I needed a way to throw some dice simultaneously and clicked this together in tinkercad. This one holds up to 12 D6 dice. It's not pretty but works very well - you can even pinch it together a bit so the dice don't fall out of it if you hold it upside down, and then you can release them into a tower: https://streamable.com/z5775c

Edit it at tinkercad: https://www.tinkercad.com/things/6ZhvnWZvxy1-dice-loader/edit?sharecode=9y3_xqXv8v_ylKWgfIurKUSYUS2j7QlweMtiV2yjx3Y

Dice used: https://www.thingiverse.com/thing:147883