> > >>>>> I had a brain storm today on a roadable aircraft.
> > >>>>> It is always in the back of my feeble mind :)
> > >>>>>
> > >>>>> I realized one of the unique features of the rotary
> > >>>>> is its very simple e-shaft. If one makes it longer and
> > >>>>> larger in diameter on the front end  one can get power out of

both

> > >>>>> ends. One end is mated to a stock VW transmission and the
> > >>>>> other end uses one of Ken Welters 3:1 cog belt reduction drives.
> > >>>>>
> > >>>>> You take off in first gear and get much better acceleration to
> > >>>>> flying speed. This is due to the traction you get out of tires
> > >>>>> as opposed to a highly slipping prop. As soon as you run out of
> > >>>>> RPM in first you push in the clutch and shift into neutral.
> > >>>>> the prop takes over.
> > >>>>>
> > >>>>> For road work you remove the canard and main wings
> > >>>>> and tow them behind you. The only drawback here is the weight
> > >>>>> of the VW gear box and drive shafts.
> > >>>>>
> > >>>>> Its a motor cycle on the ground as that circumvents a load of
> > >>>>> EPA and DOT rules.
> > >>>>>
> > >>>>> Paul Lamar
> > >>>>
> >
> > ------------------------------
> > >>>> Roadable airplanes ARE flyable. There are no technological
> > >>>> break throughs required. The vast majority of the
> > >>>> parts are off the shelf.
> > >>>>
> > >>>> The main challenge is minimizing the weight penalty.
> > >>>> Most roadable aircraft designs use twin booms for the tail but
> > >>>> the Ruttan Canard configuration  is a better fit with roadable
> > >>>> requirements IMHO. To my knowledge nobody has tried the canard
> > >>>> configuration yet.
> > >>>>
> > >>>> Paul Lamar
> > >>>
> > >>>
> > >>> Paul,
> >
> > -------------------------
> > >>>
> > >>> With modern high
> > >>> strength to weight ratio materials and the canard configuration
> > >>> the aircraft performance does not have to suffer that much.
> > >>>
> > >>> There are a zillion VW rear suspension and drive line, three wheel
> > >>> custom motorcycles on US roads and they suffer no performance
> penalties
> > >>> what so ever. Particularly with Mazda rotary engine power.
> > >>>
> > >>> Sure it won't be as fast as a Long EZ but it will get you there
> > >>> a lot faster than a car. Especially to remote areas like Baja.
> > >>>
> > >>> An honest person could make some money selling well designed
> > >>> kits.
> > >>>
> > >>> --------------------------------
> > >>>
> > >>> With the gear retracted there will be near zero aerodynamic
> > >>> penalties.
> > >>>
> > >>> -------------------------------------------------
> > >>>
> > >>> One of the design parameters one needs to pay a lot of attention
> > >>> to on a roadable is the weight of the wheels and tires.
> > >>> I suggest dragster forged aluminum front wheels and tires at 15 by

3

> 1/2
> > >>> for the rear. You need diameter as the cruise RPM on
> > >>> the ground using the VW tx requires a rather large diameter
> > >>> tire.
> > >>>
> > >>> The front tire can be a light weight motorcycle wheel
> > >>> and tire. Motor cycle disc brakes will also keep the weight
> > >>> down.
> > >>>
> > >>> Paul Lamar
> > >>
> >
> >
> > My suggestion for the structure is to use 3/4 inch thick foam carbon
fiber
> sandwiches
> > in a box like structure. 1 to 10 layers of carbon according to the
stress
> > and one layer of glass to insulate it from metal attachments.
> >
> > The engine is cantilevered from an aluminum plate between engine and
gear
> > box. The prop shaft is large diameter carbon fiber Charlie Airsmen
> > style. Prop is carbon fiber Perry Mick style large diameter hub.
> >
> > Front suspension will not be the traditional motorcycle type. I have
> > a new design I used on a Breedlove 3 wheel land speed record car that
> > distributes the loads better into the structure. Went 400 MPH no
> > problems.
> >
> > What do you think of the structure Vance? Got any suggestions for
> > improvements or changes?
> >
> > Paul Lamar
>
>
> I often dream and sketch a concept of a very light sport car where the
body
> itself
> is the major "frame" - semi monocoque like many composite planes. A car
that
> would make a Lotus 7 look like a truck. The sills and the seats can be
major
> sections in bending and torsion. You are not looking for F1 handling -

use

> rubber bushes for suspension and engine mounting - carbon BI over foam
> core - approach the structural elegance of the egg.. wheels coolie hat
cones
> with narrow high pressure tires - you would be able to carry the whole
thing
> on the back of a bicycle - except for that overweight Wankel.
> Vance
>
> OK Vance give us a sketch :)
>
> Paul Lamar


>Here is a rough sketch of the structural concept in the basic envelope of

a

roadible
canard. The foam filled sills with BID shells act like large chassis side
rails
and the seat structure fulfills a central X section effect . End box
sections
close out the frame. The seat back forms a roll over structure and main

wing

connect point. Non structral panels provide access to the drive line.
Vance


You do nice fine art drawings Vance. I envy you.
We need another sketch of how you intend to atach the rear suspension
and mount the engine and gear box.

Paul Lamar

 Paul I would be tempted to integrate the engine, trans, and portions of the
suspension into a single unit carried in a sort of tube engine mount bed
mount. this would be tied into hard points tabbed and ribbed into the
"side rails" simple swing axle - airbag suspension - vacuum pump
to pull up the wheels, The belt redrive may or may not be a structural
part of the package. The whole unit to drop down after a non structural
aero shell is removed from the bottom. The suspension loads dumped
into the mount - much as on nose wheel struts to bed mount engines.
The rough sketch gives a general view of this type of layout.
Numerous other options are also available. The roadible airplane is not
 a daunting engineering problem, but mostly one of logistics,
marketing, and operation under the existing systems.
Vance

I added your first sketch and comments to the ACRE web site
under Advanced Topics and Roadable.
I'll add this one as well. Hope you don't mind.

Paul Lamar