I think that if you do complete the second level of port royal the cannons start to
Appear
Again but if not then there are other places you can get them. If you have discovered the
Tron world called space paranoids then in the canyon and stimulation hanger there are
Space paranoid versions of the cannon that also drop blazing stones. Also as an extra
Hint
If you are looking for a high drop rate then equip the sweet memories keyblade (if you
Have it) and turn on all the ailities in yours, donalds and goofys called "lucky lucky"
As
This increases the dop rate of items more and mre with each ability turned on plus if you
Have them you can equip to donald the staff "meteor staff" and to goofy the "genji
shield"
As there abilitys are lucky lucky