Has anyone ever attempted to make a rubber pump cup or piston seal before?

I am in the midst of researching but thought I would inquire / pick a few brains here as well..

Can something like a pump cup be produce out of rubber on a small lathe? I have most tooling for cutting metal such as carbide inserts but for rubber I am not sure if it requires special cutting tools or maybe the procedure cannot be done on a lathe?

Thanks. .a