche (*miau*) programmiert.

DEF CON 22 Capture The Flag

The team on the last day
The team on the last day

So, some time earlier this year we made second place at the Boston Key Party CTF. The BKP is one of seven CTF events this year where the winner qualified for DEF CON CTF. The one who came in first had already qualified at that point, which meant we got the spot. The DEF CON CTF is the big CTF event of the year, and one of the bigger events at the (in)famous DEF CON hacking conference in Las Vegas. H*ck yeah road trip to Vegas!

The CTF happened early August, and by the time I finally got to write this blog post, other teams had published great writeups for almost all challenges. So unlike other CTF-related posts, this one’s gonna be a travel report for our casual readers rather than a writeup for the techies. There won’t even be code, I promise!

Das Holodeck steht!

Endlich ist es soweit! Wir können verkünden: Das Holodeck steht! Ein Wochenende lang haben rund 10 Entitäten kräftig gewerkelt und das “Hochbett” in den Space gestellt. Hier finden sich nun noch einige Fotos vom Bau und dem fertigen Holodeck.

1. CoderDojo im Stratum 0


Heute am Samstagnachmittag trafen sich 8 Kinder und Jugendliche bei uns im Stratum 0, um gemeinsam Programmieren zu lernen. Innerhalb von drei Stunden erstellten die Kinder Spiele und Animationen, zum Teil ohne jegliche Vorkenntnisse im Bereich Programmieren.

Mirroring MediaWiki with Git-Mediawiki and gitolite

This post was originally posted on my personal blog. Nevertheless, I think it fits here as well.

From Murphy’s Law we can deduct that Internet failures always come when you least expect them. In my case, the Stratum 0 wiki was offline for a few minutes (only, thankfully!) when I really urgently(1!11) needed to look something up there. If I only had an offline clone of the wiki…