I am on the other end of the scale. I have worked as a chicken egg packer up to the space shuttle announcer and I started a solar company and a scuba communication company. I am used to not knowing if I would have a paycheck from month to month. Are you? Do you have a family to feed? The single common thread in successful business entrepreneurs is they have a spouse or partner to support them wholeheartedly. Do you have someone? If you think you can pull this off I would say go for it.
This whole 3d printing thing is like when Altair and Apple computers came out and you can see how that turned out. Life is too short to be stuck in a job you don't like. If any of this sounds intimidating you can start part time, keep the day job until the side job can hold it's own. I did this with both of my companies, but more importantly I did it with several other companies that didn't make it. My advice is go for it but don't be stupid.
Mike