This glider is an exercise in designing and printing a tapered wing in vase mode, using three specific airfoils. The airfoils are NACA 4415-4412-4409 as described in the 1946 model airplane book "Airfoil Sections" by R.H. Warring. Very happy with the wings - they look great!
The fuselage is rudimentary--just a quick sketch to test the wing. UPDATE: A longer fuselage is now posted, in two parts: long_fuselage_nose.stl and long_fuselage_tail.stl. Also included a slicer view of the fuselage laid out on print bed. Again, this is a quick and fairly weak fuselage. Building one with balsa or CF tube would be better. As designed here, weight needs to be added at the nose to balance the CG. The calculated CG is 27% back from the leading edge (measured at the root where wing meets fuselage). At 400% scale (the intended scale), that is approx 19mm back from the front of the Leading Edge of the wing root. UPDATE: The longer version is TOO long! See comments for notes of a good flight with original fuselage.
All parts are designed to be scaled to 400% for printing on i3 Mk3 or similar.
The wings are designed to be printed standing up from root to tip,. At 400% scale they are 200mm tall, each wing.
The fuselage is designed to just fit on the bed at 400% scale.
Wings should be printed individually. All other parts can be combined for one print.
There are three choices for the wing join, which creates your dihedral. There is a 2%, a 6% and a 12% dihedral. Two percent made a nice flat run for the top of the wing, but is the worst for a free-flight glider. If you want fly it, try the 12% first. These should be printed on one side.
The wingtips are identical and are simply for gluing in to close the end of the wing.
The hook should be printed bottom side down. Hook is optional, if wish to use rubber band launcher, and snaps right into place (be sure to glue).
The "glider.stl" included in the files is not for printing. It is provided for showing the assembly / viewing in Thingiview.
If you try it, I'd love to hear. See comments for more updates on flights, progress. This is how we learn to Fly!
any PLA, PETG
Wings and wing join are printed in PLA (I have not tried PETG yet for wings).
Started printing fuselage in PETG, as PLA fuselage was breaking when model "landed."
Standard vase mode for wings worked perfectly.
For the wing join, see the image of the join and wingtips laid out on print bed (slic3r view). The general layer profile is the ".20 Quality" setting. The wing join is port side down. I use the layer edit feature to shift the starboard edge of the wing join to the highest resolution (.05 layer) to create the best surface for the dihedral join. The rest of the print is at .20 layer height.
Fit (and glue) fuselage nose and tail together.
Glue wings to wing join.
Glue wingtips flush into open ends of wings.
You can either glue the wing to the fuselage, or affix via rubber band(s).
Add weight to nose to bring CG to the point described above (I tape on steel washers).
Test glide and add/remove weight as needed for trim.
I used Fusion 360 to create the model. The wings were created using the Loft tool, from sketches created by drawing over a canvas (imported from jpegs) for each airfoil.
Slicing was done with Prusa's Slic3r PE.