Hi guys, I just wanted to let you know that the Replicape is available for pre-sale now! This is a BeagleBone Black cape that has been designed to make the BBB into a very powerful 3D-printer electronics package. So if you are looking to make a fast printer with a fancy GUI, 1 GHz >> 16 MHz.
http://www.thing-printer.com/product/replicape/
isn’t too expensive?
Well, it’s an open source project, so you could build it from scratch if you want. That would save you would save a few dollars in exchange for a few hours work. But then there are no RMAs and you need some mad skills with a solder iron 
I have a blog post about it if you want to give it a try: http://hipstercircuits.com/replicape-revision-1-how-to-assemble/ (blog post is old, get rev A4A if you are making a new one)
first of all: I love my BeagleBone and I like you project. I was just curious how do you want to compete with other electronics (for example with Smoothieboard or Duet).
And the most important question: do I need so powerful device for my printer?? 
Ok, thanks! It’s a premium product, so I have chosen components with higher quality and solutions that cost a little extra. (Programmable stepper power, DRV8825’s, individually programmable microstepping, 12…24V input tolerance, high power connectors etc). That way your electronics doesn’t die if you unplug a stepper motor with power on, you don’t have to adjust anything with a screwdriver and you can use a 24V PSU but still have 12V fans.
As for your second question, I guess you can compare it to having a smartphone. It’s not strictly necessary, just more convenient : )
For that price I would hope it would support four or more extruder motors.
is it possible to use it with Octoprint?
Mike, it supports two out of the box, but there is an expansion-board in the pipeline giving an extra three extruders.
The site says it has five stepper drivers is that correct?
If so thats only one for a large selection of reprap build such as the prusa i3’s and what not.
I’m using Octoprint on my BeagleBone all the time! but it’s connected to printer electronics via USB. What happens when Replicape is attached? How to connect to it?
@Mike_Ashcraft since it’s an open loop system anyways, a parallel connection of the steppers for the Z-axis should be fine. DRV8825’s are 2.5A peak so they should handle the extra load. I have not tried this yet, though…
@Jarek_Szczepanski Replicape has a daemon running (Redeem) that accepts G-codes from USB, Ethernet and via a local pipe (tty0tty). All commands coming in are responded to the same way. Octoprint should be able to communicate with it as though it was a normal serial port.
Pity that Christmas has passed only a month ago
Looks nice and I approve of the choice of connectors (locking molex for the motors and Phoenix 2-part screw terminals for everything else).
Given the location of the stepper drivers and the motor headers, how thin are the tracks between the driver and the stepper connectors? You really want lots of track width to avoid any drop in voltage/current.
@Elias_Bakken as already confirmed by @Jarek_Szczepanski , OctoPrint runs perfectly fine on BBB. My guess is though that using the named pipe as a serial port via pySerial (which is what OctoPrint would do) wouldn’t work out of the box. However, I’ve finally started to work on a modular communication backend which should make it easy to use named pipes (or raw sockets or whatever) as transport medium. Still in its early infancy though (just started coding on it yesterday) and not yet pushed anywhere.
@foosel it would probably not work out of the box if you have a filter on the device list which I’m sure you do. However, I did get Pronterface to run locally on a BeagleBone using the same pipe. As far as I know, Pronterface uses PySerial as well, but perhaps with some different options(?).