Hey Driller,
I just made a Blackhole Generator. I think I figured out why its confusing and didn't work in the beginning. The actual recipes say to add in this order: Recipe; Item; 6 runes.
When you put in the recipe, in yellow text in the chatbox, it says to place them in this order: Recipe, 6 runes and then Item.
The order from the yellow chat text is the one that works. Maybe change the wording of the recipes to match that order.
Brett