Here's a little about what I have going on. A few months back I bought a 2-up 3d printer kit and put it together knowing that I wanted to be able to print on a much larger scale. Before producing a completed successful print (extrusion problems) I made the decision to build something that would satisfy my desire to go bigger and at the same time give me a more reliable platform.
I upped the size of the 'z' and 'y' motors to nema 23's and have micro switches for both ends of each axis. I got a couple of bowden extruders and an ep3 chimera hot end.

It took a bit but I have reached the point where I'm starting into control check-out. Using the ramps board (from the original 2-up) I turned the pots down on the drivers and powered up the board. I was able to control 'z' fairly well though it needs some mechanical tweeking, but have not got anything out of the other 2 axis yet. What I've been able to find about tuning the drivers (drivers rated at 2 amps and the 23's are rated 2.8 per coil) leaves me hesitant and wanting to reach out before I let the smoke out of something. (This part of the process is what I have the most to learn about.) It looks like my useful build-space when complete will be 24"x 22"x 13.5". I'll post a pic in the not to distant future.
Looking for suggestions to best proceed.
Ed