Metal vs Wood or T2 vs VP (Part II)

I'm still getting LOTS of messages from guys who just Don't Get It.

So let me try it again.

It is NOT a question of an RV vs a Falco. The most basic factor is
COST which means we can rule out such high-priced examples. Right now
I've been making comparisons between the VP-I as the 'all wood'
example and Calvin Parker's 'Teenie Two' as the all-metal example.
That will change in the IMMEDIATE FUTURE as more Thatcher CX4's and
Bruce King's BK-1.3 come flying out the door of garages across the
country.

In virtually all cases the ENGINE is the most expensive component.
(The exception is a few ultra-lights.) But ALL of the examples
presented under this 'Metal vs Wood' comparison use a converted
Volkswagen engine. In this comparison I am advocating the use of a
conversion in which the propeller is mounted on the CLUTCH-end of the
crankshaft AND a dynamo coaxially-mounted on the PULLEY-end of the
crankshaft. The induction system uses an updraft carburetor from a
Model A (Tillotson Model X is one example) or from an industrial
engine (various models of Bendix and Zenith).

The ignition system is either stock Volkswagen but using a distributor
having mechanical advance (ie, centrifugal advance). This system may
be upgraded by replacing various components with their electronic
equivalents, such as using an electronic switch instead of the
mechanical breaker points. The best-case would be the CompuFire DS-IX
or similar, in which the single coil is replaced with a dual-coil,
waste-spark system that is electronically triggered. The lower body
of a distributor having mechanical advance would be retained, allowing
the engine to be hand-propped yet able to run efficiently at speeds
above 3000rpm.

As for the airframe, the selection is based on the availability of the
required TOOLS and before we get into the issue of tools too deeply it
must be understood that regardless of your choice SOME tools will be
required.

All of the METAL airframes mentioned mentioned above can be built
using ONLY hand tools, whereas for the 'wooden' airframes, a table saw
is a virtual necessity. Fortunately a portable electric saw may be
pressed into service as a TABLE SAW at a very small price, allowing
accurate production of the required longerons and, in the case of a
'Chugger' type wing, of the sticks needed for ribs.

Performance on the whole is left for future posts but one aspect of
performance must be addressed at the outset and that is the
relationship between flying and safety. To be a good airman, in my
opinion, DEMANDS a given number of landings per month. Ideally, a
group of airmen would keep one or more airframes available to all.
I'm not strong on clubs, having found most degenerate fairly quickly
by non-flying types who see the club as a SOCIAL activity and who tend
to lean their financial shoulder rather heavily on those who are
primarily interested in FLYING rather then dunking their donuts. Yet
it's difficult to define the needed group without making it sound like
a club.

As for doing all of the flying in just one or two airframes, this
reflects the COST of hangars and tie-downs. All of the airplanes
discussed here can be road-towable but in a growing number of cases
the folks running our airports are AGAINST someone flying out of
'their' field unless they pay certain fees. I've nothing against
that; we've all got to eat. But I AM against being forced to pay
hundreds of dollars a month simply to maintain my proficiency. My
suggested solution is to base one or two airplanes at such airport but
to allow those airplanes to be flown by OTHER-THAN their registered
owner.

A couple of people have said it sounds as if I am AGAINST the social
aspects of grass roots aviation. Actually, I'm just the opposite.
What I'm against is some ground hog trying to run us through the
financial wringer simply because we happen to own an airplane.

But what I'm also against is the pilot whose only flight experience is
gained to and from an airshow. Or having them look like duffers when
they are told to land long, or to put it on the green or whatever.
Toward that end I would like to see them practicing precision landings
at some low-traffic field... or at ANY field, when it comes right down
to it. (It is the organization needed for this type of practice that
leads to the 'club-like' definition.)

While none of the planes mentioned here are especially hot STOL
performers, neither do they need a mile of concrete. Without
exception, all can do a full-stop in less than a thousand feet... and
the touch-and-go needed for a spot landing can be done in much less.

Finally (with regard to commonality) all of the planes mentioned here
use a converted Volkswagen engine and, within that frame, a VW engine
using MY methods of conversion, which means the prop is hung on the
clutch-end of the crankshaft, there is a dynamo installed on the
pulley-end of the crank, and the ignition system is an automotive
unit, meaning the Compu-Fire DS-IX or similar. This method of
conversion is not only the least expensive, it is the lightest in
weight AND the most reliable.

Hopefully, that has brought us back to the main theme which is wood
versus metal. Ever bent a LONG flange in metal? Most who haven't are
convinced they can't, unless they use an equally long metal brake.
Long metal brakes are hellishly expensive and if one is needed it
would pretty well blow my argument out of the water. But the fact is,
one is NOT needed. In a similar vein we run into non-metal users who
are convinced using real rivets is either difficult or expensive when
in fact, it is neither.

Over on the other side of the hangar all of the metal-smiths are
pointing fingers at our TABLE SAW, insisting the fact one is required
is proof that it costs MORE to build from wood than from metal. They
have a pretty good point in that a table saw IS needed to achieve the
accuracy required in long cuts, but they've overlooked the fact that a
portable electric saw can be made to serve as a table saw.

Then comes the 'Yabut' arguments: 'Yeah, but if I gotta make a table
saw...' from the metals group being bounced off the 'Yeah, but if I
need an air compressor...' The truth is, you can do rivets using the
SMALLEST of the available air compressors, which leaves both groups
milling around looking for another argument to throw at the other.

While I'm over here laughing :-)

Because the tools you'll need to convert and MAINTAIN your VW
engine exceed by at least an order of magnitude those needed to build
EITHER type of airframe.

Herez why:
Head-plate. Needed to establish the volumetric balance of the engine.
Exhaust valve tool: Needed to determine valve stem-seat wear.
Adjustable push-rod. Needed when setting valve-train geometry.
Chamber volume tools. Needed to measure the volume of your combustion
chambers.
Timing Wheel: Needed to adjust your valve timing.
Valve Spring Tool: Needed to determine valve spring compression
height.
Connecting-rod Tool: Needed when adjusting rod balance.

Shall I get into the tools specific to making your propeller? I think
not. (In fact, I already have... but they are specific to the prop
and listed in the section on propellers.)

The point here is that your decision to build a 'wooden' or a metal
airplane depends largely on what TOOLS you have. But the wood vs
metal argument has no merit because because when it comes to tools --
and that's what it boils down to -- the ENGINE requires more tools
than either type of airframe.

-R.S.Hoover