Two potentially disruptive 3-D printers are expected to hit the scene later this year, which could make life more difficult for 3D Systems (NYSE:DDD) and Stratasys (NASDAQ:SSYS). German-based injection-molding specialist Arburg plans on introducing the Freeformer, the first production 3-D printer that doesn't rely on proprietary materials and instead uses industry standard (and significantly cheaper) injection-molding materials.

Hewlett-Packard (NYSE:HPQ) will also be making an entrance into the 3-D printing space later this year with a 3-D printer that's aimed at professional service centers. HP hopes to shake up the industry by delivering a 3-D printer that emphasizes speed, affordability, and innovative new materials.

In the following video segment, 3-D printing analyst Steve Heller sat down with the head of Motley Fool's industrials sector, Blake Bos, to discuss these printers in depth and what 3D Systems and Stratasys investors should watch for. (The relevant segment can be found between 11:47 and 15:24.)