My foreman told me to try a different riser size on the 12-inch gear blank pattern
He said to go with a 1.5 inch riser instead of my usual 2 inch. I was sure it would cause shrinkage, but we poured it yesterday and the casting came out perfect, no defects at all. Has anyone else had a similar tip from an old-timer that went against your gut but worked?
You mentioned your gut said it would cause shrinkage. I've found that sometimes a smaller riser can actually work better. It cools a bit faster and can create a stronger directional solidification toward the riser itself. It really depends on the specific geometry of the casting.