High Quality Plan Sets and Laser Cut Partial Kits for Radio Control
Aircraft
Page 3
Antonio Arria's San Josè
Before assembling the wing panels, verify
that your spars are the proper dimensions to slide snugly in to the ribs.
If they are too tight sand the spars until they fit properly. The image above and the two following are
of the left wing panel parts which I built second. I put them here
as I felt they gave a better picture of the initial steps
in alignment of the spars and ribs. In this photo the
outboard end of the lower spar is blocked up and trapped by pins in the
correct position. The rib is pressed on to the spar to locate it
fore and aft. The upper spar doublers are installed to
the upper spars before the ribs are slid on, using the center dihedral
brace as a jig to locate them the proper distance from the ends of the
spars. The ribs will be slipped on to the
upper spar first and slid into their approximate locations, then once the
ribs are in the final position the lower spar will be pulled up into each rib
sequentially from one end to the other.
A laser cut jig is supplied to set the
positions of the spars at the root end. There are marks on the plan
to position the jig.The root end
of the spar is against the root jig and pinned fore and aft.
I
slipped all of the ribs on the upper spar, and
pulled the lower spar up into position. Then the root rib 2 and
the last rib 4 were positioned
accurately, and after checking the spar locations at the jig, those two ribs were tack glued.
Bob Holman's fixtures come in
real handy for this task. (bhplans.com)
Then, the remaining ribs were postioned accurately and tack glued. A partially assembled right inner wing
panel. The trailing edges are fabricated from 1/4 X 1 soft balsa
sawn from 3 inch sheet. I get better weight and straighter wood from sheets than
when
I buy it in precut widths and it is less expensive. See the cross
section drawing on the plan for the profile to plane and file to. Notch for the ribs. Three lengths of 1/4 square were sawn from
the same sheet for the leading edges. When installing the trailing
edges make sure the bottom of the ribs are
even with the bottom of the trailing edge and the aft edge of the
trailing edge touches the building board.
As all the fabricated parts were
done as the right wing panel was built, the left one progressed rapidly.
I left the leading edge 1/4 square uncut and built the polyhedral section before I
cut it. I left all the auxilliary spars and the leading edge long
and will cut them after the spars are joined.
