Junkers Ju-52/3m

[aleatorylamp]

Hello Folks,
This thread will be for a new CFS1 model project, to be built with AF99 and animated with
Aircraft Animator, with support by SCASM for the virtual cockpit:

The famous old Tante Ju, or "Auntie Ju", also known as "Iron Annie".

The Junkers Ju 52/3m was one of the most successful European airliners ever built.
This tri-motor (3x720 Hp BMW-132-A3 or -T radials) was designed for Deutsche Luft Hansa
in 1932, and could carry 17 passengersor 3 tons of freight, and had excellent short-field performance.

By the mid-1930s, European and Latin American airlines were flying them, and during World War II,
they were the Luftwaffe's primary transports, and some served as bombers.

A total of 4,835 Ju 52/3ms were built, as well as 170 under license by Construcciones Aeronauticas
(CASA) in Spain (with 3x785 Hp Spanish ENMA Beta-B4 engines - licence built BMW-132´s), and over
400 by Ateliers Aeronautiques de Colombes in France.

The Ju 52/3m continued in postwar service with military and civilian air fleets well into the 1980s.

My intention is to supply a Spanish version by CASA, a green camo German version as in the picture,
and a paratrooper version that I still have to investigate the colour scheme for.

I expect it will be another entertaining, fruitful and didactic experience, and you are all invited to
participate, the main thing being, to have fun!

Cheers,
Aleatorylamp

 

[smilo]

oh boy, this should prove interesting.

 

[aleatorylamp]

Hello Smilo,
Yes, I agree!
I´ve been doing an inventory of what we already have from other German aircraft.
Material to be used would be the engines, engine gauges and 2-pitch, 2-blade
propellers of the Fw200A Condor, all thanks to Ivan´s efforts and cooperation
with that model.

The engines on one of the earlier versions, the -G3E, are similar to those on the
Fw200A Condor, but a slightly different variant: BMW-132-A3, with 725 Hp at 2050 RPM.
Later versions had upto 830 Hp, and will also be taken into account to make other model variants.

So, for a start I used the Condor .air file to make the 3-engined .air file, entering the
Ju-52/3m-G3E dimensions and weights, and aimed for the specified S.L. base-performance,
which is 165 mph with 725 Hp at 2050 RPM.

Preliminary tests after adjusting Torque and Zero Lift Drag, give quite close results:
167.1 mph, with 725 Hp at 1951 RPM.
The slower RPM was to be expected because the Condor´s speed was 60 mph higher,
so a slight adjustment in one of the Propeller tables will be in order, and will be no problem
after what I have learnt from Ivan!

At the moment I´m putting the scale onto some very good 3-view drawings I found, to get the
basic measurements into AF99, and hopefully I will soon be making a CFS1 toy "cardboard model"
with coloured 2D parts, to get a general feel of dimensions and sizes, and to show a screenshot!

Cheers,
Aleatorylamp.

 

[aleatorylamp]

Propeller and Performance Adjustments

Hello Folks!
Further research has revealed that the 2-blade propellers on the earler
Ju-52 were 9.5 ft in diameter, and on the flight model, this parameter
adjustment increased RPM a little. (The Condor had 9.7 ft propellers).

Then, aiming for 165 mph with 725 Hp at 2050 RPM, slight adjustments
on the propeller power coefficient table for the curves J=0.6, 0.8 and 1.0,
as well as other very small changes in Drag and Torque, finally gave very
close results:

S.L. horizontal speed at full throttle is 165.2 mph, with 726 Hp at 2046 RPM,
which is quite pleasing, and can be quite acceptable, at least for the moment.

Now that I have a reasonably well-behaving three-engined airfile, I can start
making the AF99 cardboard mock-up model.

Update:
Hello Smilo,
Attached with this post is the new CFS1 .air file, for any trials or experiments
you may wish. It´s called Ju52-3m.air, and will have to be re-named it to fit an
existing FS98 model that you may be experimenting with at the moment.

Cheers,
Aleatorylamp.

 

[aleatorylamp]

Hello Folks, Hello Smilo,
I thought it would be a good idea to have a 3-engined panel for testing as well,
so I adapted the functional look-alike panel I did for the Condor, also fixing
the 3-engined generic throttle gauge with better handles.

By the way, there´s a new .air file named Eacasa52.air (for the FS98 Spanish Ju52 model
serving as a test-bed for the new CFS1 .air file), included in the panel folder because
I hadn´t activated the flaps option in the previous one.

Here is a screenshot and the panel and the panel.config with the new
custom 3-engine throttle gauge it contains.
The other custom gauges are in the FW200A Condor I uploaded some time ago.

Also enclosed, just in case, is the CFS1-SDK which contains sound and panel
config information.

Enjoy...
Cheers,
Aleatorylamp

 

[aleatorylamp]

Engine 1 and 3 angles.

Hello All!
On the Ju-52/3m, the only engine that is aligned parallel
to the longitudinal axis is Engine No. 2 in the nose.
The others are almost at right angles with the wing leading
edge, i.e. facing outwards. The reason for this seems to be
to make the aircraft easier to control in the event of a
wing-engine failure.
Also, it seems from the 3-view drawings, that they are very
slightly slanted downwards.

I had taken for granted that simulator models had to be built
with propellers perpendicular to the aircraft´s longitudinal axis,
but Aircraft Animator in a very able manner, appears to offer
the possiblity of slanting them any way you want!

Unless I am very much mistaken, it is only the .air file that
positions engines at x,y,z, with no possibility of thrust inclination
in any direction. I seem to remember that Jet .air files offer an
up/down thrust angle offset, but not propeller air files.

So, at least we can feature this charismatic visual effect.

Here´s a screenshot of an older FS98 model in Aircraft Animator.
The engines in the lower part of the compound picture show the
engines lined up perpendicularly, and the upper ones show the
propeller axis inclination we can put in.
I fear I´ve exaggerated the angle a bit too much - it should actually
be slightly less than perpendicular to the leading edge backsweep.

Of course, the propellers and engine nacelles must then be built
according to plan, with the proper inclination - without perpendicular
correction for the model!!

Cheers,
Aleatorylamp

 

[aleatorylamp]

Toe-out

Hello Folks,
Well, it works!
There´s a 5-degree toe-out and a 1-degree downward inclination
on wing-engine nacelle components and propellers.
The animation works well. For the moment I´ve kept it simple.
Now I have to do the prop-axels.
Cheers,
Aleatorylamp

 

[aleatorylamp]

Hello All,
Well, the basic shapes are there, and I´ve also got the axels on the propellers, and they look the part!
I managed to make slanted structures for the left and right prop-axels. A bit confusing, to say the least.
Fuselage, wheels, nose and tailfin are all structures, as I´m saving components for everything else.
Here´s a screenshot showing a bit of progress - it´s got a bit of ambience already!
Cheers,
Aleatorylamp

 

[smilo]

that, she does...well done, Stephan,
and thank you for the progress report.
looking forward to many more.

 

[aleatorylamp]

Hello Smilo,
Experimenting with nacelle structures, top and bottom halves.
At the moment there´s not much point, except for entertainment,
and to get the shapes.

Wings are still 2D, so nacelle structures behind the engines are too
prominent, and too parts-hungry anyway. However, they will serve
as the basis to make nacelle components later on when the wings are 3D.

The cabin glass is also a transparent structure, until I get the component
frame and the windows in there.
Cheers,
Aleatorylamp

 

[aleatorylamp]

Cockpit area, main gear and inner wing

Hello Folks,
In the last 3 days I´ve been working on the cockpit area.
Initially the windows were transparent, but it was taking a long time to fight all the bleeds,
and only with limited success, so to get ahead a bit again, for the time being at least, I´ve
made it opaque.
In the meanwhile I´ve also improved the landing gear struts, and the wing-root and innerwing are 3D now.
You can see how the outer wing is still 2D. I haven´t adjusted the provisional engine nacelle shape very well - it´s only for some kind of visual reference anyway.
Here´s some new screenshots of the progress.
Cheers,
Aleatorylamp

 

[Ivan]

References

Hello Aleatorylamp,

I have been hanging out at a rather interesting Russian site and found some pretty good references on the Ju 52.
Are you in need of any particular data or drawings?

- Ivan.

 

[aleatorylamp]

Ju-52/3m Drawings, Engines and Propellers

Hello Ivan,
I found the Wikipedia ones quite good and I´m using those.
For the Spanish version with the bigger engine cowl I´m using photos.
I wouldn´t mind looking at the russian site - I´ll see if I can find it, perhaps the drawings are even better!

I can see from different sources that there is a lot of generalization as regards performance, and they state the same for all motorizations, which is absurd, of course.
165 mph S.L. max is fine for the BMW-132-A3 725 Hp motorization, but not for later models that had upto 850 hp engines. (I am not including the few earlier versions with Hornet engines).

However, one or two sites give better details here, and performance seems to go up to 170 and 175 mph for the Spanish ENMA BETA 750 and 775 Hp versions, and upto 183 mph for the 830 Hp BMW-132-T2 version. My calculation for a BMW-132-Z 850 Hp engined version would be 187 mph.

Another thing has to do with one of my 2 favourite propellers: The 2-speed 2-position propeller. (The other one is the wooden 16-degree pitch Sensenich one!)

It is obvious that the 2-pitch prop was being used on early models, from the 725 Hp ones, through to the Spanish engines, and perhaps even upto the BMW-132-L 800 Hp BMW engined.

After that, I´d wager all later models would have had the 3-blade CV props.
My trials with .air files and propeller tables would corroborate that.

Anyway, I would indeed welcome any help or suggestions from you if you like!

Cheers,
Aleatorylamp

 

[aleatorylamp]

Sonorous question

Hello Folks, Hello Smilo, hello Ivan.

There is something about aircraft sounds that I have always found strange, but never noticed consciously until Smilo pointed it out and started experimenting to see exactly what´s going on.

Using the same alias to call an aircraft sound, there is a difference between how CFS1 .air files and FS98 .air files present the sound change for accelleration from idle to maximum RPM, and of course the other way round, for decelleration.

It is much more gradual and begins sooner for FS98 .air files than for CFS1 ones. The latter will not change the sound at best until after 40% throttle with an FS98 stock aircraft sound, and up to 70% with a CFS1 stock aircraft sound.

I was originally using an FS98 .air file from an old Ju-52/3m model, before making a new CFS1 .air file. The difference is clearly noticeable - the two .air files deal with low RPM sounds very differently.

In the event of absence of Record 505 for CFS1 engines, the Hp setting in record 500 applies directly to the sound and engine power, but if Record 505 exists, Hp is calculated from the engine parameters entered, and the resulting Hp seems to regulate sound in a different way, possibly ignoring lower RPM values except idle power.

I wonder if anyone has found how this can be corrected.
Cheers,
Aleatorylamp

 

[Ivan]

Industrial Sound & Drawings

Hello Aleatorylamp, Smilo,

That sound question is interesting. I have never really noticed the sound effects because normally I have the sound turned down VERY low.
One has to do that when all the other folks in the house are sleeping and one is still playing on the simulator!

If you want me to look at the CFS AIR files and where the issue might be, please email me a pair of AIR files for FS98 and CFS.

I have actually been wondering about how to generate some other sound files such as for a Napier Sabre engine or the starting sounds for an inertial starter or Coffman Cartridge starter, but those ideas are way low on the list. The Ki 61 needs to get finished first.

Regarding Drawing from Wikipedia....
In general, the line quality is pretty good, but the accuracy of those drawings is always suspect in my opinion.
I have found in the past that the artists often invent details and shapes that were not in the original aircraft.

Here are a couple drawings with some useful dimensions so that you do not need to scale off the Wikipedia image.

Is there a particular model designation of the Ju 52/3m that you are building? Apparently there are a lot of variants.

- Ivan.

 

[smilo]

many thanks for the air file engine sounds offer.
i will gladly take you up on it in a day or so.

i think most of us here were not aware
of the issue regarding sound pitch increasing
with acceleration from idle.
i know i wasn't...let's be honest,
we get into game, start the engine,
and then firewall it, balls to the wall.
nobody cares about taxiing around the tarmac,
listening to a radial rumble at low rpms
or, better yet, hearing one accelerate from idle.
we want to get into the air and blast stuff.
am i right or not?

leave it to an old man to notice such things
and want to remedy the situation.

that said, i do not want to hijack this thread
with a discussion about sounds, even though,
in the end, they can be used for the ju52.
i believe a CFS AIRCRAFT SOUNDS thread is in order.
i'll set one up in a day or two.


ps;
as for bothering others in the house
with the sounds of cfs,
i eventually ended up acquiring
a jim dandy 5.1 surround sound headset.
dang, talk about immersion...wowzers

 

[aleatorylamp]

Hello Ivan,
Many thanks for the Ju-52 schematic drawings.
I´ve put them into my building folder, and I´ll check that the dimensions on my model are correct.

The armed Ju-52 is curious, isn´t it? with that soup-pot ventral gunner position. They actually called it that when they were used in the Spanish Civil War.

As regards CFS1 engine sounds, the flaw applies to all aircraft with CFS1 .air files.

I definitely agree with Smilo, that it is truly excellent being able to listen to an idling radial engine sound, and then progressively increasing RPM onto the runway and then slowly apply full power for take-off!

For a given aircraft, using the same sound.cfg and sound files, an FS98 .air file will produce sound results that are different to those produced by a CFS1 .air file.

As we know, FS98 uses Records 500, 501, 503 and 504 for its engine and propeller table records, and CFS1 uses Record 500, followed by CFS1 Records 505 to 541.

You can put CFS1 engine and propeller records 505-541 into an FS98 .air file, even without deleting the three FS98 records 501, 503 and 504, as the latter will be overridden.

However, you have to put in ALL the CFS1 propeller and engine records - 505 to 512 (apart from 513 onwards, which do different things and may not all be necessary).

Incomplete or partial installments for files 505-512, expecting CFS to use FS98 records as fall-back, will not work!

It appears that the CFS1 engine sound is regulated by the resulting Hp calculation done with data from Record 505, as deleting this Record will eliminate the engine startup sound in the Sim, and of course, the engine will not work.

Then, although it´s beside the point, I haven´t tried out what happens with selective deletion of records from 513 onwards. What I do know though, is that FS98 fuel tanks can be used instead of CFS1 tanks in Records 525-533, should anyone be inclined to do so, but that´s not the point anyway, as these don´t affect engine sounds, which is the issue in this case.

I don´t mind at all if this is being discussed here, but if you want a separate thread for the CFS1 Sound issue it´s OK by me.

Cheers,
Aleatorylamp

 

[aleatorylamp]

Hello Ivan,
I´m sorry, forgot to answer one of your questions:
The models I intend to provide for the moment would be three:

1- An early one with the 725Hp BMW-132-A3 engines and 2-bladed, 2-pitch position propellers,
2- A later one with 830 Hp BMW 132-T2, or 850 Hp BMW-Z2 engines, and 3-bladed CV propellers.
3- A post WWII Spanish built CASA 352 (different nose-cowl ring), with 775 Hp ENMA BETA B4 engines and two-bladed propellers.

Then, I have found further information as to the performance of the different motorizations:
- The 725 Hp engined version quoted at 165 mph top S.L. speed, did 172 mph at 9800 ft.
- The Spanish 750 Hp ENMA BETA B3 engined version did 170 mph at S.L.
This leads me to suppose that the 775 Hp ENMA BETA B4 version did 175 mph top speed at S.L., and that these two ENMA BETA engines would do about 178 mph and 183 mph at 9800 ft respectively.
- Then, top S.L. Speed for the 830 Hp Version seems to have been 183 mph, and 192 mph at 9800 ft.
So, I suppose the most powerful 850 Hp version would have done 187 mph at S.L. and 196 mph at 9800 ft.

I woder if you would agree with my suppositions.
Cheers,
Aleatorylamp

 

[Ivan]

Hello Aleatorylamp,

It sounds like you are much further ahead on the CFS versus F98 AIR File sound issue. I actually have not ever looked at it because I almost never fly FS98 AIR files or with any significant sound. My focus in the AIR file arena is fairly narrow.

I WILL warn you though: Using the FS98 Fuel Tank records for a CFS AIR file MAY work, but I believe it has some side effects.
This was something I tried way back when I first started working on AIR files because it was certainly the simpler approach.
It was in my first attempt at an AIR file for my F6F-3 Hellcat and although it flew well under normal circumstances, there were some weird effects when I tried some extreme maneuvers. For example, I was never able to successfully belly land that Hellcat which meant that it never passed that part of testing.
I never did figure out exactly why it was happening but I seem to remember that problems went away when I went to the CFS Fuel Tank configuration and I didn't try FS98 Fuel Tanks again.

The Ju 52 data I found was a PDF which is a bit too large to email. I went through a lot of sites and links very quickly, so I don't know if I can find the download site again. At the time, I was less concerned with the PDF stuff I found than the DJVU stuff because I had no easy way to look at DJVU files.

From what little I have been reading from the PDF, it has been covering Lufthansa birds with engines in the 550 HP range.
What is the significance of the Spanish Ju 52 with the ENEMA engines? Did that post-war bird do anything noteworthy?

- Ivan.

 

[aleatorylamp]

Hello Ivan,
I don´t know about negative side effects of FS98 tanks when used with CFS1 - all I know is that they work because I saw some CFS1 piston planes using FS98 tanks - until I substituted them because the configuration was inaccurate.

The earliest versions of the Ju-52-3/m had 550, 660 and 715 Hp engines, 525 Hp American Hornet Radials, 575 Hp 12-Cylinder Hispano Suizas, or Jumo diesels, of which Lufthansa got a few, and they even got a very good improved luxury civil version with 880 Hp BMW 132 Dc engines, a model which was also exported.

With the outbreak of the war, the first military versions received the 660 Hp BMW 132A and a bit later the improved 132-A3 with 725 Hp. The engines were then further improved and progressively the Ju-52 was equipped with 800, 830 and 850 Hp engines, which I have mentioned in a previous post.
It also appears that there was also a 750 Hp BMW132 engined version that did 180 mph top speed at S.L.

Regarding the Spanish "Auntie Ju":

The first Ju-52´s that Spain received were 8 or 10 for the Civil War, with German 660 Hp BMW-132A engines, which were used as bombers, and were then given as a gift to the Government that won.

Later, the Spanish Aircraft Company CASA (Construcciones Aeronáuticas Sociedad Anónima) started building the Ju-52/3m, under licence from Junkers, calling it CASA 352, with 660 Hp BMW 132-A engines, of which they built about 100 units until 1950. I still haven´t found a top speed reference for this motorization, but it doesn´t really matter as I´m not building this one.

Due to BMW132 engine shortages, a Spanish Engine Manufacturer in Barcelona called Erizalde supplied licence built Wright R-1820 Cyclone 750 Hp radials called Erizalde E9C. Shortly afterwards, the company was nationalized, becoming ENMASA (Empresa Nacional de Motores de Aviación Sociedad Anonima). These engines were then renamed to ENMA BETA B3. Power had gone up from 660 Hp to 750 Hp, and top speed was 170 mph. About 40 units got the Erizalde E9C aka ENMA BETA B3 engines.

German Duralumin also became scarce after the war, and CASA had to use the slightly heavier Spanish corrugated aluminium. This would appear to be the reason for the CASA 352 to have had a top speed at S.L. 10 mph lower compared to a similarly engined German unit.

ENMASA aparently then went on to produce licence built improved BMW 132A radials giving 775 Hp, and this was the ENMA BETA B4, with which the restly new 30 units were equipped. Eventually, the rest of the 170 Spanish built units were eventually all re-motorized and called CASA 352L.

These were used as military transports, trainers, paratrooper aircraft and bombers, and were used actively as bombers in the Ifni War in 1957/58, and the last Spanish Air Force unit was retired in 1974. One last unit was still being used in the Parachuting School of Alcantarilla until 1978. The rest were sold to museums in many parts of the world, for exhibition and restoration. The majority of the 8 units still flying nowadays are CASA-built ones, and a few more are currently being restored.

The Ju-52/3m appears also to have successfully served in the Argentinian Chaco war, for logistics in a remote region. Despite its slow speed, it was famous for being reliable and rugged. There was also a spectacular rescue mission involving a fully laden Ju-52/3m crossing the Pamir mountains in India as well. Quite a feat for such an aircraft!

So basically this is a summary of what I have been able to find out.

Cheers,
Aleatorylamp