The NEFPV SpecWing is made from 1/4" foam board covered
with contact paper. Very fun to fly, whether tooling around or
racing. Lots of speed and tracks well. Wingspan is 35 inches.
There are several YouTube videos that go over how to do the build --
the
one I followed was: 2013
CNC-HP-WING The 10 Minute Build Video. At 9:24 in the video
is contact information for ordering a kit containing pre-cut foam,
motor mount, and some hardware.
For my build I used white wood glue on the inside spars (so I wouldn't
have to worry about it firming up too fast) and let it dry
overnight. I used Foam-Tac for gluing the foam pieces together, and
epoxy for the motor mount and control horns.
Weight (without battery) is 482g. The CG-balance point is 8.5" back from the nose.
I put all my electronics inside, held in place with velcro; no bays
except the opening for the battery. One trick I do with the
velcro is to slide things in with a ruler or piece of paper underneath,
and then remove the ruler/paper to let the velcro attach. In
addition to getting the CG right, you also want to get the "lateral"
balance even (so one side is not heavier than the other). One
good bit of quick-and-easy reinforcement is to put a layer of
packing tape on each leading edge of the wing.
I think this is the foam board that comes in the kits:
Owens Corning FOAMULAR 1/4 in. x 4 ft. x 50 ft. R-1 Fanfold Insulation
Sheathing $47.00/pallet http://www.homedepot.com/p/100320301
Model# 10UM SKU# 409692
I created a launcher made from $1 yardsticks (qty 10), #6-32 3/4" bolts and nuts,
small wood screws, and some packing tape. The "rails" are about
12 inches apart. If they are wider, the wing has a tendency to
"fall through" the rails. I taped a couple of guides (made from
strips of EPP foam) to the bottom of the wing to keep it centered (pic).
The prop torque makes it lean to the left on takeoff, so I twist the
rig a little to make the right-side rail a bit lower. Putting a
weight on the front "leg" of the launcher prevents it from toppling
over.
