RV-8/8A
SECTION 9
FITTING THE CANOPY
9-1
8s9r3.pub 6/19/01
The RV-8 uses a large bubble canopy that affords excellent all around visibility. The windshield is fixed to a
sturdy roll structure. The aft portion slides to the rear on a simple three-track system, uncovering both
seats. Fitting the canopy demands careful attention to fitting details and careful handling of the big Plexi-
glas bubble. Work slowly and methodically. Make changes in small increments and be careful that a small
“tweak” in one place has not moved something somewhere else. The key to a good fit is to visualize where
the outside surface of the canopy and skirts must be to match the fuselage, then work from the center out
so they match as closely as possible.
INSTALLING THE SLIDE RAILS
Make the C-805 Canopy Slide Spacer as shown on DWG 46. The forward end must be trimmed as shown
on DWG 46, Detail A.
Bend and fit the C-804 Canopy Slide Cap to C-805. Fastener hole pattern per DWG 46.
Rivet the slide cap and spacer together to make the center rail. See DWG 44, Detail A.
The final position of the center rail on the fuselage is determined by pulling a thread from the center of bulk-
head F-807 to the center of bulkhead F-810A. The pre-punched fastener holes in the fuselage skin are
used to establish the centerline. Mark center on the fuselage with a sharpie and place the center rail on the
fuselage. Lightly tape it in position and drill the screw holes for F-825.
Attach the slide cap/spacer assembly to the fuselage using the hardware shown on DWG 44, Detail A.
Prepare the C-803 canopy rails for installation by trimming to length and locally relieving the forward ends
per the canopy rail detail on DWG 44. Tape or clamp the C-803 canopy rails in position on the fuselage per
Section Y-Y’ on DWG 44.
PREPARING THE CANOPY FRAME
Begin by temporarily installing the C-658 rollers, the C-661 Slide Block, and the C-806 Anchor Block to the
Wd-819 Canopy frame.
C-658 roller detail is shown in Sect. Y-Y’ on DWG 44. The exact height of the canopy frame has yet to be
determined, so do not drill the Wd-644 Roller Mount to the canopy frame yet.
Pin the C-661 slide block to the rear of the canopy frame per Detail A, DWG 44. Proper position of C-661
slide block relative to WD-819M pivot arm yields a 1/16” to 3/32” gap between the end of WD-640H anchor
pin and C-804 slide cap when C-661 is on the flat portion of the C-804/C-805 canopy slide. The outer sur-
face of C-661 must be counterbored to allow the head of the clevis pin to be flush; otherwise the slide block
will not fit into the receptacle in the fuselage.
Temporarily installing the C-806 anchor block is simply a matter of sliding the WD-640H anchor pin on the
canopy frame into the hole in C-806. See detail A, DWG 44. Friction should hold the anchor block in place
on the canopy frame. The engagement of the anchor pin in the anchor block determines the most forward
position of the canopy frame. This important detail must be considered when making the necessary adjust-
ments during installation.
FITTING THE CANOPY FRAME TO THE FUSELAGE
Install the canopy frame on all three canopy rails and gently slide it forward to the closed position. Reposi-
tion and re-tape the rails as necessary. The C-803 side rails should align closely with the inboard edges of
the F-816 cockpit rails.
The WD-819 canopy frame is a finished steel assembly, welded in hard tooling, but because of minor varia-
tions in construction, it may not exactly fit your fuselage. The builder must make any minor bends that are
necessary to make it fit exactly.
The front bow of the canopy frame should be wide enough that the contour of the fuselage blends smoothly
into the contour of the canopy frame. This can be verified by clamping a roughly 6 inch long strip of scrap
0.040 aluminum in two or three places to each of the forward ribs of the canopy frame so approximately 1
inch of the 0.040 strips overlap the fuselage. Slightly “curl” the 0.040 strips to approximate the canopy
frame rib curvatures. (See DWG 44, Sect. Y-Y’. Look closely at the relationship of the frame and skirt to
the fuselage side.) The canopy frame front bow is the correct width when the overlapping 0.040 strips are
just touching the fuselage sides. Corrections to the front bow can be made with carefully controlled muscle
power. With the canopy frame front bow adjusted to the proper width and the 0.040 strips holding the can-
opy frame centered on the fuselage, the final position of the C-803 canopy rails can be established. Adjust
the position of each of the C-803 canopy rails as required to center the canopy rollers inside the rails. See
SECTION 9: FITTING THE CANOPY
SECTION 9
FITTING THE CANOPY
RV-8/8A
9-2
8s9r3.pub 6/19/01
DWG 44, Section Y-Y’. Be sure that the rails are parallel to each other and to the inboard edges of the F-
816 cockpit rails before drilling and clecoing to the fuselage. The dimension shown on the drawing, giving
the spacing between the canopy rails, is a place to start, not an absolute. The rails should be located so
the canopy skirts transition from the lower canopy frame tube to the fuselage side with no gaps.
Using a #40 bit, drill the four forward most holes in each C-803 canopy rail per View X-X, DWG 44. Do not
drill the two aft holes in C-803 as these will be match drilled from existing holes in F-816.
The aft end of the canopy frame may also require some spreading or bending to fit the fuselage. Particularly
the canopy frame aft bow may need adjustment to achieve the correct gap between the bottom of the aft
most part of the tube and the canopy slide cap, see DWG 44, Canopy Side View. Again, small corrections
to the frame can be made with carefully controlled muscle power.
With all canopy adjustments made and the rails drilled and clecoed in their final position, the aft-most two
holes in each of the C-803 rails can now be back drilled from the holes in the F-816 cockpit rails. See DWG
44, view X-X’. Note that the aft portion of the C-803 side rails must be trimmed to fit along the outside of the
fuselage and the aft screw is mounted inside the roller track as shown on Detail B, DWG 44.
When the rails are permanently installed, attach the C-806 anchor block to the F-807 bulkhead as shown on
DWG 44, detail A. Proper position of C-806 is established simply by placing it on the canopy frame anchor
pin and sliding the canopy frame all the way forward, then drilling holes through F-807 into C-806.
FITTING THE C-801 PLEXIGLAS BUBBLE
The Plexiglas canopy bubble is one of the most expensive and fragile components in the kit. Miss-handling
and cracking it is one of the most disappointing, gumption-robbing experiences a homebuilder can have.
Here are a few Plexiglas tips.
x
Plexiglas is dramatically less brittle when it is warm. Do not try and work on the canopy in a cold shop.
Cutting or drilling Plexiglas in temperatures under 60
q
F is asking for trouble. Heat the shop to 75-80
q
--
it may be uncomfortable to you, but your canopy loves it. Many builders will put a small space heater
under the canopy when trimming, just as insurance.
x
Regular twist drills have tips that tend to fracture Plexiglas. Special Plexiglas drills are available from
tool suppliers. We have also found that a small Unibit makes excellent holes in warm Plexi. Using a
regular twist drill to enlarge a pre-drilled hole is almost guaranteed to crack a canopy.
x
Do NOT try to use a saw of any kind. You might get away with it once or twice, but eventually you will
crack the bubble. Cutting discs, supplied with the kit, do an excellent job when used in a high-speed
die grinder. They will also cut fingers without a second thought, so support your work well and use two
hands to guide the grinder. Die grinders turn at very high rpm and can throw chips and dust at un-
dodgable velocities. Eye, ear, and respiratory protection are essential!
x
When fitting the canopy, an assistant is a big help. Start with him/her inside the cockpit.
The Plexiglass canopy cannot be molded to fit the steel frame exactly. The sides of the canopy may be
several inches from the side tubes of the frame when fitting begins. Naturally, when the Plexiglass is pulled
in at the sides to meet the frame, it changes shape fore-and-aft as well. Be sure to have the sides pulled in
and held to the frame with spring clamps while fitting the canopy to the fuselage.
The canopy must be trimmed to fit the Wd-819 canopy frame as shown on Sections A-A’ and B-B’, DWG
44. It must also be trimmed to fit around the forward deck of the fuselage, although this fit does not need to
be exact -- a small gap is of no structural concern, and will be bridged by the fiberglass fairing shown. Be-
gin fitting by dropping the C-801 Canopy over the closed canopy frame and sliding it fore and aft to find the
best match to the frame and fuselage. There are trim lines included on the front and back of the canopy.
These lines were taken directly from a canopy installed on one of our prototype aircraft with no extra trim
allowed. The lines should NOT be used as the sole means of trimming! Leave some extra.
Use the mark on the forward part of the canopy to double-check the fore and aft location of the canopy. The
dimension given in the canopy side view on DWG 44 is based on the forward mark. Mark the initial trim
lines. Most of the initial trimming will take place around the base of the windshield and the rear of the can-
opy, where it curves over the fuselage. As the canopy is lowered, notches must be cut in the lower edges
to clear the WD-819C,D,and E ribs .
Cut these notches carefully -- improperly done, they are perfect places for cracks to start. In our shop we
use sanding drums on a drill to cut a curved notch. This is followed with a Scotchbrite drum to smooth the
Plexi, and every edge of every notch is rounded over and sanded smooth (to about 180 grit) before the can-
opy is lifted for the next trial fit. If this sounds like a lot of extra work, think about how much time you’ll
spend if you cut corners and crack the canopy.....
It may take several progressive trim-and-try cuts to fit the canopy to the frame. As the forward portion that
will become the windshield is fitted the fuselage, it will come down and rest on the Wd-814 roll bar. At this
