Originally Posted by Tclanton
Last two tier I did was a 10 & 8 inch square. I kept both tiers in the frig until the am of pick up. Took out - placed 4 sharpened dowels in the 10' - placed the 8 inch, and then drove a sharpened center dowel through both tiers into a foam core board.
You don't need to sharpen the support dowels in the 10" cake. (SPS legs, straws, push-in pillars, and hollow hidden pillars aren't sharpened to a point, they are flat.) When you sharpen the support dowels, the points can puncture the foamcore board at different depths for each dowel from the weight of the above tiers which can cause the cake to lean.
The exception would be if you hammer each sharpened dowel in as far as they will go (on purpose, to be positive that some don't settle more than others on their own).
If you were using sharpened support dowels on top of plywood, masonite, plastic plates, or anything else that wouldn't be punctured by the dowel, you'll run the risk of those pointy dowels becoming displaced. I hope this makes sense... a table doesn't have legs sharpened to a point.