I have been wanting to add a fun 50cc sized plane to my hangar but wanted
something a little different than what was on the market with excellent
flight characteristics for aerobatics and 3D. Over a year ago I was talking
to Dennis about what was coming next for Carden and he filled me in on
the CUDA project. At the time I was finishing my Carden 35% EDGE 540.
After listening to Dennis describe what the CUDA was going to develop
into I was on the list for the first production build. The little brown
truck has delivered and this time I will be building two CUDA’s
side by side – one for Bill Layton and one for me.
Now for the plane specifications and equipment specifications for the
Carden CUDA.
For a complete list of parts used and available through
Aero Protect, please visit: Hardware
Kits Section > CUDA.
The wings and tail feathers follow a Carden standard of solid foam core
with balsa sheeting.
Working with the sheeting and the wing foam wing cores is where you
can start seeing the attention to detail and quality of product Carden
Aircraft puts into their designs and kit.
For ailerons the hinge line is 35.75 inches giving a centerline at
17.88. If you are used to building a constant cord aileron be careful
when laying
out the servo location. These ailerons are not constant cord; make
sure you are working perpendicular from the hinge line and not the
trailing
edge of the foam core. I will be using 2.5 inch Pro-Links with RCL70’s
8-32 Swivel Offset Clevis on the control surface and AirWild 1.25
inch servo arms with RCL87L (Left thread ball links). With this setup
I measure
0.63 inch back from the hinge line and 3.38 inches up from the center
line for the servo output shaft centerline. Total distance from aileron
8-32 screw mounting center to the servo output shaft center is 4
inches. Even though the servo arm will be 1.25 inches, I offset the
servo only
1 inch which greatly reduces the amount of angular offset that occurs
when the servo arm rotates through its full motion. This was based
on a suggestion that a customer of mine, Joe Cotton, had heard from
another
builder. I put together a sample hinged surface measuring the servo
offset at 1.25 inches and 1 inch to verify what was being suggested
and what
I found is it does reduce the angular offset by half with the 1 inch
offset. Just a recommendation.
Wing1 \ Wing1A My first step with the wing core is to cut
the servo bays, servo support notches, and servo wire exit slot. I have
made templates from lite ply and hot wire cutting tools from 12 gauge
copper wire. I place wheel collars on the wires and use them to set the
depth of cut. Using a soldering iron with the copper wires I first cut
the servo support slots then the servo bays. I then use a long straight
edge and cut the servo wire exit slot. Accurate measurements are critical
to make the servo bay cut outs after sheeting.
Wing2 Hot wire cutting complete.
Wing3 Servo mounts epoxied in place.
Wing4 Servo wire exit slots.
Wing5 Wing phenolic tube with balsa end cap in place and trial fit
of the socket support plate. CRITICAL: When gluing in the wing tube
make sure the wing tube is placed all the way in through the cut out
and contacts the foam side surface. If the wing tube is not inserted
all the way in the aluminum wing tube will not fit properly.
Wing6 Wing tube socket support scribed to sand to shape.
Wing7 I use Pro Bond to glue the phenolic tube into the cores. With
a ¼ inch drill make a few small funnels in the top of the wing
core along the hot wire groove. This makes it easier to get the Pro Bond
down in the tube slot.
Wing8 I still choose to glue all the sheeting together. This makes large
sheets that can then be cut to size. A lot of encyclopedias work well
on a flat table to keep the sheeting flat while it dries.
Wing9 The big sheets being cut into wing panels. Invest in 3M stock
before starting this project because you will be using a lot of masking
tape.
Wing10 Place the phenolic tube into its slot up to the first funnel
and squeeze Pro Bond down the funnel. Slide the phenolic in and out twisting
it and working your way down the slot. Make sure the tube is well coated
and finally fill the hot wire slot. Tape over the slot and tape the tube
socket in place. Place the wings in their cradles and weight them down
for the glue to cure.
Wing11 I prefer gluing the sheeting together first because it allows
me to pre-sand both sides on a flat surface with a palm sander and long
sanding bar. After the panels were all dry and the tape removed I sanded
each surface with an electric palm sander down to 220 grit. It is definitely
worth the time at this step to sand everything smooth because after assembly
onto the wing cores all that is left is final sanding. I also prefer
sanding a flat surface than a curved surface.
Wing12 Sanding wing cores prior to sheeting. Notice the Pro Bond filling
the hot-wire groove.
Wing13 Bottom of the wing panel ready for sheeting. Notice the servo
bay support slots have been filled in with scarp foam pieces.
I use Elmer’s Pro Bond Polyurethane glue to bond the foam cores
to the balsa sheeting. The key here is to make sure you do this on a
very flat surface so you don’t build in any warps to the surfaces
and pile on the weight to force the glue into the foam core of the wing.
I use 300 pounds of weight on each wing panel. After the glue has cured
(over night) the weight is removed and the leading and all edges are
sanded flush with the foam cores and trued. The leading and trailing
edges are glued and held in place with masking tape
Wing14 Using a micro plane remove the majority of the excess leading
and trailing edge balsa.
Wing15 When the plane brings the excess balsa down close to the surface
lay on 3 to 4 layers of masking tape to prevent the sanding bar from
biting into the balsa sheeting surface and causing gouges. Remove the
masking tape and use the sanding bar to bring the leading and trailing
edges down to the wing skin surface.
Wing16 This picture shows the ¾ inch total width removed for
the wing trailing edge and the aileron leading edge. I draw the area
to be removed on the top and bottom the each surface (wing and stabilizer)
cut with a knife close to the drawn line and angled towards the side
that will be removed. Cut top and bottom and the waste area drops out.
When you do it take a second to see how the Pro-Bond has penetrated the
foam cores. Take a long sanding bar and carefully sand to the lines.
Take note on the planes that the aileron isslightly tapered away from
the fuse side and make sure you are cutting enough away because you will
be adding a balsa sheet to cap the aileron at the root.
Wing17 Another view of the material cut away and removed.
Wing18 When you are building two CUDA’s next to each other it makes
for a lot of wings and tail feathers.
Wing19 Going through the same process for the wing trailing edge and
aileron leading edge as was done earlier. Razor plane down close and
final sand flush. Buy stock in whatever tape brand you will be using
because you will be buying a lot of rolls.
Wing20 Servo bay cut out and all leading and trailing edges install and
sanded flush.
Wing21 Another view of the wing and aileron.
Wing22 Close-up of the wing tip area notice how tight the leading and
trailing edges are for the wing and aileron.
Wing23 Getting ready
to hinge the wing surfaces. I add a few additional robart hinges on
each control surface at the root and tip. For the
wings the spacing is the first hinge location 1 inch in from the
tip, the second again 1 inch in from the first, then each hinge spaced
4.5
inches until you get to the root where the last two are again spaced
1 inch apart. Ailerons each wing panel 10 hinges total 20 for the
wings. Draw a center line on the trailing edge of the wing and the
leading
edge of the aileron. Measure and mark each hinge point location – be
very accurate for the two parts so everything lines up nice when
the surfaces are hinged. I press in the pencil point a little at
the center
to give a starting hole for the drill bit.
Wing24 I tried something a little different this time and used a 3/16
dewalt drill bit for wood that has a sharp starting tip. I did not
find the bit wanting to wonder as it drilled the hole. Only go through
the wood and a little way into the foam. Mark your drill bit with a
piece of tape to control the depth. Take your time it is a lot of holes.
Wing25 To put he bevel on the ailerons and wings I make a small template.
Because the wings taper root to tip the bevel lines are not straight
on the edges. I make a template from stiff paper that matches the bevel
for the root end of the surfaces. In this case the thickness of the
surface –cord – by the thickness of the leading or trailing
edge 3/8 of and inch. Mark the center and draw the bevel. Place it
on eh root edge of the surface for the bevel and draw it on. Use the
same template for the tip end and connect the two ends with a long
straight edge root to tip. You will see the line is not parallel to
the edge.
Wing26 Tip
Wing27 Root
Wing28 Bevels marked on the wing and aileron - Root
Wing29 Bevels marked on the wing and aileron - Tip
Wing30 Cutting the bevel to shape using a razor plane
Wing31 Aileron and wing beveled.
Wing32 Checking the bevel evenness at full deflection of the aileron.
Wing33 The wing 1/8 balsa root cap has been glued in place and sanded
to shape using the same taping and sanding method used for the leading
and trailing edges. Notice that the servo extension wire exit hole has
also been cut. A ½ diameter brass tube with a sharpened end was
used to cut the hole after the root cap was installed. Take some measurements
for the exit hole location prior to gluing on the root cap and you will
be all set when you go to cut the hole.
Wing34 A picture of the 1 x 1 x 3/8 plywood mounting points for the wings
that will receive the anti-rotation screws. Number 6 blind nuts have
been installed.
Wing35 The plywood blocks epoxied in place. A couple of important points – carefully
cut the root cap and foam for the blocks. I mark the 3/8 inch depth on
the knife blade so the foam is also cut to the right depth and easily
removed. Vacuum out the cut out to make sure all lose material is removed.
Apply Vaseline to the threads of a number 6 screw and thread it through
the block into the blind nut and allow it to extend a few threads past
the blind nut. Add a little more Vaseline to the extended thread to keep
the screw from being glued in place when installing the block. Mix epoxy
and liberally coat the inside of the cut out. Install the blocks wiping
away any excess epoxy and let cure. Remove the screws.
Wing36 If the control surface hard points were not marked when the ailerons
and elevators were drawn and cut out then insert a couple of hinge points
(root and tip) and attach the aileron to the wing section and the elevators
to the stabilizers. Mark the mounting point on the control surface and
draw the mounting block cut out on the control surface. Mark the center
point of the block, drill and tap for the 8-32 hardware. Countersink the
hole on the side that will be glued into the surface so the head of the
screw is flush with the block. To cut out the surface for the block draw
a line on an exact-o blade 3/8 inch from the tip as a depth gauge when
the balsa and foam is cut. By doing this the foam is only cut as deep as
the block. Fit the block in the cut out and when flush with the surface
mark and sand the bevel cut shape into the block. Before epoxing the block
in place back out the screw several threads and apply epoxy to the threads
and head of the screw. Tighten the 8-32 screw in place and embed it in
epoxy in the surface cut out.
Wing37 Time to take care of shaping and installing the balsa tips
for the ailerons, elevators, stabilizers, and rudder. I have chosen
to do it at this step of the construction – it can easily be
done earlier on in the construction process of the wings and tail surfaces.
Draw center lines in the top and bottom of the balsa blocks.
Wing38 I traced a template from the tips of each of the surfaces onto
paper with the center line for positioning.
Wing39 The template being transferred to the balsa blocks. By Carden
cutting the general shape of the block for you has really simplified
this part of the construction.
Wing40 I used a scroll saw to cut away most of the waste material and
get very close to the shape needed.
Wing41 After the general shape id cut out them the inside surface
is hollowed using a Dremel tool. Be careful you do not go to deep and
remember the tips still need to be shaped and rounded so you do not
want to get to thin to the outside surfaces. The other point to remember
is the wing tips do not have the aileron tips cut free so don’t
hollow back into the aileron area.
Wing42 Tape off and sand the balsa block to shape using a razor plane
and sand paper use the same process that was used for the leading and
trailing edges.
Wing43 The wing final sanded and ready for covering.
Wing44 Closer shot of the wing tip after final sanding.
Wing45 Aileron servo and linkage installed
Wing46 Full view of servo mount and linkage. Rocket City RCL70 on
the control surface, Titanium Pro-Links, into RCL87L (Left Hand Thread)
ball ink and 1.25” AirWild servo arm.
Fuse1 Building the truss sides on the board. I place a long straight
edge along the top to make sure the surface is straight. The top surface
is placed on the planes when the fuse is framed up because it is done
upside down. Keeping everything square is critical.
Fuse2 Using the drill press with a sanding wheel to shape the stabilizer
cradles for the rear of the fuse.
Fuse3 Stabilizer cradle installed and the modification made to mount
the rudder servo. Build one truss side as shown on the planes. Then
the other (I am placing the rudder servo on the right side of the
plane) is built with the following change. Leave out the vertical
3/8 square support and replace it with two pieces of ¼ by ½ hardwood
spaced for your servo. I will be using one JR8611 with a 1.5 inch
AirWild servo arm into a Left thread RCL87L ball link, 2.5 inch titanium
pro-link, into and RCL87 which is part of the RCL70 8-32 swivel clevis.
The spacing is 4 inches from the center of the servo arm to the center
of the mount on the rudder. Using the ¼ x ½ hardwood
works well because the 3/8 stock covered by the 1/8 stock makes the
mount flush to the side of the fuse.
Fuse4 Marking the location of the lightening holes on the side motor
box pieces.
Fuse5 Marking the rear of the motor box for the 4.5 inch lightening
hole.
Fuse6 When drilling the holes make sure you fixture the parts so they
don’t move while drilling. There are some good size holes so
take it slow and easy. Keep all ten fingers you will need them to
fly.
Fuse7 Drilling the smaller lightening holes.
Fuse8 All the holes drilled out and the edges cleaned up.
Fuse9 I will be running the header pipe and canister on the DA50 so
the lower lightening holes need to be back filled with balsa to protect
the foam from the heat in the tunnel. I used 3/32 balsa and the Dremel
hole cutter attachment. A little setup time goes a long way towards
making perfect plugs.
Fuse10 The lower balsa plugs are CA’ed in place flush to the
outside surface of the motor box.
Fuse11 Cut the ½ x ½ hardwood to shape to match the dimensions
needed for the landing gear plate. Also cut the ¼ x ¼ balsa
to size and shape for the sub floor mount.
Fuse12 Hardwood and sub floor mount epoxied in place.
Fuse13 Epoxing in the wing tube support to the fuse. Remember you have
a left and right half for the trusses now if you modified one for
the rudder servo mount. The wing tube support goes on the inside
of the truss. I place a couple of other pieces of plywood under the
truss for spacing and pin everything down tight to the board.
Fuse14 Place a wing tube in place and make sure it is square getting
ready for the next step.
Fuse15 Place a wax paper piece between the truss halves and place the
other truss on top of the first. Position it and make sure it is
square to the first truss half. By using the wing tube and making
sure it is square will assure the wing tube supports will be properly
placed and square.
Fuse16 The fuselage trusses have been sheeted with the 1/8 balsa sheeting.
The wing tube hole was cut using the fuselage wing tube section. The
wing tube section was sanded to a sharp edge using a Dremel tool and
then strengthened with CA. I used the wood glue and applied it to the
truss side then line everything up placing the wing tube in the fuselage
socket and make sure it is square to the truss side. Pin it down or
weight it down while the glue dries. I choose to add the sheet extensions
to the rear of the truss sides because it will be easier to mark and
cut them for the elevator and rudder servo cut out.
Fuse17 Rear truss sheet extension marked for the rudder servo cut out.
Fuse18 Sheet extension cut out for the servo bay and rudder servo mounting
glued in place. Remember the hardwood mount is ¼ x ½ so
it will be flush to the 1/8 truss sheeting.
Fuse19 Marking the
center line and the 9/32 in. offset for the motor. Look close the locations
drilled are not correct! The motor mounting holes were
based off the center line and not the offset so at this point the
motor is not offset. This will be corrected with an explanation how
a little farther down. Working just a little to fast – remember
measure twice cut once.
Fuse20 Motor box under construction – a lot of clamps will be
needed but it is not difficult to keep everything straight and square.
Take your time.
Fuse21 \ Fuse
22 Additional views of the motor box.
Fuse23 The basic motor box framed up.
Fuse24 Another view.
Fuse25 Using the drill press to drill the 1/8 inch holes for all the
1/8 inch dowel pins.
Fuse26 Dowel pins have been glued with epoxied and tapped in place.
Fuse27 This picture shows the corrected F1 firewall. The ¼ inch
holes that were drilled have been backfilled with hardwood dowels and
the proper hole locations marked and drilled.
Fuse28 Pre-cut and sand to shape the top and bottom 3/8 square cross
members before installing the truss sides. In this shot there are
4 of each cross member because 2 CUDA’s are being built at
the same time.
Fuse29 The wing tube is in place (not glued) for a test fit of the
truss sides. The picture also shows F3 and F4 glued in place with
epoxy. For F3 a 1/8 inch thick scrap piece has been CA’ed on
the 3/8 square piece and sanded to the proper angle prior to installation.
Fuse30 The motor box is positioned and blocked in place on the top
view of the planes. The wing tube is slid in place (not glued) and
the truss side’s trial fit in place. Make sure the openings in
the truss sides for the wing tube fits properly taking into account
the angle the truss side fits to the motor box. F2 has been sanded
to shape and the truss sides have been glued to F2, F3, and F4. The
horizontal cross pieces have been CA’ed in place and the truss
sides held square to the board with carpenter triangles. F5 has been
installed.
Fuse31 Rear view showing the installation of the truss sides and the
top horizontal cross pieces.
Fuse32 The diagonal pieces (1/4 inch square stock) have been installed
and the bottom horizontal cross pieces have been installed.
Fuse33 All the bracing is complete for the truss sides. The wing mount
plywood plates have also been installed.
Fuse34 The bottom deck has been sheeted and trimmed to fit around
the motor box. Take your time – measure and trim carefully. The
side pieces after the center section has been cut out are a little
delicate during this step.
Fuse35 Bottom deck has been glued in place on both fuselages. Now
it is starting to look like something!
Fuse36 The ¼ cross grain balsa pieces behind the landing gear
plate have been cut to size and positioned. The air exit hole still
needs to be cut in prior to gluing them in place. The rear tunnel balsa
deflector has also been cut to shape and is ready for installation.
The motor was mounted along with exhaust to check fit and placement
of the very nice water jet mount made for the MTW canister. (Contact
Desert Aircraft). The mount will be positioned on top of the gear plate
towards the rear. For proper fit it will need to be trimmed 1/8 inch
top and bottom to keep the canister centered in the tunnel.
Fuse37 The exhaust canister mount needed to be trimmed down an 1/8
inch from the top and an 1/8 from the bottom to have it fit perfect
in the tunnel mounted on the rear of the landing gear plate. I also
added a ¼ inch square strip in front of the mount to give it
some added strength.
Fuse38 The ¼ inch cross grain balsa pieces have been cut to
size and trial fit.
Fuse39 The ¼ inch cross grain balsa pieces have been cut to
size and glued in place. An air exit hole was cut out at the rear of
the exhaust tunnel. The cut out measures 4 inches long and 3 inches
wide.
Fuse40 The bottom of the motor box rough sanded to shape.
Fuse41 Top view of the fuse showing inside the exhaust tunnel and the
installation of the 3/8 square balsa along the edge of the motor
box and the ¼ cross grain balsa bottom sheeting.
Fuse42 View of the antenna tube mounted inside the fuselage along the
lower edge of the truss.
Fuse43 View of the rocket tube installation for the servo wire extensions
to the rear of the plane. The mounts are scrape 1/8 balsa and glued
in place along the top truss edge diagonal to the antenna tube.
Fuse44 Another view of the rear of the fuse with the antenna tube and
servo extension tube installed.
Fuse45 The wing tube has been positioned and alignment verified. Alignment
is done by placing the wing phenolic tube in place and slide in the aluminum
wing tube. Using a robart incidence meter, level, or digital level, make
sure the fuselage is level and measure the wing tube distances from a flat
work bench (glass table top – dinning room table – understanding
wife is required) to assure a level wing tube. Then measure the distance
from the ends of the tube on each side to a center point at the tail of
the plane. Make adjustments if needed so the tube is perpendicular to the
fuselage length wise center line. In other words make sure it is square
to the fuselage. After everything is square epoxy it in place. Once it
has cured mix up a 50 – 50 ratio epoxy and denatured alcohol and
apply it to all surfaces of the tunnel for fuel proofing. Make sure you
apply it to the underside of the gas tank plywood piece of the motor box
before gluing in place.
Fuse46 Another view.
Fuse47 Bottom motor box being glued in place. The oval cut out will allow
the canister to slide in and out without any problems. Clamps and tape
work well.
Fuse48 Another view with the clamps removed and the front trimmed flush
with the fire wall.
Fuse49 Inside picture of the motor box. To add the ¼ x ¼ stock
to the back of the lower motor box piece cuts were made in the wood to
allow it to bend without cracking. Stock was also added to support the
1/16 inch thick cross grain balsa tunnel cover. At this point it would
be best to coat the lower motor box cover and ¼ inch square stock
with the mixture of epoxy and denatured alcohol while it is still easy
to get at. I also applied it to the bottom of the tunnel cover before
installation.
Fuse50 Tunnel cover cut and size and ready for gluing in place.
Fuse51 To seal the seam between the plywood and balsa tunnel cover a
piece of 1/16 inch thick balsa was glued in place.
Fuse52 The support frame using ¼ inch square stock has been added
for the motor box top plate. The plate will be glued on later after working
out the details for mounting the throttle servo.
Fuse53 A view looking from underneath the fuselage.
Fuse54 Getting ready to set the wing incidence. First step is to block
the fuselage in place so it is reading 0.0 degrees across the fuse.
Fuse55 Next make sure the fuselage is reading 0.0 degrees front to back
on the fuselage. This reading is taken off the motor box side plate.
Fuse56 Install the wing tube and wing and align it so it also reads 0.0
degrees incidence to the fuselage. A long robart incidence beam and
mount are being used with the digital protractor for accuracy to a
1/10 of a degree.
Fuse57 To make marking the holes in the fuselage easy for drilling a
3/8 square balsa block it lightly CA’ed in place along the trailing
edge of the wing holding the wing in the correct position. After the
incidence has been set and the holes drilled the block can easily be
removed and any marks left filled with body filler and sanded smooth.
Fuse58 To mark the fuselage for the anti-rotation screws a 6-32 screw
head has been modified by cutting off the head and grinding a centered
point on the other end.
Fuse59 Thread the pointed 6-32 screw into the wing blocks front and back
and slide the wing on the wing tube. Carefully bring the wing up to
the fuse making sure the trailing edge is in contact with the locating
block that has been glued in place. With everything aligned slide the
wing against the fuselage to make indents for the anti-rotation screw
locations.
Fuse60 Close-up of one o the markings on the fuselage.
Fuse61 Front 6-32 screw with washer in place with the wing. A larger
washer will be used for the actual mounting of he wings.
Fuse62 Rear anti-rotation mounting screw.
Fuse63 Wings mounted on the fuselage.
Fuse64 Another view of the wings mounted.
Fuse65 Take some time and carefully
position the stabilizer making sure it is centered and set with a
zero degree incidence (done the same as the
wing). True the stabilizer horizontally (up and down) incidence (front
to back), and square to F1 and the wing tips. After everything is set
take it off and epoxy it in place taking the time to reposition and true
everything.
The top extension pieces have been glued in place.
Fuse66 To make the top extensions they need to follow the contour of
the stabilizer. An easy way to copy it is to place a contour gauge
on the surface and copy it onto the wood. Cut and sand to shape it
the pieces will fit very tight without much adjustment.
Fuse67 Starting to add the cross grain 1/8 inch balsa bearing plate for
the fin.
Fuse68 Adding another cross grain piece.
Fuse69 The rudder bearing plate completed.
Fuse70 The fin has been glued into place. As with all the other setups
make sure the fuselage is blocked up level. Zero degrees front to back
and side to side. Install the fin and using a roofer’s square
position the fin square to the fuselage using the center line drawn
on the fin for the hinge and bevel as a reference.
Fuse71 The bottom of the fin has been shaped and the tail wheel assembly
installed. Don’t forget to add a hardwood mounting block along
with the plywood tail wheel plate.
Fuse72 Starting to shape the fin cut out on the top turtle deck. Careful
trimming and sanding will get a very nice fit.
Fuse73 Another view of the turtle deck being fitted. Remember to cut
out for the 1/8 inch balsa cross grain fin bearing plate.
Fuse74 Top turtle deck glued in place. The deck was installed the same
way as the lower deck using tape and tacked on balsa stock to hold
the turtle deck in position.
Fuse75 A closer view.
Fuse76 Turtle deck, elevator, and fin in place.
Fuse77 Another tail view.
Fuse78 Lower tail view showing the rudder servo mount location.
Fuse79 To make, CA2 place a sheet of paper over the front of the turtle
deck and shade with a pencil to get the outline. Use that as a template
to cut out CA2 and then shape to desired size to allow for the canopy
to be flush with the turtle deck.
Fuse80 Dry fitting the canopy frame.
Fuse81 Front view of the canopy frame. Use a square to make sure CA1
is positioned perpendicular to the fuselage.
Fuse82 Canopy frame is taped in place and epoxied. Make sure you use
wax paper under each glue joint.
Fuse83 The rudder has been beveled and is trial fitted with a couple
of hinges.
Fuse84 Elevators have been put in place with a couple hinges to get an
idea of what the tail of the Cuda will look like.
Fuse85 The canopy is trimmed to size and taped in place to see how everything
fits. To mark lines for cutting a Sharpie works very well. Denatured
alcohol on a paper towel will take any marks left off.
Fuse86 Both canopies
in place. Notice the floor of the canopy has not been put on yet that
is to allow easy access to putting in the hold
down spacers and tabs.
Fuse87 Gas tank mount is complete with Velcro and ¼ inch foam
underneath. With this mount the tank is line to line with the canopy
floor. When the floor goes in a relief will be built in to allow room
if the tank expands a little.
Fuse88 3/8 plywood support glued in for the canopy lock down tabs.
Fuse89 Rear spacers for the plywood tabs being glued in place.
Fuse90 Front spacers being glued in place.
Fuse91 Rear canopy hold down tabs being glued in.
Fuse92 Front canopy hold down tabs being glued in.
Fuse93 The
cross grain balsa sheeting has been added to the floor of the canopy
structure. The gas tank is Velcro wrapped in place with
a ¼ foam
pad under it causing the tank to protrude into the canopy area. The tank
can be left exposed and visible through the canopy if you would like – my
choice is to build a cover for it.
Fuse94 Standoff rails have been added to start framing the opening for
the tank.
Fuse95 The standoff frame completed
Fuse96 The top balsa cover has been added to the standoff frame to enclose
the tank. The inside area will be sanded and painted with speckle automotive
trunk paint.
Fuse97 The motor needs to be mounted with a 2.5° offset for proper
alignment with the cowl and right thrust offset. The firewall offset
has already been taken care of with the position of the motor mount holes.
To offset the motor from F1 I cut spacers from ¾ inch dowel on
a miter saw putting the 2.5° angle on one side and a 90° square
cut on the other. I found the easiest way to center drill the spacers
is to drilling a shallow ¾ inch hole using a forstner bit into
a piece of scrap wood. Place the standoff with the square side down
and center drill the standoffs for the engine bolts.
Fuse98 Place the standoff with the square side down and center drill
the standoffs for the engine bolts.
Fuse99 The DA50 mounted with the 2.5 inch aluminum standoffs and the
2.5° wood dowel spacers. At this point I realized the carb on the
motor is mounted reversed to how it is shown in the construction photos
supplied with the CUDA kit. The first option is to leave the carb in
the position received from Desert. To do that means the throttle servo
mount would need to be inverted from the picture and the chock would
need to be operated with a bell crank setup because of its orientation.
The second option is to remove the carb and flip it 180° allowing
the throttle linkage and servo to be installed as shown in the Cuda
picture included with the kit and a very simple push pull rod for the
choke.
I opted to go with option 2. I had Desert rotate the carbs for me.
If you have not placed your order for the motor yet, when you do, ask
Desert
to rotate the carb for you. If you already have the motor not a problem,
it is a very simple exercise to unscrew the carb, rotate it, and re-install
it. You may need to replace the tubing from the carb and extend it.
Fuse100 The “L” brackets that are used for mounting the
cowl need to be drilled for mounting first and then the edges squared
on a disk sander prior to installation.
Fuse101 The top of the cowl ring being setup. Hex head cap screws, washers,
and lock washers are usedthroughout.
Fuse102 The hardware installed.
Fuse103 This pictures shows the top cowl ring installed. Notice the “L’” brackets
are installed on the motor box with a blind nut and a mounting block.
The hardware used is the same – hex head cap screw, washer, and
lock washer. Just my preference.
Fuse104 The lower cowl ring pieces all set to be installed. Same as the
top cowl ring.
Fuse105 The canopy cut and glued in place. Make sure you use wax paper
under the canopy floor so excess glue does not cause the canopy to
be glued to the fuselage. My preference – ZAP RC56 Canopy Glue.
Fuse106 The RC56 takes about 3 hours to really take a set. So at 90
minutes I take the canopy off the fuselage (carefully) and place a piece
of ¼ x ½ hardwood
along the lower edge of the canopy. Heavy duty paper clamps are them
used to clamp the wood against the canopy and let dry over night. This
makes sure the canopy edge is glued down tight to the floor section.
Using the hardwood strip distributes the pressure on the canopy and should
give a uniform edge. Again – just the way I do things.
Fuse107 Canopy in place and 1/16 inch balsa strips taped in place as
spacers for the cowl installation.
Fuse108 Cowl taped
in place and ready for tacking in with CA glue.
Fuse109 Canopy removed again to get the CA glue in along the top cowl
ring and top section of the lower cowl ring.
Fuse110 The wheels being used are the 3.5 inch Sullivan Skylite Wheels
with Aluminum hubs. I do not like the hardware that is supplied by Sullivan
so if you order the wheels through Aero Protect a zip lock bag with new
hardware is included. It carries SS hex head cap screws, SS washers for
both sides of the wheel and nylock nuts to keep everything together.
Fuse111 I make an extra modification to the wheels that is not required
but just my preference. I use a 7/32 diameter brass tube in the hub.
The hub is drilled slightly undersized. The brass tube is placed in the
freezer and the hub heated with a hair dryer. The two slide together
and become one very quickly.
Fuse112 Another view of the hub with brass tube.
Fuse113 Nylock screws installed.
Fuse114 Wheels assembled.
Fuse115 The gas tank vent location is placed in front of the landing gear mounting
area.
Fuse116 The gas tank installed along with the “T” fitting
from the tank for filling and to the carb. The vent line is looped
back the length of the tank to help prevent gas leaking out while moving
the
plane and rolling out for taxing.
Fuse117 Another view of the vent line installation.
Fuse118 The switch location cut out. Because the location for the switches
is along the lower part of the fuselage the switches will be mounted
in foam. Square balsa stock has been added to each side of the cut out
to allow for some material to mount the switch assembly into.
Fuse119 Another view of the switch cut out location.
Fuse120 All the fiberglass along with spinner and landing gear have been
painted. PPG base coat clear coat was used for a high gloss finish..
Fuse121 The firewall has been drilled out with a 1.5 inch hole saw and
covered in the back with balsa to allow better air flow around the carb.
This is not a required step but one suggested by Desert Aircraft.
Fuse 122 Top of motor box installed with mounting locations for the
ignition module, throttle servo, and ignition battery pack. Notice
an access hole
has been also drilled to allow access to the gas line “T” fitting.
The hole will also serve as a pass through for wiring and will be back
filled with a foam block when all the work up front is complete.
Fuse 123 Landing gear panted and additional wheel pant screw added
to keep the wheel pants from rotating during flight – don’t
laugh I have seen several planes land on the wheel pants and not the
wheels. The SIG wheel pant holders are used on the axle – this
additional screw goes into a blind nut “T – nut” just
above the wheel pant holder.
Fuse 124 and 125 Detail drawings for the small extension that needs to
be made from .032 aluminum that will allow easy open and closing of the
choke.
Fuse126 The choke extension mounted with pull lever. Notice the small
mount the pull lever goes through to keep it from moving around during
flight. It is jus a balsa piece with a small piece of golden rod inserted
and fuel proofed. Also take note that the firewall has a relief sanded
in it to allow room for the choke extension to move without coming in
contact with the firewall.
Fuse127 Another view of the front end.
Fuse128 Top of motor box with ignition module mounted, battery pack and
throttle servo.
Fuse129 Front end complete. Motor mounted and ignition braided cable
wrapped in plastic spiral. Things get a little tight up front but everything
goes together well.
Fuse130 The choke pull needed to be bent to shape to allow full closure
of the choke for priming. (DSC00024)
Fuse131 Choke pull installed (DSC00025)
Fuse132 All the hardware installed - picture not the best - will take
some with better light and show the receiver installation. (DSC00028)
