by Frank Justice
At present these instructions are written around the sliding canopy
only since that is what I built. You can still use some of the
sections if you have the tip-up.
Brake Hoses and Tubing
- The single brake system for the RV-6 is shown on drawing #40 and
the RV-6A and dual brake systems are shown in drawing #49. There
is also some information in the construction manual. Install the
fluid reservoir and the lines and elbows on the cylinders. The
elbows need to be screwed in fairly tight right up to where they
should be pointed; if you have to back them out a little bit they
may leak so be careful. Use gasket sealing compound on the elbows.
In order to get the brass inserts to go all the way inside the
plastic tubing you may need to put the outer ferrule on the tube,
start the insert in the tube, heat the end in near boiling water,
and then force the insert in by pushing the tube end against a
wall. If on the other hand the insert is too loose and won't stay
in place, put a little sealing compound on it first to hold it.
The reservoir needs to be installed above the upper firewall stiffener
just high enough that you can screw in the nylon Tee fitting to
it after the reservoir is mounted; keep in mind you will need
to be able to see the fluid level at the top.
- Install the elbows in the firewall (RV-6) or straight fittings
in the angle on the firewall (RV-6A) and connect the hoses from
the master cylinders to them. For the RV-6A install the elbows
along along the sides of the fuselage and connect aluminum tubing
from these back to the fittings on the firewall angle. The elbows
should be placed far enough forward of the F-602 bulkheads so
they do not interfere with the later placement of the F-696 tank
attach angles (drawing #46). There is room between the wing and
the fuselage to later route the brake line from this elbow along
the fuselage to the gear leg. The elbow is not placed right next
to the gear leg because there is a gap between the fuselage skin
and the heavy gusset in this area and tightening the elbow in
place deflects the skin.
Tank Vent Tubes
Install the tank vent tubing inside the fuselage as shown in drawing
49. Make a hole about 3/8" diameter in the fuselage side skin
for the tube to go out to the tank. The hole location is not critical
as there is plenty of room between the outside of the skin and
the inside wall of the tank to make bends in the tubing. There
should be about one foot of tubing outside the hole. If you do
not have the bottom skin on at this time just leave a little extra
length at the forward end of the tube so it can be fitted later.
- The empenage is faired in with a molded fiberglass top piece F-649B
and aluminum strips F-649A on the sides under the horizontal stabilizer.
These are shown in drawing #46. The fiberglass fairing normally
needs considerable rework; most builders find that it will not
go far enough back to properly fit around the leading edges of
the horizontal stabilizers because it hits the vertical stabilizer.
If it is cut out around the vertical stabilizer enough to allow
the leading edges to lay properly on the horizontal stabilizer,
it may not overlap the F-610 bulkhead where attaching screws must
go. It is actually fairly easy to cut off a section that is incorrect
and remake it to the proper shape.
- Trim the fairing as necessary to make it sit in the desired location.
If your fairing is as described above you can trim some at the
front of the vertical stabilizer (but not so much that it moves
so far back there is not enough fairing left to attach to the
F-610 bulkhead), then cut off the part of the sides that do not
conform to the horizontal stabilizer leading edges. You then only
have to rebuild those two small areas as described below.
- Hold the fairing in place and drill #40 the holes for attachment
of it to the stabilizers, making sure they all go through rib
flanges and miss other ribs and rivets, where you can attach nutplates
later. Also drill one hole on each side at the front just above
the cut-out area such that it will go through the flange of the
bulkhead and not just the topskin.
- On the inside of the fairing grind off all high spots, and if
you had to cut through any flanges that go right against a skin
bevel them back about one inch on the inside.
- Coat the area on the skins where the fairing will touch them with
fiberglass mold-releasing compound to keep new resin from sticking
to them. A film of old-fashioned carnuba auto wax will also work;
put it on and allow it to dry. Auto polish will not work well,
and do not use a wax with silicone in it as it will keep paint
from sticking later. Some types of packaging tape also work well;
test it first, and lay it on without any creases.
- Working with polyester resin and cloth is quite easy if you do
it right. Get a bunch of cheap acid brushes (stiff, ragged bristles,
metal tube handle); these are used to mix the resin, to apply
it, and also to move the fiberglass cloth around. Nothing else,
not even your fingers, will have to touch the stuff. Things to
remember: the strength is in the fiberglass, not the resin; use
only enough resin to wet the cloth at each stage; make sure the
cloth is thoroughly wet (no white spots remain) and that there
are no gaps between cloth layers (also visible as lighter-colored
areas); the wet cloth will stick to and be pulled out of shape
by anything you touch it with except the wet brush; wet fiberglass
cloth can be easily made to conform to any shape imaginable, although
you may have to experiment some with the best angle to cut out
you piece with respect to the direction of the weave of the cloth.
One other trick when working with larger pieces is cloth (you
may not need it here) is to brush on some resin, let it start
setting up, then stick the cloth to it; it will stay in place
and you can work it with your fingers. Also, remember to thoroughly
clean any surface that may have the wax or mold release compound
on it before trying to apply another layer of resin.
- Cut out a few pieces of medium weight fiberglass cloth of the
right shape to make new areas and also overlap the existing fairing
by about one inch. Mix a small batch (about two teaspoons) of
polyester resin (auto body or boat repair types are fine). You
will have about five minutes from the time you mix a batch until
it starts getting stiff. Brush it on the inside of the fairing.
Lay a piece of cloth on the fairing and wet the rest of the cloth;
lay another piece of cloth on the first. Put the fairing in place
and cleco it down. Use the brush to work the cloth into the right
shape and to get it completely wetted. Lay another piece of cloth
on top and wet it. After this hardens you can do more layers until
you get the new area formed. Then grind off the outside in the
area around the joint just deep enough that you can do one layer
of fiberglass there. Be sure to pull out the clecos before the
resin gets too hard (about 1 hour).
- To finish the fairing, trim it all around until it extends only
about three-quarters of an inch past the future screw holes. Then
lay a layer of fiberglass and resin on the inside on all the surfaces
that lay against the empenage skins and cleco the fairing down.
Use the brush to smooth and fill all the edges. When the resin
sets up, smooth out the new areas and round all the edges. The
final thickness of the flanges where the screws go must be at
least 1/8" to provide enough material to countersink for the screw
- While you are waiting for resin to set up you can make the F-694A
gap covers (bottom fairings) as shown in drawing #46.. An easy
way to get them the right shape is the carpet-layer's trick; measure
the distance down from the lowest point on the horizontal stabilizer
to where the bottom edge of the fairing will be (about the same
level as the bottom of the main longeron), tape the fairing material
on the fuselage with the bottom edge parallel to the main longeronand
the forward edge butted against the top skin rather than overlapping
it, mark a point on the fairing the same distance up from the
bottom and the same location as what you measured previously,
measure from the bottom of the horizontal stabilizer down to this
mark, then make a series of marks this same distance down from
the horizontal stabilizer. Cut along these points and it should
fit almost exactly along the stabilizer and will not need trimming
on the bottom edge. Mark good locations for mounting holes down
on the side skin where you can see them with the fairing in place.
Tape the fairing in place and drill it #40 to the main longeron.
Remove it, drill out the holes to #30, and dimple them.
- Remove the stabilizers. Mount nutplates on the stabilizers and
the fuselage at F-610. Drill out the holes in the fairing and
countersink them. Drill out the holes for the bottom fairing in
the main longeron. The drawings show to tap these holes for 6-32
screws, and countersink them. This is not easy because the tap
has a tendency to bind up and break in thick aluminum. Since you
can install this fairing now and never have to take it off again,
it is easier to just use locking nuts on the fairing attach screws.
If you do tap the holes, do not tap them completely; stop at a
point where when you put the screw in it is a little hard to turn.
Use cutting oil or kerosene for a lubricant and work the tap in
and out as you go to reduce friction. Install the bottom fairings.
- You can now permanently install the stabilizers, the top fairing,
the rudder, and elevators, or you can set them aside for later
if you expect to have to move the project to finish it.
Sliding Canopy Windscreen Supports Installation
- Thi section describes mounting the Wd-641 windscreen frame and
its forward support on the cockpit deck as shown in drawings SC-1
and SC-2. First drill the holes in the Wd-641 bottom plates such
that the bolts will go through the canopy decks just inside of
the main longeron. Then drill the holes in the canopy decks through
them. Rivet the four C-668 spacers (found in bag #908) in place
to the main longerons with a single AN426AD3 rivet each, then
drill them for the bolts. Do not make the shims for the forward
bolt holes yet. Mount the Wd-641 using non-locking nuts (1/4-28
or 1/4" FINE or 1/4" UNF thread) but do not tighten the nuts on
the bolts completely.
- The standard windscreen frame support bar Wd-643 is made out of
a steel alloy that can cause errors in compass readings if the
compass is mounted on or next to it. For this reason Van's makes
a non-magnetic stainless steel support bar as an option at a small
extra cost with trade-in of the standard bar. You will not need
this if you are planning a panel-mounted compass located in the
middle of the pilot's half of the instrument panel; a compass
is best not located in the center of the panel anyway because
that will put it too close to electronics which are likely to
cause indication errors.
- Cleco the forward structure and forward topskin in place. Figure
out where the Wd-643 windscreen frame support bar will go. Use
drawing SC-1 which shows the plate on the bar extending aft of
the F-6109 plate on the center rib; this will probably give you
the best results in terms of the lower end of the tube part of
Wd-643 laying flat on the topskin. Exact placement of the Wd-643
is not critical; it just must not touch the F-6105 bulkhead flange.
Decide where the rear end of the slot must be for the Wd-643.
From the underside drill a hole #30 right next to the left side
of the center rib in the general area of the slot; use this hole
for reference to make the rest of the slot. To make the shortest
possible slot, plan on holding the bar vertical, putting the plate
through the slot, and then tilting the bar back and down into
place. Trim the bar and plate as required to allow it to sit right
on the skin without distorting it. Cut the excess off the top
end of the bar so it will fit in the channel in the Wd-641. Verify
that the Wd-641 is vertical (actually, perpendicular to the main
longerons). Drill the bolt hole just over 1/4" for attaching the
Wd-643 to the Wd-641windscreen support. With the support bar in
place put a bolt in the hole. Verify again that the Wd-641 is
vertical, then drill one of the two holes #12 for the bolts that
will attach the Wd-643 plate to the F-6109 plate and F-6108 center
- Find the thinnest piece of aluminum strip you have that is no
more than about 1 1/2" wide and is as long as the distance between
the firewall and the plate on the Wd-643. This is to be made into
a template for cutting the piece of angle that will go between
the firewall and the Wd-643 plate as shown in drawing SC-2. Slide
this strip between the end of the F-6105 half and the center rib,
then trim its ends to be just like the angle must be; make sure
you have oriented it to take into account the one mounting hole
you have already drilled. Mark on the F-6105 bulkhead where it
must be cut out to allow the angle to pass through. Remove the
strip and use it to make the support angle. Cut out the F-6105
for the angle to pass through. The side of the angle that sticks
out is toward the bottom (one view on SC-2 shows it on top which
is incorrect). You do not need to cut out the flange part of the
F-6105 if you don't want to. Put everything back in place and
drill the support angle to the Wd-643 and the center rib and F-6109
plate in two places. Drill #30 the support angle to the firewall
- Remove the topskin and drill more holes as needed to secure the
F-6109 plate to the center rib; avoid areas where they would hit
the support angle or the Wd-643 plate.
Finishing Rear Top Skin and Canopy Decks for Sliding Canopy
- Place the steel canopy frame on the fuselage with the front end
almost touching the Wd-641 windscreen support. Place the C-677
channel pieces on the canopy deck located as shown in drawing
SC-1; the rear edge of the channel should be about even with the
point of the "V" made by the canopy frame rear hold-down pin and
the plate it is attached to. Mark the position of the forward
end of the C-677 channels on the canopy decks.
- Attach the rear top skin F-6112 (labelled incorrectly as F-674
in earlier drawings) with a few clecos and mark a line on the
inside of it that follows the curve of the rear edge of the canopy
frame. Set the canopy frame and windscreen support aside. Remove
and trim the canopy deck ends.
- Remove the rear top skin. Make a new line on it about two and
one-half inches to the rear of the one drawn along the canopy
frame except right at the ends. See drawing SC-1 which shows the
edge of the skin as trimmed with the funny little curve near the
main longerons. The skin should overhang the F-606 bulkhead along
the top of the fuselage by about one and one-half inches. Trim
the the skin along the new line. Save the piece that you cut out
as a template to give to fellow builders.
- Replace the rear top skin on the fuselage and drill the F-6111
stiffener channels to it. You will have to move the stiffeners
around to find the exact place where the web part matches the
curve of the skin, then bend the flanges in or out as required
to make them lay against the skin so they do not alter the natural
curve of it. Otherwise, you will have a tough time making the
canopy rear skirt close on the skin right. Dimple and rivet the
stiffeners to the skin.
- Rivet the rear top skin to the fuselage.
- Rivet together the forward structure (it may be easier to do this
on the bench instead of on the fuselage) including the three ribs,
the F-6105 bulkhead halves, and F-6109. Rivet the forward structure
to the fuselage and firewall. Rivet the canopy decks to the fuselage
and the forward structure.
- Put the Wd-641 windscreen support in place. Make the wedge-shaped
shims that go under the Wd-641 at the front bolts, making sure
that they are of the proper thickness that the Wd-641 is perpendicular
to the canopy decks. Put the bolts in to hold down the Wd-641
still using non-locking nuts.
Canopy Frame Mounting
- Assemble the canopy frame forward end rollers to the Wd-644 brackets.
The roller parts are found in bag #908; see drawing SC-1. The
smaller brass spacer may have to be forcibly pressed into the
larger one in a vise; the ends line up on one end. The screw is
a washer-head type, and the locknut is a thin type. Tighten the
nut firmly; if the roller does not rotate freely, shave a little
off the flat side so the screw head will squeeze only on the brass
spacers and not on the roller. Tape the roller assemblies to the
canopy frame for now; do not drill them.
- Cut the piece of canopy track extrusion material C-657 in half
and lay the pieces on the canopy decks. Mark and cut the tracks
to the same length as the canopy deck pieces. Set the canopy frame
in place with the tracks on the rollers; clamp the tracks in place
such that the canopy frame stays centered on the fuselage and
the rollers stay centered in the tracks as you move the canopy
backward and forward. Drill 11/64" the canopy tracks to the canopy
decks (for #8 screws). Secure the tracks to the decks with a couple
of screws and non-locking nuts.
- Look carefully at Detail B of SC-1and you will see a flap of the
rear topskin that is bent down starting at the forward edge of
the F-606 bulkhead. This flap is two inches wide and centered
on the fuselage (the gap where the flanges of the two bulkhead
halves meet). Slice the skin and bend it down as shown.
- The rear canopy track is made by drilling and riveting the C-662
strip and C-663 bar together. First place the bar on the topskin
as shown in SC-1 detail B. Modify the straight part if necessary
to make it lay flat against the skin. Bend the strip to match
the bar curvature. In the center of the bent-down part of the
strip at its forward end drill a hole for attaching the C-664
1/4" threaded rod. Drill and rivet the strip to the bar as shown.
Note that the bottom side of the bar is countersunk as well as
the top side of the strip. Put the rivets in from the top side.
- Drill the C-661 plastic block to the canopy frame 3/16". Note
that this block must pivot to some extent as the rear of the canopy
moves from an open to a closed postion; locate the holes carefully.
Put in a bolt to hold the block in place.
- Mark lines on the topskin sideways out from all the rivets that
are along the fuselage centerline.
- Put the canopy frame in place with the rollers in the tracks.
Slide the rear track into the rear block on the frame and tape
it to the fuselage positioned so that as the canopy frame moves
rearward it stays centered on the fuselage. Mark the position
on the track where the rear edge of the block sits when the canopy
frame is slid back to where the rollers come to the ends of the
canopy tracks. Cut off the rear track just aft of this point.
Drill the track to the fuselage 5/32" (for #6 screws) using the
previously-made rivet locator marks to avoid them. Countersink
these holes. Attach the track with the proper hardware; it will
not have to be removed later.
- Slide the canopy frame back and forth to make sure nothing binds
up at the rear.
- Drill a hole through the F-606 bulkhead for attaching the rear
end of the C-664 1/4" threaded rod; the hole does not have to
line up precisely with the hole in the track. Put the C-664 rod
in place but do not tighten the nuts. The three AD316-4 nuts called
out here may not be in your kit; you can either call Van's to
get them or find ordinary zinc-plated steel 1/4-28 nuts (may be
labelled as 1/4 FINE or 1/4 UNF) where a large selection of hardware
- Place the C-677 channels (in bag #908) at the rear ends of the
canopy tracks and drill them 3/16" or #12 to the canopy decks
as shown in drawing SC-2 detail A. Make sure you avoid existing
rivets and the flange of the bulkhead. Attach them securely with
the washer-head screws using non-locking nuts.
- Put the plastic blocks C-665 (in bag #908) in place in the channels
and drill the attachment holes 3/16" or #12. Make sure these holes
are out of the way of the opening you will be making for the canopy
frame pin (see drawing SC-1).
- Drilling the holes in the blocks for the canopy frame lockdown
pins properly requires a little thinking. When the canopy is completely
closed the outer edge of the frame should be 1/16" inboard of
the outside of the side skin; this allows for the thickness of
the canopy side skins which will be put on later. The canopy frame
is actually slightly wider than this at the rear, so it must be
pulled in by the pins engaging the blocks as the canopy closes.
It is also helpful in sealing the canopy edges if the canopy is
also pulled downward slightly as it closes. The holes in the block
are drilled at an odd angle; this angle is determined not by the
amount of pulling but by the angle of the locking pin on the canopy
frame. The angle of the locking pin with respect to the frame
is designed to provide the proper pulling action. In order for
the pulling actions to occur properly, the entrance of the holes
on the rear edges of the blocks must be located such that they
correspond with the desired position of the locking pin body when
the canopy is completely closed.
- Punch a hole in a piece of duct tape the same size as the canopy
frame locking pin. Slide the canopy frame all the way forward.
Hold the rear corner of the canopy frame slightly down and inward
as described above and attach the tape over the rear of the C-677
channel with the locking pin in the hole in the tape. Slide the
canopy out of the way and ecure the blocks to the channels with
screws (no nuts required). Mark the entrance hole using the hole
in the tape as a guide.
- Drill the C-665 blocks starting with a #30 and then enlarge the
hole with a drill that is just a little larger than the locking
pin. The angle of the hole in the block is not critical but should
match the angle of the locking pin. Slide the canopy frame forward
and file the rear edge of the block as necessary to accomodate
the plate that holds the locking pin and also the downward movement
of the pin as it is pulled by the block.
- Place the big brass bushing C-667 (in bag #908) on the shaft of
the Wd-642 latch handle as shown in drawing SC-1 section A-A'.
It may be necessary to file out the inside of the bushing slightly.
Attach the C-654 latch as shown. It may be necessary to file the
latch to allow it to fit completely over the bushing. Drill holes
for the spring and attach it.
- Slide the canopy latch assembly into the tube in the canopy frame.
Trim off the latch mounting tube on the inside of the canopy frame
just enough to allow the latch arm to swing into the the proper
position on the latch pin on the windscreen support frame.
- Put the canopy latch mechanism in place up as far as it will go.
Set the upper latch handle on the tube sticking out of the top
of the canopy, leaving just enough space for the C-671 plastic
ring to fit between the handle and the top of the canopy frame
tube (this is the rain seal). With the latch in the closed position
turn the handle so it is pointing rearward and drill the latch
tube through the hole in the handle. Remove the latch, drill out
the latch tube big enough to accomodate a #8 screw, and tap the
handle for a #8 screw (you will probably have to drill the handle
to about #24 for this). Countersink the hole in the handle. Do
not install the handle at this time.
- Leave the latch closed for fitting the canopy.
Fitting the Canopy and Windscreen to the Frame and Fuselage
- The following instructions are for more recent canopies sold by
Van's; earlier canopies may require slightly different techniques
in the early stages of trimming.
- Put a piece of duct tape over the top of the latch tube that sticks
out of the canopy frame to keep it from scratching the canopy.
Put masking tape over the surfaces of the canopy frame and the
windshield frame everywhere the canopy will touch them; do not
push the tape down hard; lay it on lightly.
Initial Canopy Placement and Drilling to Windscreen Frame
- Trim off all parts of the canopy related to its support during
the molding process; that is, everything that you know will not
be there in the end. Use the abrasive cutoff wheels supplied in
the kit (bag 908) for this. The best tool to drive the cutoff
wheel is a drill that will run about 800 to 1200 RPM and is variable
speed. A die grinder doesn't have enough power. Push down with
moderate pressure and move the tool fast enough that you only
cut about one-third of the way through in each pass. If you lay
a strip of masking tape with its edge along the cut line for the
final trim you will be able to make a straighter cut. Always move
in the direction that the cutting wheel pulls you; if you are
cutting the other way when the wheel cuts all the way through
it will be pulled down into the slot and this may cause trouble.
Be especially careful in making the last pass in areas where the
cut line is curved; the wheel will bind up and try to jump out
of the groove.
- The canopy needs to be located at the right fore-aft position
so that it touches the canopy frame (Wd-640) and windscreen frame
(Wd-641) at all points except possibly at some points along the
front bow of the canopy frame. (The front bow of the canopy frame
and the windscreen frame may not have quite the same curve so
you fit to the windscreen frame and later put shims in as required
between the canopy and the canopy frame front bow.) As the canopy
comes from the factory it sits much too high off the frame to
be able to determine the right fore-aft position. The canopy latch
rod will at some point in the process get in the way by holding
the canopy off the frame, but by the time you have reached that
point you should be able to determine the correct canopy position
so the hole for the latch tube can be drilled in the canopy. To
accomplish proper fitting you must trim the canopy a little at
a time, mostly at the front, slowly bringing the canopy down and
always rechecking the fore-aft position. Move it forward and backward
until the curve of the top of the canopy seems to match that of
the top fore-aft bar in the canopy frame. When the canopy is close
enough to the frame that you can tell it is correctly positioned,
cut off the rear of the canopy about 1" aft of the canopy frame
rear bow. When the canopy gets so low it hits the top of the latch
tube, carefully center it by seeing how the front of it sits on
the forward top skin and how the rear sits on the canopy frame
rear bow, then drill the hole for the latch tube to go through
the canopy. Before trimming further you must pull in the sides
of the canopy so they touch the canopy frame side bars. This is
necessary to make the front fit correctly (as you pull in the
sides the front changes shape). You will have to trim off the
sides of the canopy about even with the center of the canopy frame
side bars in order to put clamps on. Keep trimming the front until
the canopy sits on the windscreen frame and the canopy frame top
fore-aft bar, and does not quite touch the forward top skin.
- Push the canopy down on the windscreen frame and canopy frame;
as you do you will see the masking tape turn darker right where
the canopy touches it. This marks the line you want to drill on,
as it will be centered on the tubes. If there is any point where
this mark is not made on the windscreen bow because the canopy
frame front bow sits higher than the windscreen frame, file down
one or both ends of the canopy frame front bow where the roller
brackets go so it will sit lower. Tape the canopy in place at
the front and drill it #40 to the windscreen frame, starting at
the top and working down on both sides.
Final Front Roller Adjustment and Drilling to Canopy Frame Front
- Try pushing up on the canopy frame from inside; if it will go
up some before it contacts the canopy at the top, hold the roller
bracket down while pushing up on the frame and fill the resulting
gap between the bracket and tube end by wrapping a turn of wire
of the proper gauge around the roller bracket tube.
- Drill #40 the canopy to the canopy frame front bow. Be careful
to center these holes on the tube and to make them perpendicular
to the canopy surface where you don't have a mark on the masking
tape to go by.
- Make shims about 1/2" square with #30 holes in the center as required
to fill any gap between the canopy and the canopy frame. Label
the shims to correspond to their proper locations. A quick way
to do this is to make a bunch of small strips of thin aluminum
and record how many srips are required at each location to fill
the gap. Then make all the real shims later using the number of
strips as a measurement guide. I thought about trying to modify
the shape of the canopy frame front bar so it would more closely
match that of the windscreen frame but did not try it. Another
builder told me he tried but found the bar was too hard to bend.
Drilling to Canopy Frame Top Bar
Refer to drawing SC-1 section C-C' for the attachment of the canopy
to the top of the canopy frame. Mark a line down the center of
the C-653 and C-678 aluminum strips. Make some marks on the canopy
so you can place the C-653 strip exactly centered on the canopy
frame fore-aft tube. Drill #40 through the C-653 strip, the canopy,
and the canopy frame tube. Remove the C-653 strip and use it as
a guide to drill the C-678 strip. Cleco the top strip and the
canopy to the canopy frame; set the inside strip aside for now.
Cutting the Canopy Away from the Windscreen
Make this cut approximately halfway between the windscreen support
bow and the canopy front bow tube. You can remove some of the
clecoes holding the canopy to the windscreen frame for this operation.
When you make the cut, do not cut all the way through at the bottom
and right at the top until you have cut through everywhere else;
this will hold the two sides together so they won't bind up on
the cutting wheel. Replace the clecoes in the windscreen frame.
Making Side Skirts
- Clamp the rear of the canopy to the rear bow of the canopy frame
Starting at the top and working down, making sure the canopy makes
good contact with the tube along its length. Make sure you have
good marks in the masking tape for the center of the canopy frame
side tubes, then trim off the sides of the canopy even with the
tops of the canopy frame side bars. Make a mark along the center
of the dark mark in the masking tape.
- Using a straightedge make marks on the forward top skin and the
aft top skin that correspond to the center of the canopy frame
side tubes and to the top of the canopy deck. Also verify that
the side tube does not bow up or down; if it does, note by how
much at the center. Lay a strip of masking tape on the canopy
extending up from the bottom edge by about 1". On this strip make
a series of marks exactly one inch above the center of the canopy
frame tube. Cut off the joggled part of the inside side skirt
C-659 at and beyond where it would hit the upright bows of the
canopy frame. Also cut off just enough of the main part of the
skirt aft of the rear bow to clear the aft top skin. File off
any welding bead along the side of the canopy frame that would
keep the skirt from laying flat on it. Put it in place as shown
in SC-1 (Canopy Rivet Detail) and SC-2 detail A. Using the marks
on the top skins mark the centerline of the rivet holes for attaching
the skirt to the canopy frame side tube. Verify the location of
this centerline using the marks on the masking tape. This line
must bend if the tube was bowed up or down. Mark the location
of the rivet holes. Remove the skirt and drill #40 the rivet holes.
These holes must be centered on the tubes precisely or the canopy
skirt will lean in or out and not line up with the fuselage side
skin; if you do have a problem with this you can "move" the holes
a little as you drill them out to final size later.
- Lay the drilled side skirt on top of the C-660 outside side skirt
with one edge of the C-660 even with the edge of the C-659 nearest
the joggle. Drill #40 the C-660 through the C-659. Also drill
#41 the line of holes for the rivets that hold the inner and outer
skirts together at the bottom; the rearmost hole of this line
should be at least two inches forward of the end of the side tube.
Cut off the rear end of the outside skirt so it will not overlap
the aft top skin.
- Put just the C-659 inside side skirt in place with the mark on
the side tube visible through the holes in the skirt. Carefully
drill the side skirt to the tube, making sure the drill does not
wander and take the side skirt with it. Remove the skirt, cleco
the outer skirt to it just at the center, and cleco this assembly
to the side tube just at the center. Working from the center outward,
cleco the assembly to the tube and redrill through the holes so
the clecoes will go in easily (This is necessary because you drilled
the outside skirt with it flat but the relationship of the holes
between skirts shifts as you bent them to fit the canopy frame
tubes.) This should result in a nice even curve of the skirt.
- Drill #40 the side skirts to the canopy. With clecos in these
holes the side skirts will probably swing out at the bottom and
not align with the fuselage sides anymore. This is because the
canopy side is not exactly vertical where the skirts attach. This
will be fixed later. Put in place the thick plastic strip that
the canopy attachment screws go into. This is labelled C-652 in
earlier drawings and manuals but is later kits use C-624 for this.
Drill this through the holes in the skirts and canopy.
- Mark a line on the outside skirt so you can trim it even with
the top of the canopy deck and just forward of the aft top skin.
You can also trim the skirt so that it overlaps the side skin
a little in order to give a better seal; not that in order for
the canopy to slide open you cannot have this overlap in the forward
few inches of the skirt. Remove the skirts and trim. Put them
Fitting the Canopy Rear Skirt
- Remove the clamps holding the rear of the canopy to the canopy
frame. The clecos in the side skirts must hold the canopy in place
against the frame rear bow or very nearly so. If not, you must
use heavy tape secured to the frame, not the fuselage, to achieve
- Make a 4" long straightedge out of scrap. Hold this with the forward
end even with the center of the canopy frame rear bow and the
rear end straight behind against the aft top skin. If at any point
the straightedge ENDS cannot touch the canopy and the skin at
the same time, fix it so they will. This may require trimming
more off the rear edge of the canopy or adjusting the position
of the nuts holding the end of the rear track to the fuselage.
- Cut out the C-666 rear skirt halves using the pattern already
marked on the aluminum sheet. Deburr the edges.
- Apply masking tape to the canopy at the rear, starting just forward
of the center of the canopy frame bow center and extending forward
from there by about three inches. Make a series of marks on this
tape at 1/2" forward of the center of the tube center and 2" forward
of the tube center.
- Raise the rear of the canopy frame at the rear by about 1/8" by
loosening the rear holddown block bolts and sliding shims under
the blocks. This will allow you to get a tighter final fit of
the rear skirt to the aft topskin when the canopy is closed.
- Lay a rear skirt piece on the canopy and fuselage. Bend it to
make it fit without requiring significant force to hold it down.
This cannot be done by brute force. The bending must be along
a diagonal rather than straight across the skirt, that is, bend
and twist at the same time so that the skirt will lay down on
both the canopy and the skin as it curves down and forward. Bend
just a little at a time so as not to develop waves in the skirt.
Neither the front nor the rear edge of the skirt will line up
properly with the canopy frame or the aft skin; just make sure
the skin front edge does not completely uncover any of the marks
that are 1/2" forward of the canopy frame tube. The skirt will
probably overlap both the fuselage centerline at the top and the
side skirt at the bottom in the best-fitting position. Start at
the top; when the first third is properly curved tape it to the
aft skin at the top and pull down and forward on the bottom edge
to see how the rest will fit; pull down to make it conform to
the canopy and pull forward to make it conform to the aft skin.
Recheck the position and shift it if necessary. Then remove, bend
some more, and repeat.
- When the skirt is bent enough that it will stay in place when
taped down, mark a cut line on it that is 1/2" forward of the
canopy frame tube using the marks you have on the masking tape
for reference. Also mark the fuselage centerline at the top and
an area to notch out to clear the canopy rear track. Remove the
skirt and trim it. Replace it and tape it down securely. Using
the marks on the tape for reference drill #40 the skirt to the
canopy and canopy frame starting at the top. Use 2" spacing; earlier
drawings show 3" on one view. Drill the rear skirt to the side
skirts by continuing the lower line of holes in the side skirts
rearward, making sure none of the holes will hidden behind the
canopy frame rear pin support plates where you won't be able to
buck rivets later.
- Mark a line on the bottom edge even with the bottom edge of the
side skirt. Make a mark on the side skirt at the forward edge
of the rear skirt. Note whether there is a slight bulge in the
skirts where the side tube and the rear bow of the canopy frame
join; if so this will be fixed later. Remove the skirt and trim
the bottom edge.
- Make the skirt for the other side in the same way, except after
you drill it cleco the first skirt on top of it and mark the top
end of the first skirt onto the second. Remove the rear skirts.
Trim the second skirt along the line.
- Reattach the rear skirts at least at the top. Make a cover for
the area at the top where you notched out the skirts to clear
the rear canopy track. It should be about three inches wide and
should extend rearward of the rear of the skirts enough to insure
that rain will not come in. Joggle it in such a way that it is
flat at the front but a channel develops going rearward that is
just high and wide enough at the back to clear the track. It will
be very difficult to make the required bends in aircraft aluminum
alloy unless you have a press brake, so get some soft aluminum
about 0.016 thick (flashing material or the stuff they make the
walls out of for outdoor aluminum room enclosures). Cut out a
rectangle 3 1/2" wide and about 1" longer than the width of the
rear skirt at the top. Mark two parallel lines 1" apart down the
middle (long way). Make another line outside of each, meeting
the other line at one end and 5/16" away at the other. Bend more
than 90 degrees along the inner lines to make a channel, then
bend out along the other lines so you wind up with a hat section
at one end an a flat surface at the other. Trim to suit your eye.
Drill it #41 to the skirt halves in the area between the plexiglass
and the rear topskin. Remove this item and the rear skirt halves.
If the track cover also covered up holes for attaching the rear
skirt and canopy to the canopy frame, back drill the cover through
the side skirts.
Completing the Canopy Assembly
- Enlarge to #30 and countersink the holes in the side skirt that
are for attaching them to the canopy frame tubes.
- Enlarge the holes in the rear skirts to #30 except the ones that
are for joining them only to the side skirts and to the rear track
cover plate. If the rear track cover plate covered up one of the
holes for attaching the rear skirt to the canopy frame, cleco
the cover to the skirt and drill it through the skirt. Enlarge
the holes in the canopy frame.
- Remove the side skirts and the top strip. If you had a bulge in
the side and rear skirts due to the canopy frame rear bow, mark
on the canopy where it hits the rear bow, remove the canopy, and
grind out a depression about 1 1/2" long and about as deep as
the bulge was so the canopy material won't push the skirts out.
Round the edges of the skirts and top strip where they lay against
the plexiglass. Bevel the underside of the rear of the rear skirts
and so they won't dig into the paint on the aft topskin.
- Dimple the lower and upper row of holes in the side skirts, all
of the holes in the rear skirts and the rear canopy track cover,
and the holes in the top strip. Countersink all of the holes in
- It is easier to paint the canopy skirts and top strips on their
inside surfaces with the finish color now before you attach them
to the plexiglass. The canopy frame, canopy latch mechanism, windscreen
frame, and windscreen support bar should also be painted now.
In fact, this is really the best time to paint the whole inside.
Then you won't have trouble getting paint into corners and you
won't have to mask anything. For best results remove the canopy
tracks and rear brackets for painting.
- Make sure the canopy frame roller brackets are oriented in the
frame so the rollers will roll straight. Clamp the tube tightly
so it squeezes on the roller braket. Drill #12 the canopy frame
to the roller bracket. Attach the roller brackets to the frame
with the proper hardware.
- Install the canopy tracks and the windscreen frame with the correct
hardware. Set the canopy frame in the tracks and put in the bolt
to hold the rear slider block (no nut needed now). Install the
rear blocks at the end of the tracks. Leave the frame back a few
inches rather than in the closed position. Set the canopy in position
on the frame.
- Rivet the rear skirt halves together with the rear track cover;
this should be at least partially done with a couple of clecoes
holding each rear skin to the canopy and frame so that the rear
skirt assembly will fit later. Remove the rear skirt assembly.
- Cleco the outer side skirts to the canopy just well enough that
you can lay a strip of masking tape on the canopy even with the
top of the skirt. Cleco on the rear skirts and do the same. Remove
the skirts. Lay a fairly thick bead of clear RTV or regular aircraft
windshield sealant on the inside of a side skirt right at the
top (don't go below the line of holes). Cleco the skirt to the
canopy only, using a cleco in every hole. Do the other skirt.
Lay a bead of sealer along the leading edge of the rear skirt
assembly and put it in place with a cleco in every hole including
the ones that attach it to the side skirts.
- After the sealer has set up, remove the clecoes holding the side
skirts and carefully put the inside part of the side skirts in
place. Put clecos in the holes through the canopy first to avoid
loosening the canopy to skirt seal. Rivet the bottom row of holes
that hold the inner skirt to the outer one and also to the rear
skirt. You can loosen clecoes that hold the canopy to the frame
if necesssary to reach all of these rivets.
- Cleco the side skirts to the canopy frame and close the canopy.
If the bottom of the skirt lines up with the fuselage side skin
you can rivet it to the canopy frame now. If not, you will have
to force the canopy into the right alignment with some kind of
hardening filler such as Bondo between the skirt and the canopy
frame so that when the filler hardens the skirt will keep its
- Put the top strips in place and rivet the canopy top to the canopy
frame. Rivet the rear skirt and canopy to the canopy frame. Rivet
the front of the canopy to the canopy frame with the shims. The
rivets supplied with the kit for this may be either too long or
too short. In some cases the remainder of the mandrel may protrude
out from the head of the rivet and it must be cut off with a cutoff
wheel. In the area where you had to use shims at the front bow
of the canopy frame, make sure the rivet grips properly; it won't
if the shim had to be more than about 3/32" thick. You must obtain
longer grip length rivets for these locations.
- Seal around the hole in the canopy with RTV and assemble the latch
mechanism to the frame. You may want to use a rubber O-ring rather
than the plastic washer supplied in order to get a better seal
between the handle and the tube.
- Verify that the canopy will open freely; the shop heads of some
of the rivets you just put in may hit the rear topskin. Trim and/or
bend the topskin as required.
Completing the Forward Topskin
- Notch the forward top skin approximately as shown in drawing SC-2
and put the windscreen in the slot. Mark the skin for trimming
aft of the slot so it will overlap the canopy by about 3/4".
- Drill the skin #30 to the fuselage in any areas where you did
not go previously, such as in the area aft of the notch.
- Remove the skin and trim. Also round off the sharp corner forward
of the notch to a radius of about 1"and bevel the outside edge
of the section of skin where it will lay against the outside of
the windscreen. Dimple the skin as required. Countersink any remaining
holes in the fuselage. Replace the skin.
- If you plan to install a lighted compass on the stainless steel
windscreen support bar, drill a hole in the skin for a pair of
wires to go up through the bar and put a grommet in it. You will
also need to drill a hole in the bar for the wires to exit. Note
that the windscreen bow is an aircraft alloy steel and can cause
errors if the compass is too close to the top of the support bar.
While the compass can be compensated for this to some extent you
might end up wanting to move it down on the bar a little; keep
this in mind when drilling the hole for the wires. About 6" down
the bar is a good location.
- Install the windscreen support bar with the proper hardware (put
the compass light wires in it first, making sure the wires are
tightly twisted together for the upper eight inches so they will
not create a magnetic field that interferes with compass operation).
- You can rivet the topskin to the fuselage except along the firewall
flanges now but it is not essential for finishing the windscreen.
If you have already riveted on the forward bottom skin you should
seriously consider not riveting on the topskin at this time because
there is still a lot to be done under it.
Finishing the Windscreen
- The procedure for finishing the windscreen in the construction
manual is straightforward and calls for attaching it permanently
with made-in-place fiberglass-epoxy trim. I decided to see if
I could make the windscreen more removable so that the fiberglass
work would not have to be redone if the windscreen ever had to
be replaced. I was also worried about rain getting in where the
canopy meets the windscreen. The following procedure is the result.
For those who hate fiberglass work it is a little easier.
- If necessary trim the lower edge of the windscreen so it does
not quite touch the forward topskin. There should not be any large
gaps however as that make finishing harder. Finish the rear edge
so it is straight and does not have cutmarks in it. It should
be a smooth edge or rain leaks will occur. The gap between the
windscreen and canopy edges should be consistent. You can gauge
the straightness better by filing it while it is still attached
to the windscreen bow.
- If you want to make the windscreen removable make a hold-down
bracket for the front of the windscreen. This is not shown in
the plans because in normal construction the windscreen is simply
bonded to the fuselage with adhesive. It is a strip of 0.032"
aluminum about 1 1/4" wide and 6" long, bent up about 30 degrees
along a line 1/2" from one side. This is slipped under the windscreen
at center with the smaller side against the topskin and the larger
side against the back side of the windscreen. Drill it to the
topskin, drill the winscreen to it in two places near the ends,
mount platenuts on it at the two windscreen holes, and rivet it
to the topskin. Put temporary screws in to hold the windscreen
in place at this bracket. Additional shorter brackets can be placed
at various points along the topskin but these are not necessary
if you use a strong sealing compound when you mount the windscreen.
- Van's manual calls for making a molded-in-place fiberglass strip
to overhang the windscreen at the rear by 1/4 to 1/2". This covers
up the gap to provide smooth airflow and hold down the canopy
front but by itself will not seal out rain. It also presents the
risk of serious finger shortening if you aren't careful closing
the canopy. The latch seems to do a good job of holding the canopy
down. You will need to have a thin strip of rubber in the gap
between the windscreen and canopy anyway, so you could just make
the strip overhang by just enough to cover this. Do not try to
get by without this strip; if you install flush-head screws directly
into plexiglass it will soon crack at the holes from the lateral
stress caused by tightening the screws.
- Instead of making the gap cover strip out of fiberglass, you can
easily make it out of aluminum instead. Remove the clecoes on
one side of the windscreen, including the one in the center. Drill
#30 through two or three of the holes for screws that will hold
the windscreen to the bow on that side. Countersink the windscreen
at the enlarged holes and put in #6 flathead screws. If you use
throwaway screws (you can force them in but it tears up the threads)
you won't have to tap the holes.
- Make a heavy paper pattern first. Cut a strip about 6" wide and
long enough to reach from below the forward topskin lower edge
to past the center of the windscreen at the top. Tape it at the
lower end and then force it down on the windscreen at the trailing
edge. Mark it along the underside at the edge of the windscreen.
Remove the pattern and trim it so it is a curved strip about 2"
wide. Mark this onto a piece of 0.032 aluminum and cut out the
strip. Smooth the edges of the strip and and lay some tape on
the windscreen to avoid scratches. Verify that the strip fits
like you want.
- Since it would be difficult to find and reuse the holes already
drilled in the windscreen, we will mark their positions on the
trailing edge of the windscreen and drill new ones that avoid
the old ones. You also need to record how far back from the windscreen
edge each hole is.
- Starting at the lower end force the strip onto the windscreen
so that it lays flat and overhangs the edge of the windscreen
by the amount you want plus about 1/2" extra. Drill new holes
#40 starting just above the forward topskin edge and continuing
around to near the center. Also drill a hole that will hold the
top edge of the forward topskin and the windscreen to the bow.
Be very careful to drill these holes perpendicular to the strip
surface. Mark the windscreen center on that end of the strip,
the top edge of the forward topskin on the other end, and the
edge of the windscreen on the underside of the strip. Remove the
strip and trim the ends. Trim the long edge leaving an overhang
of 1/8 to 1/4" or whatever your choice is based on the previous
discussion of this.
- Drill out the holes in the strips and the one in the top of the
forward topskin to #30, dimple them, then drill them out more
if necessary to allow a #6 screw to go through.
- Make the strip for the other side in the same manner.
- Remove the windscreen. Drill the new holes in the windscreen to
allow a #6 screw to go through. Countersink these holes.
- Drill the holes in the windscreen support bow to #36 and tap these
holes 6-32. Be very careful here; the tap will tend to bind up
in this hard steel and break unless you hold it aligned exactly
with the hole. You should also work the tap in and out, advancing
in very small steps.
- Bevel the front edge of the strips and round the rear edge. Set
the strips aside for now.
- The fairing around the front of the windscreen can be made partly
or completely out of aluminum. The part that starts at the rear
edge and goes about 12" forward does not need to have a compound
curve so it can easily be made of aluminum. The area covered here
is fairly large and in fiberglass represents a lot of labor. The
rest of the fairing around the front of the windscreen would normally
have a considerable compound curve to it so would be harder to
make out of aluminum without a metal shrinker. It can be done
without this if you are patient and use pure soft aluminum such
as roof flashing material rather than an aircraft alloy. If you
can make the strip narrow and thin enough you will be able to
force it to conform the the windscreen curve without buckling
due to the windscreen-to-topskin bend. One builder says he even
left the strip flat and it still looked good. On the other hand,
this area is fairly easy to do in fiberglass. If you plan to make
the windscreen removable and want to do part or all of the fairing
in fiberglass, apply masking tape to the windscreen and wax it
where the resin will touch it. If you do this you can use polyester
resin instead of epoxy since the resin will not touch the plexiglass.
You can finish installing the windscreen now, but if you plan
to put in defrost ducts or make some kind of dashboard cover you
should leave the windscreen out until that is done.
Windscreen Defrost Suggestion
- No provision is made in the kit for windscreen defrost. You should
consider making this based on your own experiences and flying
plans. Here is one way to do it if you have the sliding canopy.
There is very limited space behind the instrument panel for defrost
ductwork; it is so tight that for some instruments you may have
to punch a clearance hole in the bulkhead behind the panel.
- Cut 2" diameter holes in the F-6105 bulkhead (the one behind the
instrument panel) about 1" below the topskin and 1" to the outside
of each F-6107 rib. Buy two of the 2" duct flanges from Vans (part
number VENT DL-03) or make your own and drill them to the forward
side of the F-6105 bulkhead at the holes.
- Make a wedge-shaped plenum to go aft of the bulkhead to direct
the air from the hole in the bulkhead to a hole in the topskin
(not made yet). This plenum should be about 5 1/2" wide, 5 1/2"
from front to back, and about 2 1/2" high at the forward edge.
Make a template out of stiff cardboard first, then when you transfer
it to aluminum add tabs all the way around. Bend this up and drill
it to the topskin, the rib, and the bulkhead.
- Use the holes you drilled in the topskin as a guide to make an
air opening in it. This hole should be about 4" long and about
1" wide. Make a screen for the hole to keep things from falling
in an rivet it in place. Rivet in the wedge and the tube flange.
- The rest of this is left to the builder to connect. You can now
install the windscreen if you desire.
Cowling Mounting Hinges
- Measure the thickness of your cowling to determine how thick the
spacers under the hinge sections should be. The drawing calls
out 0.032 material for the spacers but a thicker one is likely
to be needed, especially across the top, so that you don't have
to shave down the cowling to get a smooth skin line. See drawing
- Drill the 17" long heavy hinges to the firewall sides including
the spacer material as shown in sections D-D' and E-E'. Use the
piece of hinge material that is just over 34" long for these.
Verify that the side skins completely covers the spacer and the
firewall side pieces; if not, trim them carefully making sure
you do not cut into the side skins (the straight edge of the side
skins makes it easier to trim the cowling to fit). Rivet these
on and the remainder of the side skin to the firewall, but leave
out about two at the bottom so you will be able to get the forward
bottom skin on later.
- After riveting, check the lay of the skin line in this area to
make sure it is satisfactory to you; the angle of the flanges
on the firewall sides is normally not quite right but it tends
to improve after riveting. If you want to make it straighter make
a heavy wooden block to fit inside the flange, notched to clear
the hinge eyes, and beat on the skin side (protected with a smaller
- Make the hinges and shims that will support the cowling top as
shown in drawing #31. Make sure the gap at the top is on the right
side of the aircraft (or on the side where the oil dipstick access
door will be for the engine you plan to use). Rivet on the hinges
and spacers to the topskin and firewall. Hold the mating hinge
sections up to these; note that because of the bow in the hinge
you will have to file the hinge eyes to make the hinge sections
fit together easily. You will also have to flute the cowling hinge
to make it not stick up the wrong way.
- Make the short hinge sections that go on the bottom of the firewall.
Note that the bottom skin is thicker than the side and top skins
so the shim required under the hinge may not need to be as thick
as the others. Do not rivet these on.
Mounting the Engine Mount
- Sometimes the engine mount you get will not line up exacly with
the holes in the firewall. Most of the time the error is not great
enough to cause any trouble. There is a fair amount of flex possible
in the upper two mounting points but not in the bottom. For this
reason the process of enlarging the bolt holes starts at the bottom.
- Have an assistant hold the engine mount up to the firewall and
see if the two bottom holes can be lined up almost exactly with
the holes in the firewall. If so, drill out one of the holes to
3/8", put a bolt in to hold that point, and drill the other hole
through the engine mount to get perfect alignment. If there is
considerable misalignment you will first have to file one or both
of the holes in the direction that will produce better alignment
so that the drilling operation will not tear up the engine mount.
Put a bolt in the new hole.
- Drill the other two bottom holes through the engine mount by first
drilling a smaller pilot hole. You will find a piece of 3/8" outside
diameter tubing in the kit that you can insert in the engine mount
hole to use as a guide for a smaller drill bit. The drill out
the holes to 3/8".
- Verify that the upper engine mount holes line up with the holes
in the firewall. If they don't, file them out so they line up
better. Drill the upper two holes to 3/8".
- Install the six bolts and tighten them. Do not put in the cotter
keys. Normally the bolts would be put in from the cockpit side
so you can tighten the nuts more easily; if you expect to remove
the engine mount later and are by yourself it will be easier to
get the mount on installing the bolts from the engine mount side.
Sequence of Engine Mounting/Cowling Fitting/ Bottom Skin Riveting
You will need to mount the engine in order to make the cowling
and to do everything else in the engine compartment and firewall.
You will probably want to leave the forward bottom skin off for
a while to do the instruments and engine hookups but you need
the skin mounted at least temporarily to fit the bottom cowling.
You can't drive some of the bottom skin to cowling hinge rivets
with the engine mount in place unless you use pop rivets in a
few places (depending on how skinny your squeezer or bucking bar
is). The engine is hard to get mounted on a Dynafocal motor mount
but it is easy to get the motor mount lined up with the firewall.
The following is a brief description of the order in which these
instructions go. You should consider changing the order if it
does not fit your long-range plans or if you don't mind using
pop rivets. If you already have the bottom skin riveted on but
not the top skin, this is not a concern because the motor mount
does not interfere with riveting the top skin. The considerations
might include how you plan to transport the finished fuselage
to the airport. When you have reached this point nothing is made
extremely difficult or impossible by having the forward bottom
skin riveted on.
- Mount the engine more or less permanently to the motor mount.
- Cleco on the forward bottom skin.
- Trim the top and bottom cowling to fit.
- Cleco the cowling bottom-attach hinge halves to the firewall.
- Finish the cowling and leave it off.
- Remove the bottom skin.
- Finish the engine hookup and instruments.
- Remove the engine by removing the motor mount to firewall bolts.
- Rivet on the forward bottom skin and hinge.
- Remount the engine/motor mount assembly permanently.
Mounting the Engine
- Engine mounting is adequately described in the construction manual.
Use the right hardware so that the holes in the bolts line up
with the slots in the nuts. The exact number and type of big washers
to use is determined partly by the motor mount design, so look
in the construction manual for this rather than in the sheet that
comes with the rubber shock vibration absorbers. As of this date
there is a washer between the engine and the rubber mount on the
bottom bolts but not on the top. You can put in the cotter keys
now but you might as well wait just in case you need to readjust
the hardware. If so, put tape at the bolts so you won't forget
before you fly. Some builders have reported that after the engine
was run for a little while (a few minutes to a couple of hours)
the rubber mounts would compress and allow the engine front to
sag by about 1/8"and not line up with the cowling any more. Not
all builders have seen this. Either you find some way to run the
engine for a while before fitting the cowling or you plan to fix
it by either adding another washer later on the bottom (the bolt
is long enough) or you leave off the extra large washer on the
bottom mount while fitting the cowling then add it back in later.
- If you are building a -6A you will need to provide some means
to prevent the fuselage from falling on its nose when you mount
the engine. You will also need to have the nose gear leg in place
to finish the cowling on the -6A. To solve both problems, put
the nose gear leg in place in the motor mount but twist it upside
down (the bottom end pointing up), with some blocks of wood under
the end. On the -6 you may need to add some weight or a tiedown
to the tail; any brace you put under the engine would be in the
way of cowl fitting.
Carburetor Air Box (first steps)
- The carburetor airbox needs to be made and mounted to the engine
before the cowling air scoop can be fabricated and attached. Van's
sells kits for airboxes for different engines (the O-360 is larger).
- The air box and the air scoop on the cowling must be aligned and
built together. For now, attach the VA-131-C mount plate to the
carburetor and cut out an opening to clear the carburetor drain
structure if necessary with your carburetor. You may also find
it necessary to make a gasket to go between the carburetor and
the mount plate so the plate will sit flat and not hit some built-up
areas on the carburetor. Do not bother to cut the nose off the
airbox at this time as the directions say. Remove the mount plate.
Tape the mount plate to the VA-131-B top plate with the 5 degree
angle as described (this is because the carburetor on the O-360
is located about 1" to the left of the engine centerline).
- If you are building an RV-6A, attach the mount plate/top plate
assembly to the carburetor. Make a cutout in the rear of the air
box so that the box will not come closer than about 1/2" to the
nose gear leg when fitted onto the top plate. The rest of the
air box is finished later.
Mounting the Cowling
- The instructions for making the cowling in the construction manual
section 12 are fairly complete but not in the right order (things
you need at the beginning are found at the end). Read that whole
section before starting. There is a separate article from the
RVator (Cowling Installation: Making that Other Material Work")
which describes how to use heat to get the distortion out of the
front of the cowling sections. Do this first. It is not necessary
that you get it perfect at first; you will go back and tweak it
later. To quickly understand the nature of the distortion, tape
the top and bottom halves of the cowling together and set this
assembly nose-up on the floor. Place the spinner rear bulkhead
on top and note that it doesn't lay flat. You must reach inside
and squeeze the ends of the air inlet ducts together to force
the front surfaces into alignment while applying heat. You will
find it useful to place a 1500 watt room heater on the floor inside
this assembly to help provide heat since hair dryers do not work
very well on the white outer surface. While you have the top and
bottom sections taped together and the spinner bulkhead laying
on them note about how much you will be able to trim the cowling
edges where the top and bottom meet so that you will have a perfect
circle at the front.
- If you have the right cowling for the propeller and extension
you plan to use, you will only have to trim an inch more or less
at the rear of the cowling. The rear spinner bulkhead is used
as the reference for the location of the front of the cowling.
For a fixed-pitch prop mount your prop extension on the starter
gear ring and mount the spinner bulkhead on the extension. If
you are going to mount a compact-hub constant-speed propeller
(like Van's sells) the rear spinner bulkhead mounts on the propeller
rather than behind it. Since it is easier to work on the cowling
without the prop in place, make a spacer block out of wood that
is 2" thick. This comes from how far forward of the starter ring
gear front surface that the FRONT surface of the rear spinner
bulkhead sits on the compact-hub constant-speed prop (2 1/4")
and the thickness of the spinner bulkhead. Here you mount the
rear spinner bulkhead REAR surface on this block to help you fit
- Carefully mark a trim reference line 1 1/2" back from the front
edge of the side and top skins.
- During the trimming process it is very important to have the cowling
fixed firmly in the proper position and you must be able to take
it off and get it back on in exactly the same position. To get
the top cowling aligned properly for trimming first make horizontal
marks 2" long on the side skins 17 3/4" up from the bottom of
the firewall as mentioned in the manual. Tape the spinner bulkhead
to the starter or engine block so it cannot rotate. Stick some
foam rubber or wadded-up newspaper on top of the engine to hold
the cowling front about the right level until you can clamp it
to the bulkhead.
- Put the top cowling in place and clamp it directly to the spinner
bulkhead (the bulkhead is already about 1/8-inch rearward of its
normal position if mounted on the propeller). Make sure the front
of the cowling is level by measuring up from the floor to points
on both sides; if you try to do this just by looking at the front
you may be fooled because the engine doesn't look the same on
both sides. Make marks on the spinner bulkhead and the cowling
so you can later get the cowling back on in the exact same position.
Make sure the cowling bottom edges overlap the marks you made
on the sides an equal amount on both sides. Mark the rear trim
line on the cowling using the reference marks on the side and
top skins as a starting point. Remove the cowling and and cut
along your line, preferably using the cutting disk supplied with
the kit for cutting the canopy. Put the cowling back in place
and clamp it to the spinner bulkhead. Make a reference mark at
the center of the rear of the cowling onto the top skin so you
can easily get it back in the right position. You can now trim
the rear edge of the cowling for a perfect fit. The side of the
cutting disk works well for this but don't push too hard and break
the disk. It helps to tape one side to secure it while you trim
on the other side. As you trim the high spots you can add spacers
between the spinner bulkhead and the cowling. You should wind
up with about 1/8" spacing between the cowling and the spinner
bulkhead; with the propeller installed the gap will be somewhere
between 3/16 and 1/4".
- Grind off the inside of the rear of the cowling to make the thickness
the same in the area where the hinges will attach. Attach the
cowling half hinges to the firewall half hinges with a piece of
.095" hinge pin (smaller than the pin that came with those hinges).
Make sure the hinges are fluted enough in the curved part that
they won't hold up the cowling. Lay the cowling in place and verify
that the outer surface aligns with the top and side skin surfaces.
If not, grind some more; you can also bend the hinge eyes up or
down a little if necessary.
- Drill #40 the cowling to the hinges.
- Mark the bottom edge trim lines. Use the reference marks on the
side skins as the starting point at the rear. The manual refers
to some trim lines on the cowling bottom edges. These are very
hard to see but they are there. Don't cut on those lines; use
them only as a reference to keep your line straight and level.
You should actually try to cut off as little as possible of the
top cowling as necessary to get a straight edge all the way around
it. Leave the cowling off when finished.
- Cleco on the forward bottom skin just a few places along the side
and right in the center at the firewall. Mark the trim reference
line on it.
- Trim the bottom cowling to clear the gear legs for the RV-6. For
the RV-6A trim out an area almost as wide as what you will remove
later when you install the air scoop but only go forward enough
to allow the cowling to clear the nosewheel leg and mount. For
the RV6 trim to the same width but go forward only about 5" for
now; this provides access to clamp the cowling to the bottom hinges
without making the cowling too floppy to handle easily.
- Clamp the cowling in place to the side skins and to the spinner
bulkhead with the 1/8" spacers and mark reference lines on it
and the spinner bulkhead. Mark the rear trim line just along the
bottom and around the corners; not up the sides. Remove the cowling
and trim it. Clamp it back in place against the bottom hinge eyes
and mark the sides for trimming. Remove and trim.
- Attach the cowling hinge halves to the firewall hinge halves with
the proper hinge pins. Trim the cowling to fit properly. Drill
it #40 to the bottom hinges only. The radius of the corner of
the cowling will probably not match that of the forward bottom
skin; if not, heat up the cowling in the corners and modify the
radius (but it might be easier just to use Bondo to reshape the
radius). Then drill the cowling to the side hinges.
- Set the top cowling down on and overlapping the bottom one and
use it to mark and trim the top of the bottom cowling. Trim a
little at a time until the top and bottom halves mate properly.
Remove the top cowling.
- Remove the pin and cut the hinge pieces that will join the top
and bottom cowling halves out of the long piece of hinge. Cut
the pin in half. Drill the hinge halves to the top of the bottom
cowling. Attach the top half hinges to the bottom halves with
the pins. Set the top cowling back in place and drill it to the
top half of the hinges. Remove the top cowling by pulling the
- Finish shaping the hinge pins at the front to provide a means
to lock them in place. See the construction manual for ideas.
Another variation is to trim a little off both the top and bottom
cowling and bend the pin so that it follows the cowling contour
in this gap all the way around the front and back into the air
inlet where the end can be bent and held with a screw or just
stuck into a plate-reinforced hole in the cowling. Make sure any
bends made are not very sharp and you do not nick the pin during
bending; otherwise the pin will break under the heavy vibration
experienced in this area. The fanciest method is to make the pins
removable from inside the cockpit so that nothing is seen from
- Make and install the hinge pieces that hold the top and bottom
cowling halves together just aft of the spinner. Be sure you use
the special hinge with the eyes that are solid, not bent over.
There is a lot of force and vibration in this area so make it
strong. You may prefer to do this area with a plate riveted to
the bottom cowling and nutplates on it to attach the top half.
It is easy to get screws in and out in this area with a stubby
screwdriver. You must always install the screws tightly with a
countersunk washer to avoid having the holes in the top cowling
elongated in flight.
- Remove both cowlings. Bond and rivet all the hinge halves to the
bottom cowling and just the bottom edge hinges to the top cowling
(not the ones at the firewall). Join the top and bottom cowling
halves with the hinge pins. Work these pins in and out of the
hinges or spin them with a drill until they move reasonably freely.
Rather than making an exact cone point on the pins, make the point
offset since the hinge is curved. If they go in and jam up suddenly
at some point look for a hinge eye that has been distorted by
the riveting operation. Polish them with a scotchbrite pad or
very fine sandpaper. Coat with light oil or a dry lubricant.
- Make the final hinge pins for the sides of the bottom cowling
out of the steel pin that was supplied with the kit. Work these
pins as above to make them go in and out more easily. Bend the
top of the pins over to make a handle to pull. The softer pins
that came with the hinges are used on the bottom of the cowling.
For now these pins are left long and straight. Put the bottom
cowling back on the fuselage.
- Install the inlet ducts in the top cowling as shown in the manual
SK-101. With the top cowling off drill holes for the clecos. After
applying the adhesive, you can pop-rivet the front ends on, put
the cowling in place, drill new cleco holes in the rear of the
ducts through the original holes in the top of the cowling (the
duct will have shifted when you installed the cowling), put in
the clecos, and let the adhesive start to set up. Pull the clecoes
out as soon as the adhesive is firm enough to hole the ducts.
Later you can smooth out the front end and fill the cleco holes
- Make the access door for the dip stick and top hinge pins in the
cowling top as shown in the construction manual. If the finger-operated
latches offend you, buy the screwdriver-operated fasteners. Leave
the top cowling off when finished.
- Mount the carburetor air box mount plate/top plate assembly to
the carburetor and push the air box onto the top plate. Cut out
the bottom cowling some more as necessary to allow this. Place
the air scoop on the bottom cowling such that the front end is
centered laterally on the cowling, there is adequate clearance
between the inside of the scoop and the air box (at least 1/2"),
and the contour of the scoop closely matches that of the bottom
of the cowling. This should result in the rear of the scoop being
about centered on the fuselage also; the scoop has a bulge to
accomodate the offset carburetor placement. The rear of the scoop
will probably overhang the rear of the cowling by about 1". If
necessary, rough trim a little off the nose of the airbox to allow
the scoop to be properly located. Mark the outline of the scoop
on the cowling.
- Remove the cowling and set it upside down on the floor. Line up
the scoop with its outline and drill the scoop #40 to the cowling
at about 3" intervals. Trim off the cowling around the scoop inside
edges as described in the airbox and construction manuals. Do
not bond the scoop on yet.
- If you are building an RV-6A cut a slot right in the center of
the scoop just wide enough to clear the nose gear leg. It will
have to be about 14" long to start. The gear leg will be in the
way of getting the lower cowling on and off easily. Remove the
air box from the carburetor and lengthen the slot in the scoop
until you can get the cowling on and off. The spinner rear bulkhead
should be in place for this. The forward edge of the slot needs
to be rounded. You can enlarge the slot a little to the side if
you didn't get it properly centered. That part of the slot behind
the gear leg needs to be widened to 1 1/4" to accomodate the rear
hold-down to be installed later. The width and shape of the slot
at and forward of the leg is not critical; you will finish it
- Attach the airbox to the carburetor and see if you can still get
the cowling on and off with the spinner rear bulkhead in place.
If not, you can shorten the nose of the airbox and/or lengthen
the RV-6A scoop slot. The nose of the air box will be about 1
1/4" back from the rear edge of the air intake hole in the scoop
at this point.
Remove the scoop from the cowling.
- Attach the bottom cowling to the fuselage. Cleco on the scoop
and note whether the centerline of the airbox nose points directly
at the center of the airscoop opening. If not, loosen the tape
holding the airbox mount plate to the top plate and shift the
direction of the nose as described in the Air Box Alignment section
of the air box manual.
- At this point I found that I could not continue with the airbox
construction exactly as described in its instructions. Because
of the angle of the airbox nose with respect to the centerline
of the fuselage the predrilled outer bolt holes in the VA-131-C
mounting plate were not in a good location for attaching it to
the VA-131-B top plate or for holding the filter retaining clips.
Also, in one area there was not enough overlap of the two plates
to allow holes to be drilled in more correct locations. There
were three solutions I could think of. One was to drill the six
bolt holes in the VA-131-B top plate in the proper locations (four
need to be the right distance from the edge of the large opening
so that the filter retaining clips will overhang the opening just
a little), then make a new larger VA-131-C mount plate drilled
using the top plate as a template. Another was to use the existing
mount plate but drill new bolt holes; one of the holes would almost
or completely miss the mount plate because the edges of the two
plates did not overlap enough. In my case the edge of the bolt
head still caught the edge of the mount plate so this worked but
it looked unprofessional. The third was to rivet the top plate
to the mount plate and use screws rather than rivets to attach
the fiberglass air box to the top plate. This offers two advantages
for filter servicing; a screwdriver can be used to remove the
air box easily whereas a wrench is required to gain access to
the filter with the first two methods, and you do not have to
touch the carb heat system connections. If this method is used,
metal countersunk washers must be used with the screws to avoid
having vibration enlarge the holes in the fiberglass box. It is
not essential that a lot of screws be used since small gaps in
the seal will not affect air pressure inside the box. This method
cannot be used with the RV-6A because the nose gear leg is in
the way and you cannot get the airbox on over the filter without
knocking it loose from the retaining clips and you can't get the
filter back in the right position with the box in place.
- Finish the airbox and its seal to the air scoop as described in
the instructions. To make this easier do a final trim of the nose
of the airbox at an angle to the top plate centerline so that
it is perpendicular to the centerline of the fuselage when installed.
If you are planning to fly IFR in cold conditions you may not
get enough carb heat with the air box pulling in engine compartment
air as described in the instructions. An approach at low power
will result in the engine compartment air cooling off to just
a few degrees above outside air. Modify the air box to accept
air from an exhaust heat muff instead. This will require attaching
a hose connector to the air box nose and changing the door operating
mechanism. Vans sells a 2" tube flange (part number VENT DL-03)
that can be used. For this, make only a 2" opening in the top
plate and make a long slot in the plate to allow the door actuator
arm to extend through it. The actuator must attach to the bottom
of the door rather than the top so that the door will swing all
the way up.
- Bond the scoop to the cowling as described in the manual. You
can grind off the outer edge of the scoop to a feather edge before
attaching if you desire so you will not have to do much finish
work at the joint.
- Sand the surface of the cowlings to remove the weave marks so
they won't show after painting. You won't see these until you
begin to sand and look at the cowling in a direct light. Also
sand off almost all of the white surface at the front around the
sharp bends. This is gelcoat; it is quite brittle and cracks easily.
Coat any areas where the gelcoat has been removed with a primer
that fills; these areas are likely to have a lot of pinholes that
will show through paint. Also, be sure to seal the edges with
primer as moisture can get in and cause the edges to swell.
Engine Cooling Baffles
- The plans show how to cut all the pieces used to make the cooling
baffles for the engine so you can make your own. I recommend buying
the baffle kit from Van's instead; all the pieces are already
cut approximately to size and all the bends are done. Also, the
baffle kit includes all the unique hardware required. Constructing
the baffle system must be taken very seriously; the vibration
it experiences is intense and any sloppines will lead immediately
to cracks and failure.
- Van's baffle kit uses the top cowling as the top of the airbox;
if you are really ambitious you can design and build your own
baffle system that has a top as part of it and does not require
the air to make any sharp turns. If done right you can decrease
your cooling drag and gain a few miles per hour in top speed.
- The directions that come with Van's baffle kit are fairly complete,
but as always some things are out of order and you need to read
the whole thing through a time or two before starting. In spite
of what the directions say about compatibility, expect to have
to trim some parts to make them fit right. Also expect that some
parts will not be trimmed quite like the drawings show.
- Be very careful in locating holes for rivets especially in the
front area where several pieces come together as you can easily
come out with a situation where it is impossible to drive some
of the rivets.
- It is practical to mount an oil cooler on the rear baffle on the
left side as is done in some factory airplanes. The cooler that
Van's sells will fit here. If you do this, be sure to strongly
reinforce this area or the engine vibration together with the
heavy cooler will shake the baffle system to bits.
Landing Gear Finishing
At this point if you have left the forward bottom skin loose so
you can more easily work in the forward part of the cockpit it
will be easier to get in and out if you raise the fuselage up
by installing the landing gear. In the -6 this is no problem;
just pick up the front end by the engine with a hoist and insert
the gear legs. In the -6A it is a bit more work.
Nose Gear on the -6A
- Remove any support you had under the rear of the fuselage and
lift up the front by the engine far enough that you can turn the
gear leg over in its normal position. Install the bolt that holds
it to the engine mount (it will not have to be removed after this).
- Attach the fork to the gear leg as shown in drawing #62. The two
disc springs U-611 are placed so that only their outer edges touch.
Tighten the castellated nut until the proper force is required
to move the fork as described in the construction manual. Drill
the gear leg for the cotter key that will hold the nut and install
the cotter key.
- Assemble the tube, tire, and wheel, making sure you do not pinch
the tube between the wheel halves. Inflate the tire.
- Assemble the wheel to the fork as shown in the drawing. You may
find that it will not go in because the U-610 spacers stick out
too far. You can shave them down, but note that as you tighten
the bolt the fork is supposed to push the U-610 spacers against
the wheel bearings and the U-609 axle is not supposed to be hit
the fork. This way tightening the bolt will force the tapered
wheel bearings inward and seat them securely.
- The way to tighten the bolt is to tighten the nut until the wheel
no longer spins freely, back the nut off some, then tighten it
again just until the wheel will only go around about three times
when you spin it as hard as you can. This takes up all the play
in the wheel bearings. Do not tighten the nut on the bolt for
- Make the nosewheel fairing as described in the construction manual.
It will probably be necessary for you to cut a hole in the bottom
of the nose section of the fairing to clear the bottom of the
gear leg. Make a fiberglass dome to cover the hole. You can permanently
install the fairing at this time or wait until you have painted
it. For now, leave the wheel installed.
- Make the fairing and wooden reinforcement for the leg. Oak is
the best wood to use for this as it provides the best dampening
in case of poor landings. The least finish work will be required
and the most crack-resistant structure will be obtained if you
cut a single piece of fiberglass cloth large enough to extend
the full length of the leg and go around it at least four times.
Glue the wooden stiffener pieces together, then glue this to the
leg. When set up, staple the edge of the cloth to the stiffener.
Finish the fairing by wrapping the cloth around the leg three
times applying resin as you go. Pull the cloth tight directly
to the rear using the excess cloth clamped between two sticks
as a handle until the resin begins to set up. A hair dryer will
speed this up.
- Smooth out the fairing by adding another coat of resin and sanding
it down. Make the fairing at the top between the leg and the cowling
by installing the cowling, covering the bottom side around the
leg hole with packaging tape, and builing up a fairing with Bondo
or Microballoon filler. The top edge of the fairing should not
be larger than the opening in the cowling so that the cowling
can drop down for removal.
Main Gear on the -6A
- Make a sawhorse out of 2x4's that is 36 inches long and 28 inches
high. Pad the top with about one inch of very stiff foam rubber.
- Attach an engine hoist to the engine mount as far back as you
can (the crossbar behind the engine is OK) with a rope or fabric
sling and lift up the front a few inches. This is essential to
keep the fuselage from falling over while you raise the rear and
it also makes the rear a little easier to lift. Work the sawhorse
under the fuselage starting at the rear and move it forward until
you get it right under the baggage compartment rear bulkhead F-606.
Adjust the height of the engine hoist so that some but not all
of the engine weight is supported by the hoist.
- Remove the old support legs from the wooden temporary spars.
- Install the landing gear mounts using at least four bolts each
and non-locking nuts through the wooden spar substitute. The bolts
and screws holding the mounts to the side of the fuselage can
be permanently installed now.
Main Gear Mounting, -6 and -6A
- Put the gear legs in place temporarily. It may be necessary to
tilt the fuselage a little on the -6A to start the legs into the
- Mount the brakes, wheels, fairing support, and wheel fairings
to the legs as described in the construction manual and drawing
#57. The brake caliper is mounted with the caliper to the rear,
the bleed valve pointing down, and the main body inboard. Remove
the two bolts holding the caliper assembly together to take the
wheel on and off. Your plans may show an AN5-17A bolt attaching
the brake attach flange to the gear leg. A bolt head is too large
to work here so Van's supplies an allen-head screw instead and
this is included with more recent kits. Some gear legs were made
too large so that the wheel bearings will not fit on them. Sand
down the legs just enough that the bearings will go on without
forcing. Cut a fairly generous section out of the inside of the
wheel fairing to allow it to be placed over the gear leg; this
area will be rebuilt later to fair it to the gear leg fairing.
- Make the section of brake line that goes up the leg to the fuselage
and tape it in place.
- Make the gear leg stiffeners and fairing. The aluminum fairings
provided in the kit are easy to build but you can make fairings
out of fiberglass with a lot more labor that look better if you
get closer than three feet. With the aluminum fairings you can
replace the brake line later if you have to. To do the aluminum
fairings, attach the wooden stiffeners to the rear of the gear
leg using at least three layers of fiberglass cloth and then sand
off any big bumps (the aluminum fairings fit tight and any bumps
will show through). Paint a smooth layer of resin over the leg
so that the aluminum fairing will not be worn through by the leg
as it flexes.
- Run the brake line up the front of the leg and tape it in place.
Connect the tube to the elbow on the fuselage side. Make sure
you do the loop of the tubing at the lower end around the bottom
of the axle and back up to the brake cylinder as shown in the
construction manual so that activation of the brake will not flex
the tubing very much at any one place.
Fitting the wings to the fuselage should be the last thing you
do before taking it to the airport if you are working at home.
The idea is to have as little left to do as possible when you
take it to where working on it is less convenient. Almost all
of the wing mounting tasks can be done in a two-car garage or
similar space if necessary by a process involving doing one wing
at a time. Since it is not possible to set the wing sweep accurately
with only one wing installed you cannot drill the front and rear
attach bolt holes or the fuselage skin-to-wing holes. You can
make the wing root fairings and install the nutplates for them
on the wing but figure that you will have to trim the inboard
edge after final placement of the wings.
- You are now ready to assemble the wingtip rib to the wingtip,
build in whatever lighting you plan, and install the tip on the
wing. You may want to make the wingtip removable if you expect
to try to use wingtip antennas or install strobe light power supplies
in the wings. If you bond it on, it is useful to place the wingtip
position light fixture in line with the largest (forward) lightening
hole in the main rib so you can install or pull out the aileron
push rod without removing the wing.
- With the wing on the fuselage, in a cradle, or on a cart, install
the aileron with temporary bolts and nuts but using the right
washers and spacers. Fix the aileron in the neutral position.
- Clean all the excess gelcoat out of the indented edge of the wingtip.
Measure on the wing the maximum depth that the tip can go in and
trim the edge of the tip if necessary to insure that it will go
far enough in that the wing skin completely covers the indentation
for it. Stuff the tip with foam rubber scraps or newspapers as
necessary to make it slightly fatter than the end of the wing.
Hold the tip up to the wing, see where it hits the aileron brackets
and trim the tip to clear them. Also trim to leave approximately
1/4" between the wingtip and the aileron.
- Insert the wingtip rib into the wingtip with the flange side out
and flange edges about 1/4" inward from the wingtip edge (there
is no right and left rib; both are the same), and shift it fore
and aft until it forces the rear of the tip to have the same shape
as the aileron. Drill the rib to the wingtip #40 only at the rib
ends. Leave the rib clecoed in place for all the following steps
so the rear edge will not curl up or down as the wingtip is forced
to fit the wing.
- Tape several stiff wood strips to the top of the wing extending
out over where the wingtip will be; these are to insure that the
wingtip surface lines up straight with the rest of the wing surface.
You should also verify the skin line using the airfoil template
made from the side of the wing crate. Getting the wingtip to align
properly on both the top and the bottom at the same time is a
little tricky since there is some twist and warp in this part.
It may even be necessary to split the tip at the rear and up the
side a little ways and re-bond it to get it to match the airfoil
shape. Put the tip in place and insure that it goes in far enough
that the wing skin comes all the way to the edge of the indented
area on the wingtip on top and bottom at the same time. Push the
tip as far forward as possible. If its shape does not match that
of the leading edge skin very well, heat up the wingtip with a
hair dryer and reshape it. Drill the wingtip #30 to attach it
to the top side wing skin starting at the forward end and spaced
3" apart. The drill the bottom sde starting at the front. Remove
- If you want to make the tip removable, make strips of .032 aluminum
about 3/4" wide as backup for nutplates. Half-inch 6-32 flathead
100 degree stainless steel screws (AN507C632R-8, available from
Van's) work best here. Bend the strips to match the contour of
the wing and hold them in place inside the tip to drill them #30.
Then mount nutplates on the strips and bond them in place inside
the tip. Use screws as well as clamps to hold the strips, but
pull the screws out before the adhesive has fully cured. You can
use K1000 nutplates, but rivnuts (threaded inserts you install
with an upsetting tool, ATA2-632 from Van's) work just as well
and are much quicker to install. Countersink the wingtip holes
and dimple the wing holes with a standard 1/8" flush rivet dimple
die. If you are using the rivnuts, you can dimple the aluminum
strips with the dies for 8-32 screws before installing them so
the strip will lay flat against the inside of the wingtip.
- If you do not want to have the wing removable, make strips of
.025 or .032 aluminum to as backup for pop rivets and bond them
to the inside of the tip. When secure, drill them #30 through
the holes in the tip. Countersink the holes in the tip and dimple
the holes in the wing skin. Do not bond in place yet.
- If you plan to bond the wingtip rib in place you need only put
rivets in the holes previously drilled at the ends of the ribs.
If you want to use rivets, drill the rest of the rib to the wingtip
#40. You can permanently install the rib now using either all
flush rivets or mostly epoxy structural adhesive.
- The standard molded wingtips supplied with the wing kit may begin
to get wavy across the top in the first summer after installation
on the wing. You can purchase an improved wingtip from several
sources (ask Van's who is currently selling them). You can also
improve the wingtips you have by making a sandwich reinforcing
area on the inside of the top; use polyester resin (not epoxy)
and fiberglass cloth over a 3/16" thick by 6" wide panel of balsa
wood or 1/2" rigid foam that is compatible with the resin. The
grain of the balsa wood should run fore and aft. To start, put
resin on the inside of the top of the wingtip and put the balsa
wood or foam in it. Stuff the tip with foam rubber tight enough
to force the wood or foam to conform to the shape of the wingtip
and attach the tip to the wing. When this sets up, finish with
couple of layers of glass and resin.
- Most bulders seem to prefer the three-way wingtip lights; red/green
forward, white aft, and strobe all in the same fixture, with a
power supply in each wing mounted on the outboard rib. This meets
the FAA requirements and requires the least work because no other
lights are needed. The reason for using the more expensive dual
power supplies is that you will not have a long run of wire carrying
the noise-generating pulse of current to the flash bulbs; this
could interfere with navigation radios but so far I have not heard
from anyone who actually had a problem with this. The light fixture
must be mounted out far enough that the colored and white lights
will be visible from straight forward and straight back. The strobe
lights must be visible upward and downward also.
- To mount these lights you can buy a molded mount from several
sources including Van's or make your own. The advantage of Van's
is that it can easily be mounted flush with the wingtip surface
so that almost no finish work is required. To make your own mount,
make a solid mount out of modeling clay, using a little water
on your fingers at the last to help make the surface smooth. Bake
the mold just enough to dry it out good. Use that to make a female
mold out of clay. Make an aluminum mounting plate the same size
as the base of the light fixture and attach nutplates to it to
allow easy removal of the light fixture later. If you are bonding
on the wingtip the hole in the plate should be large enough for
the aileron push rod to go through (1 1/4" diameter). Make the
mounting platform for the fixture by laying up several layers
of fiberglass and resin in the mold, with the mounting plate on
the inside. You can also just lay fiberglass on top of the clay
mount you made to form the final mount but this may actually take
longer in finishing the outside surface.
finish.doc 4/13/96 by Frank Justice
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