Printing ABS on the Ultimaker 2 with Fan Running

The art of 3D printing is a balancing act.   On the Ultimaker 2 the fan comes into play as a particular challenge when printing ABS.   In my experience you need a fan to achieve good quality on details when printing ABS, whether on the Ultimaker 2 or my Wanhao Duplicator 4S.  I have read that others can achieve quality prints without the fan by ensuring that print temperatures and speed are low enough to allow for cooling that the fan can provide.

There are downsides of low temperature and low speeds that a fan can help avoid.   Low temperatures can lead to problems with bonding between layers and low speeds are just too slow!  I also find it to be a struggle to hit my low temperature target without undershooting ... and when you are printing that low of a temperature that can lead to a bad layer or a nozzle jam.   This is even though I use Simplify 3D and hit my target temperature by lowering a degree a layer.

The above picture illustrates the challenge that I, anyway, experience.  The best looking Marvin (center) was printed with the normal Ultimaker 2 fan running starting from layer 2 at 60%.   The total mess in the front was also running with those parameters and the fan combined with poor first layer adhesion resulted in a pop off from the build platform.   The Marvin on the left was printed with no fan and the one on the right was printed with my Ultimaker 2 fan modification described earlier.

I think that I can adjust my fan modification to replicate the quality of the center Marvin and still avoid the fate of the Marvin in front.  It is all a balancing act that requires extreme levels of patience though!