When I first began working on my project I couldn't sleep as I was so anxious to finish and had ideas and questions racing about my mind. I really believed that I could build this thing in two years. HA! It is feasible to build a corsair in one year assuming that you have these things...
Unlimited money
Full knowledge of tasks ahead ie: how to weld, machine metal, work with fiberglass etc...
No distractons like friends, wife and kids. (I love my wife and would not trade the joy of having her over this plane)
A three or four car garage
All tools and materials in your shop and ready for use
If you don't have these things lined up then you can expect a build time of three to eight years.(Sorry) The good news is that it is worth it. The knowlege I've gained and the quality people I've met have made me a better person. I've also learned a great deal of history about this plane and World War II in general. We owe our armed forces more gratitude than many realize - building and flying a plane that keeps the memory of those dark days alive in time reminds people how fortunate we are.
METAL CONTRUCTION TIPS AND CREATIVE SOLUTIONS FOR EQUIPMENT
The wood constuction took me one month (120 hours) and I would reccomend doing it after you have the metal hardware finished. Dry rot (fungus) is a problem with spruce and you need to seal it as soon as possible. It will take you a great deal of time to fashion the metal parts and it would be better to install the metal for a test fit before sealing the wood. This eliminates two steps that you might incur. Firstly, having to reseal a freshly drilled hole. Secondly, removing the sealer in order to add another peice of wood. If anything is going to test your resolve it will be the metal work. I purchased a used TIG welder and consider this the only way to go with oxyfuel welding being a second choice. Don't be tempted to MIG weld your plane as it is not as controllable and therefore a lower quality process on thin wall aircraft tubing. You can get away with MIG welding your 4130 but be sure to do lots of test welds/bend tests before declaring anything airworthy. The drawback of MIG is the cold start at the beginning of each bead. The landing gear requires precision found in machine shop equipment and measuring tools to work reliably. I went to Vo-Tech for a few months and had access to everything needed for fabricating metal on the plane.(TIG welder, mill, lathe, brake,shear you name it) At our school we were encouraged to work on outside projects. I ran out of time to go to school and bought my own equipment. Find yourself a good surplus yard and used equipment dealer or make some good friends with equipment. Deals on equipment also come at auctions and school equipment cleanouts. The guy I bought my 300 amp TIG welder from admitted to paying a few hundred dollars for it's purchase from a local school.
If you have a set of newer plans from Carl (WAR Replicas of Florida) you will see many revisions. After talking with other builders there are more revisions. You may want to consider changing certain parts from aluminum to steel as cracking has occured in some cases. The parts include the aileron bellcrank bracket and gearbox aluminum plate. One corsair owner had side loads imposed on his gear and had the gearbox aluminum plate cracked under the truss. (His plate was 3/4 inches thick). This same owner advised me to get a much thicker tube(smaller ID same OD) for the cross tube between two aluminum plates.(Toggle pivot assembly) His tube cracked where the 4" half gear has a hole drilled into the tube. Control hinges should be made of thicker material and bushed with bronze as the pivot points wear..
My idea for the landing gear is to get rid of the u-joints chain and the gears and replace it with pneumatic cylinders. The 4" half gear on the toggle assembly would be driven by a steel rack propelled by a 3" double-acting air cylnder. The air cylinder just fits in the truss assembly. The gear door design as shown in the plans is no good so my gear doors would be actuated by smaller cylinders. The gear stays down and locked because of the over-center lock on the toggle assembly. This system reduces the complexity and pilot workload and will be tested atop my pickup truck at approach speeds.(My affordable wind tunnel) I am not the only loon using pneumatics! There is a chinese military plane that uses air for landing gear, flaps and engine starting. I'll post pictures of the gear when it's made.
Looking for wheels and rims??? Look no further! Northern Hydraulic has them and they are cheap! The tire size is 5.30-4.50x6.00 and you need to alter the dimensions on your wheel hub as the bolt pattern on these rims is larger. I believe my hole to hole distance measuring across was 4.70" and the O.D. for the hub (which I made) is 5.5". Tire and rim part# is 1333-c151 or 1333-b948 depending on which catalog you have. They also stock tubes and tires separately. IMPORTANT!!! The WAR hub and Margay rims have a smaller lug spacing than this rim. (see above)
BOOKS AND FAVORITE SUPPLIERS FOR METAL
PERFORMANCE WELDING This book is a must have!
MSC (catalog) 1-800-645-7270 Great supplier of machine shop equipment and materials
ENCO (catalog)1-800-873-3626 Great supplier and better prices of machine equpment
WICKS AIRCRAFT SUPPLY 1-800-221-9425 My absolute favorite! I got all of my wood there including pre-fabricated spar caps.
AIRCRAFT SPRUCE 1-800-861-3192 Good info in catalog and a few more items than Wick's. I'd stiil rather use Wicks!
DILLSBURG AEROPLANE WORKS (717) 432-4589 Lowest cost on bulk 4130 steel (don't bother them with little pieces or orders
NORTHERN HYDRAULIC 1-800-556-7885 F4U Tire and rim headquarters
WOOD AND WOOD TOOLS ADVICE
I drove to Wicks to pick up my wood order and inspected it before purchase. They are a great bunch of midwesterners who really try to help builders along. You should have a materials list for wood on the back side of your builders manual. I opted to purchase my seatback at Home Depot (paraply) because aircraft plywood is so expensive. Other than this my plane is 100% spruce. Don't bother trying to skimp on cost for your wood. The dimensions used for the wood are adequate but only if aircraft grade wood is used. I spoke to Jim Kern (one of the WAR founders) and he said the prototype was made of douglas fir. Go with the good stuff (spruce) as it is easier to work with. My work table was 13 feet long and two feet wide which fit nicely in the single car garage with all the other equipment. The wood makes so much dust! Read your plans, EAA WOOD book and CAM 18 (the old FAA book on aircraft maint.)carefully before beginning, to minimize mistakes. For instance, the uprights at the front of the plane are drilled for fuel tank hold downs. I missed these and had to hand drill them later. The longerons were scarfed per CAM 18 specs and epoxied. Your longerons then need to be sized down to 1/2" aft of the seat per plans. This is best done using a drum sander which is also the best way to scarf your plywood. I don't agree with the table saw method of scarfing as seen in the builders manual and think that a drum sander is the way to go. My sanding drum was mounted on a radial arm saw accesory shaft and allowed for precise angle and depth control. I was given this tool and it would be a waste of money to buy it for your purpose. There are plans for scarfing tools available from Wicks and others.
Make sure you get a few pieces of plate glass or razors to scrape your woodwork.(See CAM 18) You will need a table saw for cutting the large plywood sheets when they are joined.(get a cheapie) Get a cheap bandsaw and a good belt sander. I got the $225.00 Sears bandsaw with variable speed and now realize that cutting metal ( thin aluminum) could be done at any speed. What matters is throat depth. The bandsaw works great on diagonals, uprights plywood cutouts and thin aluminum. It doesn't splinter the wood like a table saw might.
For the plywood cut outs in the fuselage an old router with a straight bit and a bearing on the end (countertop bit) worked great. A 2x4 on the back side of the plywood and up against the members provided a straightedge and proper spacing of the holes. You are asking for trouble if you attempt to cut these lightening holes before plywood is bonded to the fuselage.
Every builder has his own opinion on glue. I say epoxy for anything but laminating because of it's gap filling properties. Epoxy for your fuselage and spars should be a good structural grade (ask Wicks) and have a long cure time to allow permeation. NO 5 MINUTE EPOXY ON STUCTURAL WOOD!!! (One builder used it) For laminating such as outer spar caps and plywood to the rear spar I highly recommend rescorcinol as it is light and easy to apply. It needs good clamping pressure and no gap, otherwise, it holds better and is much lighter than epoxy.
The plywood cutouts for the ribs etc.. are best laid out by cutting them out of the plans and tracing them with carbon paper onto the plywood. To save time I then stapled the plywood together and taped it as necessary to cut out the shapes. This way I had two identical parts. Holes were drilled, and the router mounted on a table made quick work of the lightening holes.
One area that some people overlook in it's importance is the joining of the fuselage sides. They need to be in perfect alignment in every axis. (Imagine having your left wingtip a foot forward of your right) Use 3/4" or thicker ply for this jig. A water level helps greatly in wing and elevator alignment. The wood is sooo easy but requires that you pay attention to precision.
WOOD BOOKS AND SUPPLIERS
EAA aircraft building techniques WOOD Very informative
CAM 18 An absolute must have! (for the wood)
WICKS AIRCRAFT Used to make premolded spars for the WAR F4U. It may not hurt to ask if they still do. I favor them for buying my spruce. Their catalog also has the above mentioned books.
I am building this engine for several reasons. You wouldn't think it, but it's reliable! Jack at HCI has flown his "5" quite a bit.( He and his flybaby are still in one piece) It is lighter than the Continental 0-200 that is called for in the plans. This engine costs less than a certified engine. (Try buying Continental cylinders for the same price as Volkswagen cylinders) The seven cylinder produces more torque and horsepower than the O-200. Jack Hereford (The designer of HCI radials) says that this engine runs surprisingly smooth for a radial. The engine also fits nicely in the cowling and has a realistic scale sound right down to the gear noise.
Just to let you know HCI will probably produce turn key versions of this engine in the future. The engine has to be tested thoroughly before it goes into production. I've met Jack at his HCI Sun n Fun booth and saw his excellent work. I hear that he uses CNC machinery for his parts. You would do yourself a favor to buy one of his engine kits if you can't afford the turn key version as it takes a lot of time to make the parts accurately. Jack has made improvements to the original design and experimented with variations. He is a wealth of information but I would advise you not to bug him too much as he suffers from many repetitive questions. The people asking these questions are there to shoot the breeze and are not interested in buying anything. He's a great guy and loves to talk but he also likes to make money. I own a business myself and can't stand people who tie up my time and end up never generating revenue.
ENGINE REFERENCE MATERIAL
THE INTERNAL COMBUSTION ENGINE IN THEORY AND PRACTICE Vol. 2 by Charles Fayette Taylor Great reading as the book is very detailed about every aspect of engine design. It contains a lot of material pertaining to radial engines as well as references to other books. A MUST HAVE!!
THE DESIGN AND TUNING OF COMPETETION ENGINES by Phillip H. Smith Deals more with building high revving racing engines. Has some good info that is relevant to this project. Written in laymans terms.
AIRFRAME & POWERPLANT POWERLANT HANDBOOK #AC65-12A (FAA BOOK) This one has good basic explanations of radial engine design and systems. This book has examples of several different radial engine designs and is easy to understand. Don't confuse it with the other FAA airframe book which is everywhere. I happened upon this one at Embry Riddle University.
MACHINERY'S HANDBOOK If you will be making your engine or any of its parts you need this book.
MACHINING FUNDAMENTALS by John R. Walker A great book for beginning machinists. Teaches basic techniques and has simple formulas. For more precise calculations (custom gears in cam drive) use MACHINERY'S HANDBOOK.
I will add more to this site as time allows. The books and material references on this page are but a few of the resources available. I omitted the obvious ones (Tony Bingeliss etc...) and included my favorites(maybe unknown to most) and the essentials.
In my search for the "perfect" engine for this bird I looked at many good candidates. The candidates and my reasons for not choosing them is as follows...
Cont or Lyc 100hp(plan's engine) Too expensive to rebuild. Oval cowling required to house the flat engine. Otherwise OK
Subaru watercooled 100hp A bit on the heavy side with that PSRU and water to carry around! But still OK. I know a KR-2 piot that has had good luck with his"subie".
Corvair 6 cyl Pietenpol guys use this one. Once again a little too heavy for me. Prop RPM's are high(No PSRU) meaning that you use a smaller diameter prop. This one would probably work though.
Wankel rotary I looked at this one quite a bit. I can't remeber why but I found some things out that wouldn't jive with this plane. Too bad.
Two stroke engines For those of you who really like forced landings. Two stroke engines have a nasty habit of seizing due to the nature of their construction and RPMs they operate at. This is why they are OK for ultrlights but not as desireable for full size birds.Even though they are very light they cost too much for the headaches they produce. You'd be better off sinking your dough in a 0-200 complete rebuild.
