In Dragon’s Dogma for the PS3 and Xbox 360, some of the items you come across in the game may lead you to believe that you can craft weapons using them, but this is a bit misleading.
You can’t craft weapons from scratch in the game, but you can enhance items however.
If you visit a weapon merchant in the game, you’ll see an option for weapon enhancement.
There are three levels of enhancement. The first only requires gold, the second requires fairly common items and gold, and the third requires uncommon or rare items and gold.
Each level of enhancement will increase the stats of the weapon, and lower the weight.