Tuesday, July 30, 2013

Guillow's Lancer Rubber Power Model

This past winter I built a Guillow's Lancer rubber powered model airplane with just a few modifications. The wood actually seemed fairly light so I did not substitute any of the wood but I did use Esaki tissue for covering instead of the tissue included. Modifications were made to nose area so that the nose was removeable for stretch winding and I tried my new idea of using foam on the sides of the nose block to create more friction so it did not fall out in flight, this is working well.

Landing gear was made removable with one rubber band holding it on but I find it flies better without the landing gear. The weight was 23 grams without landing gear and rubber which started as single loop of 3/16" rubber but is now 2 loops of 1/8" rubber. Instead of the 6" propeller included I used a 7" diameter propeller but might experiment with 8" diameter propeller.

The Lancer flies well but I guess I was hoping it would climb like a competition model which it does not.  Changing to the two loops of  1/8" rubber improved the climb but then the number of turns that can be put in the rubber is less.  Flights are very consistent and you can launch the plane hard almost vertical and it keeps climbing without a hesitation. For the price of the kit and the fact that the kit is fairly available I think the Lancer is a pretty good sport model for someone with some previous rubber model experience.

New 4-22-2015 : Checkout my Building and Flying Guillow's Models webpage

Bill Kuhl

Monday, July 29, 2013

Creativity, Following Directions, & Failure

The contents from my blog article College for Kids the FirstTwo Days I sent to a modeling aviation listserve and also to several individuals. This did provoke some interesting responses which I will try to summarize. It brought up the issues of creativity, the role of failure in learning, and the inability of some students to make simple measurements for a project.

Rubber Powered Foam Plane in Flight

My comment: “"I would say to cut a piece 2" x 4" out of foam plate and some would cut much smaller pieces. My idea was to give them general proportions but let them use some of their own creativity."

Someone questioned if some kids could measure out a rectangle 2” x 4”, I would hope by the 5th grade this would not be an issue, it would have been better for me to work in metric but I thought that more difficult.  I think the issue is more about not following directions for whatever reason.  One person said that he gave the kids a template that they could modify outside of the boundaries. He went on to say that kids are desperate to modify their aircraft and try new things with it, on that I can concur.

Wing is Much Too Small

The Role of Success and Failure in Learning

One person gave a statement that I have a little trouble with but I do see their intention:

“The number one requirement in class is that every single airplane must fly successfully. 

Creativity by the ignorant is a prescription for failure.”

I think the point here is that kids will lose interest in a hurry and not pursue an activity further if presented with failure from the start. This statement by a fulltime science instructor mentions the inability to work through failure as one the largest weaknesses he sees in students:

“Students have a tough time sticking it out, especially when it gets hard for them. The lack of risk taking and failure in their lives lessens their ability to work through failure.”

So much to consider when teaching, my next class will be just building the foam airplanes so I am going to trace out the pieces and see how it goes.

Related Blog Posts

Spatial Ability and Building Models  Written After Another Model Airplane Build

Important Concepts Learned Through Projects   What I have Learned by Trial and Error

Monday, July 22, 2013

Reflections on College for Kids 2013

In my first report on College for Kids I might have been slightly negative but I think it improved as the week progressed.  Most days I had two good helpers which really helped move the class along. After each year I try to evaluate where the projects might be improved for the next year based on the problems students were having.  For the model wind turbine I used heat shrink tubing over where the lead wires are soldered to the motor leads, still a couple of them broke off but it was much better than without the tubing.

Heat Shrink Tubing on Leads

On the mousetrap cars I used hot glue on the mousetrap to lever arm connection and wrapped with string. In the past the kids would not let the hot glue setup hard enough before moving the lever arm and it would come apart. That was not an issue this year but one mousetrap pulled apart, I guess somebody needs to build a better mousetrap. (groan)

The new project “Syringe Hydraulic Arm” went well for the first time though but the issue that I was afraid of turned out to be a problem; the tubing leaks connected to the syringe. I had wanted to find a solution to this but I just ran out of time.  I am thinking that I can put a tube over the tube on the syringe and then it would be a tight fit for the tubing.  The order I had the students assemble the parts for the project seem to work out fine.

Syringe Hydraulic Arm New This Year
All Screws Were Phillips Head & I Found Screwdrivers for .70 Each

3/16" Tubing over Syringe End Makes Clear Tubing Tight
Fix 7/28/2013

In the past I think some of the students were a little older, I specify grades 5 to 8 but this year it appeared more students might have been going into 5th grade.    Most of the harder or more dangerous steps were done by me, that is why it takes me so long to get ready for this class.  What I do fits the situation pretty well where a shop with many tools is not available.

Bill Kuhl

College for Kids First Two Days Report

Creativity - Following Directions - Failure

Spatial Ability and Building Models

ALES Sailplane Contest - Altitiude Limiting Electric Sailplane

There was a period in my life where flying model sailplanes was really an addiction; I flew as much as I could, I read as much as I could on the topic, and when I started to get somewhat proficient I went to contests.  I never was an expert but no doubt in my mind I was more proficient than I am now.  In 2001 I competed in a very large model sailplane contest in Arizona in the 2 meter class.  Probably more by luck or bad luck for other contestants I took home a trophy for third place in the two meter class.
2001 Southwest Classic Sailplane Contest
3rd Place Trophy
For the last few years the amount of time and effort I put into my sailplane flying has been much less because of putting more priority on other activities, much was related to project building sessions with kids.  Thanks to the efforts of Wayne Norrie in Rochester MN promoting model sailplane activity I have been able to attend some contests while visiting my mother.  The contests have been fun and low pressure but everyone appears to be improving their flying skills because their performance is measured.

RC Sailplanes

Landing Soon

Last Saturday we had an event for electric sailplanes with almost everyone flying either the Radian or Radian Pro.  The launches are limited to 150 meters in height by the electronic CAM unit so hopefully most flights started at about the same altitude for everyone.  So performance is mainly measured by the ability to find and make use of thermal air currents with some additional points added for landing within a spot. Three planes flew at the same time so those planes had the opportunity to fly through the same air conditions.

Wayne Norrie Launching EverythingHobby Radian

On the first round I did rather well which maybe gave me some over confidence as I had the high time, still under 6 minutes when we were trying for 7 minutes and some landing points.  Throughout the contest some pilots were getting 7 minute thermal flights and I kept going down.  To the casual observer flying in thermal lift might appear to be so much luck, but yet the better pilots will always do better because they are reading the subtle signs of how their sailplane is flying through the air or know the better areas of the field to find lift.
I Landed the Tail on the Spot but it Should be the Nose
Hopefully I will find time to sharpen my skill in the future but I really felt better seeing that others have improved so much.
Bill Kuhl

Wednesday, July 17, 2013

College for Kids Report First Two Days 2013

I have been teaching a class at the local university for several years now known as "College for Kids". In the first years I taught a model airplane building and flying class, but the last few years I created a course I call "Engineering Through Models" that includes several different model projects over the one week course. I try to switch in a new project every couple of years, this year we will be building the Syringe Hydraulic Arm for the first time but will drop the model solar cars.  The lineup for this year includes; foam plate gliders, rubber powered model plane from foam plates, model wind turbine, mousetrap car, and syringe hydraulic arm.

Launching FPG-9 Gliders

Launching Rubber Powered Planes

The first day of the College for Kids class could have gone better, the students did OK with the FPG-9 gliders but when they started building the rubber powered planes there was some confusion. I would say to cut a piece 2" x 4" out of foam plate and some would cut much smaller pieces. My idea was to give them general proportions but let them use some of their own creativity. Some of the flying surfaces turned out way too small, I replaced some of the really bad ones. We did not finish the rubber powered planes on the first day as I had hoped.

Typical Rubber Powered Foam Plane

Flies More Like Missile

Day #2 and there was another helper and a bigger room to use which were both Welcome. We finished up the planes in another 20 minutes and flew them in big atrium room. Some of the ones with the tiny wings flew like missiles but some planes flew pretty well. The one student had his plane climbed up to the ceiling which is 3 stories up and flew just below the ceiling, everyone was in awe. We moved on to build the model wind turbines and some of those were finished today so we are back on my schedule.

Wind Turbines

If there is enough time left on the last day, I plan to have the students fix up there planes from what they have learned and fly again.

I really think this activity has potential, very little balsa is needed and the foam is cheap. There is some breakage but not as bad with many balsa and tissue planes. Low temp glue guns work fine for building the planes in a hurry.

Bill Kuhl

Reflections on College for Kids 2013

Creativity - Following Directions - Failure  

Spatial Ability and Building Models

The Evolution of my Mousetrap Car Design

Join My Facebook Group for Simple Foam Free Flight Airplanes

Tuesday, July 16, 2013

AR Drone Flying Robot

In the past I was normally more interested in models that fly by wings rather than with propellers; partially because my experience with model helicopters has been rather frustrating at times with so many broken parts. Last winter I purchased my first quadcopter, the tiny Helimax 1SQ which I could fly inside my tiny house, never broke any parts on it so far. This quadcopter flies with a radio transmitter much like the radio control helicopters.

The AR Drone can be found in hobby shops or possibly where cell phones are sold because it is controlled with a wi-fi signal from smartphone or iPad. Finally I decided it was time to get a smartphone partially so I could fly the AR Drone. It might have been better to buy an iphone instead of an Android because the ios version seems more mature, hopefully this will change.

AR Drone Flying Outside

Demonstration Flight

Flying the AR Drone has been somewhat frustrating but it keeps getting better the more I understand the technology. As the title describes this is more of a flying robot with many sensors that try to keep it stable, with some radio control guidance. In some ways it is really easy to fly, just press a button to take off and press the same button and it lands itself. You can set many flight parameters in the app that controls it, understanding the setup helps a whole lot in getting better flights. There are times when the AR Drone seems to have a mind of its' own and either does not respond or moves without controlling it.  In doing a demonstration for some park and rec kids my AR Drone started flying out of the park and landed in some one's backyard.  Since then I have limited the height and have not had that problem so maybe it was getting out of range which is only about 160 feet.

Picture Taken from AR Drone as it Landed Out of the Park

Evening Picture in Low Light Conditions

Video is transmitted to the screen of the controlling device in realtime but with bright sunlight the screen is almost impossible to see. The video or still shots can be recorded as well.  Often I fly it in the evening when sunlight is less intense and the wind is near calm, wind gusts appear to be a problem for the AR Drone.  There are some really technical documents about how the AR Drone operates and descriptions of the software that controls the AR Drone which runs on linux.  The more I read about the AR Drone, the more I appreciate the very complex technology used and can understand why it might not always operate perfect.

Two Ultrasonic Sensors and Bottom Camera

View from Top Shell Removed

Look for more posts in the future on the AR Drone as I understand it better.

Technical Documents:



Bill Kuhl

Thursday, July 11, 2013

My Start in Computers and Software Business

My start in computers began with taking a community education class on BASIC programming on the Apple II computer.  This sparked some interest for me and my father showed me some advertising for the Texas Instruments TI99/4a computer for around $300 so I ordered it.  I taught myself the TI BASIC fairly well and started coding some game programs for this computer.  At some point I tried to make some money selling the programs so I put ads in a magazine for the TI99/4 computer.

TI-99/4A Computer

Sales started out pretty slow but started to increase to the point that it was just paying the cost of the advertising.  I received a business proposition from a Stephen Shaw in the UK, to have the rights to copy my programs and send me royalty payments for each sale.  This was a good deal and Stephen would send an interesting letter along with the payment, he later published a book on the TI99/4a and sent me a copy.  Later I had a similar deal in Canada; this was great but the payments never did amount to very much money.

Just found this link to Stephen Shaw:

Ad for Game

Then the bottom dropped out of the TI99/4a market and this computer was being sold for really cheap almost everywhere and then it was discontinued.  About that time I found out that a relative of mine was marketing programs for the Radio Shack Color computer so I started writing programs for that computer.  Twice I went with him to trade shows, once in Chicago and once in Fort Worth.  That fizzled also but led to a custom program assignment of writing a billing program for a building contractor. I learned the importance of having backups at multiple locations as someone broke into the office and stole the computer with the program disks.

After this I realized to get a real computer programming job I needed a 4 year degree from a university so I went back to school to get a 4 year degree in computer science.  The experience I had before returning to school really did help in my course work and I was offered programming job where I was doing my internship.  I still work with computers but my job is mainly in a support capacity.

My advice to students is get all the experience you can along with the education,  as the experience will set you apart from those with only the course work.

Bill Kuhl

Wednesday, July 10, 2013

4th of July as Science Guy

I spent 4th of July in Stewartville Minnesota displaying my science projects as part of their annual Summerfest celebration.   It had been awhile since I had done an event display of my projects. It is always fun to talk to people and to see their reactions to what I have created.  When I first started doing this sort of thing I would have to pay just to be there but more recently I have only been giving up my time for a chance to display.  This year I was invited to display for STEM Day at the Minnesota State Fair which seems like a big deal to me.

With a nice spot on a hill I was close to live music, a fishing contest, and a small gas engine powered train driven by Captain Kirby.  There was wind to run model wind turbine some of the time but mainly the wind came in gusts that tried to blow everything off the table.  I try to tape everything down but that makes it hard to demonstrate.   The morning started pretty slow but more people came over to talk with me as the day progressed.

For me I just never seem to tire from all the questions the kids have; “what is this?, how does it work?”. Too bad as they enter into adolescence the curiosity starts to wane.  One person I talked to was a scout leader and had seen my website before, another person was a homeschool mom.  Some parents stop by to use the projects as an opportunity to explain a concept to their kids such as what a solar panel does.
Retrieved Foam Glider

When it was slow I launched foam gliders in the park, as luck would have it one flight my Hammer Down Catapult glider flew too well and glided out in the pond while fishing contest was going on. Some kids tried to bring it in with their fishing line but I could tell they did not try too hard. They were winning some pretty nice prizes in fishing contest so I offered $5 to bring in my plane, in less than a minute I had my plane back.

It was a nice way to spend the 4th of July in a small town, I met up with friends afterwards and watched the parade.

 Bill Kuhl

Tuesday, July 9, 2013

STOL Aircraft - I Learned Something New

If you are the curious type like me, opportunities to learn something new are in front of us all the time. Last weekend I was at an airshow at Max Conrad Field and spotted this rather strange looking airplane. What really caught my eye was that the horizontal stabilizer had an airfoil that would appear to be inverted. The function of the stabilizer on an airplane is normally to keep the wing level by some negative pressure applied at the rear of the plane. Some model airplanes normally of the free flight type have an airfoil that is lifting the complete opposite direction but on these airplanes the balance point of the wing is much further rearward.

Sky Jeep STOL Aircraft

To learn more about this airplane I could have researched the name on the side of the plane, "Sky Jeep" but I inquired about the design through an online model airplane group. My Internet friend Gary sent a link to the Zenith Aircraft Company website section about the tail of the aircraft. It turns out this plane is designed for short take offs and landings, STOL is the acronym for Short Take-Off and Landing aircraft.

Inverted Airfoil on Stabilizer Caught my Eye

There is a fair amount of technical description on the website but basically the downward lifting stabilizer applies more pressure on the tail to bring the nose up so the plane can fly at a steep angle, even when taking off. There are also "flaperons" on the wing which are ailerons that have some separation  from the trailing edge of the wing that function as ailerons and as flaps in less disturbed air flow. There are also leading edge slats but I had not noticed this when looking at the airplane, this further helps the airplane fly at a high angle of attack. The entire vertical fin acts as a rudder for more turning power too.

Company Video of Short Take Off and Landing

Bill Kuhl

Monday, July 8, 2013

My First Sailing Lesson

I like hobbies where I get to interface with nature like with the power of the wind; yesterday I had my first sailing lesson.  Winona Parks and Recreation own a used sailboat for giving lessons on Lake Winona and learning to sail is something I have wanted to try.  I have a small radio control sailboat which gave me some knowledge of the sailing terminology and the basics of operation.  Zack McKinney gave me some on shore training and then we paddled out to where the sailboat is moored.  There is a fair amount of work in preparing the sailboat to sail but not too much.

Paddle Boat Used to Get to Sailboat

With main and jib sails attached we were sailing, the wind did not always cooperate.  It was in a direction also that was somewhat blocked by the bluff.  There were those times also when we would catch the wind pretty well and the boat would pick-up speed in a hurry.  As this was my first time out I really didn’t want to experience real strong wind.

Main Sail

Jib Sail

There is so much more to sailing than piloting simple powered or paddled boats.  We had to zig zag into the wind being careful not to get too straight into the wing or the sailboat would be in the dreaded “put in irons” condition where the sailboat will not move from the wind. Another condition is where the sails begin to “luffing” that is when the sails rapidly flap in protest of not being in proper trim.  Zack turned the controls over to me about half way into the voyage out.  So much for the skipper to work with, controlling the sail ropes, steering the rudder, and not letting the boom hit you in the head.

Duck Under Boom as Sail Swings

There were also other boaters on the lake in fishing boats, kayaks, and canoes. So you must avoid the obstacles but pilot the boat to best work with the wind.  The downwind run went pretty smooth and I could use a relatively straight course to get back to the dock.   So much fun, I sure want to do this again.

30 second video of sailing 

Bill Kuhl

Wednesday, July 3, 2013

Rubber Powered Helicopter Event Park Rec Summer Camp

In a previous post I had mentioned the Guillow's rubber powered helicopters and how I thought it worked pretty well. Yesterday was my first experience of using the helicopters with a group of kids and I thought it went really well. Kevin Guy owner of Everything Hobby in Rochester MN had given me a good deal on a box of the helicopters, if you cannot find the helicopters at a hobby shop other stores such as craft stores might sell them.

Assembling Rubber Powered Model Helicopters

The presentation started with giving a little historical background into how Alphonse Penaud had built a successful rubber powered model airplane and rubber powered model helicopters in the mid 1800's.  The Wright Brothers had received a Penaud designed model helicopter for Christmas one year which inspired their interest in flight, resulting in the first full-scale powered airplane.

How to Launch

Flying High

Assembling the helicopters goes pretty quickly maybe 15 minutes with children that might be in 8 to 12 years old. Some kids did need some help but all could do at least some of the work. The winding of the propeller is something that needs to be covered well with the kids or the helicopter just will not fly. I also demonstrated using the Estes Alti Trak Altitude Finder which no doubt was a little advanced for many of the kids but I thought the math exposure would not hurt them either.

Another Great Flight

Helicopter Went 44 Feet High Using Trig

As luck would have it the weather was perfect outdoors and the kids had some great flights with the helicopters. Some of the helicopters went really high so I wonder if some thermal air currents might have helped. I demonstrated flying my AR Drone which the kids thought was cool.

AR Drone

Bill Kuhl