Some of my current temporary cooling for my stepper motors. On the two 30-40 minute prints I have done the Extrude Motor gets very hot. Not to mention the X and Y motors get pretty warm. I can only imagine what they would be like for a few hour print.
A thin ceramic plate attached to the extrude motor with a cooling fan blowing down on it did the trick! Only limits me to a small print area for now (ok no big parts yet)
Haha the fan wiring I'm proud of. I used an old scavenged server power supply fan with a very high airflow rate. I ran the wire back to a nine volt battery that is taped in place to one of the Z axis motors. I also hooked up a scavenged 115/230V switch out of a power supply (works just like an on off switch if you know how they work). Some alligator clips, electrical tape, and a paperclip make it complete. Oh yeah and the zip ties holding the fan so it blows onto that ceramic plate
X axis cooling. Now I particularly like this one. The are three ceramic L shaped pieces with a hole in them. The fit pretty snug to the motor and were easily zip tied in place. Will do the same to the Y axis.
Ceramic is an excellent conductor of heat. These small amounts of ceramic are very efficient at pulling heat off the motors. These ceramic parts are scrap parts from my workplace and I do have permission to use them.