hollow jack stand pattern

This is a casting pattern for a machinist jack stand.
It has a hollow base and with care you can get the pattern to pull out of casting sand. I know this because I have tested it.
You may want to pull out the pattern after doing half of the sand ramming and re-powder and so if the core sticks then the pattern may pull out of the opposite half of the mold. Another idea I have is to flip the mold over when separating to maybe have the weight of the sand in the core aid in separation. Just an idea.
The extra base size was to allow a large taper inside for helping pull out of molding sand.

THIS PATTERN WAS SPECIFICALLY DESIGNED FOR LARGE JACK STANDS WHERE
YOU DON'T WANT TO USE SO MUCH METAL.

If you want I suspect you could make this into a bell :)