Details Matter in Model Aviation

Becoming successful in model aviation requires that one be detailed oriented, a very good skill to have but not always a trait that comes naturally to many people. This statement in an article in Inc. Magazine I found applies well, “Details often make or break accomplishments.”  Although I feel if one tries to become too perfect all at once it can be overwhelming and frustration will follow. For example I am learning the hard way when model plans specify a certain weight of wood and type of grain of wood, there really is a reason the designer specified that. In the past I might have used whatever I found at the hobby shop. Often the plane ended up too heavy to fly well but more recently I have used wood that was too light for the particular spot on the airplane.  

Bad Axe Embryo has Fuse DT 

An example of this was on the fuselage of a contest winning embryo design the Bad Axe from Volare. This was a short-kit which provided the more difficult to cut out sheet pieces but the builder provided the balsa strip pieces in the kit. It is normal practice to use hard balsa longerons for the square pieces that run the length of the edges of the fuselage and lighter wood for the cross members. With too light of wood for the longerons I was breaking the pieces just trying to construct the fuselage, if I added reinforcement in a spot it would just break next to where the reinforcement ends. Trying to cover the model with tissue and not get sagging areas is impossible too. When you try to fly the model it is so difficult to hold the model without breaking a fragile longeron even with a fairly gentle grip. 

Lighter Guillow's Super Cub Flies Well

Building a model that is too heavy is not good either and easily done. Several years ago I built a Champ kit that just had too heavy of balsa in the kit. No doubt this can happen even in what would appear to be a quality kit. It was easy to cover the model with tissue as the structure was rigid and it did not seem terrible heavy lifting it as it was a small model. Trying to fly the model it was difficult to adjust and it always appeared to me to be flying at the edge of a stall, I added more rubber which helped but now it was flying faster and crashing harder. Each repair added a little more weight and after major damage I gave up. I had trouble with a Guillow’s Cessna 180 also so when I built the smaller Super Cub kit which has the same basic structure I built it lighter by building a lighter tail with balsa curved around a form. The plane did not need any nose weight and it flies well.

Champ was too Heavy

In a more current project I believe my airplane came out too heavy for the wing area and the amount of rubber the model was carrying. I wanted to try a new to me electronic DT system that added 9 grams which does not seem too heavy but when you are on the edge it might be. Test glide without the rubber motor and tiny amount of clay for balance looked good.  Reduced winds test flights were a constant battle with a stall after the rubber ran out. I added right side thrust, down thrust and right rudder tab. To me the 16 strands of rubber seemed like a heavy load. Before destroying the fuselage the last time I had glided the model from a small hill, the glide looked flat but not diving. When it landed gently, it broke the vertical fin. I will rebuild the fuselage and use a fuse DT this time.

Gollywock Crash

Bill Kuhl

Related Links

http://scienceguyorg.blogspot.com/2017/03/bad-axe-embryo-thermals-do-not-care.html

http://scienceguyorg.blogspot.com/2014/06/herr-champ-first-flights.html

http://scienceguyorg.blogspot.com/2014/07/herr-champ-update.html

 http://www.dave-cushman.net/aircraft/balsa_selection.html

 http://www.modelaviation.com/balsa

http://www.nclra.org/Programs/BalsaDensity.php