On Friday, February 9, 2018 at 10:58:59 AM UTC-8, wrote:
...3D printing/plastic sticking together technology

In terms of cost per unit mass, 3D printing is actually pretty pricy. Note that Toyota isn't exactly 3D printing Camrys. I use it for one or two parts where the benefits outweigh the costs. I'm also looking at using 3D printed molds for some parts.

In terms of cost per unit strength or stiffness, 3D printing ranges from mediocre to terrible. Once they can reliably cost-effectively 3D print 1" long carbon fibers, it will be time to take notice.

The technologies to watch for in glider manufacture are robot tow, tape, and swath placement for conventional composite materials (carbon, aramid, fiberglass). We'd use them to supplement and eventually replace the kinds of skilled labor it takes to make large composite moldings like fuselages and wing skins.

One thing I could really use is an overhead gantry robot that could:

* Lay down and saturate carbon fiber for a wing skin or fuselage shell. It would scan the shape of the mold and distribute and cut off the swaths accordingly, and also saturate the carbon with epoxy. It would also react appropriately to minor irregularities in the placement of the plies or core foam panels.

* Cut and bevel sandwich core foam panels.

* Distribute beads of epoxy paste for bonding operations (fuselage and wing clousures).

* Locate and drill alignment holes

If I had one of those, I could really ramp up production and lower prices. It would also make it much easier to demonstrate compliance with ASTM standards, so I could justify the expense of a certification program and sell finished, flyable S-LSA gliders.

--Bob K.