Azimech

[Stock Helicopters & Turboprops] First flight around Kerbin! (page 49)

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Jakalth    444

I have a nice heavy duty turbo shaft you guys can play with if you like. It's a bit of a heavy weight(yeah, I tend to overbuild my engines) but can handle some pretty extreme stresses at lower RPM. Yeah, this engine needs to be kept at low rpm due to turbine blade expansion... But, at low RPM, it can handle heavy weight and lots of lateral forces. I have also switched over to a structural fuselage main shaft with 1x1 plates for turbine blades. Seems to work the best for this type of setup. With only 6 "cylinders" it is a little underpowered at times though.

jakst6xturboshaft_zpsfbk9rtv0.jpg

I used this turbo shaft in the big helicopter I showed earlier, but have since cleaned up part counts a bit and streamlined the engine a little. It's been tested with the helicopter, where most failures are from rotor blade separation. This cleaned up engine has had some interesting static tests done to it with good results. In a compression test, it can handle 82 Tons of mass pressing down on it from above, and still spin that mass.

jakst6xcompressweight_zpsedfo4qgg.jpg

And in an inverted hang test, it can spin over 61 Tons.

jakst6xhangweight_zpsiiqwof5v.jpg

Part count of engine: 214

Mass of engine: 21.7 Tons(with a Rockomax X200-8 Fuel Tank as it's fuel source)

Doubt it will win any beauty contests though. Also doubt it would work as an aircraft engine. But as a heli main rotor engine it works well. Or as a static rotating platform for a full scale display piece. ;)

Download: Jak-TS6x Super Heavy Turboshaft

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Redshift OTF    1307

Azimech, is that a Spitfire or something? My history isn't that good. Also, what problem did you have with your propellers and how did you fix it.? Looks awesome btw. Jakalth, I will have a look at your engine, I'm sure I could get it to spin faster.

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Azimech    5930

No, it's a Focke-Wulf Fw-190A. And it's almost ready for download :cool:

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The problem was that I didn't know how to increase propeller thrust with the proper amount of propeller blades. I've found the trick.

:wink:

Edited by Azimech

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Redshift OTF    1307

Ooh yes, very impressive. Your other plane tended to torque a bit to the right I think but it is hard to stop that with a single engine craft. Maybe add a bit more SAS?

Jakalth, you have built a pretty robust engine there. I haven't managed to solve the problem you have with the turbofan blades pulling apart as there is not much room on the structural fuselage pieces to try something different. Have a look at my engine to see my method for that. I see there are 2 lines of thought regarding wheels on the bearings. You guys use a mix of horizontal and vertical wheels which are more stable but use more parts. I went for angled wheels that use less parts but aren't as stable holding heavier loads. Not sure which is best but it's good to see different methodologies.

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Azimech    5930

Redshift: Good news! The 190 is very stable and needs only minimal trim at sea level!

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SlabGizor117    142

Amazing. I love the 190, looks just like it, but I don't see any gear. Detached after takeoff? Also, I assume you play War Thunder? :P

- - - Updated - - -

Also, I challenge you to..... A B-25 :P I was thinking a B-17, maybe later. Get on it! :D

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Azimech    5930

Yep, detachable undercarriage.

No, I don't play War Thunder. I used to fly the IL2 series for years though.

B25 ... maybe. B17 .... I ain't got enough horsepower under the table!

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Avera9eJoe    2244

MY GOD THESE ARE AMAZING! I'll try and duplicate. All credit to you. That gigantic twin blade VTOL is quite impressive.

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Azimech    5930

Thank you! And that giant VTOL is actually a bit like the Mil-V12 helicopter, it was the largest helicopter in the world (and so is mine :D)

By the way ... I see you like Powder Toy ... in that case, what do you think of the topic in my signature?

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EladDv    397

So far i've been successful of reducing a single turboshaft core (no engines) to a 2.5m' maximum diameter but the wheels are the limiting factor here. update 1.0 with stationary tiny wheels should make it more feasible although i've yet to try rover wheels as a solution for 1.25 m shafs but engines are still a problem unless we will be using non air breathers

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SlabGizor117    142

No War Thunder? Wow. It's a free to play MMO Flight Sim that goes from 1930s to 1950s aircraft. Americans, for example, start at P-26 Peashooters and end at F-86 Sabres. VERY good game, you would enjoy it. It has a real money currency but playing for free is not limiting at all. Try it, it's a large game, as in, long download, but worth it.

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Guest   
Guest

I'm gonna give a spin (literally) with your 190 plane. Love its neat cockpit.

Very nice job overall here. I wish I could give you some rep ;'(

Im thinking about designing a vtol with a tiny high speed turboshaft

hidden inside its frame now... Damn you!

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Jakalth    444

@ Redshift: yeah, there is at least 2 different ways of going about turbo shaft engines. Small and part minimal, and big and sturdy. Both work well, but for different uses. The light weight engine design you've been favoring is better at being scaled down to smaller sizes. While the heavy weight I gave you guys to play with, does not scale down well. That is about as small as it can get(not part count wise). It's all a matter of taste and application. Would be neat to see how small of a craft can be made using the design you favor. :)

I might have an idea for an engine that could fit the look of a radial engine. I'll see if I can get it working and stable.

Edited by Jakalth

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Gojira    55

How do I get the godforsaken engine to start turning?

Do I decouple, then throttle up?

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Azimech    5930

Yes, just hit the stage button and throttle up.

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Jakalth    444

So far so good. I already have an 8-cylinder Radial engine design that you guys can try out. This one is fairly big. It's only been limited to static testing so far since I don't have an aircraft design that I can mount it to. But the results so far are interesting. Spins fairly well, but has an odd way that it registers changes in throttle. It acts like it has a 4-speed transmission. This model runs best at up to about 85% throttle. It can handle 100%, but things start to get very shaky at full speed. At least it no longer self destructs. :wink:

8cylradialfront_zpsnz8wmhuj.jpg8cylradialside_zpsew17apki.jpg

It's compact in length yet still stable enough to use, pending further testing. It also has a fairly radial engine look to it, which can be improved by using extra detail parts. The propeller is also untested and mostly there to add some weight so it doesn't just spin its self apart.

Part count: 164

Weight 23.2

It's a bit heavier then I wanted and I'm not really sure why. At least the part counts are lower then my heavy duty. I'll do some more work and see is I can make a much more compact version, smaller diameter at least. Just need to find the correct replacement for the TR-38-D Decoupler that gives this engine it's short profile.

Download: 8-cyl Radial Engine

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Azimech    5930

Jakalth, That is nice, 26 rad/s with my standard test prop! My compact 8 blower in the FW190 reaches 24 at sea level, and starts to vibrate. Although I haven't tuned that one yet.

Edited by Azimech

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Jakalth    444

There is something about that TR-38-D decoupler... Tested it myself with a quick and dirty helicopter and rotor. Was getting 28 m/s climb rate and over 60 m/s horizontal speed with a basic 4 blade rotor hooked up to this engine. Held the rotor quite steady as well. Odd really considering how thin the whole thing is.

Haven't had much luck making the engine smaller, yet. Still have a few tricks too try though. Just need to find the right part or parts to use as a central bearing race. The ones I have tried are either too uneven or just break right away...

One thing I would like to ask, about how much smaller would I need to make it for the engine to be usable in one of your aircraft designs as a radial engine?

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Azimech    5930

Wow _Bugs ... don't know what to say!

I'll look into the welding soon, if I'm satisfied, I'll make a separate category and publish welded/modded crafts.

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Azimech    5930

Added drop tanks, tanks behind the cockpit and A LOT of piping to get the fuel where it needs to be. Now it uses 2 central fuel hubs to distribute the fuel to the blowers. And no more problems with blowers running out of fuel.

And an improved prop as well! Increases the max altitude before the engine starts to red line.

Also, I moved the probe core behind the cockpit instead of behind the engine. This reduces vibrations a lot and thus the SAS doesn't get confused anymore.

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_Bugs    26

I'd really appreciate it if you did take the time. Good luck!

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EladDv    397

i must report that rover wheels have produced limited success as they do spin but often creating bugs and clipping issues yet i will try to use a certain design i found to maybe make a real 1.25m heli with a chemically powered turboshaft

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