может кто займётся переводом?
WING CONSTRUCTION
The wing of the Sky Pup is of the internally-braced or cantilever type. Since it is the heart of the primary
structure, care in its construction is of utmost importance. Building the wing represents at least half of the total
project, so don't be discoursed if it seems to go slowly at times. You will have no other fittings, struts, or brace
cables to fabricate, so your time will be spent in building the wing as carefully and accurately as possible. This will
insure a good-looking and nice-flying aircraft.
The wing is constructed in three separate sections: two detachable outboard panels, and a centersection
which remains attached to the fuselage at all times. The outboard panels are joined to the centersection with
typical steel fittings, the centersection containing the "male" portions, and the outboard panels bearing the "female"
portions. Each wine section features a single spar with a "D" type plywood-skinned torque/drag box
ahead of the spar. The spars in the outboard panels are mirror images of each other, but the centersection spar is
significantly different. Foam nose ribs are typically spaced 8" from center to center down the front face of the
spars. The ribs aft of the spar are spaced at 24" intervals, and are also of foam with wood caps. For general
discussion purposes, foam pieces in the ribs or spars will be referred to as "webs" or "cores".
Wing construction should begin with the three spars. Start by cutting out the foam webs for these spars.
The dimensions of these webs are obtained by subtracting the spar cap thicknesses from the total spar dimensions
given in the plans. The foam webs can be cut in any of several methods, but hot-wiring with the use of long
straight edges is probably the easiest. Since the foam webs can be damaged easily until the wood caps are added,
careful handling is necessary. Any dents or gouges in the foam will prevent a good bond later on.
Available thicknesses of foam vary from one locale to the next. If possible, obtain your foam in billets large
enough that the entire foam web can be cut in one piece. If pieces this large are not available, the webs can be
built up using smaller pieces. The best method for building up webs from smaller stock is to simply "spot glue" the
pieces together while you cut the total webs to shape, and then come back and bond the pieces together
permanently after they are cut. Five minute epoxy will work well for spot bonding, but use only enough to hold
the parts in place while you cut them. If you use too much, the pieces will be difficult to get apart for the final
bond. If you try to bond the pieces together permanently before cutting the web to shape, you'll find that the hot-wire
will not pass through the bondline, and erratic cutting will result. Butt joints in foam are fine, (since the epoxy
is stronger than the foam} as long as the joints are tight-fitting and have no gaps or voids.
After the foam spar webs are cut to shape, set them aside and prepare the wing attach bearing blocks.
These blocks are very critical to the proper alignment of the wing joints, and considerable care must be exercised
in their fabrication. The ul¬timate purpose of the wing attach bearing blocks is to transfer the fitting loads (via the
attach bolts) into the spar.
The most important feature of the bearing blocks is the proper alignment of the bolt holes. This
alignment can be achieved in several ways--select the method best suited to your tools and capabilities,
1. If you have access to any milling equipment, or a very accurate drill press,
the blocks can be made in one piece and the 1/4" holes can be located exactly. Since the drilling
operation involves considerable depth (four inches), precision is crucial.
2. The majority of builders will not have access to milling equipment, but can
accomplish the task with equal precision. If you have a router table, the
blocks can be made in upper and lower halves with each half routed 1/8"
deep with 1/4" round-tip router bit. During this operation, each block
should be routed at each fence setting to assure that all the block are
exactly alike. Always run. a piece of test stock through and measure it to
verify correct location and depth of "grooves" before routing the actual
blocks. Obviously, the same result can be obtained using a circular dado
blade in a tablesaw.
3. If neither a circular dodo nor a router table are available, the jig can be done using a reqular
tablesaw blade. Rather than cutting a semi-circular groove, kerf cut the block halves so that they
will have kerfs 5/16" wide and 5/32" deep, centered at the correct hole locations. After the halves
are made, bond them together with epoxy while placing tubes in the kerfs so that the tubes will
provide bolt holes down their inside diameters. Steel or aluminum tubes may be used, and the
appropriate size is 5/16" O.D. and 1/4" I.D. The tubes should he cut to four inches in length, and
will be permanently bonded in place when the block halves are joined. Care should be taken to
insure that no voids are left in the epoxy between the tubes and the inside of the kerf hole. The
blocks on the center section would use 7/16" O.D. and 3/8" I.D. tubes in similar fashion for the 3/8" attach holes.
METHOD 1:
Block is made from single piece of
wood with holes drilled in the proper
locations. When using this method,
accuracy during the drilling operation
is of utmost importance.
METHOD 2:
Block is made from upper and lower
halves with semi-circular groovs cut
in each half. When joining halves
together, clean glue or epoxy out of
holes before cured. This will prevent
holes from becoming clogged.
METHOD 3:
Block halves are kerf cut with dado
or regular saw blade. Tubes which
will provide bolt attachment are in
position when block halves are
joined with epoxy. Epoxy must fill
all voids between round tobes and
square kerf holes.
Regardless of wich method you chose to fabricate your blocks. The end result must be four centerction
blocks and four outboard spar blocks (they are different) with holes perfectly aligned and located correctly
down the length of the blocks. Once you have completed your wing attach bearind blocks, you will be ready to
fabricate the steel wing attach fittings.
The fittings should be cut from 1/8” steel stock to the appropriate dimensions and match drilled off of
the bearing blocks. As long as all the holes in the bearing blocks are spaced equally all the fittings can be match
drilled from on of theblocks and a perfect fit with the others will be guaranted. Do not drill the 3/8” attach
holes in the outboard fittins at this time. Pilot them with 1/8” bit and leave the drilling of the larger hole until
later. Test fit the fittings to the blocks using 1/4" bolts tu assure thet ewerything is progressing properly up to
this point.
The wing attach bearing blocks should now be inlade into the ends of the foam spar webs. This is last
operation where the proper mating of the fittings at the wing joint is the question. Cut the foam away to allow
the blocks to nest into the foam. Proceede carefully, working on one joint at a tome, and check constantly
for alignement of the bearing blocks with the surfaces of the foam webs, and the proper matong of the
centersection to the outboard panels. Once these blocks are bonded in place the alignement will be
established. Don’t hurry. When you are certain that the blocks are fit into the inlay cutouts with proper mating
and alignment, go ahead and bond them in place using a mixture of epoxy and micro balloons. Use enough
micro to keep the epoxy from “running”, and be shure to wipe of any excess on the spar faces. The epoxy
is difficult clean off after it’s cured.
After the wing attach bearing blocks are installed in the foam webs, the fuselage attach bearing blocks
should be inlaid into the centersection. These blocks are located directly between the eventual location of the
wing support members, and require no drilling. Simply cut them to size and inlay them into the foam, taking
care that the surface of each block comes out even with the surface of the foam web. There are four fuselage
attach blocks in all. Bond them in place with mixture of micro and epoxy.
With all the blocks inlaid into the spar webs, you are now ready to add the spar caps. The cups can be
cut from the single piece of wood, or laminated up as material permits. If the caps are laminated from more
than one piece of wood, the pieces sould be glued together edge to edge before adding the complete cap to
the spar web.
Each piece must be continuous lengtwise—no splices.
When gluing the caps into place, be sure that no twist is introduced into the spar. Keep one surface flat at
all times. It may be necessary to stack weights (any thing will work) onto the cap to insure good glue squeozeout
and a consistent bond. Uhen weights are used, they should not be laid directly onto the surface of the cap, but
rather, use wood blocks to distribute the load across the caps. Particular attention should be given to the bonds
between the spar caps and the bearing blocks. Large C-clamps and/or strapping tape may be used to obtain good
clamping at the block.
Install the upper cap to each spar first, since it is thicker and will help provide more stability in holding the
spar straight until the lower cap is added. Note that the lower cap of the centersection will be bowed slightly on
installation. This will not present any problems, as long as the upper surface is held flat and true. Strapping tape
and small blocks will be very effective in holding the cap tightly to the web until the glue has dried.