Scienceguyorg Ramblings: Busy July Class and Free Flight Contests

Wednesday, July 5, 2017

Busy July Class and Free Flight Contests

July is a busy month for me with College for Kids class and free flight model airplane contests. It is a good thing I spent the time in June fishing as my fishing success now has the fish winning as I am not catching anything. I noticed on a recent beautiful evening weather wise that there was almost no one else fishing either. The fish cannot just quit eating can they?

Super Pearl e202 E36

As the wind goes down later in the evening I have been flying the Mountain Lion Mark II outdoors to get it adjusted for consistent flights using the included 3/32” rubber and also 1/8”. The plane appears to fly much better to the right but will switch to flying left before the rubber has completely run down. Plastic propeller with hangers appear to have right thrust built in which should be good as the torque normally forces a model to fly towards the left. The Mountain Lion Mark II has a rather small vertical fin that seems really sensitive to adjustment, I just wonder if the built-in right thrust is too much for this design.

Pearl e202 Climbing

New Vertical Fin

BMJR e36 Starduster

My two e36 electric free flight models appear to be flying better all the time as I make improvements. These models seem sensitive to some adjustments I make and not to other. The Super Pearl e202 that I have been flying for over a year has had some improvements. The balsa pylon that has broken several times I covered with thin fiberglass cloth using Sigment. A lever arrangement was created under the DT servo so I could put a lot more tension on the spring connected to the DT line. As I did not use C-grain balsa for the vertical fin, it had warped. A new one was created using to layers of thinner balsa running at opposing directions, an A-stop Rudder Adjuster was added purchased from Larry Davidson. On my BMJR Starduster e36 I discovered the rubber bands were not tight enough so I corrected that. Both models are climbing in consistent power patterns.

Lever under DT servo Super Pearl e202

In working with the competition free fight models I feel like I have learned so much about aerodynamics and getting a model in proper trim. One of the most important lessons has been to get the CG (Center of Gravity) location where the plans indicate and then make small adjustments to the incidence angle. With my simple rubber powered beginner models I tend to move CG around to adjust the climb and glide.