One thing that was very successful for me when I was casting the Helicopter Cube parts was to drip about 2 drops down the side of the cavity to fill the tip before pouring in the rest of the resin. By doing that, I virtually eliminated the tip bubbles.

I find it helps to poke a toothpick or paperclip down into the bottom to release any air bubbles.
Just be careful not to poke too hard so you don't damage the mold.

I forgot to post a picture of the cast hollow pillowed pieces on the mini-2x2x2. It came out pretty well, much less resin and weight. Although I believe Lucas mentioned he liked the weight of the solid cast one last time we spoke...



Dave