After many long months of trial and error, I finally have a successful print! Woohoo!

Here's the original STL file. I scaled it down by 50% to get it to print faster. The gear in the pictures below is about 30mm in diameter, and 5mm thick. It took about 2 hours to print (approx. 50mm/s), so that's something I still need to work on. For now, I'm happy that it worked.