Wednesday, August 2, 2017

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

Related Links
P. Visser's "Wilbur" Nostalgia Mulvihill per Zaic '53    Item ID  NOSR9   Propeller Blanks  FAI Model Supply - bearings and bushings Band Burner


  1. Enjoy hearing of your aero-adventures, Bill.

  2. Very nice experience, especially that you found the plane!