Monday, October 26, 2015

Pushing the Edge With Small Field Free flight

Last Sunday was a treat for outdoor activities in Minnesota with very little wind and a high around 60 degrees. I took good advantage of the nice fall weather for model airplane flying at two different flying sites with a variety of model airplanes.  The first flight was with the electric powered Starduster free flight I had repaired after a break in the fuselage. When I launched I thought I was upwind and it would circle around to the right and drift down the field. Under power it went out from the field farther than I thought and when it circled back it appeared to be going to cross a busy road and head for a woods. It did come back and landed on the field, what a relief.  I really wanted to fly it again and launched in a different direction, this time it went too far in the opposite direction heading towards a building but landed short of that in a bush. At this point I thought I pushed my luck far enough.

AMA Maxi Jr

Electric Starduster Coming Back to the Field

I flew a RC glider for a time and chatted with two other guys that were flying RC gliders. In my car I had one of the Fantastic Foam Flyer rubber powered airplanes that I always keep in the car. With more room than I normally have for flying  it I decided to give it a good number of turns in the rubber motor. A nice flight but it looked like it was headed for trees on another border of the field. I moved farther the opposite way and cranked in more turns.  This time it was really getting high and headed over the road again but circled back.  It was getting time to leave and I thought I had pushed my luck pretty far.

Fantastic Foam Flyer

After a quick dinner I decided it was still warm enough and the wind was light; I would fly a couple of balsa and tissue rubber powered free flight models. I started with the AMA Maxi Jr model which flies so well. One of the first flights it had come close to a flat roof building on the field but landed a short distance from it. I changed the direction I was launching from, flight after flight the airplane made nice circles fairly close and landing really close.  

AMA Maxi Jr Evening Flight

Flying Over the Roof

The draw to have the free flight airplane to climb higher and stay up longer was overruling my common sense. I cranked increasingly larger number of turns in the rubber motor, this was really cool to watch. The last flight, not by choice the airplane made a nice circle but then straightened out. It was headed for the trees and there was a pond beyond the trees and that darn building to the left. Just before the trees it started to circle again and went over the building. Could I possibly be lucky enough to dodge another bullet; no my luck had run out.  Now I am hoping for wind before it rains to blow the airplane off the roof.  This might be the end of this story but maybe not.

Good News - AMA Maxi Jr Recovered

It turns out maintenance staff had recovered my airplane before the rain. They had sent me an email which had gone into my Spam folder. About three weeks later I happened to find the email and went back to pick up the airplane. The propeller was missing and a small break in the stab, otherwise the airplane was fine.

Flying Again with Orange Propeller

Bill Kuhl

Related Links

Friday, October 23, 2015

Flapping Freebird Almost Flies Away

Yesterday was one of those perfect fall days that I just had to take advantage of for some outdoor model aviation fun with a wind forecast of 2 mph and plenty of sunshine. I also wanted to get some video and images for some projects.  In the demonstrations I have done I bring along a rubber powered ornithopter; a model that flies by flapping the wings. This is to demonstrate that man first tried to fly by trying to emulate birds. The model I use is the Freebird which can be built from plans found on the Internet.

Freebird Orinithopter

Normally I fly the Freebird indoors but the wind was so light I thought I would try to get video of it flying outdoors. To get a good number of winds in the rubber motor you should use a rubber winder but I just turned the front of the cranking mechanism. The first couple of flights were really short so I cranked in a couple of extra turns in a rubber motor that is really short. I launch again and it is flying around my head, I struggled to get the camera focused on it. 

As I continue to watch it through the video camera view finder, I think why is it still flying? The Freebird is getting smaller too so I keep trying to zoom in on it. Finally I realize it is in a thermal air current and it is getting higher and farther away. At this point which just shy of one minute I put down the camera and start running towards it. By now it was beyond a small hill with small trees, from on top of the hill I was able to spot it in tall grass.

I was so happy that I had video of this even with small sections of it not in focus. For something with such a poor glide ratio I would not thought it could fly so well in thermal lift. It did and I had the proof. After this I flew my Allegro Lite RC sailplane and encountered thermal lift that was fair but not real strong.  The lift appeared to diminish as the afternoon slipped away so I flew several rubber powered free flight models.

Bill Kuhl

Related Links

Freebird Plans

Freebird Ornithopter Blog Post

Pioneers of Aviation Blog Post

Leonardo Da Vinci Ornithopter Blog Post

Allegro Lite Blog Post

Video of Freebird in Thermal Lift

Monday, October 19, 2015

Last Sailplane Event for Season

October 17, 2015 our casual group of RC sailplane pilots had our last monthly event for 2015. Normally there is competition unless it is so windy that we go slope soaring, this year the wind was of a reasonable level for all events.  We started a little later than normal because it was chilly to start with but it soon warmed up and the thermal lift was pretty good.  This was a fun fly event where any type of sailplane could be flown but as it turned out most of the sailplanes were classic gliders with a lot of wood structure.

No doubt the highlight of the event was when Wayne flew the giant Sailaire glider he had refurbished. At the first event of the year Wayne had brought out the bare structure to show us, he did an exceptional job of refinishing this glider. I had posted a picture of this sailplane and other classic sailplanes to the Facebook group The Golden Years of RC Sailplanes and Modern Hybrids and there were so many Likes and positive comments. One person said, “One of the most beautiful Sailaires I've seen in a while!!! Congrats.   Wayne did some test glides which look real good and then put it on the winch. He carefully pulsed the winch but the wing had a rather severe bend to it, Wayne assured me that was normal.

Another classic sailplane was Craig’s Oly 2 which flew for first time in 30 years; he said it needed very little trim. Craig also had a beautiful Bird of Time with a T-tail.  There were also a couple of Wanderer sailplanes of two different sizes.  Wayne also flew his Raven and I flew an old sailplane that was a combination of different sailplanes. I think I must try too hard even in relaxed competition because my landings are a 100 percent better when not contest flying. Without risking the sailplane going downwind of the field in wind that was rather strong at times, I had a couple of 5 minute flights.  

There was a new (to me) pilot to the field from out of town that knew the guy that first helped me get into RC sailplanes and indoor free flight rubber competition. He had several sailplanes and appeared to be having a great time flying with us.  Sunday it was windy again but I did slope soaring, I really do not want the model flying season to end.

Bill Kuhl

Sunday, October 18, 2015

More Dynamic Soaring Adventures

I have had a good run of weekend slope soaring lately, today the forecast was for south wind which should be good but it appeared to be veering east and very gusty at times. First flights were done with a foam glider again, it was getting tossed around on the front side but I wasn't going to let that stop me from dropping around the back side. After flying a fiberglass glider on the backside for a couple of flying sessions I thought I might do better with the foam glider now. For a couple of laps I did but then it would be off course. The speed it was hitting was really good at times, one time I noticed it shudder as it pierced through the boundary layer. Somehow I managed to hit rather hard and knocked the wing off which also pulled the aileron connections, now I would have to fly the fiberglass glider.

Launching Dart fiberglass glider I gave it a wimpy throw and it was blown into the hill, it was so windy right then that it was hard to hold. Waited for a dip in the wind and gave it a good throw, it was flying good. It was flying fast on the front side; getting tossed around but I could handle this. I was thinking maybe I should be content flying on the front but no I wasn't going to be a wimp.

After the last flying session I put more down into the Dart trim, flying on the front it was fine but when it got speed up on around the back side I was pushing a lot of down. The speed was really fast some of the time, I heard the whistling sound a couple of times. There is much work I need to do yet to be flying the optimum circuit but at least I am not all over the hill like I was the beginning of the season.

So far with the foam Super Scooter the best I have done is 11 DS circuits, I decided I would beat that with the Dart. Lap after lap it went until it had done 12 laps and was starting the 13th lap but a gust caught it going around the top and sent it bouncing. Pretty good landing at the bottom so when I got up the hill I proceeded to try again. Again I did 12 laps but lost speed coming up the back side and stalled the glider. Very minor damage but I didn't have any epoxy along.

There will be time when the wind will be better and I will go lap after lap, I can feel it now. For sure I will not give up trying until I do.

Bill Kuhl

Previous DS Posts

Taking RC Dart Glider to Back Side

Dynamic Soaring Goal Raising the Bar

Friday, October 16, 2015

Efficiency and Model Aviation - II

In February of 2015 I had written a blog post entitled “Efficiency and Model Aviation”; the article placed emphasis more on simpler rubber powered free flight although it did mention the super-efficient F1D indoor free flight competition models. As the comfortable outdoor flying season is winding down where I live I am thinking about some of what I learned about model airplane efficiency. Much of this is related the radio control glider flying I do but I am now thinking about more efficient outdoor free flight models also.

My Allegro Lite RC Sailplane Efficient but Not Compared to Larger Sailplanes

Recently I watched a NOVA program entitled “Making Stuff Faster”; it can be watched online at this link . Of particular interest to me in this program was the Oracle sailboat which is capable of top speeds over 50 mph and the Velox 3 bicycle that set a world record of 83.1 mph.  New technologies made possible by new lightweight materials made the high-speeds obtained possible.

Foam Super Scooter Not Real Efficient

Fiberglass Shadow More Efficient

Radio Control sailplanes I fly stay aloft because of lift from deflected air created by the wind blowing against a slope or from rising thermal air currents.  For the slope flying I have been moving away from gliders made mainly from foam to gliders that are more rigid built from fiberglass and other rigid materials. Flying from the same slope with the same conditions on a particular day the difference in performance is amazing.  At times the foam gliders will not stay airborne for more than 30 seconds while with the more efficient fiberglass gliders I can fly easily for several minutes. The reason for this goes back to my first article where Lift / Drag were discussed. 

Xplorer Sailplane Very Efficient

Circling in Thermal Lift

This summer I also flew in some thermal duration sailplane contests. Compared to other sailplane pilots my sailplanes did not perform very well. Much of this was piloting skill but still I was at a disadvantage flying smaller sailplanes in competition against sailplanes with twice the wingspan. There are aerodynamic factors of why these larger gliders are more efficient in using the available lift from thermal air currents than my smaller sailplanes.

Electric Starduster Climbs Steep 

Pearl E202 Construction

Electrical Components Texas Timers

Looking ahead for 2016 I plan to do more flying of larger, more efficient outdoor free flight models. A big factor in outdoor free flight competition is how high the model will climb before going into the glide. I am building the Pearl E202 E36 electric powered free flight but to test the electric components it will use, everything was installed in a larger glow powered airplane. The power system of brushless electric motor and a lithium battery that provides current at a very fast rate allow this plane to climb darn near vertical.  

Lidberg NJAPF P30 Model

Brought out from collecting dust in the basement recently is a rubber powered P30 competition class model. With old rubber strands for a motor, the climb rate was not too impressive on some trim flights. I have been given much advice on the strand make up of a rubber and how much to wind it. No doubt the airplane will give much longer flights in the future when flying more efficiently.  The previous summer I had experimented with a free flight discus launch glider. I went through phases of learning how to launch it without breaking, getting more consistent high launches, and then adjusting for a longer glide. Next year I plan to finish another glider as the first one flew away in a thermal air current.

Bill Kuhl

Vendors Mentioned

Texas Timers – electrical components for E36 free flight 

PearlFreeFlight  - E36 free flight kits  

AA Lidberg Plan Service – NJAPF P30 rubber power free flight kit 

Xplorer RC Sailplane 

Related Blog Articles

Efficiency and Model Aviation

Slope Soaring a Heavy 2-Meter Glider on a Small Slope

My Small Slope Soaring Webpage

Allegro Lite Finished and Flying

Watching the Super RC Sailplanes on Saturday

Unwinding With Free Flight Discus Glider

Free Flight Glider Discus Update

Tip Launched Glider Slow to Come Down

Goodbye to My First Tip Launched Free Flight Glider

Monday, October 12, 2015

How Do Fish Get into Small Ponds

I have been fishing for largemouth bass in one particular pond fairly often and someone had asked me how did the fish get into the pond?  That is a question I have pondered also, sorry bad pun opportunity. Searching the Internet it seems like many people have asked that same question. Probably the most popular answer is fish eggs attach to the feet of water fowl and travel with them to be deposited in new bodies of water. Some people really questioned how often that actually happens but other people replied it only has to happen rarely and fish multiply quickly. Times of flooding are another opportunity for the fish to travel to new areas.

I thought I would do a little experiment on my own and check out a small man made pond that was created by Apache Mall in Rochester Minnesota. After purchasing some red worms at the Scheels sporting goods which is just across the highway from this pond, I threw out a worm on a small hook with a bobber. The bobber had barely touched the water and it started to go under. I pulled back and started reeling but there wasn’t much resistance, it was a tiny bluegill about 3 inches long. About this time circling vultures started to come closer, probably just to see what this crazy guy was doing by the small pond.

In the process of maybe 20 minutes I caught three more bluegills that were all the same tiny size. I also tried fishing in a small lake in Rochester where I caught only the more silver colored sunfish, these were somewhat larger. I have heard there are largemouth bass in the lake. In the pond I do not know, maybe without a predator fish the bluegills remain stunted in the pond.

More research no doubt could be done on these observations. 

Bill Kuhl


Low Investment Bass Fishing

Monday, October 5, 2015

Fantastic Foam Flyer

It is amazing how sometimes with the right combinations of factors something that appears so simple can perform so well.  I received a kit for a simple all-balsa rubber powered model airplane known as the Blue Ridge Dart. I assembled it in less than an hour and was testing it outdoors even with snow on the ground. I was amazed at how stable it flew and the duration was good. My thoughts soon went to designing a similar model using foam plates instead of thin sheet balsa as the primary building material, the fuselage is still balsa. As the amount of flat material is limited in a foam plate, I built a 3-piece wing with flat center section instead of a 2-piece wing, the tail surfaces are slightly smaller too.

College for Kids Class

The prototype airplane was assembled using low temperature hot glue as this would not destroy the foam and is a quick method to build.  First flights were very promising; this plane really climbs on 1/8” wide rubber. It has a long fuselage which makes for easy winding by hand if there is no slack in the motor loop yet still gives a pretty long motor run. I wanted a very stable flying foam airplane for kid classes that I teach and previous design ideas didn’t seem stable enough in some cases.

Fantastic Foam Flyer

This past summer for the Engineering Through Models class which is part of College for Kids at WSU I introduced this plane to the kids. I had built the simple balsa fuselages and traced out the parts on foam plates, this way they only needed a scissors and low temp hot glue gun to build the airplanes. Construction went well and they flew the planes indoors because it was rather hot outside. The planes flew well and survived many hits to the walls and floor pretty well, I was impressed. On the last day of class I showed the students how one of these planes could fly outdoors when really wound up. It was a calm day and the plane flew very high over the campus but landed close to where it was launched, they were impressed.

Flying High over WSU Campus

3-Panel Wing

My longest flight outdoors ended up in me losing sight of the model after close to 3 minutes as it became a tiny spot hoisted aloft in a thermal air current. An online friend of mine that built one of these planes had a similar experience and lost his on the first flight after watching it for over two minutes.

Denny Dock and Grandsons built planes for camping trip

Paul L. Built a Gull Wing Version Too
Propeller from Sky Streak Worked Well

The article on my website has very detailed construction steps and the flying surface templates can be downloaded in PDF format. Propeller assemblies can be taken from other all-balsa planes such as the ones sold by the Guillow company.

Construction Article Link   - Fantastic Foam Flyer

FFF at 30 Second Film Festival

Blue Ridge Dart 

Bill Kuhl


Glue Plane Quickly

Flying High Over WSU

30 Seconds Construction Video

Flight Phases Shows Over Minute Flight