2016 First Soaring Event

April 23, 2016 was the first RC soaring event for a group of people mainly from the Rochester Minnesota area although often there are many people from out of town.  Like so often on the first event of the year it was windy. In the earlier years we would have been content to just talk sailplanes but as we get more experienced we fly in windier weather.

I brought out my heavy Shadow 2 meter that slides to the wind really well; the other fliers flew foam gliders. Wayne flew a Highlander 2 meter and George flew his Radian. There was lift but it was hard to stay with it for very long. I made the mistake of landing slightly cross-wind with the Shadow glider and broke the fuselage, something that has happened before.  I then brought out my Hyper-DL and hi start launched it, it penetrates pretty well for a smaller glider. On one occasion I was going downwind across the field low and a gust hit it and not enough room to recover, broken stab resulted.

The other pilots did better but Wayne had some damage to the fuselage of his Highlander by the stab by the end of the flying session. George took his Radian home without repairs needed. That afternoon George received his high-power model rocketry certificate with an amazing launch.

As we were packing up to go we noticed a hawk very low and close to us catch a thermal and start circling upwards. Following the hawk were two crows that appeared not to be very happy with the hawk.  Hopefully next month the winds will be lighter.

Bill Kuhl
http://www.ideas-inspire.com

Scout CLG Drowns

At least that is my theory unless it was eaten by a monster bass in the small pond it landed in. Flying free flight model airplanes from tiny fields is always a risky endeavor but you work with what you have. Last evening the wind went down to almost still around 6:30 pm although the sky was completely overcast. I wanted to try out the new winding stooge, heavy duty winder, and a p30 class rubber model that I have added a DT system too.  As much of this is new to me I was really clumsy trying to make everything work but I had several short but really stable flights with the p30 model. 

Scout CLG

Scout Last Seen Floating

Another rubber model, the Guillow’s PC-6 Porter was tried with the new winding equipment and it flew well also. It was getting rather dark but it was so still, I had to try the Scout CLG model that I carry in my car. To start with it had too much turn and would spiral into the ground; I tweaked the rear edge of the vertical fin the tiniest amount and now it was gliding in the opposite direction in a very large circle. The glide was amazing, so slow and long.

Should have increased the turn or called it quits but I had to try one more flight. Up it goes; perfect transition and then it just glides and glides and glides. Oh no, it is getting close to the pond. Sure enough it lands in the middle of the pond. As quick as possible I pack up my stuff and go to get my fishing pole from my house a mile away. Come back but it is getting dark by now. I casted and casted but could not reach it, so run around to the other side. Still not able to snag on to it, but now my line is tangled on the pole. With much trouble I break off the line and tie a stick on, but that is way too heavy. It is really getting dark now so I give up.

Flying P30

P30 on New Stand

According to the forecast the wind was going to increase during the night in a direction that should bring it in to the close shore. I decided I would go over there before work and it should have drifted into the shore. The wind had come up and it was starting to drizzle but after walking the entire perimeter of the pond there was no sighting of the glider. 

No Sign of Scout in the Morning

Scout Pieces

Stan Buddenbohm created a really simple to build glider in the Scout, I have the plans and could easily build another. I think the glider really needs a dt system as it flies so well.  How I didn’t lose the glider one other time as it was circling in a thermal I will never know.

Bill Kuhl

http://www.ideas-inspire.com

Stan's Catalog

New Life for an Electric Glider

Several years ago, I am thinking it has been over 10 years, I had purchased an ARF electric glider with a 60” wingspan. The fuselage was a heavier fiberglass fuselage but the wing was built-up balsa with a transparent covering. There was very little work left to be done, where ever this plane was built the labor cost must have been very low.  

Before Conversion

Speed 400 Gear Drive

Power for the electric motor was first from nicad batteries and later a nimh battery. The motor was the popular Speed 400 but it was geared down to spin a larger propeller. This system was adequate to climb to altitude but only a couple times at the most. Despite the rather heavy weight I had some good thermal flights with it. The real downside was needing multiple batteries and the need to do field charging to get much flying in. At some point it went on a shelf and never converted to 2.4 mhz radio.

Before First Flight of Conversion

Not long ago I thought I really should fly that glider again with modern equipment such as lithium battery, brushless motor, and 2.mhz receiver. The servos were moved way back for balance but were small servos, I thought it might be tough to get the CG located with lighter equipment so I decided I will mount the motor out front of the glider. This might have not been necessary as I am using the rather large 1350 mah lithium batteries that I use in my Radian Pro. 

Brushless Atlas Motor

Slowly I am learning about electric power but instead of trying to calculate the proper motor size needed I just inquired on soaring club listserve. Several people gave me good ideas but someone offered to send me two electric motors to try, Thanks Rich you are the best.  The one motor was designed for a rear mount so that is the motor I used. Before putting much effort into the project I just epoxied a plywood bulkhead to the front of the glider and attached the motor with wood screws. Taped in the battery and went flying. 

Magnetic Hatch, Messy Micro Balloons

This motor seemed to be the perfect match; it easily pulls the glider to altitude. Soaring performance is still not going to be wonderful but it is perfect to grab after work with one charged battery and do a good amount of soaring from a small field. It is working so well that I went to the extra effort of blending the nose to the firewall and installed a magnet system to hold the hatch on.

Now maybe I should look at a couple more old airplanes on the shelf.


Bill Kuhl
http://www.ideas-inspire.com

Google Trends Might Not Figure Out STEM but Can Spot a Wrecking Ball

Recently I did some web searches using the Google Trends web utility because I was curious what search data might show for terms related to the projects on my website and STEM education in general. My observation from the summer class I have been teaching is that the interest has diminished somewhat over the last few years although the traffic to my website is higher than it has ever been. Increased traffic to the website no doubt can be correlated to adding new material and my social media efforts to relate back to the website.  Locally I have not done any promotion of my website or projects for some time so that could explain some of the local decline.



Data provided by https://www.google.com/trends/ 




To use this free web utility just bring up https://www.google.com/trends/ . I noticed the information Google provides says “a percentage of Google web searches are analyzed”, I wonder how much that might detract from the accuracy?



I started searching for the acronym “STEM” but in the suggestion of search terms it was suggested to
use all the words, Science Technology Engineering and Mathematics. There is a good reason to do that because just entering STEM could give results related to stem cells. I ran into this issue when I typed in “kites” and so many results came up for one month in 2010, turns out there was a movie by that name released around that time which spiked the results.




In demonstrating this utility to a friend I picked out someone with some celebrity status, “Miley Cyrus”. It was interesting to note there was a big spike in August 2013, my friend said that was the time Miley had come out with her song and video “Wrecking Ball”.  To verify this theory I entered “Wrecking Ball” and darn if the spike appeared in the same time segment.





Back to my searches related to STEM and project ideas; STEM spelled out the graph is pretty level until 2011 then it starts going up. September 2013 there is a huge spike and then it goes gradually up. “STEM education” starts a gradual climb upwards in 2007 until a peak the goes up and down until the present.  If anyone has ideas what has caused these trends, leave a comment.



What has been more puzzling to me is searching on the different project areas such as mousetrap cars, syringe hydraulic arms, and water rockets have shown a decline and then leveling off in recent years. As far as a spike in for STEM in 2013 there was a (STEM) Education 5-year Strategic Plan published in May 2013 on the Whitehouse website.

Bill Kuhl
http://www.ideas-inspire.com

Calibration and the Free Flight Model Airplane

In recent months I have been experimenting with the Lego NXT robotics that I had purchased a few years ago. My focus lately has been to learn the different methods in algorithms for following a black line on a white background. Simpler methods work but result in a somewhat jerky path around the black line track.  Then I tried a program that starts with a “self-calibration” before going around the track and the performance was amazing, it followed the path really smooth and much faster.

Lego NXT Following Black Line Around a Track

Quadcopter Must Calibrate to Ground Below

This had me thinking about the definition of “calibration” and all the different places this idea is used. Calibration is adjusting to known or unvarying measure. Quadcopters do this to figure out what is level in relation to the ground below but what about some areas that are not so high tech? How about when you tune your musical instruments by comparing to a few notes on another instrument that is in tune? My mind then started thinking about free flight model airplanes and selecting the launch position and adjusting the power phase of the flight. During this process you are adjusting to the flying conditions at the time, would this be like a calibration process.

Rubber Powered Free Flight Should Drift Away from the Trees

For a free flight model airplane instead of using electronic instruments to record data such as light levels or distance from the ground you most likely will just feel the wind on your face to determine where to launch although contest flyers might use electronic devices for thermal detection. As the model plane normally will drift with the wind you will want to position yourself far upwind in the field boundaries. The velocity is what is important; in the physics definition, velocity is a combination of speed and direction.  Where the free flight airplane lands downwind normally results from the direction the airplane drifts and the speed the wind is blowing. In strong wind the airplane will normally drift farther.

Electric Free Flight Should Land Before Trees in the Background

If it is windy you will position upwind as far as possible but further adjustments might be possible to shorten the length of the flight. For rubber powered models reducing the number of winds should shorten the length of the flight. If it is a glow engine or electric powered model the timer that shuts off the length of the power at a time period is what you adjust.

Until the flight has ended you really do not know what to expect although experience in similar conditions will give you a better idea. I start out adjusting the length of power run to be really short and gradually lengthened as I observe how far down the field the airplane lands.

AMA Maxi Jr Launch

AMA Maxi Jr Path Changed and Landed on this Roof

The real life scenario of flying a free flight model airplanes outdoors is so much more complicated than this in that the air movement can quickly change, velocity (direction and speed) and the airplane can change course and fly a different direction. Thermal air currents cannot only take your airplane much higher but also change the velocity of the wind on the field. For this reason I normally fly my sport free flight model without dethermalizers early morning or evening when thermal activity is less prevalent. 

Indoor Free Flight Launched Close to Wall

Flying a rubber powered free flight indoors hopefully the amount of moving air will be very minimal but still there will be adjustments needed to best utilize the flying space. Based on the minimum width and height of the flying area you will need to adjust the diameter of circle that the airplane flies and have the airplane circle to the inside of that edge.  The maximum height the airplane can obtain will be limited by the ceiling height. If it is a smooth ceiling some bouncing from the ceiling might be alright but if there are rafters that the airplane could be caught in it is preferable to avoid letting the airplane climb over a certain height. Fewer winds can be used in the rubber motor but more common is to use a smaller width rubber strip or a different propeller.  

Sky Bunny Almost Landed in the Lake

Calling the launching of free flight model airplanes calibration might really be a stretch in that values are not normally measured and the values can vary a great deal. Yet I think my general point of the article is valid in that before launching a model airplane that flies completely with no control from the ground it is important to think about the factors that could influence the flight and adjust accordingly. With practice hopefully your human algorithms will be refined.


Bill Kuhl
http://www.ideas-inspire.com

Related Links

Basic Quadcopters   - my webpage

AMA Maxa Jr Perfect from the Start


Pushing the Edge with Small Field Free Flight

Good Flying for Winter Build FF Gliders

This winter I decided I would build free flight gliders instead of the stick and tissue rubber powered free flight air planes that I had built other years. I started off with a simple kit the Mini Flash, I had built one before but converted it to catapult launch. To try something different I covered the wing with Monocote which was mentioned on the plans for ding resistance. Another hand launch glider was the Boweevil a larger glider, this one I wiped on spar varnish and then spray painted the tips for visibility.

Scout CLG and Dynomite TLG Stan Buddenbohm

Boweevil

The other two gliders I built were the Scout CLG and a tip launched glider Dynomite both kits from Stan Buddenbohm. Before winter really started I flew the Scout Catapult Launch Glider without finishing it, I was amazed for such a simple design how well it flew. Both of these gliders are featured in a DVD available from the National Free Flight Society, “ How to Build and Fly Catapult and Tip Launch Gliders” .  I plan to write about each glider in future blog posts.

Boweevil HL 

Last Saturday was relatively warm for March in Minnesota and the wind was light. Further adjustments are needed on the Dynomite and the wing broke loose from hitting the ground after a stall. I started launching the Boweevil and after a few throws it connected with a thermal, it kept circling while slowly moving across the field. Thought this might be the last time I saw this glider but it came out of the thermal before getting to the edge of the field.

As I walked upwind I noticed a father and two kids were trying to fly kites. As there was little wind, it was not going well for them. Remembering I had a Fantastic Foam Flyer airplane in my car so I gave it to the father and gave them a quick lesson on the basics. The kids were having so much fun with the airplane but I think the father was having more fun with the rubber powered model airplane.

Mini Flash HL

After they left I made some flights on the Mini Flash hand launch glider. With the Monocote covered wing this glider is a little heavy but it sure launches nice. A few good throws and the tiny glider was bouncing around in a thermal. The more circles it made the faster it went and before reaching the edge of the field it went into a steep spiral dive that stuck it into the soft ground. After pushing my luck so many times without losing a glider I thought giving the Scout a wimpy catapult launch it would be too low to be captured by a thermal. Wrong it started circling higher also but popped out of the thermal.

Mini Flash Survived High Speed Dive

At this point I really, really had pushed my luck and decided to take my winter glider fleet home. 



Bill Kuhl
http://www.ideas-inspire.com

Related Links

Campbell's Custom Kits Modern Hand Launch Gliders on NFFS website

National Free Flight Society (NFFS) website

NFFS Catalog including Videos

DiscU.S.Kid Stan Buddenbohm

Fantastic Foam Flyer - Rubber Powered Free Flight Airplane

Variety in Model Aviation Hobby

“Variety is the spice of life” is a popular idiom and is how I pursue my model aviation hobby. Many people tend to limit the hobby to just radio control model airplanes or just free flight models or possibly a narrow subset such of either type.  My start in model flying was control line glow powered models which I would like to try again with electric power someday.

Diving RC Slope Glider Over a Windy Ridge is Fun Now

Some people probably limit the type of model airplanes just because that is where their interest lies.  There could be a huge number of other reasons also for limiting the type of model airplanes they fly such as flying sites, time available, help available, vehicle to transport, or money.  If competition is your main focus in model aviation then most people will probably achieve greater success if their effort is more focused.

Gas Powered Airplane Would not fit in my Small Car Now

I have tried many types of model airplanes over the years and currently do not fly many of those types of models at all.  After becoming fairly competent at flying glow powered radio control trainer aircraft I took up pylon racing with glow powered engines of the .15 cu in and later .049 because the club I belonged to hosted these events. Later my father and me designed and built large gasoline engine powered models.

RC Thermal Soaring Contest

After taking off ten years from the model aviation hobby when I started flying again I wanted to try something different so I looked into RC soaring which is my primary focus now. At the same time I built a simple rubber powered free flight which lead me to find another local modeler that was an expert in indoor free flight which I pursued also.

Flying an Indoor Free Flight

100" Span Balsa Glider

I have to believe that an exposure to a variety of model aviation activities can help you develop skills that can be helpful in completely different areas of model aircraft. For example after building delicate indoor free flight models you get a feel for handling delicate structure without breaking it.  When I built a 100” span balsa RC glider last year handling the larger balsa pieces was really easy.  Flying RC gliders from small slopes has really shown me the differences extra drag can make and the need for flying smooth. Using minimal control movement is equally important when thermal soaring RC gliders but flying close to yourself on the slope it is much easier to see what the glider is doing.

Lately I have been giving more thought to how I would like to divide the time and effort I put into my model aviation hobby

*  RC thermal soaring – many people in my area fly this and hold contests

*  RC slope soaring – great for windy weather and group trips

*  Free flight sport flying – great for flying in the evening when wind is really low

*  Promoting simple free flight models – I have been most active in promoting models constructed primarily from foam plates for kids.

Building E36 Electric Free Flight

For the future I would like to pursue outdoor free flight competition more and try electric powered control line.

Bill Kuhl

http://www.ideas-inspire.com