Over the years, builders of W.A.R. Corsair aircraft have found a number of problems with the plans as they are delivered. One persistant problem has been the landing gear. The most frequent problem has been twofold. The first being the landing gear retract motors. The suggested motors are just not strong enough to do the job. A good suggestion has been to replace them with 12 volt, industrial permanent magnet, reversable motors.....ie off farm equipment. The second landing gear problem has been landing gear failure on touch down. The brackets that attach the gear to the frame should NOT be made from aluminum. Construct the same bracket from same gauge steel and add triangular braces to each bracket as illustrated in the following diagram;
Another problem with the landing gear has been the landing gear doors. The mechanism on some models does not work. Many have commented, "Don't even bother to make all the pieces". A solution used by some has been to use a line and pully system, particularly on the F4-U Corsair.
RETRACT Motor: The Cessna flap motor suggested in the plans is not suitable. It just lacks the power. The Sept/Oct '76 issue of the old WAR Newsletter states Piper part #21286-00 electric motor has the power to operate the retracts properly. Another suggestion from Chris M. in England is to use the Parvalux PM4 with gear box. It is a 12volt DC perm magnet which fits into the existing system with minor mods. The motor is Type PM 4D TENC, 120 watts, 4000 rpm, 242 output. $154 U.S. 18 seconds to close & 16 seconds to open. It adds about 3 extra pounds. It uses relays to reverse the movement instead of limit switches. See the Parvalux website www.parvalux.co.uk/about.asp for the U.S. representative.
Foam:
One enterprising builder modified the installation of the foam. He used the blue "Rutan" foam on the wings and 2 lb foam on the fuselage. He also did some experimenting with glue. The plans call for 5 minute epoxy, he did some experiments with a hot glue gun. He discovered that the foam broke without affecting the glue joint when a hot glue gun was used. The hot glue joint was STRONG ! He also recommends marking the edge of the foam formers with a black marker. Cut the foam filler pieces on a bandsaw curving them slightly larger than needed to reduce the sanding time. When sanding, sand down to but DO NOT remove the black edge of the formers. You have now attained the right shape for your particular aircraft.
Landing Gear:
General Suggestions:
Fabricate you metal parts FIRST! This is the most time consuming part of construction. You don't want your wood sitting waiting for the metal parts before you seal it. Spruce is very sensitive to rot. The wood construction goes very quickly.
Give consideration to routing wiring etc. BEFORE closing it in.
Think of adding 2 inch panels down each side of the cockpit for controls
Control surface hinge points: DOUBLE what the plans call for and use bearings as this is a major wear point.
Balance the ailerons during construction. One builder used angle iron , another used 1/2 inch conduit filled with lead to achieve the desired balance.
Add 6" gussets to the outer wing panels to increase strength.
Tail pivot point - MAKE SURE it is tight and make an access panel to replace the pin. This another major wear point and can cause serious accidents as the spring will not only compress but bend sideways
There is more detailed general construction information on Jim's Project page.
The following suggestions have been submitted by various builders. Hopefully it will prevent other builders from re-inventing the wheel, as it were.
Corvair 120 - 140 HP conversion. About the same weight as the Cont 0-200 but with more horsepower, cheap and readily available.
Canopy:Roger Smith sent me a great email about WAR canopies Our canopies if "blown" are done with a "double sided" mold as the shape is critical. Generally canopies are "draped", as in heated OVER the mold and it conforms to the mold shape. The problem is maintaining clarity of the plastic as it melts. It is not uncommon for the canopy to get blurry at the curved portion. Not a good thing in an aircraft. If you notice on the canopy you have purchased, it has to be cut to size. This is a result of the "drape" Also, the thickness if the material is important. The greater the speed of the aircraft, the thicker the canopy material needs to be.
FLAPS for your W.A.R. Bird
George Dawe has kindly given me permission to place his flap design on the website. George has designed a "split flap" system for his FW-190. It uses the KR-2 flap handle, a torque rod, push rod and three "elevator hinges" per flap. He is using hinges he designed, similar to the hinges on the WAR plans except the "male" part of the hinge is a "T" not an "L". Georges' hinges also have no "slop" because of the close tolerances between the male "T" and the female "TT" parts. George also designed in oil impregnated brass bushings for longer hinge life and safety.
George's "split flap" design is covered with one layer of 5.5 ounce Carbon Fiber cloth on the flap itself, the inside of the flap well. The flap is then covered with one layer of 8 ounce fiberglass cloth.
I want to thank George for allowing me to present his design here. George has a great site detailing the construction of his FW-190. You can find a link to George's website by going to my "Favorite Links" page. Great job, George! And Thank you!
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Setting Toe-in:
The following was taken from Frank J. O'Brien's book "HOMEBUILTS, A Handbook for the First-Time Builder, TAB Books, Inc. ISBN 0-8306-2375-2
Click on the button to view the text. The diagram illustrates the text.
