I want to injection-mold several thousand of a part that fits in a 6" x 6" x 2" bed.
I would like to be able to use only tooling that I can make myself, so I can rapidly iterate on the tooling as production problems are discovered.
I know that typical injection-mold "hard tooling" is created using electrical discharge machining, which requires first CNCing a carbon positive and then using that as an electrode to spark-burn out a negative mold from hard steel.
However, I do not have the equipment for EDM. Instead, I would prefer to directly CNC the negative mold. I know that a soft enough steel to be CNCed will not last very long as an injection mold, but like I said, my run size is tiny, and I am ok with making a new mold every 500 units or so if necessary.
I am open to buying an endmill that is diamond-tipped, to work with harder steel, but then the limitation will probably be how much torque the CNC can produce on the endmill.
What are some recommendations or links to helpful resources? In particular, what is a good CNC with enough torque, and what blend of steel should I use? Thanks!