router cooling ...
Most table routers exhaust air upward, and do not suck it down into the motor. I suspect that the Craftsman motor has a design issue, either the soft start, the variable speed control or housing design that just doesn't work for this application.
Do not give up on your project, just return the newer router for $$ and get a different brand. I use Porter Cable router with great success so maybe that's a choice, AND Sears may offer those also.
I would seriously consider a very powerful shop vac suction located right at the cutter to remove as much aluminum dust as possible.
The answer to your question will only be as detailed and specific as the question is detailed and specific. Good questions also include a sketch or a photo that illustrates your issue. (:< D)