I'm installing a 52" Hampton Bay ceiling fan in my bedroom that has a vaulted ceiling with a 45 degree pitch. The canopy that came with the fan does not have enough room for the downrod and ball to angle correctly. Any suggestion? Thanks

Use a metal bracket or wooden beam to lower the fan sufficiently.
Make sure that the entire set-up remains stable (by balancing the fan properly).
Success!
;)

There is a company that makes a wooden wedge for vaulted ceiling fan installations. However it might be easier to pick up a vaulted ceiling kit for steeper ceilings. Home Depot sells a Hunter one for about $15.