BMatthews

It's an interesting technique but until the plastics used and fused together can achieve the same tensile strength and flexibility to match so many of the materials we use currently it still needs some help. For example he didn't "print" on the covering. The material is likely simply not strong enough or stretchy enough to do the job correctly. Also I don't see the fused plastics being great for major load bearing elements such as spars.

BUT, if that glider were "printed" with slots for inserting carbon fiber rods or flat rectangular sections which would be glued into place then you'd have a composite construction that uses the best of both worlds. A printed airframe of low tensile plastic with inlaid carbon stress carrying spars and stringers where and as needed.