5mm gem stone shake counter tray

We volunteer at a dance studio doing "stoning" or gluing tiny 5mm gemstones onto costumes to make them sparkle under stage lights at dance competitions and recitals. Volunteers need one gross (144) stones per costume and they come in bulk bags so we needed a faster way to count out bags of 144. We tried counting by weight but even with a 0.1g scale we were having issues so we came up with this shaker design. This is a surprisingly finicky problem to solve but this model works well with 5mm stones.

Print one base and one lid. Fusion F3D file included in case you want to modify the stone diameter or number of stones.