Friday, November 18, 2016

Model Airplane Building in Full Swing

Although it has been warm enough to fly model airplanes outdoors so far, the daylight hours have dwindled until it is getting dark just as I leave work.  My evenings are now spent building model airplanes for next flying season although last year I flew some outdoors all winter long.  For next year I am building a variety of competition outdoor free flight model airplanes. 

Wilbur NOS Rubber Model

Selecting models that introduce me to new building techniques that I have not yet tried in previous models makes the build even more interesting, or I might try a new covering type that I have not used before. After going to the 2016 Free Flight Nats and meeting Jim O’Reilly I decided I wanted to build a nostalgia rubber powered model. Jim gave me some recommendations and I settled on the Wilbur rubber model that was designed in the 50’s. This introduced me to a type of fuselage construction where the fuselage was constructed almost entirely of angled strips of balsa. It was a fair amount of work but the fuselage is amazingly rigid.

Polecat X Wing


In the 2016 flying season I flew a beginners P30 model the NJAPF at the Nats and two smaller contests, it worked well for me but it is not considered a super high-performance model. I had previously had purchased plans and rib kit for the Polecat X P30 designed by Don DeLoach so decided to build that model for next contest season. This model introduced me to carbon capped ribs and building a rolled balsa fuselage, I have not attempted the fuselage yet. I plan to cover the model with ¼ mil Mylar covering which will be new to me.

Retro Gnome

Texas Timer Micro DT

Sky Demon E20

Ready for covering is a Retro Gnome free flight hi-start glider, the building techniques are not really new to me but I have to setup the auto rudder function. Auto rudder keeps the glider going straight on tow but when tow line releases the rudder moves enough to cause the glider to fly in a circle. I am also using the Texas Timers Micro DT for the first time. This is a mechanical timer which should be more accurate than the viscus and fuse DT’s.  I am also building a Sky Demon e20 model with conventional construction but will use an electronic timer/DT from BSD Micro that I have not worked with before.

Recently I have had some pictures and writing published in model aviation magazines. A couple of mentions in Aeromodeller Magazine published in the UK, the latest issue mentioned my Fantastic Foam Flyer simple rubber powered model and the after school program created by teacher Jon Kemm in the UK. Ronnie Espolt who lives on the US west coast and works with the foam airplanes also was mentioned. Pictures I had taken of 2016 Nats were in NFFS Digest and my description of the Nats was published in November 2016 Model Aviation Magazine. My hope is that getting the name of people that are promoting model aviation for young people and I into media will create more awareness to what we are trying to accomplish.

Bill Kuhl

Related Weblinks    - Wilbur   - Polecat X   - Retro Gnome  Texas Timers Micro DT  - BSD Micro electronic timer/dt for E20 - Sky Demon e20  - Aeromodeller Magazine  - Model Aviation Magazine - Jon Kemm  - Fantastic Foam Flyer

Monday, November 7, 2016

The Enjoyment from Fast Free Flight

This past year I spent a major amount of my model aviation time learning with competition free flight model airplanes. I still fly RC sailplanes both thermal and slope with some sport electric RC as well. My point in mentioning this is I have a fair amount of experience building and adjusting model airplanes, yet not the complete skill set for fast free flight airplanes. Adjusting the flight of the Pearl e202 E36 model has been much more challenging than the NJAPF P30 rubber model I fly. With my P30 model there has not been a single crash that I can remember, the only adjustments are with the climb and circle amounts.

Pearl E202 E36

P30 Rubber Model Easier to Trim

In previous articles I have mentioned some of the challenges I have had with my e36 model, it has crashed several times but I have been able to repair it fairly quickly. Carbon fiber reinforcement has been added in several places, I think I would do this on a new build. I thought I had the plane adjusted pretty well but this past Saturday the plane started turning to the left on launch in the climb, luckily I used a really short DT, it saved the airplane. I gave it what I thought was a very small amount of right rudder trim but it curved to the right after launch and hit the ground.

Damaged Model

The front of the pylon was smashed like it has been several times before but worse was one wingtip that was broken in many places underneath the covering. I collected the pieces and started the repair job but spent much of the afternoon flying RC gliders. The repairs were finished that evening but I also noticed the dihedral joint in the opposite wingtip was flexing easy. Now I do not know if it happened in the crash but my theory is this issue has been present and causing the model to be out of trim. I should have inspected the model before when I noticed a change in the flight pattern. My excuse was the colder temperatures I was flying it in.  There was nothing visible that you could see to spot the problem but putting any force on the joint it would be obvious.


Flying Again 
I got out early the next morning for test flights before there was any wind. As Hank Nystrom had reminded me, I started with the shortest motor run and quickest DT. That looked good but it was really short, increased the motor run a little more and still looking good. Next I gave the DT just a little more time so I could see the transition; that looked good. Just a little longer DT as I was flying from a small flying site, it looked really good with no stall between power and glide. I was elated and it gave me back some confidence that I was again making progress.

Flying From Farm Land but Trees on Edge

For me the enjoyment in free flight models with a fast climb rate comes from the more challenging aspects adjusting the model and building it correctly to start with. It forces you to really observe the model closely when flying and theorize how it might be improved. When you watch so many power models fly at a contest it looks way too easy because you do not realize the time and effort the experienced modelers put into getting their models to fly so well.

Bill Kuhl

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