I have mostly stayed away from commenting on this thread out of respect (and friendship) with Cees. I tremendously enjoyed the "Ed Kazmirski's Taurus" thread, and learned a lot from Cees and all the other contributers. I got to know some wonderful guys from around the world...Cees, UStik, Ray, Pimmnz, Chuck Noble etc. So I like and respect Cees. This is his thread, and he is certainly entitled to "spin" his theory of the "Oldest Taurus on Earth".

That being said, everyone who reads this thread should realize that there isn't universal agreement about everything Cees believes. In the other thread I tried hard to understand, follow, and believe his conclusions, but in the end I came away believing more like Evan above. Cee's theory is elaborate, and is all built upon the Taurus on the right side of the crate being the original. Once you arrive at that conclusion, all the "facts" have be made to fit that theory, and it influences everything that is said from that point on.

If it IS the oldest Taurus fuselage, then the original stab, vertical fin, and top block were all removed and replaced because there is no evidence on the existing top block that it had ever been REPAIRED or that an older pilot figure INSIDE the fuse had been replaced by one glued to the surface.

The quote on post #229 about the "old reliable" Taurus could just as easily be understood to be the actual plane Ed flew at the "worlds", (flown on reeds), compared to the "Carrier-wing" Taurus which we know to have been the backup because of the FAI stickers still present. The back-up would be understood by most people to be "new" meaning it was a straight trailing edge, taper-wing version of the original Taurus with a thicker airfoil and stab...and designed to fly on proportional instead of reeds.

Don't get mad at me Cees or verbally "slap me down" too badly. Good luck with the Wester Taurus...I'm sure it will look and fly great. It probably will be lighter than the Taurus that sold first on eBay last fall. We have a lot more in common than we have differences. We all love the Taurus, and are interested in its history. We just don't agree about every detail of that history.

Duane

No piano wire Cees? No paint? I recommend you have a look at the image, note the date and the name of the guy holding the Orion. There is a photo of the same chap displaying his Taurus, from a year or so later, I wonder if it was the one he built to accompany Ed on the trip? I have evidence that Ed may have left the plan and cassette tape in England on his way home from the African trip, Aeromodeller again, so the English had the original Taurus plan around May 1962.
Evan.

????

Pimmnz,

I do not see an Orion in the photo you attached, just a f/f and 2 scales planes. Different page, maybe?

WEDJ . The perspective make them look rather small but the bottom left hand shot shows two Orions, one held by - Dennis Hunt.

Ray

Ben

Sorry for the delay between this post and my question, but I'm just reading this for the first time.

I'm interested in knowing your reasons why the Taurus isn't the "...perfect pattern plane..." I think I know a few, but I'd like someone with your credentials to comment. The problems I see are:

1) The semi-symmetrical wing, and the effects of that on inverted flight
2) The vertical fin, small rudder, and diagonal rudder hinge line and its effects on Knife Edge
3) Limited side area

Maybe a better question to ask would be "...was the Taurus the "perfect" pattern plane for ITS TIME, meaning an age of reeds, and the maneuvers it was expected to perform at the time, (which didn't include Knife-edge)??

Hope you're still following this thread.

Duane

Aha - thx for the explaination

Duane I want to chime in here on the Taurus in regard to its pattern abilities. I have flowen a Taurus for more than a 1000 flights it was my first pattern plane. I flew it in 1984 to 1986, At that time in Canada we were changing from AMA style pattern to turnaround. I flew the Taurus to a second place finish at the 86 Canadain Nats in Advanced. The Taurus will knife edge very nicely but you have to fly it a little faster than it was probably designed to fly. I used a HP 61 with a 11x7.5 prop at 13000 RPM so it moved. Inverted flight is a small chalange but fly a little on the tail heavy side and it gets a lot easer. With turnaround it only suffers from being short coupled but in the lower classes it is still competitive. Just my .02

Cygnet,

In post 239 you did tell me a half story, there was another side we read now, you were a very success full contest pilot. So some extra explanation I realize my answer was too short.

I know that we can make a (individual!) contest plane fly better by adjusting the dihedral but, it also depends on the location of the CG in the fuselage (high or low), also the drag of engine and exhaust, landing gear I think.
Because my Taurus is much heavier than normally used (+/- 4000 gram, propeller 13 x 6!, exhaust, big engine with lots of drag ) I cannot give any advice, maybe other pilots did fly contest and did research on that.
Also my wing construction isn’t standard and so heavier and I cannot split up the wings.
So slow roll is oké and in the past we didn’t have four point roll in the program, I do read Ed did have that.

Just as yours my story has also another side, see the picture.

No contest but practicing!

On final I did have to pass a diagonal polder ditch and barbwire! So with wind I have to be very careful with the flight level because of turbulence. The strip isn’t as long as it looks like, so too high flight level is also wrong. Touch and go is difficult the way is written down in the program, so dihedral and brakes are important. The brakes also to stop before the end of the strip.
Picture 2 is the same position as the plane in post 240,

Now I use a nose gear with suspension, the mains are positioned more backwards behind the C.G and the ATTITUDE is a few degrees positive now like a P63 King Cobra!

Cees

Pimmnz
I did transport your post 252 date 1/15/2009 and answer to the thread Ed Kazmirski’s Taurus.
I think that is a better place to discus about this cases.
Cees

Gents, direction stability.

Normally there is a lot of posts about the horizontal stability.
Asymmetrical airfoils? Most people are not even finished with that!

But now the direction stability? Do we think it is just making a windshield with a barn door??

Gents, to check the direction stability I have my personal wind tunnel vision!

When an airplane is in the air, pointing exact vertical to the earth with one wing and has no speed, it will fall in a stall.

The first correcting force to get back the flight direction and speed starts on this important moment.
The total side surfaces and the distance of these to the CG is important for this force. The force to give the plane the normal flight direction again is ; dynamic pressure (difference) x surfaces x distance to the CG.

(Before you react, Yes of course also air friction of the wings and shape of the fuselage etc, etc, but this is my method to give me an idea without difficult wind tunnel activities and/or calculations and I do not use swept back wings and forget for a while the dihedral.)


THE PICTURES
Picture 1 Backside of one of the Taurusses.
I did glue cardboard on the backside. The weight is now the equivalent for the side surfaces. But??? It has two main wheels. So double cardboard on the wheel.
The piano wire (heat threatened steel, yes I have it !!!) of nose leg I did made a little wider and to compensate I removed the cylinder head. The Wester Taurus did have a piece of the shaft because it will fly with an exhaust.

Picture 2 balancing on the lineal (knife edge rule?) !!!
On the pictures I did note the distances in mm because the ratio is important not the value to compare. The both Taurusses have the calculated dimensions so the surface of the noses are the same.
Distance to CG op Flite Taurus is 59, Wester Taurus is 48.
The effective side surface of the Top Flite Taurus is about 15 % more .
So the “right direction regenerating force” of the Top Flite Taurus will be 40 % more.
In simple words, the Taurus is one big weather vane and we all know, I think it also gives the problems to start a spin with the thick wings. The wind vane is also the background of my special landing gear, to make it possible to turn on the ground with higher wind speeds.

Picture 3 Because I did not see the TE of the rudder on the crate picture I have to “test fly” with this part of the plane. To give myself an indication what is the effect in a stalled situation I add a piece of (calculated ) surface. The direction stability in total stalled situation is now 30 % less than the op Flite Taurus instead of 40 %.

Picture 4 When Ed did design the op Flite Taurus after his first contest Taurus he probably knew the direction stability was more than enough. With this added surface the stabilities are nearly the same. Later we see they did shorten the Top Flite fuselage without enlarging the rudder. Voila proved.

Now picture 5, a drawing and that’s an interesting picture.

The total side surface of my Wester Surface is small (+/- 15 % less than the Top Flite Taurus) and has a much better shape so, to generate lift during four point and slow roll I need a lot of down force of the fin and rudder.
It is very important to use the most effective and RIGHT TAPERED combination we can design and Ed did know that of course.
Look to the pictures.

TOP: Taurus fin is narrow (on top) and the rudder wide. We see this on all the taurussen!
Of course not on the Orion, with his frise ailerons and high positioned thrustline!!!
I did make mirror image of the fin and rudder, see the green airfoil. With maximum deflection it looks like a highly cambered airfoil with a positive AOA. That’s all right.

BOTTOM: This is what is happening when we enlarge the fin!!!!
We need the AOA of the fuselage to generate lift but an enlarged fin is behaving like a highly cambered airfoil in negative AOA, result drag. So that is not good!!!

”One big doghouse! So you make a tialdragger from a Taurus!" Ed would have say I think

The pictures shows us also something about downwash, (this is up wash for the rudder and fin I the pictures).
A2 > A1 for the Taurus fin and rudder, so airspeed V1>V2 and Daniel Bernoulli tells us: P static A2 > P static A1.
Result of this pressure difference is upwash (normally downwash when looking to wings). The difference is more in practice, look to the light blue arrows.
(We can explain downwash also with Newton but that’s another story).
Down wash of the bottom situation? That kind of “wind tunnel vision” I do not have.

CONCLUSION
My method is not high tech, but Ed did not have the equipment for that either I think.
The position of the neutral point of the side surfaces during slow roll or four point roll will be nearly on position as shown on the drawing (not as the pictures!!!) and will do, I do not expect any problem. I always can enlarge the rudder a little to give a better result.

Interesting will be the way the spin will be “start”, but also “stop”. I think it is better controllable than with the Top Flite Taurus.

And Duane your post 251, I think you did forget my post 220, page 9.


Cees

Gents,

I still have a picture of the fuselagerepair after the crash, The wings only did have a little crack in the bellypan, no structural damage. I think thats the profit of the strong D tube so the silk does not have any damage.

Cees

Ouchie !!!!

Cees, what happened?

Hello Nic.

We did make pictures and the sky was clear blue.
We were talking about, it would be nice to have some top view pictures, views from above, but we didn’t have a high ladder (LOL).
No problem I said to my brother I will make a low altitude inverted flight-by with medium speed so you can make the pictures. Later we will turn the picture upside down to show.
Of course you know what happened then, exactly in front of us in the first passage the engine did stop.

I was lucky also, the field next to the airfield I have to land in, was ploughed, so coarse/loose? (soft)
I did not want to touchdown inverted, because of the engine, so I did try to make a half roll in the last seconds.
After some more as the first quarter the earth could touch to the wing.

The fuselage was broken in two parts near the wing bolts you can see on the picture. The wing bolts were oké!
The only damage was the broken fuselage, balsa push bars of elevator and rudder and the scratch in the belly pan (I tought!)

I did mount the front and backside of the fuse on the bench in right position and rebuild the splintered section.

After all was repaired again , (and a data logger installed), I did want make the next flights.
I was loading the plane in my car, by coincidence I discovered one of the dowels was fractured inside the LE, I simple could take the front side out of the LE of the wing.
I did drill the old part of the dowel out of the wing and did replace new one. This all was 1,5 years ago.

I am working on the dowels again and make the construction for a “centre line pylon” for video transmitting, that was the picture in the other thread of airbusdrvr a few weeks ago.

Cees

Interesting story and nice repair!

Yes Nic,

But it was also to show how it is possible to change the fuselage, for example make the tail cone longer if you want to enlarge the tail moment without adding too much extra weight.

Cees

Gents,

A little note how I calculate the wing and stab incidences.

The calculating example is of the Orion with a positive angle of the stab and the wing, so both angles are positive.
I think Ed was clever. On every plane he did use we see the “0” reference line somewhere on the fuselage. Picture 1.
This is a great profit because during test flying he did change the incidences of both, wing AND stab. The ecalage you can calculate simple. See picture 2

My “0” reference on the Orion is the bottom of the red dash from nose to tail (picture 3).

The Taurusses also have a reference line beneath the stab, the bottom line of the black painting beneath the root of the stab on the fuselage (picture 4). When Ed want to change the incidence of the stab I think he did make a tape along that reference line long enough and measure the old incidence with a caliper. After changing the incidence we only have to “repaint” the black part of the tail and some white.

Maybe your question is: “Why changing the incidence of the stab?” The reason is the washout of the wing! But also he did try different surfaces of the stab I think, so you need a very good reference to mount a new stab on the fuselage.

Designing the plane Ed did count with everything.

The Wester Taurus has a 0 degrees incidence angle of the stab in the beginning.
Test flying will first only include changing the saddle of the wing to adjust the right incidence of the wing in combination with the position of the CG.
Next step will be taking pictures and see if the fuse has the right ATTITUDE during flight, I think that will be oké. If not I put a saw in the tail, no problem. This all I do before the last crate picture is taken.

Important is to understand that only the difference between TE and LE and the chord of both wing and stab you have to know. The reference also can be the bench but that is not easy to take along to the airfield, again Ed did know it all (I THINK).

If you use a 0 reference line take a look if it’s really straight.

Cees

Gents,

A picture (not scaled) to show the detail of the mounting of the stab on the fuse.
To get a rigid mounting of the stab, also I can change, I use a clamp in the last former in the fuselage in front of the LE of the stab.
This is the “double security” of the mounting of this important part of the Wester Taurus
Think about the outside loops and the vertical eight but also because the stab is really loaded during landing approaches because of the cambered wings.

Cees

Cees,

The page you scanned is unreadable - too low resolution.

Interesting connection.

Andy

Andy,

Some extra info,

The stab of the Orion and Taurus both are very strong and rigid.

I use silk and dope covering and also for that reason vibrations and other “activities” give problems near the TE of the stab near the root. For a period I use this kind of repair before new mounting the complete stab again (and again and agian).
To keep the stab on the fuse, also in bad times, I use the double safety mounting for my new Taurus.
We see on the drawing of the Orion Ed did nearly the same with the stab of the Orion, the LE is beneath the top deck, filler block. The Taurus does not have any second safety provision on the drawing.

Problems I discovered after about around 300 flights of the Taurus and 150 of the Orion, see the pictures.

I can read the 1962 rules easy, but use the button on the picture right under corner ,see picture 4, to enlarge the picture on the screen.
Are you “internetting” (nice language, easy to translate!) with a mobile telephone?
If you keep problems give me a sign.

Cees

Cool, I didn't see that button. It's very, very "ghost" on this monitor. Thanks.

Andy

Andy,

I call the file of that button the "Andy Kunz Cross" in my computer.
Now you can visit my thread and practice with your own button because even your own Andy Kunz Cross has an Andy Kunz Cross Button (AKCB).
(One spare for safety reasons)

Cees

Gents,

A short message about the dihedral

I already did discover the wings in the crate have more dihedral than the later Top Flite Taurus.

Before covering the wing I have to adjust the right dihedral as I can measure from the crate picture.

On both wingtips, near the ailerons I did make labels with (cm) dashes (rules?).
By making a pictures and measure the distances on these pictures I can make a picture of the wings identical to the crate picture, so with the same point of view and distance than the old crate picture. I also still know the distance from leaser beaming and the thread method of the beginning, this was the same point .
The result.

Al the colored lines are identical in length.

Result is we can clearly see the dihedral of the wing of the crate is more. Compare the blue lines.
The orange lines do indicate the wanted dihedral and the way we look to the TE of the ailerons.
By reading the crossing of the orange line on my labels (see yellow dots) I simply can calculate the new dihedral.

Of course this method only works with the standard wing, but the mounting position of the wheel legs in the wing shows us this isn’t a wing set with straight TE!.
The wings are glued together with a view drops of glue so changing the dihedral and making again pictures is no problem. Continuing until the pictures are the same.
When this is finished I do have to check the main legs of the gear again

I do use three wing sets in the picture, the crate in the centre and both identical on both sides. It is better to see because our human eyes do not like al that diagonal lines. Now we have some balance and not only ARE the wing sets the same but also nearly LOOK the same.

When you do not believe, take a rule and measure on your screen the lengths of the three red horizontal distances, between the tips and centre of the outside wing sets: They are really the same!!

Second picture to show what is happening when we do not used that little balance, you maybe would not believe it, they have nearly the same dimensions.

Cees

Gents.

May I present you the new dihedral, 5 ", so the old dihedral was not good, much to low.
The new dihedral is 0,5 inch more than the later Top Flite taurus (4 1/2").

That will be interesting, test flying figures like outside loops, vertical eight, tail slide and four point roll.

Look to the distances between the red line and TE of the aileron, near the orange dots.


Edit, checking the pictures Hanna and I discover the dihedral has to be more than 5 ".
The nearest wingtip isn't wide enough so the distance and angle were not right, Hanna and I will come with better results.
We have to mount the camera and wing in a fixed situation just like laser beaming.

Cees

Gents,

Still fighting for the dihedral, 6 " isn't enough.
I show a study picture, I did make nearly 50 pictures now I think, but we are close now.



Cees

Hi Duane,

I just came back in town from a trip. In general everything that you wrote fits. The Taurus was good for it's time to do the required pattern of that time and using the radios of that time which were terrible! I hated the old reed sets - you had to tune and tune and fiddle and tune - I am totally impressed that Ed could keep his Taurus in one piece for as long as he did.

It seems that Ed wanted an airplane that required an airplane that needed a minimal amount of control inputs. Line up the level approach for the maneuver and push one lever until the maneuver was done and watch it fly out level. With the pattern requirements of that time it resulted in a semi-symmetrical airfoil and relatively high dihedral wing for mostly upright flight. Then add a swept tail to hopefully get a bit of up elevator effect. But whether or not the Taurus was the best at that time is so totally influenced by the pilot flying it that it is a real problem to be sure. I remember seeing models at the time that I believed had better aerodynamics for that pattern. However Ed's flying ability (resulting from a lot of practice in the previous years) was good enough to beat the pilots flying the other airplanes. Remember that the winners and runner-up scores are not that much different in the contests.

You can make the Taurus do some of the popular maneuvers of today but that doesn't mean that it is "comfortable" doing them. A much better airplane, even for the old patterns, is one that can be seen at any modern FAI or AMA contests. These look like flying fish and are totally symmetrical. You can command any control deflection and get a result that is just what that control should give. With motor control available (especially with electrics) the speeds are nicely slow and totally constant in all attitudes and maneuvers. The airplanes would probably fly just as will with reeds - you would have to do a little more beeping on the reed levers since there is no attitude stability built in.

With this as a measuring stick the Taurus falls into the aileron trainer class. I am in the process of gluing sticks together to build an Astro Hog but only because I wanted one so badly when I was a kid that my teeth hurt!! The Taurus would fit in the same category. I would love to have one but I certainly wouldn't expect it to be capable of doing everything that I have in my mind with respect to maneuvers.

Oh yes, back to the vertical tail - it is a wild guess as to how much effect a swept vertical/elevator would have. You would have to build an airplane that has easily interchangeable vertical tails (bolded on) and fly the airplane with each tail. Even better would be the ability to stick it in a low speed wind tunnel.

People typically don't do that. They change the vertical tail and then think, hummm, let's change the xxxxx a bit and maybe the yyyyyy a bit and soon it is a different airplane and they have no idea if the original change made any effect at all. Then if someone asks about it the original reason is stated with no proof.

In full scale airplanes the vertical tails are sized to give a certain dampening rate after a displacement in yaw angle and the rudder sized to give a yaw rate after control input. We don't do that. As Cees noted we look for the results on maneuvers such as snap rolls, spins, stall turns, 4 point rolls, etc. There can be a lot of variation in vertical tail sizing that work when we are using observation for our analysis.

It is interesting stuff...

Ben