The major model ship scales for gaming appear to be 1/1200 and 1/1250 (in the 70's), then 1/2400, and then 1/4800 and 1/6000. I think 1/2400 and 1/4800 would be ideal scale for modeling ships using the 3D printer. Note that there are metal cast ships in this scale on the market. Aircraft scales appear to be 1/144 and 1/600. There are a wide range of 1/144 aircraft NOT being made. There are two companies making 1/600 aircraft WWII and Modern to support gaming in those scales. Again, these two scales as well as 1/300 or 1/285 are popular with gamers.