Oops. A user pointed out that I posted the wrong Alibre file. Updated 28 May 2013 While battling ABS warping, I designed intake and exit ducts for the hot-end cooling fan. The intake duct will be posted separately. I was getting quite a blast impinging on the print surface from the back of the fan as well as the front. I have yet to make it back to testing ABS again. When I do, I'll give Triffid's suggestions a try. https://groups.google.com/d/msg/trinitylabs-talk/bqpClZElBpc/aW_RMmHR3usJ With the ducts installed and a bit of self-healing silicone tape, there is no significant draft from the fan. For PLA, I increased my minimum loop time until I can install a cooling fan that can be implemented in a controlled manner. Longer fan screws may be required, especially if the intake duct is used. Eugene PLA Prints at 0.2 mm layer height using KISSlicer.