I've recently purchased a Ultimaker, and while it works fine on my Windows machine, I just can't for the life of me get the Raspberry Pi to talk to it properly. The printer is running the Marlin firmware (whichever version is installed by Cura 12.10).
I've done a fresh install of Raspbian (October release, was latest at the time), and tried several different programs to connect to the printer - sendg (via Mono), printerface (pronsole.py), pronterface, Cura (which crashes in the UI), austerusG, and had no success.
After that round of failures, I've tried doing apt-get update and apt-get dist-upgrade. I've also run rpi-update. Same results on all five programs.
The printer is supposed to be at /dev/ttyACM0, and it does exhibit some reaction when I first open the port to it (it makes sounds as if motors are making a very subtle movement), but I receive a bunch of gibberish as response and none of the programs behave as expected. I've tried connecting with baud rates 115200, 230400 and 250000 (which is, I understand, the ideal baud rate). 250000 seems to behave differently, crashing the pronsole.py immediately (no error messages, it just immediately terminates) instead of estabilishing a borked connection. I've also tried overclocking the UART by 1.085x and connecting at 230400 (which would then actually be 250000), but that didn't work either (I've since reverted that change). I have not tried patching the printer firmware because it's my understanding that it shouldn't matter (though correct me if I'm mistaken) and I didn't want to risk causing issues on Windows as well.
The hardware setup is a Model B Raspberry Pi (256 MB version) with an 8 GB SDHC Sandisk card, an Edimax EW-7811UN wireless adapter connected to the top USB port and a powered USB hub on the bottom USB port. The printer is connected to the powered hub. I'm SSHing into the RPi, though I've also tried keyboard and monitor, to no success.
Lots of people seem to be able to drive their Ultimakers with the Raspberry Pi, and I don't seem to be doing anything particularly different from their instructions...