I'm printing on the MakerFarm Prusa i3v using a J-Head hot end and a 0.35mm nozzle using IC3D ABS. I find that it's important to give all of the printer/extruder information up front.
I've been having what's gone from mild to terrible warping.
I'm not sure how to fix it. I used a fan on my J-Head before, which I was told wasn't necessary. The airflow from the fan would always push air to the 11 o'clock region, where most of my warping was. Now that I'm printing without it, my prints are having really bad warping issues.
Why is it doing this? What can I do to fix it? Should I construct a housing for the printer just to keep the heat in?
ABS printing works best within an enclosure to eliminate drafts and ensure a consistent temperature. Fans are a definite no-no. Now you've turned your fan off, try to eliminate drafts as your next step.