Yes you can. Many have. The big yellow board was my first here in the forum, some of the others were designs I did here also. Others were designed and then purchased/built locally (for the user - like in Australia) and all I have is eagle files.
I have 4 board system in the works right now even. Looks like there might be 2-3 small boards to be added to it as well, for remote mounting of encoders, joystick, etc.
Others were inspired by discussions here in the forum, or by being irked that someone would raise $10K on kickstarter to make a little board up.
I update my link with new boards, a couple more were added yesterday, check them out:
www.crossroadsfencing.com/BobuinoRev17