Set 1 item not stacking

Related to my last post.. I'm making a cobblestone generator with one output slot and I would love the ability to right click and see the one slot letting cobblestone stack up to 64. However, when I got to set 1 and do the math + a number procedure, it doesn't work and then my block under update tick says "missing independencies" or if I go to test the mod, the cobblestone just doesn't exist in the generator. Just an empty slot but as I said if I just use the set 1 item then it generates one and then I have to the cobble out one by one.. I've tried looking it up but nothing helpful or useful.. 

Please send screenshots if you can so I can follow it better