Why is my fresh pasta tough? I picked up a Marcato Pasta Maker and followed the recipe included to make both fettuccine and ravioli. The instructions that came with the machine offer two basic recipes: 


500g soft wheat flour
5 eggs


or 


250g soft wheat flour
250g durum wheat (semolina flour)
5 eggs


I've tried both methods, using King Arthur All Purpose flour for the soft wheat flour, and Caputo Semola for the semolina. In both cases, I found the resulting pasta to be tough and have a considerable bite.  I tried cooking both pastas for a bit longer than recommended with the same results.  I am using the recommended thinness that the machine produces as well. The recipe notes to knead for 10mins or until the dough is smooth. I have been kneading it for 10-12 mins and still find that it isn't quite "smooth"; but I'm no expert on what that is.

I would prefer a more delicate, soft, and melt in your mouth type of pasta. Instead I am getting something with quite a bit of bite and that is quite tough. What can I do to improve the result to my liking?
Try using double-zero (00) flour, available from Italian specialty stores. You might also prefer a recipe that uses more egg yolks, or only yolks and not whole eggs. For example: https://www.chefsteps.com/activities/fresh-pasta.