Wowings Booby Instructions for use

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Wowings Booby
CONSTRUCTION MANUAL
Copyright 2005 Wowings
www.wowings.com

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Thank you very much for purchasing the Booby. Although made primarily of soft EPP foam, this
RC slope glider is still capable of causing significant damage to property and serious personal
injury or death to bystanders or yourself. Please ensure that you fly this model in a safe and
responsible manner and obey your local laws and regulations. By building and/or flying the Booby
you assume all responsibility for any damage or injury it may cause. Wowings accepts no liability
for any damage or injury caused by our products. If you do not agree to these terms, please contact
your place of purchase prior to commencing construction to arrange returning this kit for a refund.
Now onto the fun stuff…First, please ensure that nothing is missing from the Booby kit and that
none of the contents have been damaged. If anything is missing or damaged please contact your
place of purchase immediately to make arrangements for replacement parts to be supplied. Your
Booby kit should contain the following:
•2 x EPP foam wing outer panel segments (each with two panels joined together)
•1 x EPP foam wing central panel
•2 x lengths of black fiberglass spar
•5 x lengths of balsa (two marked with outlines for ailerons, two marked for trailing edge
pieces and one for elevator)
•3 x steel pushrods with clevises attached
•1 x piece of coreflute marked with outlines for two fins
•1 x black fiberglass internal spar joiner
•2 x packs of Dubro nylon control horns (total of 4 control horns)
•2 x packs of Dubro E-Z connectors (total of 4 connectors)
•This construction manual!
To complete the kit you will require the following tools and supplies:
•Sharp trimming knife (large retractable disposable type is ideal)
•Sandpaper and sanding block, screwdriver, drill, pliers and ruler
•48mm (2”) wide cross-weave filament tape
•Covering material (eg. coloured packing tape or iron-on film such as UltraCote or Profilm)
•3M “Super 77” or 3M “Multi-Purpose” spray adhesive
•5 minute epoxy glue (eg. Selley’s Araldite)
•Goop/Goo glue (eg. Pacer’s Zappa-Dappa-Goo II or Second Wind’s Shoe Goo II) or
Polyurethane glue (eg. Selley’s Durabond, Gorilla Glue or Elmer’s ProBond) or 30 minute
epoxy glue (not ideal).
•Hot-melt glue –not essential
•1mm (1/16”) thick lead flashing and/or lead pieces for nose weight
The following radio equipment is recommended:
•Rechargeable receiver battery pack (4 x AA size cells) in flat configuration.
•Receiver (minimum 2 channel)
•2 x standard size servos (eg. BlueBird BMS-621, GWS S03TXF, Hitec HS-322)
•1 x mini servo or metal-geared micro servo (eg. BlueBird BMS-380MG, GWS MINI, GWS
S3002, Hitec HS-85MG)
•1 x 300mm (12”) servo extension lead for one of the aileron servos
•1 x “Y” lead for the aileron servos

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Read through the following instructions entirely prior to starting so that you have an overview of
what is involved. Please don’t be tempted to deviate from these instructions unless you are an
experienced builder and are certain that your changes won’t negatively affect the structural integrity
or flying performance of the Booby. These instructions are based in metric units but I have also
tried to include the equivalent imperial measurement as much as possible. For your reference, 1
inch (”) equals 25.4 millimeters (mm). These instructions are also available in colour as a MS Word
document online at www.wowings.com/instructions/wowings_booby.doc
SPAR INSTALLATION
Polyurethane (PU) glue is probably the best option for gluing in the wing spar. It foams up and
expands during the curing process and penetrates into the surrounding EPP foam creating a strong
tight bond without adding a lot of weight. However, if not used properly it can create a mess and
possibly even ruin the wing. For this reason, these instructions will focus on using more fool-proof
glues instead. If you decide to try using a PU glue for the first time, it’s best to experiment a little
on some scrap EPP before applying it to your wing. Ensure there’s a layer of waxed paper between
then wing and the bottom wing bed because the PU glue penetrates through the EPP easily. Be
sparing with the amount of PU glue used and wipe the spar with a damp cloth prior to gluing in
place to help the glue activate. Ensure that the wing is adequately weighted down in its beds while
the glue is curing.
If you want your Booby to be compliant with EPP slope combat competition rules, you may need to
trim the spar by about 25mm (1”) at the wingtips before gluing in place so that it is set back far
enough from the wing’s leading edge. Please consult your local rules for specific requirements.
1. Locate the two lengths of black fiberglass spar and the internal spar joiner. Use 5 minute
epoxy glue to attach the two spar halves together over the internal joiner, creating a full
length straight spar.
2. Remove the foam wing cores from their beds. Gently bend open the spar slot and carefully
remove the foam “noodle” from the spar channel. Trial fit the spar to ensure that no bits of
foam have been left in the spar channel. It should fit easily without the spar slot opening
being forced apart. Also check for acceptable alignment of the two outer wing sections with
the central wing panel. Remove the spar and put it aside to be used shortly.
3. Glue the two outer wing sections to either side of the central wing panel using hot-melt glue
or spray adhesive (epoxy is also OK but a little brittle). Align with the panels’ spar slot and
ensure the top and bottom surface of each panel is also flush.
4. Lightly sand the fiberglass spar to roughen its surface and remove any remaining mold
release agent and wipe off the dust.
5. Gently bend open the spar slot and run a bead of goop/goo style glue (30 minute epoxy is
also OK but not as good) inside the spar channel. Starting at one wing tip, bend open the
spar slot and push the spar down into the spar channel. Once the spar has been inserted, use
a piece of dowel, or back of a pen or pencil, to push the spar firmly all the way down into
the channel so that the glue is forced up and around the spar, coating it entirely. This process
can also be helped by repeatedly bending the wing chord-wise, temporarily closing and
opening the spar slot to help work the glue around the spar and centre the spar in the spar
channel. Wipe off any excess glue.
6. Place the entire wing back into its foam beds and rest it on a completely flat surface (eg.
table or floor). Weight it down so that the wing is kept flat and completely snug with the
bottom curve of its foam beds. To avoid deforming the foam make sure the weights aren’t

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too heavy and that they are spread fairly evenly. Plastic shopping bags partly filled with
sand make ideal weights. It may be easier if you remove the top portion of the wing beds by
cutting along the leading edge. Leave overnight (or as per glue’s instructions) in this
position while the glue fully cures.
WING ASSEMBLY
7. Locate the five (5) pieces of balsa wood. Two are marked out for the two fixed trailing edge
pieces and two are marked out with the two ailerons. The fifth blank piece will be used for
the elevator. Using a fine-toothed mitre saw or sharp knife, cut out the trailing edges and
ailerons along the outlines marked.
8. Hold the trailing edge pieces up against the foam trailing edge of the panels to either side of
the central wing panel to make sure they fit nicely. The bottom surface of the balsa trailing
edges is the one with the smoother cut surface that had the cut-out lines marked on them
(and the one that meets its leading edge at a 90 degree angle). When butted up against the
foam sub-trailing edge, the bottom surface of the balsa trailing edge piece should form a
continuation of a straight line from the rear half of the airfoil shape.
9. Once you are happy that they will fit
nicely, round off the top and bottom edges
of both ends of each balsa trailing edge
piece to make covering easier later on.
10. Use 5 minute epoxy or hot-melt glue to
glue one of the balsa trailing edge pieces to
the foam. Hold in place with masking tape
if needed and use a straight edge (ruler)
held against the rear section of the bottom
of the wing and the bottom of the balsa
trailing edge to ensure correct alignment.
Once the glue has cured, repeat this
process for the second balsa trailing edge
piece.
11. Trim and/or sand off any excess glue along the trailing edge joints. Ensure that there is a
smooth progression from the foam to the balsa so that it forms a nice continuation of the
wing’s slightly reflexed airfoil shape.
12. Using a sanding block, sand a 45 degree
bevel along the leading edge of each balsa
aileron, with the 45 degree opening on
their bottom surface (ie. hinged on top
surface).
13. Round off the top and bottom edges of
each end of both ailerons to make covering
easier and put them aside to be installed
later.
14. Using the unmarked balsa elevator piece,
hold it above the foam sub-trailing of the
wing's central panel. Mark its correct
length so that it fits in-between the two
balsa fixed trailing edge pieces with a small gap of around 2mm (3/32”) either side to allow
for free movement once everything is covered. Cut the balsa elevator piece to length.

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15. As per ailerons, sand a 45 degree bevel along the leading edge of the balsa elevator, with the
45 degree opening on its bottom surface (ie. hinged on top surface).
16. As per ailerons, round off the top and bottom edges of each end of the balsa elevator piece
and put it aside to be installed later.
17. Round off the top and bottom edges of each wing tip using a sharp knife. You may also wish
to round the leading edge corners of the wing tips when viewed from above.
18. Locate the piece of coreflute supplied in the kit and cut out the two fins as marked.
19. Mark out where the slots for the fins will go on the wing. You’ll need a slot 2mm to 3mm
(3/32” to 1/8”) wide and 75mm (3”) long, with the back of the slot starting 100mm in front
of the wing’s trailing edge (trailing edge of the balsa). It should be positioned just outboard
from the panel join line so you don’t have to cut through the glue.
20. Cut out the slots with a very sharp blade, being extra careful to keep the cuts vertical. Poke
out the foam from the slots with the end of a ruler or a metal pushrod.
21. Test fit the fins to ensure they fit tightly in the foam in a vertical position and that their
trailing edge is in line with the wing’s trailing edge. When pushed all the way down they
should butt up against the contour of the top surface of the wing. Remove the fins and put
them aside for later.
RADIO EQUIPMENT INSTALLATION
If you want your Booby to be compliant with EPP slope combat competition rules, you may need to
position your battery pack and/or nose-weight further back than instructed. Please consult your local
rules for specific requirements. Doing this will increase the all-up weight of the finished model a
little due to the extra nose-weight required to balance correctly.
22. Gather together all the radio equipment you plan to install into the glider and test that it is all
working properly. If your transmitter and receiver batteries are not fully charged, charge
them now.
23. Once the glue for the spar has cured, remove the weights and foam beds from the wing. It’s
now time to install the radio equipment.
24. Draw a line 30mm (1 3/16”) back from the
leading edge of the outer wing panels near
each nose. Draw another line 20mm (3/4”)
back from the leading edge of the inner
panels near each nose. For safety and
durability reasons nothing should be
embedded into the foam in front of these
lines
25. Lay your receiver’s flat battery pack
squarely on top of the wing at one of its
noses so that two of the battery pack’s
corners are touching the lines you just
marked. Trace around it with a pen and
then cut around this outline all the way through the foam. Remove this foam plug and draw
a line vertically up its front side for later reference.
26. Hold the side of your battery pack against the side of the foam plug so that it is centered and
trace lines to mark out the thickness of your battery pack. Repeat this for all four sides and
then cut off a bottom slice (base) and a top slice (lid) along these outlines. Mark the top of
the slices with an “x” for later reference and discard the remaining piece of the plug.