Originally Posted by
sinful
sapient24,
thank you for pictures, I found the issue:
1. change your fan to the original one, and don't use cheap chineese junk, because it could lead to such problems.
2. your fan is looking the wrong way, so instead of blowing to the heat sink and cooling it, together with the bar mount and the motor, it sucks up the air from the heat sink and increases the heat inside your assembly.
Solution: Buy new fan from makerbot, mount it with the sticker looking inside and you should be good.
On a side note, you dont need any spacer between motor and bar mound to keep it cool, motor should be firmly attached to the aluminum block using 2 long screws which also attaches the fan and the heat sink to the whole assembly.