OHM SKYCRANE3

[OrbitHangar]

Author: gattispilot

Resized and Refit of Kev's Skycrane.  Now it uses UMMU.  Has changing rotor/disc.   Winch moves up/down and attaches.  Converted Kev'ss cargo boxes into UCGO carbo boxes.  It will hold 4 UCGO crates.

V switches camera.  2 position on the hook for the ease of hook up.


Extra textures included if you want the orange copter
UPDATED:
added module and fixed textures


DOWNLOAD

 

[Interceptor]

Hello gattispilot,there is a bug, both the sky crane,and cargo boxes have to textures.

 

[gattispilot]

Thanks. Sorry updated it

 

[BEEP]

A necessary and welcome update.

However it inherited a problem from the earlier version that becomes even more serious when dealing with UMMU: The mesh is too out of scale.:huh:

I researchead my references ( Salamander, Bill Gunston) and found out the scale factor to be about 0.7059

Rescaling the meshes in the Orbiter Mesh Wizard is simple and does not require any retexturing.

The problem resides on redefining all footprint and animation points and this is something that only the source file owner could do.

I can hardly wait for the corrected version.

Thanks a lot for your understanding

Beep

 

[gattispilot]

Really. So are all the meshes too big? The copter and crates? I can do easily. Ok. the length is supposed to be 21.41 m (fuselage). using meshwizard I get 27.839. So it looks I need to resize it to 27.839/21.41=.769. I can resize everything and redo the animations,..... But which reduction?

 

[BEEP]

Thanks a lot for your reply. I'm delighted to contribute to a model that I really like and has a lot of fun potential for the simulation.

I tried to look at this issue more carefully:

=========================================================================
Bill Gunston Military Helicopters Salamander

Height 5,67m
Total Length 26.97m
Main Rotor 21.95m

www.aviastar.org/helicopters_eng/sik_s64.php


Height 5,67m
Fuselage Length 21.41m

===================================================================
Calc to Main Rotor

Main Rotor Center (no point ) = -3.038894E-02 2.5716 4.232673
Main Rotor Extremity MAINBLADE16 = -12.45339 2.5369 0.060098
Distance = 13.1050578616573
Rotor total diam. =26.21011572
Factor = 0.837

Calc to Fuselage Height Including gear

Top: Mesh6 326 = 0.12898 3.2733 -13.316
Bottom: Mesh24 0 = -2.9718 -4.7588 2.3642
Dist(Y) = 8.0321
Factor =0705917506

Calc to Total Height including secondary rotor

Top
Secondary Rotor Center :-0.1583891 2.640247 -12.64978
Secondary Rotor Extremity: -0.1583891 4.721379 -13.64622
Secondary Rotor Radius: 2.30738013231977
Top: ( Y Secondary Rotor Center )+ (Secondary Rotor Radius) =2.640247+2.30738013231977= 4.947627132

Bottom: Mesh24 0 = -2.9718 -4.7588 2.3642
Dist(Y) = 9.706427132
Factor = 0.58414903 (????)

Calc to Fuselage Length
Front: Mesh6 1565 = 0.173 -2.1058 13.881
Back Mesh6 800 = 0.16346 2.7975 -13.958
Dist(Z) =27.839
Factor = 0.76906

Calc to Total Length including main rotor and secondary rotor

Front: (Z Rotor Center) + (Rotor Radius) = 4.232673 + 13.1050578616573 = 17.33773086
Back ( Z Secondary Rotor Center )+ (Secondary Rotor Radius) = -12.64978 - 2.30738 = -14.95716
Dist(Z) = 32.3344686
Factor = 0.834094425



At this time I was completely lost so I decided to take a look at some photos and check proportions. One thing that called my attention is that for people next to the cockpit , the tops of their heads match the bottom edge of the front-side-bottom cockpit window.

Considering an UMMU civilian model ( which is quite accurate) this condition is achieved with the .7059 scaling. I wasn't so lucky to find a suitable reference for the length but, after some trials, it seemed to me that the better option is to take for the length (Z axis) the calculated value of .769 and ensure the model fits prototype listed dimensions. Also seems to look better this way.

When these options are assumed it feels to me that, for the X axis, the .769 scaling gives a proportion that ( visually and intuitively) matches the blueprints better.

Best Regards and Happy New Year

BEEP


PS Once you're already reworking the model, check if the center origin of the mesh is correctly placed at the CG of the helicopter. It seems to me that the CG should be in front of the rear gear, probably around the main rotor Z pos.

 

[gattispilot]

Check this one out: All cargo and copter resized

https://www.dropbox.com/sh/rmin6wsf8t0p01e/lKp11hp3wI/SKYCRANE3.zip

 

[Astronut25]

Beautiful Aircraft

I used to work for the company that rebuilds these, they are definately a beautiful aircraft, and powerful too (the most powerful civilian heavy-lift helicopter in the world).

Just a minor nitpicking though, the model is of a civilian short-cab variant S-64E Aircrane, not the military's CH-54 Skycrane. A few differences propably only noticable by someone who has worked on them. Also, there are 6 Main Rotor Blades that are slightly offset from eachother (improves lift, but makes it VERY noisy) and 4 Tail Rotor Blades. The engines are also a bit too close together and a bit forward.

I would love to see this addon expanded with more liveries, cargoes (like the medivac pod, crew pod, cargo winch, etc) and the E/F variants, short/long cab variants.

If you'd like some pictures, I've got some, also the Erickson Air-Crane website has tons of good pictures. Also if you need some help modeling, I used to work on the actual engineering documents, so I know how this thing looks like inside and out.

 

[gattispilot]

Sounds great. I can add another blade on top . I think the tail has 4. The different cargoes could be done. It has a winch so I don't know what the cargo winch looks like.

 

[Astronut25]

Sorry I couldnt find a higher resolution image of it, if I still worked there, my boss had a good B&W picture of it.

It is just in front of the legs of the aircraft on both sides, this is only on the military variants and was used for especially large cargoes, its more stable than the crane.

I've also wondered if it was possible to animate the Main Rotor Blades flexing when throttleing.

an interesting note: the MSL landing vehicle was named after this aircraft, because of Ericson Air-Crane's involvement in helping to develop it.

 

[gattispilot]

What do you mean by flexing? What pod would be good. There is one winch in the center. the grapple claw could be done but it would go through the mesh. I think I might add it the auto hover that keeps the copter in the same area.

 

[BEEP]

Uau!

Looks a lot better isn't it?

However remember that the sound config file and the folder containing the .wav's should bear the same name and that it should be the class name. The sound didn't work at first.

I'm going on testing it and should inform you about my impressions.

Thanks and Rgds

Beep

 

[Astronut25]

What do you mean by flexing? What pod would be good. There is one winch in the center. the grapple claw could be done but it would go through the mesh. I think I might add it the auto hover that keeps the copter in the same area.

the rotors are expected to flex up to 20° IIRC

Here's a good video showing this effect (note that it isn't even at full load/throttle though)

also note that the slow rotating tail rotors is an optical illusion created by the framerate of the camera.

 

[gattispilot]

Neat. On the flexing. I don't think so. Basically right now the engine starts, hear the noise and after a while the blades rotate and then the transparent discs appear and the blades go away.

Try this new skycrane with 6 main rotor and 4 tail blades. fixed the sound

http://dl.dropbox.com/u/71242599/SKYCRANE3-1.zip


I also added the autohover J activates and O the letter cuts it off. It applies force to the opposite direction so it keeps the copter near the same position.

As far as Liveries. Any suggestions? If I had images of the pods I can add them. I could add winch pods what attached but then you would have to switch to the winch to operate.

 

[Astronut25]

Liveries

As far as Liveries. Any suggestions?

The one above is the generic "Ericson Air-Crane", the individual aircraft have its name on the front hood.

Theres also the Evergreen ones (with some kind of minitank I've never seen before)

Then there's my personal favorite, the SDG&E "Sun Bird" Livery (it even has a matching tank)

 

[gattispilot]

Ok. But I think it would just a matter of repainting. I guess one could pick a choose the color/texture.

Is that a water tank. I suppose you could just attach to the winch. Not sure what it could do in Orbiter.

Simple repaint of textures I get this:

 

[gattispilot]

I guess I will update the download with the new resized copter. I will add the new textures. So all you have to do is change the textures in the mesh. I can add a tank. It would be just a mesh. It looks like the bottom opens up. I can animate that. Maybe add a exhaust texture to look like water drop?

 

[gattispilot]

The new updated resized copter is in the hangar
[ame="http://www.orbithangar.com/searchid.php?ID=5951"]http://www.orbithangar.com/searchid.php?ID=5951[/ame]

 

[Interceptor]

Do I also need Kevs copter with this addon?because all the cargo boxes are White,no textures,and the skycrane3 is invisible.

---------- Post added at 05:22 AM ---------- Previous post was at 04:53 AM ----------

I just tried it with Kevs copter,and still the same problems.

---------- Post added at 05:27 AM ---------- Previous post was at 05:22 AM ----------

OK,you seem to be missing the modules folder in the download.

 

[gattispilot]

Updated the zip to include the module for the copter. The crates in mine are UCGO vessels so you can load up with UCGO cargo.

On the crate textures what does the log say.