Beginnings

There have been a lot of questions on how I got into the tail wheel building business. I will try to detail the “how’s, what's and where we are going” parts of this story.

I had started to get to know Fred Muder and a fellow that goes by Shelly from out on the Ohio/PA border area. They have a lot of plane building background and even own a Mountain Goat of which there are only a few flying.

One topic led to another and Shelly mentioned they sure would like to find a way to build one of Bob Barrows' tail wheels and to get it right the first time. I offered my assistance so I sent off for the plans on the tail wheel.

In looking over the plans, my brother and I could see that it could be a tough go to build all the parts, then weld them into a true working unit. We could see how this might be done with each part being built in sequence and ending up with a true custom tail wheel, but pretty hard to build 2 or a dozen exactly the same so that the parts would interchange completely.

Based on the premise that time is money, scrap is waste, tweaking is more lost time and unsuccessful tweaking is more scrap, we set about to find a better built “mouse trap”.

We had no intention of changing the design, angles, size or working process. Strictly a better building process facilitated by CNC machines, heavy duty weld fixtures and some forward thinking. All this in hopes of being able to build a dozen or so a year, to help keep me in the air with some flying money.

At the point of spending about $9,000 with no income from a completed tail wheel, but a lot of possible sales on the books, I started to wonder just where the project was going to lead me.

A  visit with Budd Davidson in AZ with his vast knowledge on airplanes assured me I was still on the right track. Then words of encouragement and a good deal of pushing from Mark Goldberg in TX helped me to get this project up over the edge. And finally, many talks with Bob Barrows on his ever present weight vs. strength philosophy also kept this project on track.

So with that background in mind, lets talk tail wheels!

Some facts:

The design- I did not copy Bob's tail wheel. I called Bob Barrows and asked if I could improve upon his design, and he said yes, with HIS APPROVAL that would work.   With 4 passings of the  "completed tail wheel units" across the country, (From Iowa to Bob's house)  2 full static tests to destruction, ($1100 worth of parts) and hours of head scratching (Now you guys know where my hair went!), I have a tail wheel that meets Bob’s standards. The static tests have been calculated to go beyond any landing that this plane was designed for.

Improvements:  (most of these can be seen in the web site photos)

a) The top cam on the main body and the main body is one piece, NO WELDING and the main body has a grease step built in from the beginning. Those that may have been built without the grease step, the bearing is really just a bushing at that point, but it still works.

b) The top steer assembly that holds the spring and locking pin is ONE UNIT. That is to say, the collar that is around the king pin and the tube and cam pin notch collar are built as one unit,  no welding of parts, no hoping for alignment when done. Now those of you with plans for the tail wheel will appreciate how much 4130N metal is laying on the floor for these two parts to happen in this fashion.  There is far more milled steel in shavings than what there is in the remaining part.

We do this for three reasons: 1) it is making a stronger and better part; 2) the time savings in not having scrap parts pays in the end 3) the end results are perfectly true.

c) I built a special machine to make the yoke arms...I can make 40 sets of yokes, and they won't vary 1/16"  Those of you that saw my display at Sun-N-Fun or Oshkosh can attest to that. The yoke arms are a bit time consuming, as you form the steel to the radius required, split in half, cut  the proper angle wedges out, weld together, cut in the 1” and 5/8" notches and then weld these to the king pin and axle bushings at the proper angle. I did stray from Bob’s wrap around enforcing strap and went instead with my tapering egg-shaped side plates.  Again, these were tested and approved by Bob Barrows.  The side plates cut out about 7” of welding per side and really beef up side torque load strength in the yoke. 

d) I TIG weld the double pocket on the underside of the cam body where a 1/4" spring plate, .190 side plates and .100 cam body come together...Those of you that get this done right with a torch of any type, I commend you highly...  Budd and I have talked about these two pockets of fire breathing hell as being one of the hardest places to weld correctly on the entire Bearhawk plane. Every time I complete one, I sit back in amazement of anyone that can sit down and do just one only without my welding fixture and have it come out perfectly the first time.  Eric Newton and others my hats off to you! 

e) I love to weld these items "correctly " and "perfectly".  That is not to say welds that LOOK perfect, but rather welds that have melded these parts into one.

 

End results:

All of this results in parts that can come out of my parts bins...and each and every part can interchange with the next part. In fact, that is how I put them together. I make a group of parts of each type and then put them together by assembling the parts. Though it looks like it will not be an issue with the prototype having nearly 1000 hours on it and the pickup trailing version that gets more abuse in one day that most planes can put on it in 20 years.

 Replacement parts:

 The wearable parts amount to about $25 to $35.    Please compare that to your Scott 3200-3400 or Alaskan bush wheel versions.

Wrap up:

All this being said, I will not say I have not had problems,  I have scrapped nearly $4000 worth of parts that I finished ahead of "Bobs approval". We ended up changing the part; such is life.  And, I wish I had a couple of parts back, now that we have found a better way to build. I am sure Mark Goldberg can attest that the first AviPro kit was not nearly as good as what they are sending out today.  By good, I mean, today you are getting more for the same dollar. That is a fact of manufacturing production items.  And, I am still working out the Chromate- painting- finish look details...but am getting down to some final choices. The tail wheel is always dirty and is always bringing up the rear, but I like to have it look good when cleaned up.

I could not be where I am today without the help of my forward thinking, out of the box, CNC machine programming brother, a neighbor that TIG welds in his sleep (my teacher), words of encouragement from Fred and Shelly out east and Jeff in Monterrey Mexico. These guys know who they are... and my heartfelt thanks to them.

I have a lot of tail wheels nearly ready to ship. I also farm row crops and run about  400 ewes under a very intense pasture management plan. I pasture lamb nearly all of them in May and June. Those of you flying over and think you see 1000 cotton ball rocks in the fields, they are really sheep.  To fill in my blank spots of time (there are none left), I also do contemporary art works in metal. That is a whole new story in itself.

Flying:

Lastly, I love flying, I love to meet the people who are all about flying...I have so many invitations to "come fly" that I could spend a year flying around the country doing just that.   (Budd, is there a book in there somewhere?)  This tail wheel work is about being able to see and be around aircraft, aircraft design and the great people involved in it.

Thank  you!

Scott Weinberg