Also it comes down to time. It is quicker to produce complete wing ribs using a CNC cutting machine, either plasma or laser, than it is to print the same number of them.

Agree completely. But that was not OP's question.

Ok - The big difference between the materials you listed and FDM printed nylon is natural or synthetic glue.  Example - Carbon fiber is in fact individual fibers but when created as Burt Rutan does, it is glued together (epoxy resin).  With FDM made parts you are depending on the parts welding themselves together thru adhesion and heat bonding.  The reason that I would not trust these parts with my life is the question have you ever have a part de-laminate  after making it.  DePartedPrinter - please make a test piece that is 12 inches long, 1 inch wide and a 1/4 inch thick then stress the part.  Does it fail and how when stressed.  Wood works the same way.  The problem with both materials is that they are not homogenous in structure internally.  In the parts that you make can you guarantee (with your life if you are flying a plane you made) that none of the parts will fail except in a know way.
I am not say to not make the parts what I am saying is there are some risks that I am not willing to take.

Bob

Carbon fiber can have delamination just as FDM made parts can. Don't forget about boeings 787 problems with delamination last year.

My experience with FDM printed nylon (taulman) is that it is almost impossible to get delamination if printed correctly. There is no question in my mind that it would be stronger than a piece of wood the same size. I would feel confident in a plane with certain parts made from it.

Have you printed with any nylon?

Also it comes down to time. It is quicker to produce complete wing ribs using a CNC cutting machine, either plasma or laser, than it is to print the same number of them.

I'd restrict the use of printed parts in aircraft building to the making of test pieces to check alignment and assembly. As a matter of fact, that is the field I am going to try to break into on a commercial basis.

Old Man Emu

Bob

Departedprinter - yes you can print the parts BUT is anyone else going to fly the machine?  Also to get FAA certification even as an experimental aircraft will take some work.  Check up on the work of Burt Rutan (SpaceShip 1 designer)

Bob

Planes used to be made from wood. Are you saying that a wing rib made from nylon or even ABS is any less strong? 

Burt Rutan uses mostly carbon fiber in his builds...

Bob

http://www.popsci.com/technology/articl … be-printed

http://www.forbes.com/sites/parmyolson/ … -printers/

HOWEVER, I suggest that 3D printing is ideal for making airframe fittings and such to be used as try-out items to see how things go together, or to use as positioning templates for holes that have to be drilled. Using 3D printed items also has the advantage that to get to the printed stage, you have to go through the CAD stage. So, if you print a part and it works, then you can use the CAD file to send to a CNC machine to make the part in the correct material specified in the plans.

Old Man Emu

I'm new to this forum and just was curious about 3d printers and home aircraft builders or experimental aircraft builders. I have seen some drawings and looked up certain designs and was wondering if I could apply a 3d printer to say making the wing spars and parts like that. I am using a book called Composite Construction for homebuilt aircraft for basic instruction on how to build the fuselage, wing structure etc. the design I have in mind I saw at a website called Luft46.com. Its a site that has cataloged different German aircraft designs from WW2. Just curious to get any input.

In theory you could print the wing spars but I'm not sure how confident I would be flying a plane that had FDM printed parts in it. The spar is the main structural support for the wing...if that fails your are not going to be having a good time

Would it be printed in pieces?

You would probably have an easier time printing the ribs for the wing.

No doubt there is a future in 3D printing and aircraft.