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BUILDERS HINTS
(From CP20, Page 4, April, 1979)
When you cut BID (Bidirectional)or
UND (Unidirectional) fibergalss, mark the cloth where it will cross the center line with a
fine felt marker. This mark can be very helpful in perfectly aligning such lay-ups as
canard spar caps, etc.
Draw lines (broad felt tip marker) on your glass cut-out table at
45 degrees to the sides on 6" centers. This is a big help when cutting BID.
Be careful when storing foam blocks, not only can sunlight ruin
it but rats and mice love to dig tunnels in it!
Finding fuel tank leaks. Purchase a can of Freon from your friendly auto air conditioner repairman, and borrow his Halogen gas sniffer. (This may require some persuasion!). Squirt some Freon into the offending tank, replace the cap, and pressurize the tank, (blow into the vent) Use the sniffer to locate the leak or leaks, mark them carefully and repair per CP #14 pg 10. This method will find even the tiniest pin hole leaks.
Check your main gear toe-in. This
can really effect the life of main tires. See the accompanying sketch, and clamp or hold
one 36" long straight edge on the outside of each main wheel , be sure it touches the
rim both fore and aft of the axle. Position of the straight edges fore and aft is not
important, as long as they are the same. Measure accurately the distance between the ends
of the straight edges at A and at B . For 1/2 degree to 1/4 degree
of toe-in per wheel. A-B=0.3 to 0.7"
Click to enlarge
An excellent cowling idea from
Herb Sanders....
Instead of gluing your cowling rib to the bottom cowl, glue it to
the main wing root. This allows you to better fair the cowling in with the wings, and
makes it simpler to remove the cowl, as either the bottom or top cowl can be removed
independently of each other without hitting rudder cable or aileron tube. This requires
four more Camlocs (or screws) on each side in the bottom cowl. The only time this would
not be convenient would be for the builder who intends to trailer his EZ to and from the
airport, requiring frequent wing removal. We have modified N4EZ to this configuration to
test the Jiran Kevlar cowl and are very pleased with it.
Jim Eggleston wired up his
instrument panel before installing it in the fuselage. He then bound all the wiring into a
harness, color coding the wires and tagging each wire. The harness was then removed and
the panel installed.
Jim also reports that he used dead soft .016 aluminum, called
handymans metal, obtainable at the hardware department of Montgomery Wards in
rolls, to make his hotwire templates. This material can be cut to size (after paper
templates are glued on) with ordinary scissors.
Before floxing VECS3 hinges into
your canard, Bondo small wood blocks adjacent to the VECS3s and overhanging the
slots cut in the canard. VECS3s can now be clamped to these blocks, templates can be
removed from under the elevators, and the elevator travel can be checked before
final potting in flox. Leave clamped until set. This tip from Minnesotas EAA Chapter
587.
Click to
enlarge
When countersinking difficult to
reach holes, e.g. 3/26 dia. holes in engine mount extrusions, a 9 long piece
of 5.16 dia. x .035 wall aluminum tube can be used. Drill and tap a x 28 thread in
one end and screw in a 100 degree countersink with a 3/16" pilot.
Click to enlarge
Many builders have requested a summary of weights of each individual part. These are weigh of the parts before any finishing.
Complete wing/winglet aileron assembly 43 lb
Above, after finishing 46 lb
Winglet before cutout for rudder 2.6 lb
Canard (142") 16.5 lb
Elevator (left) 3.6 lb with balance weights
Elevator (right) 3.3 lb with balance weights
Wings (each) 34.0 lb
Ailerons 3.5 lb
Center Section Spar 21.0 lb
Fuselage (at end of chap. #12) 65.0 lb including C/S spar
Canopy (end of chap#22) 14.5 lb
When cutting out small BID circles, as in bolt hole reinforcement in NG30s, fold up BID cloth strips to required number of plies (30) and clamp between two scrap pieces of 1/4" plywood (firewall material). Vice grips work best. Now cut through plywood and glass with fine tooth coping saw or band saw. Presto perfect circles of BID!
Gear and canopy warning - this
system has a resetting defeat feature. The main advantage is the ability to silence the
horn, while doing gear-up, slow flight or descents. The light stays on as long as the
throttle is retarded. Each time you cycle the throttle the horn will sound and will have
to be re-silenced. This eliminates the possibility of switching the warning system off
during gear-up descents, and forgetting to re-arm it for the landing approach.
Click to enlarge