For a rotary engine end housing doing parallel roughing and
 waterline finishing with pencil point cleanup to an accuracy of .0001
 takes
 about 3 minutes on a 1.8 Ghz processor computer and Meshcam3. I haven't
 used
 it on the 3.4 Ghz quad core which would be faster but I have that one to
 run
 the X-Plane simulator for the airframe testing.


 At $29.95 for the flight
 simulator with plane maker and airfoil maker included this is probably the
 best value in experimental aviation software.This software has allowed me
 to
 get an aerobatic 233 KIAS canard to glide at 58 KIAS with a vertical speed
 of 380 FPM by changing wing incidence and canard location. Also useful to
 establish CG limits and cruise speed numbers with fixed versus retractable
 gear.

 George grimes


 George,
 Do you think X-plane would work for a lifting body?
 http://www.facetmobile.com/
 Scrole to the last few pages to see the FMX-5 project.  Barnaby gave
 compelling
 reasons for this plane at an AirVenture seminar this year.  Just a
 diversion now but
 would like to build in the future.
 Dan F

 Dan F,  Included in the simulator are airplane files for a dozen types of
 planes helicopters etc. One of them is the NASA lifting body reentry
 vehicle.
 You design your flight model in the X-Plane program with the plane maker
 subprogram. If you open up the lifting body design you can see how it is
 entered.

     Basically you use a background bitmap or JPG image of the top,
 bottom, side, and front which you have saved in the resources/bitmaps
 folder to line up the edges of the parts and cross sections to enter the
 part. If you want to have it used in the flight dynamics you enter it as a
 miscellaneous wing unless it is actually a wing which is done in the wings
 section.

    If you enter it in the miscellaneous bodies section only the flat
 plate drag and similar parameters are used. Flight dynamics are done with
 blade element theory by dividing the surfaces into very fine quads and
 considering the aerodynamic forces on each individual   mesh segment. This
 is different than Microsoft flight simulators approach which uses look up
 tables and does not lend itself to a new type of design for which data is
 not known.

      If you design in Rhino, do a render and save it as a JPG or bitmap
 image. For multiple views I do copies in an array and rotate them around
 to
 different views. Then draw a rectangular box and surround all the images
 with the same box.(also done as an array) This allows lining up all the
 images to the size of the render window so everything is lined up and at
 the
 same scale (a necessity). There is a series of 32 tutorials on you-tube
 that
 demonstrates how to enter a plane in X-Plane.

    You might want to do a search for Allan Shaws "atlantica" design which
 is a blended wing body. As a generalization these designs seem to have
 good
 stability as a glider but not much control leverage to counter propeller
 torque and changes in engine thrust. You can assign buttons on the
 joystick
 or keyboard for aircraft trim in a simulator, as well as takeoff trim but
 when doing these lifting body types I would animate the actual trim
 surfaces
 for a more realistic representation of what will occur on an actual
 aircraft.

       To gain some confidence in the simulator enter  something like a PA
 28 and fly it to verify that it behaves as the real world aircraft.
 Alternatively, download a known aircraft at X-Plane.org and dissect it's
 data
 entry in plane maker to see if you can find anything that is not like the
 real world aircraft. The wing airfoils and propeller airfoil, diameter and
 pitch get extra attention.

     I am using the propeller specs from a design I found in the
 X-Plane.org /users designs which is a twin Mazda rotary design called
 Peregrinne that has an MT prop. It is showing 278 KIAS out of two 215 HP
 rotaries. If you are not doing a jet engine on a lifting body counter
 rotating
 props would be a suggestion.

 George grimes

 George, Are you and Jean still working on the rotary powered scale
 Avanta? Here are some pictures I took today of the real McCoy.


 Paul Lamar

 George,
 Thanks for the info about X-plane.  I had no idea about how powerful it
 had
 become.
 This will be a good winter project.  The RC models have no control
 problems
 and
 Barnaby did not mention...  Will be a good idea to check this out.
 And, yes please keep us updated on the Avanta and your twin canard
 projects.

 Paul, please update my subscription from Juno to xxx


 Dan F

 Send me email from your new address.

 Paul Lamar

 Dan F,  I am attaching some jpeg images of the 4 rotor aerobatic canard
 that I am flying in X-Plane. It still has not gotten to  300 KIAS with the
 reduced HP of 4 rotors (down from a six rotor of the conventional design
 from three years ago)  This airframe could be done in a 5/6 scale for more
 speed and less fuel burn or turbocharged at the current size to meet
 design
 speed. I am leaning towards the current fuel burn at 233 KIAS and cruise
 at
 180 KIAS with a significant reduction in fuel burn.  This may be a
 reasonable speed for a 4 wing surface airplane of this size but  I do not
 know of  another one to compare it with. I am investigating the 2.72 ratio
 planetary gears from a ford super duty transfer case to replace the 2.85
 ratio and want to try a Paul Lips type propeller in place of the MT
 currently being used in the X-Plane model. I need to keep the power train
 unchanged while working out the airframe adjustments but can try power
 train
 changes later. The roll stability is currently neutral with good positive
 stability in pitch and yaw. I have flown a variety of other designs in
 X-Plane and nearly all have similar roll stability. If I can get a
 positive
 roll stability at less than a 4 KIAS penalty that seems to be a good
 trade.

        As shown in the attaches jpeg there are no intersection farings
 being used on the X-Plane flight model which on an actual build would
 lower
 the drag and reduce fuel burn a little more. The under engine air inlet is
 also not in the flight model and could increase drag more than the
 reduction
 of the intersection farings.  I intend to adapt the cooling ductwork and
 exhaust augmenter from the previous conventional style airframe which with
 the much larger (23 cu ft) inside cowl volume is not a problem. The main
 wing was also from the conventional design so testing the  reduced power
 canard powertrain on the T-rex airframe may  give insight about the
 lower speed of the current design. Unfortunately I have misplaced the
 X-Plane file for the t-rex . It is hideing on one of about 800 CD and DVD
 disks but not included on the label list.

    Anyway that is the current update on my design and how I am using
 X-Plane on the airframe designed in Rhino 4.  It doesn't have the "ramp
 speed" of the t-rex design but is alright for the cross country utility
 cruiser that it is. I don't have a clue how to make it look better but it
 is
 like children where your own are never as homely as the neighbors kids.

 george grimes


 George,
 That design will certainly generate interest!   It appears that all
 airfoils
 have control surfaces, do you have coordination of these surfaces worked
 out? (yes in X-plane, what about physical linkage?)

 I remember Paul mentioning that Racing Beat had a three rotor, intended
for
 aircraft use, on the dyno putting out 1,200hp. (Paul, this seems way too
 high, did I misremember?)  While I wouldn't go quite that far you should
be
 able to reliably get up to1,000hp from a 4 rotor. The PSRU will be the
weak
 link IMHO.

 The latest  CONTACT magazine (issue 101) had an extensive article from
Paul
 Lipps about his theories of propeller design.  His props sure look
 different
 but if you want efficiency in cruise (vs. high thrust for takeoff) and
 reduced noise this may be your answer. You may end up with a 6 blade to
get
 the dia down to a workable size.

 Dan F

 I think that was intended for a ducted fan biz jet type of engine.
 I am guessing of course. It could have been intended for Reno
 unlimited before the weight minimum.


 Paul Lamar

 Dan F,  My quad rotor is a single engine consisting of two 2-rotor units.
The front of one and matching rear housing of the other are like doweled
bell housings. It can be extended with the same parts to a six rotor. The
E-shaft for a six rotor requires a build up of the accessory end to be made
into a mirror image of the drive end. The four rotor is just two stock RX8
e-shafts. The cooling is converted from series rotor housings to parallel
with external manifolds, required for the six rotor and a better idea for
the four rotor.  3dm rhino drawings available by request of all the
housings
which can be CNC cut or scaled 104% for casting patterns (no coring
required)  There is a 3 degree pattern draft on the housings.The material
is
390-17% aluminum alloy ( same as briggs and stratton cylinder blocks since
1958)  which has silicon carbide nodules in the material for the wear
surface and is stronger than cast 356.
      Jean Prudhomme with the Piaggio Avantia 180 project  has two possible
power train options. His original plan was with two crosswise mounted
 individual two rotor P-Port engines  inboard in the fuselage connected by
carbon fibre propshafts to two sprint car magnesium center sections in the
wings for the pusher props ( to turn the drives 90 degrees and allow the
propeller  gear reduction), He also wants constant speed hydraulic props
with this arrangement. Numerous comments on the newsletter couldn't disuade
him but we added ideas to where it seems build-able. He is to ground test
this rig and has collected/made most of the components. His back up plan is
wing mounted pusher engines. Jean bought detailed  drawings of the Piaggio
to scale but may choose different airfoils and he is working on a 3/4 scale
version look alike.  Jean worked for Velocity kit aircraft after Alan Shaw
left and did the wide fusalogue moulds now in use and built and
assisted/finished about 9 velocity aircraft. He showed up with one at
Sun-N-Fun this year  flown by a friend who is a partner in the Piaggio
scale
project. I got the impression that the partner felt more at ease with the
wing mounted engines,
       I have tested various mixer ratios on the ruddervators up to 80%
elevator. I didn't like the way it flew with ruddervators. My perception
viewing the external side view of the flight model was tha the additional
lift generated to gain altitude was coming from the ruddervators on the
back
and the control canard in the front. There was little change in angle of
attack. Also the main gear lifted off in 200 ft of ground roll, reducing
the
angle of attack requireing more ground run for takeoff. Simultaneously
 with
the main gear airborne the nose wheel steering was nill and it ran off the
runway regularly (left side). I tried altering CG which never cured the
mains lifting and allowed a non recoverable flat spin at stall and a snap
over tumble. Later while looking for speed I rotated the fusalogue flight
angle by reducing the mounted angle of incidence of all airfoil
surfaces.This reduced the runway angle of attack and cured the mains
lifting
problems. Ground handling is now very good. There is only one
interconnected
control at present. The control canard has a 15% of chord full span flap.
This is used to balance the  plane with differing CG loadings and fuel burn
weight shift. It  is attached to and moves with the  canard surface which
is
basically a stabulator mounted ahead of the main wing. I have designed a
simple as dirt linkage to control this which is really trick. It is just
hand drawn in a notebook so no drawing to post yet. One thing which will
probably be added during actual flight tests is a servo on the right
flaperon that is driven by the engine torque sensor. This is to counter
roll
trim change when the power is shut down  to decelerate out of cruise. These
glass planes just don't slow down worth crap and getting rid of altitude in
meaningful amounts is also annoying. I have still got problems here. With
the engine at idle power and the control canard held against the aft stop
it
does about 4 of the canard proposing oscillations of decreasing amplitude
and settles in at 58 KIAS and 380 FPM vertical speed. Trying to land to
avoid a weather front your airport will definitely be behind you. Using 10
or more degrees of flaps will increase decent rate and also makes roll
control more of a hands on flying unless the autopilot is on wings leveler.
Aleirons are effective but require some attention. This is the area I am
trying to get right before freezing the airframe design. Currently to get
this thing on the ground from 10,000 feet you need a friend with a stinger
missle. Also if enough patience is exercised to get down, unstalling the
control canard causes a huge airspeed increase which takes time to get back
to pattern speed. The winglets have out deflecting spoilers which are not
programmed in X-Plane which are expected to produce a fair amount of drag
but not nearly enough. I have a note to add main wing spoilers which could
be implemented in the "D" cell wing spar where no fuel is stored.
      There have been some interesting things learned about propeller
effects. I have done 3.4.5.6 and7 blade props with diameters from 5' to 8'
Changing the number of blades requires changing the root and tip chords of
the blades. I couldn't put enough blades on a 5'
 circle to absorb engine power and it would be impossible to physically
build. I ended up at a 6.4 ft diameter with five blades. A quad rotor
P-Port  is 500 to 510 HP WOT and reducing fuel flow from 43 to 24 GPM
reduces maximum speed from 233KIAS to 180 KIAS while allowing enough
reserve
speed to deal with harmon rockets. At this diameter 32 degrees of pitch is
optimal with prop flutter cycling at 30 degrees. Keeping a maximum prop RPM
of 2500 seems to be the sweet spot with little speed drop at lower RPM like
2300. Once a diameter is chosen and the RPM from a .8MACH tip speed I
change
root and tip chords and try different airfoils. The clark Y is pretty good,
the hartzel is slightly better and best results are with a Boeing root and
tip high subsonic airfoil. I am using an MT prop in the simulator with
Boeing airfoils. I also tried various Eppler airfoils and NLF laminar
airfoils just to see what the simulator would predict. Once the chord
widths
are optimized for the airfoil by trial and error there is relatively little
difference in performance. The range for all diameters, blade numbers, and
airfoil choices once optimized changed maximum speed between 207 and 233
KIAS.  I was looking for a large performance increase and never found
it.There is apparently a correlation relating to blade area times the
number
of blades being in the same range at optimum speed. I tried two
contra rotating three blade props which predicted one of the lower maximum
speeds. Once the best prop was specified I started with tweaking the
airframe. After this airframe design is frozen I hope to find some kind of
prop pitch control to use the prop for best drag production to get slowed
down out of cruise and decents. With the throttle closed on a rotary there
is little air flow and therefore little compression braking. I need to do
some research on this as it may not meet my safety criteria.  The
efficiency
of the Paul Lipps design is the important aspect for me since the engine
and
prop noise are all behind me. It would be desireable however to reduce
noise
on or near the ground for the long term bennefits of the experimental
aircfaft hobby.


  As a final note I remember the  turbocharged racing beat dyno engine a
little differently at 1630HP peak on a dyno pull. Watch it on you-tube and
you will see the stability and temperature of all the turbo components is
DISTURBING. What it domonstrates to me is that the E-shaft and the tapered
hub on the drive end are able to transmit  300 % of what I will be putting
through it. There was  another Racing Beat project possibly on "craigs
rotary page" at somewhere around 1000HP that had a custom front cover with
a
mechanically driven turbine compressor in the area normally occupied by the
warer pump which was relocated. These huge HP numbers come with a fuel burn
that would scare a turboprop driver.

     The superduty Ford 6 pinion planetary Tracy uses is also used on pull
trucks with large V8 engines making 930 HP admitted and likely more like
1200. For continuous service at 1000 HP you would need two E4OD
 planetaries
stacked up sharing the load. This is problematic due to the diameter of the
sun gear shaft not being any bigger. Just looking at the Ford super duty
planetary set from a 4X4 transfer case it is larger  by comparison and
rated by Ford at 720 lb ft according to Wikki/super duty/transfer case. The
ratio is 2.72 to 1 It is larger heavier and has helical gears. I am
thinking
of using it if I,  supercharge the quadrotor, otherwise the 2.85 ratio PSRU
built by Tracy Crook is well flight proven and much lighter with a 300 HP
rating. This rating may be considering the bending load on the top fuel
dragster axle he builds the propshaft from more than the planetary gears.
Next time he asks for questions at an automotive conversion forum I hope to
find out.

george grimes

I was wondering if anybody knew what happened to the Omac company and their
proof of
concept prototype ( Omac-1 ? )
The discussion on lifting bodies got me to wondering about them.


clifton younger