Have only owned a printer for around 6 months. Didn’t know a lick about CAD either.
Whole reason I bought a printer is because I didn’t want to pay for a design on Etsy for my table saw. Dude was asking stupid money for it. Refused to share the file. In spite of admitting the design wasn’t even his own. #rantover
So I bought an AnyCubic Vyper and started teaching myself CAD. Wasn’t long before I’d designed a similar part (built entirely from the ground up). Since then have about 5 other designs.
Just out of spite, I make all the files available for free. But have still sold some to guys who don’t have access to a printer. Also undercutting the Etsy guy on price. Have made a little cash printing a stuff here and there.
Best part is I’ve had customers who’d purchased the other guy’s versions. But were unhappy, bought mine to compare, and have said mine are significantly better. Both in overall quality and performance.
I have one design in the final stages of development that’s got folks really excited. But it's a pretty intensive print. So doing any sort of volume would be tough. Like the others, I'll just make it available for anyone that wants it and maybe print a few here and there.
ETA: Purely freelance side gig for me. I turn a nice little profit. But it’s more rewarding to be able to help fellow saw owners out.