well the first thing you should do is build your next printer. Even if it's from a kit - it's something you can do together.
Belive me you learn a lot about the things, drops the cost so you can buy a larger machine and you get to use the existing machine to make modifications on the new machine.
So a whole slew of varied activities.

Guess you're not old enough to gather round a warm printer of an evening with a cold beer, but cold soda works too :-)

Sounds like a great idea to me.

So ideas.
Your club could have get together evenings with a local makerspace, sign up for the artificial limb making program.
Make and sell some widgets to raise funds. 3d printed fidget spinners are currently the thing.
There is a bunch of little things you can make for a few cents and sell for a few more.

But first, you need people to form the club :-)