I've put in 2 Golden apples, 2 Diamonds, 2 Eyes of Ender and one Draconic Core into the injectors with the key in the crafting core and nothing happens. What am I doing wrong? Playing SF3 latest version.
If it's because they don't upgrade...than I'm an idiot.
Ah, I think I see your issue - you don't upgrade the key, the same key is used (and not consumed during fusion crafting I believe), and you upgrade something like your bow or armour using different tiers of the other ingredients and the same key; so the one you're doing is the first level of upgrade.
You need to have your apples, diamonds, eyes of ender, draconic core and upgrade key all on the pedestals, and the item you want to upgrade on the centre. Then to do the NEXT tier, then (assuming your pedestals are of the correct level) you use the next step up of ingredients (which I believe involves 2x Nether Star, 2x Draconic Core, 2x Emerald, 1x Wyvern Core and the same Upgrade Key).