A talk about the state of the art with metal 3D printing, and how it can let you make rocket engines much more cheaply and quickly than ever before. I will briefly describe the anatomy of a rocket engine and why the extreme conditions it must endure make designing one hard, and then introduce powder metal 3D printing and how you print an engine. I work for a company in this field, and I will show various images and videos of our engines being fired, as well as the engines themselves so that people can have a look, and some samples with internal cutaways to show the internal structures that 3D printing technology now makes relatively easy. I will also discuss drawbacks and common failure-modes of 3D printing for rocket engines, and talk about where new advances in the field might take us, such as multi-metal prints, hybrid machining, and other exciting technologies.