The QU-BD Revolution XL ('RXL') 3D Printer lacks a built-in LCD interface, and after more than a year of using the UltiController on my original Ultimaker, I found the need to hook up a computer to be really inconvenient. Plus I just don't really have the space for it in my work room, leading to a less-than-amusing incident involving a long print, a glass of wine, and a laptop keyboard. It was time for an upgrade! Originally, QU-BD was planning on offering the Panucatt Viki controller as an optional add-on for their printers, but some supply constraints upset that plan. The controllers are available now, so I ordered one, and recently set about installing it myself. I thought I'd document the process to help others facing the same thing. The specifics below relate to the RXL printer, but in general, most of it should be applicable to any one looking to hook up a Viki controller to X3 electronics - especially if you're using Repetier firmware, as the RXL does. However, from what I've seen online (thanks, Wired1, for the inspiration and info), I believe that Marlin's Viki implementation also uses the same pinouts for the same things, so it will probably also work as-is for Marlin-based printers too. I have one of the first RXL's out of the factory, and mine at least needed me to recompile the firmware with some different settings to actually get the Viki working. I'll cover the firmware side of things in two other blog posts (here and here) - but for now, this post focuses on the physical steps needs to attach the Viki to the X3.