This is just for me. I already built one for 3 axis which I use for my CNC Router (see www.masdrive.ch/myprojects). Now, I want to add 2 more rotational axis (B and C Table/Table). In order to make this a little easier, I decided to build a new controller first. The 6 Axis controller makes me independent from the hardware concept I am going to use in the future.
I've been programming 5-axis machines from the beginning of time for work and decided to take the plunge and build a machine at home for my hobbies. My first machine is based on the KYO Sphinx design. Then I saw a few of the machines on the OpenBuilds forum that are 5-axis machine and decided my next machine with also be a 5-axis design...hopefully using linear rails and ball screws rather than an rail/wheel configuration. I did see a few controllers that can handle a 5-axis configuration though I decided before I invest in the 5-axis controller board I investigate all the available controllers out there. One of the two I found is suspect of frying out stepper motor drives and the other seems a little expensive for a home controller...but if it works well I'd spend the $350. I just hoped to find another controller to check out when I saw your build.
I use the UC300ETH connected to the UB1 Mother/Breakout Board (UC300ETH-UB1 [UC300ETH-UB1] - $320.00 : CNCRoom, The Room for CNC'ers, from Mini to Big machine, from Hobbyists to Gurus - ชุมชนมินิซีเอ็นซี เรียนเล่นใช้เครื่องจักรซีเอ็นซี) . As a controller Software, I am using UCCNC and will also Test Mach 4. What I like in this configuration is the fact that there are profiles available for both (UCCNC and Mach) and that the UB1 has stepper driver connectors to connect 6 drivers (YXZABC, S+- and D+- on board) . I use Nema 23 Motors and dq542ma Stepper driver. This works all pretty good in the Test environment. As soon the controller is finished, I will use it with my CNC Machine and test the details "at work"