The way I assemble my airplanes to try and assure the alignment I want, I use three Robart incidence meters. I think I have 5 all together and watch for them at swap meets to pick them up cheap. Even at full price, they are a good tool. I set one up to attach to the engine/power plant to check thrust line against the center line. I put another one in the wing at the root. I take the third one apart to set it on top of the stab. I generally favor flat stabs, so this is easy, but if you have airfoil shaped stabs, you need to install it the regular way. I have a couple of old Black and Decker small Bench Mate vises with rubber jaws. I set up the fuselage in one of these. If I have a good, visible center line on the fuselage side still I carefully measure from the bench to the center line at the nose and tail and adjust until it's level. The table need to be level for this purpose also. . Then add all the Robart meters and check one against the other. If you are building a model that is 0-0-0, this is all pretty easy to do and measure, and gets you pretty darn close to a perfect alignment. You can eyeball the side view of the airplane at this time to see how it looks because in theory, it should look the same way in flight. I recheck all of this until I have everything assembled, adjusted and glued securely in place, them proceed to finish the airplane. I have been setting up any new models I have built following Bob Whitely's suggestions in his article about "things that always work" in Stunt News several years ago and that is usually 1 degree down thrust, wing at 0 to the center line, and 1/2 to 1 degree positive incidence on the stab. I have found that this works very well for me in that the airplanes track very well right off the board, and helps put a model very close to desired trim right off the board. Using the three Robart meters makes this pretty easy to do also. However you do it and how ever you prefer to set up your airplanes, attention to small details at this point pays off in the final result. I try to do this the same way on every airplane as I feel this breeds consistency. I think that changing style and designs of models, especially when you are climbing the skill level ladder, is counter productive in that you never get used to anything or have a chance to really decide what you like and are comfortable with. David Fitzgerald just won the NATS again and I doubt that it was with an airplane that was even a small departure from what has been successful for him in the past. ( still with the Thundergazer, I presume?) That doesn't mean that you will have the same success with the same design right off the bat. An accurately built SIG Chipmunk may fit your needs or one of the hundreds of designs that are out there. If you are at the intermediate level, Matt, I would really look hard at some simpler designs of a smaller size and at control geometry and throws that you find comfortable. You can make the airplanes look like anything you want, but always use the same "numbers" to help you get the same feel for each airplane you build. Build, fly and repeat until you reach those "Aha!" moments where things fall into place for you and you can see, hear and feel subtle differences and build confidence and consistency. It won't happen over night or even one summer. I spent about 17 years from my first beginner contest until I won my first local contest in the expert class against some pretty good flyers whose names most would recognize. But I enjoyed every minute of the 17 years, met a lot of great people and learned more than I have been able to retain probably. Chart yourself a course and plan for how you want to proceed and stick to it. When you do get to make the trip to Brodaks and other contests. Spend as much time just watching others fly, what they are using for equipment and gather information to refer back to later. Yogi Berra said it best that you can observe a lot just by watching! Others have made all the mistakes that you are about to make and anything that you can do to avoid that and straighten out the learning curve as much as you can will be very beneficial to you in your situation with not having much local help to fly and practice with. Keep an open mind about what you see, read and hear and common sense will help you sort out what is BS and what to apply to your program.
Type at you later,
Dan McEntee
Topic: Plane trimming (Read 1814 times)