Polecat X P30 at 2017 Nats

Most all of the testing of the Polecat X P30 model was done at the 2017 Nats mainly because of not a large enough flying site close to home.  I had flown it several times on smaller sites using only hand winds but as someone pointed out you cannot really see what it will do when a large number of turns are used. In my case the Polecat flew just fine as I increased the turns, this is one plane that pretty much flew with no trim adjustments needed.  If you read my build report, you know I was trying a lot of new things with this model; covering with Mylar, using tiny carbon strips, rolling a balsa fuselage, and trying the pop-off wing DT using an electronic timer.

Polecat X in Flight

Polecat X

Any concern I had about the plane landing too hard because the wing is separated from the fuselage were unfounded. The wing spins so fast on the line it slows the plane way down when coming down. One time I forgot to close one of the swivels and the wing came off the line; that did slight damage to the fuselage tube. Another time I must have had the line under the stab and it damaged the rear of the stab when the wing separated. 

Mistake with Routing Line

At first I was a little frustrated with the wing hold down method as with a slight breeze the wing would come off. I expressed my frustration to Jerry Murphy and he said I needed more tension on the DT line. I told him I was concerned with the tiny DT servo not functioning if too much tension. He gently increased the tension making sure the servo would still operate. Now the wing would stay on in a reasonable wind.

After Typical DT Landing

Selman e20 DT Timer

I never did get up to the 2000 turns possible with the rubber motor made up of 3/32” strands but did get up to 1400. As designed it climbs slowly but the propeller spins a long time. The last flights I made on the Muncie field had the plane drifting a long ways for chasing on foot. I did have my tracker on it after losing the Wilbur for a few days. Luckily I did not need the tracker to find the model but I did find out that it doesn’t go through even small hills. As high as I could hold the antenna I could not get a signal until I got on top of the small hill.

Looking forward to flying the Polecat X more, I did not fly in competition as it was windy the last day and I left for home.  The weight of the electronic DT with battery no doubt is a few grams, maybe not suitable for competition. For me at this point it is more important to be able to bring the plane down at a precise time to keep it on a smaller field.

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

Related Links

 http://www.pearlfreeflight.com/Buy.html  Pearl Free Flight website to Purchase Polecat X
http://scienceguyorg.blogspot.com/2017/03/polecat-x-p30-build-report.html

E20 & E36 at the Free Flight Nats

After coming to the 2016 with my e36 Super Pearl that had some issues resulting in no official flight, this year I came with two e36 models and an e20. Before the competition started I flew the Starduster e36 I had built over the winter but a bad launch damaged the wing. I repaired it but just couldn’t seem to get consistent flights, no doubt there are weak spots causing inconsistent flight patterns. The BMJR e20 Sky Demon flew pretty well when launched correctly.

Super Pearl e36 2017 Nats

Super Pearl e36 Climb

After last years Nats I discovered on the Super Pearl there was a weak spot in a dihedral joint and the stab was not as rigid as it should have been. The problem of diving when gliding to the right went away and I had some good flights.  For this year I covered the pylon with fiberglass cloth, improved the DT system, and replaced the vertical fin with a two-layer fin that was straight. Test flights looked really good; I was ready for the contest.

Flight at Muncie

Tuesday evening was the non-official e20 event.  My plane was the only one that wasn’t a pod and boom design, it has a full fuselage. The first flight I cheated myself in not having the DT set long enough, flying it earlier I had a hard time finding the tiny plane in the tall grass and had set a shorter DT time.  Increasing the DT time my plane did pretty well for what it is but came in 7th out of 11 entries. I was so busy flying I did not take any pictures, earlier I took pictures of Paul Bradley’s E20, Ralph Bradley won the event with a similar plane.

BMJR Sky Demon e20

Paul Bradley e20

Wednesday was the official e36 event, I knew there would be a lot of entries and most would have more powerful motors than the 1806N motor I was using.  Picking the weather conditions for me is rather like my stock market theory, if it looks like conditions are pretty good I fly early because I am afraid it will get windy later. In the market I seem to cash in when ahead but could have done better if stayed in longer but sometimes I have dodged a bullet.

e36 Starduster after Many Repairs

My three flights in e36 looked good, the E36 Pearl climbed in a steep spiral to the right and transitioned beautifully. The glide was really slow. On the last flight it encountered lift and made an easy max, at least it came down by DT after 2 minutes. That was really cool, I felt like now I was on the way to try for greater performance.

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

Related Links

http://www.pearlfreeflight.com/Buy.html  Pearl Free Flight Super Pearl e36
http://www.texastimers.com/  eMax electronic timer
http://www.bmjrmodels.com/sky-demon  BMJR Sky Demon
http://scienceguyorg.blogspot.com/2016/08/flying-my-e36-at-2016-nats.html  - e36 at 2016 Nats
http://scienceguyorg.blogspot.com/2016/10/making-progress-in-e36.html - my learning process in e36
http://scienceguyorg.blogspot.com/2016/12/sky-demon-e20-build-report.html  - BMR Sky Demon
http://scienceguyorg.blogspot.com/2017/01/starduster-bmjr-e36-build-report.html - e36 Starduster

Basic Yeller PeeWee 30 Free Flight

How I ended up building a PeeWee 30 glow powered free flight model came about in a rather roundabout way. I was ordering a used book from NFFS on power models and noticed a book on PeeWee 30 event and purchased that too. PeeWee 30 models are powered by a Cox PeeWee .020 glow engine and limited to a 30” maximum wingspan. 

Basic Yeller

 About that time I was ordering a Witch Hawk 500 kit from BMJR Models and I thought there was a discount for a second model, I added on a Sniffer kit also which qualifies for this class but not the most competitive design. When the Sniffer arrived I decided to build it electric powered with RC for DT function.  Yet I still wanted to build a glow powered PeeWee 30 so selected the Basic Yeller design which had to be built from plans.

Building from plans instead of a laser-cut kit seemed like a lot of work but it went pretty well. The structure of this plane is really thought out well with many diagonal pieces in the wing and stab. Finished airplane came out exactly at the minimum weight of 100 grams. For most of the adhesive I tried using Titebond glue using a glue syringe, this worked pretty well for more accurately applying the glue compared to squeezing it out of a tube of Duco. 

This was the first glow engine model for me in a long time; I did have a couple of PeeWee engines but obtained one with hole for fuel line drilled in the tank. Engine run time is controlled by using an eye dropper fuel tank, getting consistent run time I need to work on. DT system is a fuse which I have little experience with. Cleaning up the mess afterwards was not something I had missed but it isn’t too bad.

When the model was pretty much complete I gave it some test glides from a small hill, the glide looked really good.  I started the engine a few times and tested the fuse DT; I need more experience lighting a fuse. At the first Minnesota free flight contest, I decided to start it up and give it a launch. Darn it climbed out nicely, the glide stalled pretty bad.

There is a PeeWee30 event on the last day of the Nats but I thought I better do some test flights before the day of the event. I shimmed wing on the side to create a tilt for glide, this appeared to help the glide but might not be perfect yet. On the first runs I used 10% nitro but I switched to 25%, this helped the climb and the motor was far from lean.  It climbed to a good height on first test flights, and took a long time coming down. The first good flight went half way across the field and landed next to the blacktop, when I retrieved it the stab was down. For the next flight I made darn sure the fuse was lit before launching. What little wind there was had switched and it was gliding towards the RC soaring area. Just at the edge of where they were flying it came down by DT. 

Flying at Muncie

Contest day started out windy so I decided to head for home. I was satisfied that I had built the model pretty well and the trim was close to right. 

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

Wilbur Rubber Model at the 2017 Nats

Last week I attended my second outdoor free flight contest at the International Aeromodeling Center in Muncie, Indiana, the first time was in 2016.  After my first free flight Nats, I was so pumped up I built a bunch of free flight models, probably too many to allow for proper testing. Trying to decide how to split up my blog posts on the 2017 Nat’s I decided to describe what happened with each model in a separate post, starting with the old time rubber model the Wilbur.

Wilbur Found in the Corn

After the 2016 Nats and meeting Jim O’Reilly in person I decided I would try to build a rubber model larger than a p30, the largest rubber model I had built. Through some communications by email with Jim I decided to purchase the Wilbur plan and the Bob Holman short-kit from Jim’s business.  There were many new challenges; building a fuselage that was all diagonal braces, building a folding propeller, and fitting in an electronic band burner DT. By ordering a propeller blank through Volare Products much of the propeller work was completed.

Folding Propeller

Up to this point I had never braided a rubber motor, I attempted to braid a motor by watching a Youtube video. The resulting motor I created shook something terrible when I made test flights from hand winds because the rubber strands were uneven.  Jim and Chuck Powell gave me a demonstration on how to braid a motor the day before flying started at the Nats. Chuck had created some loops for me that I shoved in a box.

Test Gliding Wilbur

In the afternoon of the first day of competition I took out the rubber loops only to find one end of the rubber was so knotted it was unreal. I tried to straighten out the mess but gave up; this rubber could be cut up later for small models. From what I had learned I created a new motor and that went pretty well. I tried several flights from hand winds and the rubber unwound smoothly and the plane appeared to be in trim.

Knotted Mess of Rubber

Next I got out my winder and put in maybe 100 turns, this took the plane up a little higher so I could get a better idea what the glide looked like. I was happy that it flew as well as it did with no trim adjustments. It was getting close to 5 pm and I was going to put it away but thought no, one more flight. Like a fool I did not put a tracker on it, something I had just purchased used from Lee Campbell.

Walston Tracker

This time I wound in 200 turns, enough to take the model up to maybe 50 feet. The propeller folded and the model just kept gliding in a direction towards a cornfield, not the direction models had been drifting. I ran closer but could not keep up, why didn’t it land? No doubt it was in lift but having flown more RC sailplane than free flight I am not used to seeing a model stay up in lift so close to the ground. 

Wilbur Framework

From a distance it appeared the plane just barely went into the corn, but how do you know.  I looked for it for maybe 30 minutes or so and gave up. My name and phone number were on it and I thought maybe someone else would come across it looking for their plane. 


 Everything I flew after that except for my e20 had my tracker on it. Thursday afternoon I thought I would try to find it one more time.  I walked the area I thought I saw it last and darn if within about 10 minutes of looking I spotted it on top of a cornstalk. Having rained that morning the wing was warped but otherwise it was in perfect condition. I couldn’t stop smiling, Chuck Powell took my picture.

Warped Wing

There were much more dramatic airplane retrieval stories though out the week than mine. I understand Bob Hanford had a plane that failed to DT fly for 30 minutes into town and he was able to retrieve it. Sadly Mark Vancil lost a new Gollywock rubber model after watching it fly for over 6 minutes, some models landed in newly formed ponds on the field. Risk of losing a model is a part of free flight and a good reason to keep building more.

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

Related Links
http://scienceguyorg.blogspot.com/2017/01/building-wilbur-nos-rubber-model.html

http://www.jimoreillymodelplans.com/nostalgia_rubber/index.html
P. Visser's "Wilbur" Nostalgia Mulvihill per Zaic '53    Item ID  NOSR9 

http://volareproducts.com/   Propeller Blanks

http://www.faimodelsupply.com/  FAI Model Supply - bearings and bushings

http://www.starlink-flitetech.com/bbt-timers Band Burner

College for Kids 2017 - Wound Up

Another year of College for Kids at Winona State University is completed. Even teaching to smaller class size it was challenging. Building anything is not something that comes easy for many kids and probably many adults. Someone that was an educator for many years and works now with model aviation education told me once it is the spatial intelligence that many kids have a problem with. My father was a master at that and could envision complicated machines in his head such as 4-wheel drive tractors and then build them with no plans.  I would like to think I have a little of his ability.

Doc Fizzix Mousetrap Car

Again this year students built the Doc Fizzix mousetrap cars instead of the design I had on my website, which saved me a ton of work getting ready. I think I am getting better at teaching with this kit and the cars went together fairly well this year. On the same day as building the mousetrap cars students built the framework for the Mountain Lion Mark II balsa and tissue model airplane which was new this year. This is a more delicate model plane than my foam and balsa model FFF. There was less breakage than I imagined but I had cautioned the students several times about the delicate parts.

Mountain Lion Mk II

The final day the Mountain Lion kits were finished up. With the first group of students I had forgot to caution the students that although both wing halves were identical, you have to cover with tissue on top side only of each wing panel. On a couple of the planes they had to rip off covering on one wing half and recover.  Teaching the construction of this plane should go better the next time. With experience you learn what the more difficult parts are and adjust your explanations accordingly.

Add caption

The local newspaper, Winona Daily News did a very nice story on College for Kids this year including much about my class, I have provided the link. Also a student had left her Mountain Lion airplane and I flew it at local park, it flew every bit as well as the one I had constructed.

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

Winona State College for Kids Link

https://www.winona.edu/conferencing/cfk.asp

Related Vendors

http://www.docfizzix.com  - using mousetrap car kits from Doc Fizzix

http://www.lasercutplanes.com/ - Mountain Lion Mk II and other kits

Winona Daily News Article

http://www.winonadailynews.com/news/local/doing-hands-on-stuff-college-for-kids-program-still-going/article_32ae624c-f295-5ae3-89b8-ca7788a6fad0.html?utm_medium=social&utm_source=email&utm_campaign=user-share

Related Blog Articles

http://scienceguyorg.blogspot.com/2017/07/college-for-kids-2017-first-half.html

http://scienceguyorg.blogspot.com/2016/07/college-for-kids-2016.html

http://scienceguyorg.blogspot.com/2013/04/little-bit-about-my-father.html 

http://scienceguyorg.blogspot.com/2017/06/mountain-lion-mark-ii-laser-cut-planes.html

http://scienceguyorg.blogspot.com/2013/04/little-bit-about-my-father.html 

Video

College for Kids 2017 - First Half

Two out of four days are complete now for my College for Kids class, STEM DIY. This year I chose to teach two smaller classes of six instead of a larger class of 12. It has worked much better, and I can spend a little more time with individual students and not get too bogged down.

The first day we built the rubber powered helicopters and FPG-9 gliders. There is a small amount of assembly with the helicopters but not much. Just the same the students struggle to visualize how the parts fit together. The helicopters were flown both outside and inside in atrium building. Amazing how high some of the helicopters went. In one flight a helicopter flew above a tall building and got stuck on the roof. FPG-9 gliders were launched from a catwalk indoors, some glided better than others but all seem to curve during the last parts of the flight.

Day two I did some demonstrations of other foam gliders I had built and the new walk along gliders created from a new foam that is stiffer than previous ones by Sciencetoymaker. We went to atrium to try the walk along gliders but first I flew my small Butterfly mini stick type indoor rubber model. The students were really amazed how slow it flew and easily it circled upward.

Some of the students were able to catch on to the walk along gliders and enjoyed the challenge, other quickly gave up on it. I tried to help some students individually that were interested. 

Building the Fantastic Foam Flyer rubber model did not go as well as I had hoped. I brought in a sample to show but still students struggled how to visualize how the parts go together. 

The projects will get even more difficult the next two days, sure glad the class size is smaller. End result was the planes flew pretty well for the most part. If anything it will be the balsa fuselage, not the foam that breaks. 

Reporter  and photographer from local newspaper were there for a story that will run Wednesday, I will update this article with the link.

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

Related Links

Fantastic Foam Flyer - http://ideas-inspire.com/fantastic-foam-flyer/

Walkalong Glider and Foam Toy Store   http://www.sciencetoymaker.org/airsurf/store.html

Rubber Powered Helicopters from Everything Hobby http://www.everythinghobby.com

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. 

Mountain Lion Mk II

It is my hope in teaching my upcoming project building class that will be mainly model airplanes that I can relay additional knowledge on adjusting models properly from what I have learned. For whatever reasons; the program as a whole has reduced enrollment while my class is maintaining the same level.  

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

Related Links

http://scienceguyorg.blogspot.com/2017/06/fishing-success-and-opportunity.html

http://scienceguyorg.blogspot.com/2017/06/mountain-lion-mark-ii-laser-cut-planes.html

http://scienceguyorg.blogspot.com/2017/06/e36-free-flight-2017-progress-sometimes.html

http://www.bmjrmodels.com/free-flight/e-36/Starduster-E-36  BMJR Models Starduster e36

http://www.pearlfreeflight.com/Buy.html   Pearl Free Flight website  e36 Pearl e202

http://scienceguyorg.blogspot.com/2016/07/college-for-kids-2016.html  College for Kids 2016