Tech Update From FlyCorvair.com
February 26, 2007
Here's an update on a product in development that will also give you some insight on how and why we develop new items.
The History Of Our Prop Hub
Most Corvair conversions that came before my work used the prop hub that Bernie Pietenpol designed in the 1960s.
It was the standard when all Corvair engines were hand propped. Bernie's hub has very deep wells because it utilizes the original short flywheel
bolts. (The Hybrid Studs do this job on our Hubs.) Through the years, these hubs have been homemade from Bernie's drawings, or were available from Vi Kapler, personal friend of
Bernie's and a senior statesman in the Pietenpol world. As a technical note, Bernie's prop hub is not compatible with any of
our electric start systems.
Over the years, I've also seen a number of one-off hub designs, primarily made out of steel, some OK, some dangerous, none worthy of homebuilders replicating.
In the early 1990s, my friend Judith made our first Prop Hub. To get an accurate dimension for the nub on the end of the crank,
I brought eight cranks to Judith's place and let her measure them. Judith was a major player behind the scenes in experimental
aviation. She had produced about 80% of the prop extensions in the industry. The drawing in our Conversion Manual
reflects the same dimensions as this original Hub. I still have Hub #1, now sitting on the shelf in my shop. It has about 550 hours on it.
It will find its way back into service on one of our personal planes someday. The original and 17 other Hubs have drive lugs.
Only one other Hub produced since then has had drive lugs, and it is now on our 601. I had it made because all of my test props from Hub #1
were set to use drive lugs. Our early flight testing showed drive lugs to be unnecessary with the smooth running Corvair.
After we'd sold about 80 Hubs, a lot of people became interested in electric start. I worked hard to come up with an economical Front Starter
design. Rather than come out with a new hub, we developed a part called the Puck, which functioned as a
Ring Gear holder, and was CNC machined to go between the crank and the Hub. This allowed the
existing Hub to serve hand prop builders, Front Starter builders, and the then-emerging interest
in rear starters. It was a good way to cover all intrests with one Hub.
In mid 1997, we made a few minor changes to the Prop Hub design that made it slightly lighter. Its exterior dimensions and
compatibility remained the same. These alterations were made to the CNC code to produce the part, but we never went back to make a
drawing for people working at home. The new part had some gradual tapers on it that were easy for a CNC lathe to make, but people machining at
home were better served by the simplicity of the original drawing. Since 1997, we've sold hundreds of Hubs. By the time a builder buys a Hub, they are usually
well into the engine, and will go on to complete and run it. To back up my commitment to keeping the Corvair affordable, I have never raised the price
on the Hub, even though we have been selling them for 12 years.
What you see in these photos is our first major advancement in Hubs in 10 years. This new part is called "The Gold Hub." It has
been in the works for a while.
We carefully pared down the dimensions of the black 1997 Hub, and Spenser Gould, the Hangar Gang Chief Engineer, drew up all the CAD work and
interfaced directly with the CNC shop that produces our standard Black Hubs. Some back and forth on minor dimensions, and three prototypes were made.
Here is what I'm after with the Gold Hub: The Hub, Puck and Pulley are now all one peice. This not only eliminates builders having to do a close
tolerance assembly, it also eliminates the Pulley, which was previously machined in our shop by Dave the Bear. As I said in a previous post,
many of Dave's jobs will be covered by more CNC work, and this is an example. Second, the pulley is smaller in diameter. This will slow the
front mounted alternator. Depending on the engine's peak rpm, which regulator is used, and how cool the regulator's enviornment is, the stock JD
generator can produce an overvoltage condition, and the PMOV will take it off line. The easy fix for this it to move the regulator to a cooler spot, or more commonly, to have us
modify the JD unit with a larger pulley. Again, this was an in-house skilled labor job, which required the JD unit being sent to us. The smaller
integrated pulley of the Gold Hub is designed to eliminate these tasks. Additionally, it is about 1 pound 4 ounces lighter than the complete black Hub.
With the availability of electric start, very few people are intrested in hand prop motors. Rear start engines have far less interest now than
a few years ago. When proven, I expect the Gold Hub will serve most builders' needs.
The Gold Hub has all the same external dimensions and uses the same Ring Gear. It is
difficult to see in some of the photos, but the lightening was accomplished by generous radiusing and complex tapering. If we go into
production on the Hub, I'd like builders to understand there's nothing wrong with the existing Black Hub design. We won't be issuing
a drawing for the Gold Hub. It's not the kind of part that can be made at home, and it must be hard anodized to protect the pulley groove.
A lot of work has gone into this part, and I will respond very harshly to any attempt to counterfeit it.
Above is a photo of the Gold Hub on the aircraft we've chosen for the flight tests. Sharp eyes will notice that it's the Cleanex.
Dan Weseman is one of a small group of builders who have worked with us before on feedback and testing of ideas. Installing it on the Cleanex not
only allows us to have it rigorously flight tested, but Dan will also be able to give us feedback on the development of installation
instructions. Because our schedule is primarily focused on the production of ordered parts, it makes good management sense for me to tap
resources like Dan's experience and testing capability. This keeps our work force directly engaged in production, and puts a few
man days back in our schedule. The photo also illustrates an important point: notice how blunt the engine appears without its
Nosebowl or spinner. Yet, with its 13" spinner and sleek nosebowl in place, the Cleanex looks very pointy.
I have for years advocated larger spinners and sleeker nosebowls over prop extensions and small spinners. The missile-like nose of the Cleanex shows what can be accomplished following good
Above are the two assemblies side by side. The Gold Hub mounts the Ring Gear from behind, rather than mounting it on the forward face of
the Puck. It is in the same location in space, and thus works with the same Starter Brackets and
Starter we currently use. The testing will be going on in the next few weeks. Please let us get the information
before we have to answer questions about the Gold Hub. If you have a Hub on order and would like us to hold shipment until we finish
testing the new Hub, just drop us a quick e-mail. If you are one of our builders with part of the Black Hub system, know that we intend
to keep that system in production even if we go ahead with the Gold Hub. We will have more answers shortly.
We got a lot of positive feedback to my last post. I read it all very carefully, especially when builders offered comments or suggestions
on things we could do to improve customer service. The success of our business is due in no small part to my willingness to listen to
what builders need, and make adjustments accordingly. A very well-intentioned and good natured post from a friend of ours suggested that
my primary skills are in building, testing and communicating, but business management might not be where my talent lies. I understand this
comment, but don't agree with it. We've now been in business for more than a decade. Virtually every person who offered an alternative engine for
sale when we got started is now out of business. When I was getting started, there was magazine article after magazine article about a
Honda engine conversion called a Cam 100. For all the talk, I have never seen one in person, and I'm not sure what the disposition of the
company is today. They may very well have been great engines and good people, but managing your way to a success story in this engine business
requires a very different approach than what may work in other industries. The customer support and industry acceptance we enjoy was hard
won by the work of my crew and the continuous support of my wife Grace.
While it would have been a comparatively simple task to develop an
expensive product for rich guys, the real challenge with the Corvair was making it affordable and buildable for amateurs. This has required
continuous reinvestment of time and capital. Longtime friends will notice that the 1986 GMC pickup I drive today is the same one Grace and I drove to
the 1999 KR Gathering. Our priority has always been tooling, capability, testing, know how and products. Not every decision I've made has
been brilliant or even the right one, but our spearheading of the Corvair movement and where it is today have been made possible by continuously
allocating our available resources and applying them to the questions and needs of the day. As the industry shows, most people would either have
been beaten long ago or been less obstinant and given up earlier.
News and Notes
In the photo above, Morgan Hunter, left, discusses his Corvair Cruiser with Mary Jones, editor of the EAA's Light Sport Pilot magazine.
Mary is my boss at EAA publications. She has worked for the EAA for more than 20 years. She's one of the most prolific writers in experimental
aviation, and is universally admired by everyone in the industry who knows her. Mary spent the day at our airport covering the thriving LSA
scene at X50. One of the highlights of her day was the serendipitous meeting with Morgan when he stopped by our hangar while conducting flight tests.
She was duly impressed with Morgan's craftsmanship.
In the above photo, Scott Thatcher's 601 engine does jig duty in the construction of our CH701 motor mount. Like all other mounts,
it began as a standard Tray. Long and careful study of the installation, and our experience with installing engines in airframes played into
adjustments in the location as small as 3/16". An engine hoist suspends most of the weight of the engine, and a scissor jack stabilizes the
engine over the heavy duty shop table. The alignment was checked many times before the tubes were tacked in place. The mount and engine were then removed
from the stand. The mount was finish welded on the bench with a Tig welder, using great care to minimize warpage. It was then reinstalled on
the stand, and normalized with a gas torch. After cooling, I made a jig off the mount to capture its dimensions.
These are but a few of the steps in the long-term development of an engine installation that can be replicated by other homebuilders. Any
one-off installation is comparatively easy. A good example is the Skycoupe. When working on its installation, I knew
that there would probably never be another one. Thus, no jigs or tools were made, nor consideration given to the multitude of factors that
would make the path easier for others who would follow the installation. It only had to serve well on one plane.
Conversely, the Corvair/701 installation may prove to be enormously popular. Our experience pays off here and will later allow rapid
development of a highly refined installation pending positive flight testing.
In the photo above, the mount appears slightly distorted by the camera angle; it actually has no down thrust in it. We're working to have the
airplane in the air shortly. Gus is doing the lion's share of the work on the airplane. This leaves the rest of the crew working on regular
parts production. We'll do the bulk of flight testing and installation development between Sun 'N Fun and Oshkosh. Although we'll keep
builders posted with updates, keep in mind installation development takes time and we already have a busy schedule with regular production.
Oshkosh may sound far off today, but when you stare at a calendar and consider available man hours, it's realistic. I understand builders'
enthusiasm for the combination, but please be patient with your questions. Will have the flight tested answers soon enough.
Our primary focus remains the production of regular parts on order now, including the 601 Installation Manual. I remain committed to getting
regular parts production caught up before we embark on any serious 701 developmental work.
Above, Grace holds a very special flag sent to us directly from a 601 builder deployed in Iraq. We thank Anthony, and will fly it proudly.
Valentine's 2007 Update
A Message To Our Customers Direct From William
This message is intended to give our customers better insight into our business operations. Over the previous month,
there's been many adjustments to our business in response to its continued growth through 2006. The new format has only
been operating for 45 days, but has already proven itself by making a large improvement in the status of backordered items.
It was my intention to let the system run another month and then update our customers, however, an Internet exchange involving
a former customer of ours last week brought about 10 serious phone calls to the hangar. This update will answer many of those
questions directly, and show our customers what changes have been made to improve our customer service.
The Big Picture
2006 was by far our largest sales year yet. This was in spite of our January 15, 2006 announcement of the crankshaft nitriding
requirement and the testing, education and communication the crankshaft issue absorbed from our regular schedule. We had a full
year of airshows and Colleges, from California to Florida. At the end of the year, we had filled 1,700 orders. On the last
day of the year, there were 63 people to whom we still owed parts. Some of the orders were two weeks old, others much older.
This is not ideal, and I do consider it the main issue in our business. But I want our customers to understand that we still
produce and ship parts all the time.
Why are there long lead times on some items?
Nosebowls are a good example. Over the years, we've had four separate people make nosebowls for us. In the first six months of
2006, we struggled to get them from our former supplier. Backorders built up while our supplier made well intentioned plans to
catch up. After Oshkosh, our new supplier suggested a two-piece nosebowl. He said that given a few weeks, he could begin producing
a much superior part. The first ones we received proved this to be true. We immediately placed orders, but obviously it takes time,
even at his max production rate, to catch up. Certainly it's not ideal, but the solution is in place, and the parts are first class.
Our patient customers will be rewarded with a far better part than was produced by our earlier suppliers.
The same is true of certain other components. Our CNC machined components are made by two of the finest facilities in the
southeast. Included in my agreements with the manufacturers is the understanding that our work could be delayed by more
lucrative contracts. I accepted this to allow them to meet our price at their quality. On a positive note, in the past five
months larger orders have allowed us to purhcase in larger quantities, which has gone a long way toward eliminating machine shop
Craftmanship and Labor Issues
Our goal remains to develop, flight test and continuously improve the most affordable engine in experimental aviation. The
major element of our business that others don't include is the educational aspect. The consideration of teaching people about
every aspect of their engine, not just sending them parts for money, is integrated into everything we do. Over the years,
I've asked a tremendous amount from my team ... and gotten it. We have achieved the lowest cost engine on the market, we've
educated people on how to build it, encouraged them to do so and brought back an atmosphere of camaraderie and fun to the
adventure of building planes.
In September, after five years of working with us, Dave The Bear took a job with Liberty Aerospace. They're 6 miles from
his house, while we're 83 miles away. Steve Upson recovered from his heart surgery, but is not well enough to work in a hangar.
Dave and Steve are real craftsmen, and it's not possible to simply run an ad in the paper and find people to replace them.
The long term solution was to convert many of the jobs Dave did in the hangar into CNC work, and subcontract some of the
things Steve did to a group of people in a wider geographic area. Both of these solutions took time, but are now in place and
A hard look at my typical week showed that I do not get enough hours in at the welding bench, and I spent too many on
the phone or meeting with people who stopped by the hangar. While much of our business was built on the personal contact
between myself and customers, our expanded sales brought us many people who had taken very little time to understand our
mission with the Corvair.
A quick read of the Web site would answer many of these basic questions. I've learned in the age of the Internet that
being short with one out of dozens of callers can result in a lot of bad press from a guy who wanted a half hour of your time
on the phone so you could explain why a Corvair is not a good powerplant for an RV-10. Many engine companies are run by
salespeople. I'm a rarity in that I'm also a big part of our parts production workforce. Thus, it's crucial we have someone
to answer the basic questions on the phone while I produce parts. All successful businesses go through this. Originally we had
our videographer, Merrill, to cover this task.
After a long gap, a Knight in Shining Armor showed up: Our customer, Gordon Alexander, understood this was a major issue.
In a very significant act of volunteering, Gordon came from Minnesota to cover the phones until we get through the period where
we eliminate backorders and have the new solutions in place functioning and up to speed. In the years that I've been spearheading the
Corvair movement, we've seen numerous acts from people who wish to make a contribution, not so much to the wellbeing of our
business, but to the general quality of the Corvair movement. Gordon's help is good, timely and greatly appreciated. He has
already earned a place of honor in our pantheon of contributors.
2006 brought a new type of guest to our hangar. Before this, builders who knew our work well came to the hangar to learn more
and enjoy the company of our crew. These guys had already done their homework, and many times, helped with simple jobs and
always were willing to pitch in in exchange for the time we stopped to share with them. In 2006, the passing of the LSA rule
brought more people to our shop. More frequently than not, these people expected demo flights and hours of questions to be answered
without any appreciation of the mission of our crew and how it would be different than a regular airplane factory.
To stay on task building things, I've frequently opted to make parts at our second shop, near our residence. The only
visitors allowed there are our families. The close proximity to our residence has allowed me to make considerable progress on educational writing
such as our 601 Installation Manual. The most significant improvement I'm working toward this year is in the quantity and quality of
printed and DVD information from us. The quicker I can get this done, the quicker all Corvair engine builders will learn more and
build better engines. A visitor to our commercial hangar who hasn't done his homework just delays the day until the release of the
next educational supplement for hardworking builders who weren't in a position to make a personal pilgrimage to our commercial hangar.
Every aircraft engine has the right people for it. While some engines best serve people who just want to spend money on it and
don't care to learn anything, the Corvair and our work with it is ideally suited to serve builders who work by the EAA's original
motto of Learn, Build and Fly. We've spent a lot of time improving the way we deliver parts as the business grows, but it's important
that we don't lose sight of the fact that the parts are only part of what we have to offer. Our technical expertise, flight testing, educational
effort and encouragement are what set us apart from other companies that are capable merely of providing hardware.
Last Week's Internet Saga
601 builder Jeff Garrett started a small ruckus on the Internet last week by posting a series of negative messages on
a well read 601 Discussion Group. Jeff is about 35, and is an ambitious hard charging guy. I met him in person at Corvair College 10,
and have spoken with him many times on the telephone. I do not know why Jeff started his 601, but his intention in finishing it
was to power it with a Corvair engine and presell the airplane before it was finished. He was serious enough trying to be a pro builder to
buy a second 601 kit, on which he also intended to install a Corvair.
In the fall, Jeff ordered most of the installation items from us. We delivered Jeff's engine parts fairly quickly, but I gave
him an overly optimistic schedule for his installation components. This came at a time when Jeff was under extraordinary pressure
to deliver the aircraft he had already presold to a buyer in Florida. While I had sympathy for his position, Jeff has a few bad
habits like threatening to sue people all the time. Although I don't think he meant it seriously, this is a real hot button
issue in aviation, and no one who's a professional in this business ever says it casually. It burned the bridge between us, and
revealed to me that it is impossible for our business, organized to serve the educational and building needs of homebuilders,
to ever work with people whose ambitions are to build airplanes for hire.
In a bad tactical move, I made the mistake of ending my business with Jeff by supplying him with all the remaining parts in
his order. He promptly went on the Internet to say that he'd received all his parts, knowing this would stir the pot of some of our more
patient builders. About a half dozen of our builders called to say that they didn't mind waiting as long as they knew the items
were in process, but they didn't like the idea that a complainer with no understanding of the Corvair movement was served first.
I explained that in retrospect I saw it as a mistake, and only did it out of a desire to be rid of a pseudo pro builder whose
negativity and continuous phone calls were draining a lot of positive productivity from the hangar. A good illustration of the differences
in perspective of builders is the fact that Jeff was very happy to be supplied with an older nosebowl. I got it from Gordon, who is more than
willing to wait a bit for the improved two-piece nosebowl because he wants to make the best plane he can. Jeff just wanted any nosebowl so he
can complete the plane and deliver it to the buyer.
Jeff is not an evil guy, he just isn't the guy we are trying to serve. When the plane is done and delivered to the owner in Florida, Jeff
has already made moves into a different buisness. He has offered his other 601 kit for sale on Barnstormers for $13,000. If Jeff's motivations
to build were the same as our other customers, my delay in getting him his stuff would not have been the same crisis, and if he intended to
stay in aviation, he would never have resorted to tactics that removed all possibility that we would work with him in the future.
In the past few days, I have personally called most of our customers who have a back order on file to discuss the delivery situation with them.
The new systems in place allow us to see the light at the end of the tunnel and get there faster. Again I want to thank our customers for their
patience, and assure them that it will be rewarded with the finest Corvair installation parts and our permanent apprecation.
Now At The Hangar
June 2011 At The Hangar
May 2011 At The Hangar
April 2011 At The Hangar
March 2011 At The Hangar
January 2011 At The Hangar
December 2010 At The Hangar
November 2010 At The Hangar
October 2010 At The Hangar
August 2010 At The Hangar
July 2010 At The Hangar
May 2010 At The Hangar
April 2010 At The Hangar
January 2010 At The Hangar
December 2009 At The Hangar
November 2009 At The Hangar
October 2009 At The Hangar
September 2009 At The Hangar
August 2009 At The Hangar
July 2009 At The Hangar
June 2009 At The Hangar
May 2009 At The Hangar
April 2009 At The Hangar
March 2009 At The Hangar
January 2009 At The Hangar
December 2008 At The Hangar
October 2008 At The Hangar
September 2008 At The Hangar
August 2008 At The Hangar
July 2008 At The Hangar
June 2008 At The Hangar
May 2008 At The Hangar
April 2008 At The Hangar
March 2008 At The Hangar
February 2008 At The Hangar
January 2008 At The Hangar
Christmas 2007 At The Hangar
November 2007 At The Hangar
October 2007 At The Hangar
September 2007 At The Hangar
August 2007 At The Hangar
July 2007 At The Hangar
June 2007 At The Hangar
April 2007 At The Hangar
March 2007 At The Hangar
January 2007 At The Hangar
December 2006 At The Hangar Part 1
December 2006 At The Hangar Part 2
December 2006 At The Hangar Part 3
December 2006 At The Hangar Part 4
November 2006 At The Hangar
October 2006 At The Hangar
September 2006 At The Hangar
August 2006 At The Hangar
July 2006 At The Hangar
June 2006 At The Hangar
May 2006 At The Hangar
At The Hangar In April 2006
At The Hangar In March 2006
At The Hangar In February 2006
At The Hangar In January 2006
At The Hangar In December 2005
At The Hangar In November 2005
At The Hangar In October 2005
At The Hangar In September 2005
At The Hangar In July 2005
OSH, Illinois and SAA June 13, 2005
At The Hangar June 13, 2005 Part II
At The Hangar In May 2005
At The Hangar In April 2005