[Porchdog]

I haven't done anything with 3-D printed metal parts yet. I know Engineers who do - as I understand it the process seems to work best with some of the more exotic metals and alloys. I'm told that the parts can be stronger than traditional sintered parts and more precise than traditional lost wax cast parts. It's not necessarily cheap but they are getting parts that are difficult to make any other way.

The earlier and less expensive plastic printers tend to produce parts that are less dense and/or have poor shear bonding between layers - hence the reputation for being weak.

I recently designed a complex plastic clamp that's about 6" in diameter and 2-1/2" tall, with hinges and destaco clamps mounted with screws in inserts. Each half weighs about 1-1/2# and Shapeways made our prototype from their "strong and tough" plastic in less than a week for $200. each piece. That part has stood up to not only demonstrating that the idea works but to demonstrations and abuse both in our shop and at several customer sites. We are machining the production parts from Acetal at much higher cost - not because we think it's stronger but because we can't get an acceptable material certification from Shapeways. If it was for our use or for a less discriminating customer we would use the printed parts.