[Stock Helicopters & Turboprops] Non DLC Will Always Be More Fun!

[Jakalth]

last time I tried making a mk3 cargo bay based bearing, the main shaft kept linking with the cargo bay causing the whole thing to blow up, or do nothing at all...  never could get it to actually spin.  Would love a simple example of how to get one of those bearing types working, so I can see what I was doing wrong.  Might be able to coerce the design into a syncro bearing set if both ends of the drive shaft can be free floating.

[The Optimist]

I wonder if you could make smaller engines with those newfangled baby jets. Also, for some reason, the landing wheels in my downloaded plane's prop engine are clipping through the mk1 fuselage. Do you know why?

[Azimech]

11 hours ago, Jakalth said:

last time I tried making a mk3 cargo bay based bearing, the main shaft kept linking with the cargo bay causing the whole thing to blow up, or do nothing at all...  never could get it to actually spin.  Would love a simple example of how to get one of those bearing types working, so I can see what I was doing wrong.  Might be able to coerce the design into a syncro bearing set if both ends of the drive shaft can be free floating.

The trick is to mount a small separator at the cargo bay node, then slide it to a place where you can attach the axle to the separator instead of snapping onto the cargo bay node. Using No Offset Limits, nowadays I choose to have the separator totally outside of the craft.

9 hours ago, The Optimist said:

I wonder if you could make smaller engines with those newfangled baby jets. Also, for some reason, the landing wheels in my downloaded plane's prop engine are clipping through the mk1 fuselage. Do you know why?

Which plane have you downloaded? There are some changes since 1.0, any engine built in 0.90 needs to be adapted. What could work is the following: hack gravity, decouple the shaft, raise gear and immediately lower it again. Unhack gravity. If the 0.90 engine has the Wheesley turbofans then they need to be replaced with the Panther. But anyway, any craft built before 1.0 will probably never fly again.

The smaller jets work in theory but I haven't seen a design out of prototype phase.

[The Optimist]

-this was never here-

Edited December 5, 2015 by The Optimist

[FlipNascar]

21 minutes ago, The Optimist said:

PLEASE TEACH ME HOW TO MAKE TURBINES.

Mine always wobble around and fall over.

Start simple. Just make a very simple bearing and get that to work. Once you've got that part figured out, adding the whole jetwash to the scenario is fairly simple. You kinda have to learn this by doing it. Look at all the pictures and craft files in this thread.

 

Oh and if you're problem is they're wobbling all over the place, then struts. Start with a cage if you need to. Then you can begin to minimise from there. Look at Jakalth's synchro craft on the previous page. Just pull it apart and see how it works. Way easier than reading a wall of text. It's small and compact. Or you can go big and open.

And post a craft file... Can't see what your problem is if there's not even a picture or a file to look at.

[Azimech]

I might make a video one day, but I'd need some help with setting up software. And I need a good mike.

[Jakalth]

well, only progress I've been able to make so far is an inside out turboshaft.  the engines are on the inside and the turbine blades are on the outside.  Also, the center body of the bearing turns, not the axle.  it's a strange thing indeed.  But, it's very useful since the bearing can, in theory, be attached to the middle of a vehicle even easier then the cage mounted style turboshaft.  Sadly, this design still majorly lacks in the power department since it currently only works with the Juno Engines.

 

The bearing:

 

The bearing only weighs in at 1.8 tons, less once the m-beams is ejected.  The center structural fuselage is the rotational part with the landing gear and axel being stationary.  This should allow the bearing to spin even faster, since the moving part is just the 0.1 ton fuselage.  Should, is the key word here...  It can be swapped around and run as a conventional bearing simply by attaching the center section to your structure instead of the lower liquid fuel tank.

 

The Turbine:

 

The turbine it's self has 18 Juno's acting as blowers and another 18 to counter the twist the others provide.  It only runs on infinite fuel atm.  In the picture, you can just make out the 12 radiator panels it uses to spin the propellers.  They are actually attached to the propellers and rotated into position.

 

The download: Center Body rotor 4 The 4th version of this design.  still doesn't fly but does spin nicely.

Edited December 7, 2015 by Jakalth

[Azimech]

Raw and untuned test build. At least we know now stock turboshaft engines work in 1.1. Blowers: 18. Blades: 48. Part count: 246. Thrust/rpm: unknown at this time.

 

[Redshift OTF]

That is good news. Any difference in the bearing performance between versions that you can notice?

[Azimech]

2 hours ago, Redshift OTF said:

That is good news. Any difference in the bearing performance between versions that you can notice?

Nope, same quirks realistic behaviour as always: too little clearance and you have a large amount of drag, too much clearance and it wobbles & self destructs.

Edited April 2, 2016 by Azimech

[Pds314]

Made a FAR helicopter rotor with TWR>1 and mass of 9.5 tonnes (of which 1.5 is fuel). Strongly suspect >100 kN lift. Wheel-less bearing means extremely light and simple shaft. 12 Juno blowers and 6 fluid spectro-variometers for blower blades. 4x double large control surfaces for prop blades.

Planning on trying it in stock aero soon.

Edited April 22, 2016 by Pds314

[Pds314]

Yep. It has AT LEAST as much thrust in stock.

I think I'll work on this tomorrow. I think I'll need variable pitch if I want to use it for an aircraft though. Also, may just add more layers of blowers and such simply because there's room. If 12 blowers = >100 kN, then 36 or 48 must be enormously powerful. Come to think of it, I could probably have 24 blowers per layer and 4 layers. A 96-blower monstrosity motor only marginally bigger than this design.

Although I suppose making such a device would violate one of the primary design principles of these things. Torque=force*radius. And of course since the RPM limit is determined by structural integrity, aero drag and clipping drag, NEVER by radius in this design, double the radius and you can afford to halve the blower count. So maybe adding 21 tonnes of blowers to this isn't the best idea. Basically, these things scale wider really well, and scale thinner really poorly.

And the inside out configuration wouldn't help a thing. Unfortunately, it means that the angle at which the thrust hits the blades is oblique such that the radius is then determined by engine position, not blade position. The one thing I can think of for maintaining sanity and having a massive amount of torque would be to make a disk around the edge of the props and have the blowers blow on the disk from barely inside.

Edited April 22, 2016 by Pds314

[Azimech]

Here it is, my first new turboprop since 1.0.4.

 

For the first time ever it has stock variable propeller pitch

Instructions:

• You'll get best results out of this airplane if you install V.O.I.D. so you'll have an engine speed readout. Just like real life, a propeller has an optimum blade angle for every speed. Propeller speed too high means too much drag/pitch angle too low. Propeller speed to low also means too much drag but angle too high.
• For anything with turboshaft engines, stock drag is too high. Use the F12 menu -> Physics tab -> Drag tab, set "Global Drag Multiplier" to minimum.
• When using V.O.I.D, switch off "kerbal engineering calculations" or you'll get a massive performance hit.

This engine/propeller setup has an optimal speed between 28-31rad/s (267-296 rpm).

1. Decouple turbine shaft (AG1).
2. Switch to the shaft, then press AG2 to enable prop pitch adjusment.
3. Set pitch to a value between -100 and -50. Use V.O.I.D. for engine speed readout.
4. Switch to airplane, enable SAS.
5. Start the blowers (stage).
6. Keep tail to the ground, let SAS do the flying for now. Switch to the shaft to increase prop pitch, keep engine speed between 28 and 31rad/s.
7. It will lift off at around 42m/s. Double tap AG4 to retract the landing gear. Never press G or you'll ruin the engine!
8. SAS will keep the plane flying and level but keep in mind the massive torque of the engine. A right turn will be easy, a left turn is done best using both rudder & ailerons. The lower your speed, the more difficult it will be.

 

Download link

 

[Pds314]

1 hour ago, Azimech said:

• For anything with turboshaft engines, stock drag is too high. Use the F12 menu -> Physics tab -> Drag tab, set "Global Drag Multiplier" to minimum.

Wait, would it not take off in full drag?

[Azimech]

17 minutes ago, Pds314 said:

Wait, would it not take off in full drag?

Yeah, but struggles to fly faster than 50m/s. With drag set to minimum, it somewhat compares with my 0.90 aircraft. This one has a top speed of 116m/s @6000m. My fastest 0.90 plane has the record: 155m/s @ 10500m. ... just a few days before 1.0 was released.

 

[Pds314]

Just now, Azimech said:

Yeah, but struggles to fly faster than 50m/s. With drag set to minimum, it somewhat compares with my 0.90 aircraft. This one has a top speed of 116m/s @6000m. My fastest 0.90 plane has the record: 155m/s @ 10500m. ... just a few days before 1.0 was released.

 

1.0 really did a number on turboshafts. =/

[Azimech]

1 minute ago, Pds314 said:

1.0 really did a number on turboshafts. =/

Worst thing is not the aero ... we're learning to overcome it. Every plane has become a lot heavier and the new basic jet engine has no stock exhaust thrust, while having the best TWR of all.

[Pds314]

2 minutes ago, Azimech said:

Worst thing is not the aero ... we're learning to overcome it. Every plane has become a lot heavier and the new basic jet engine has no stock exhaust thrust, while having the best TWR of all.

Wait, the Juno or the Wheesley? The Juno DEFINITELY has stock exhaust thrust and the Wheesley is just awful in TWR compared to something like the Panther at full AB.

[Azimech]

1 minute ago, Pds314 said:

Wait, the Juno or the Wheesley? The Juno DEFINITELY has stock exhaust thrust and the Wheesley is just awful in TWR compared to something like the Panther at full AB.

Yep, I'm using Juno's in my newest airplane ... 72 of them. The Panther at full afterburner produces more thrust but guzzles fuel like a madman and overheats everything. Just one toggle and the Wheesley is the best engine overall - lighter than the other 1.25 engines, most static thrust of all.

[Pds314]

8 minutes ago, Azimech said:

Yep, I'm using Juno's in my newest airplane ... 72 of them. The Panther at full afterburner produces more thrust but guzzles fuel like a madman and overheats everything. Just one toggle and the Wheesley is the best engine overall - lighter than the other 1.25 engines, most static thrust of all.

But it isn't?! The wheesley masses in at 1.5 tonnes =O
Panther is 1.2. Wheesley has the best dry static sealevel TWR I suppose.

On the other hand, I bet the Panther has a better TWR at 8000 meters or so.

Also, I guess in part count, 120 Junos is worse than 20 Wheesleys.

Edited April 22, 2016 by Pds314

[Azimech]

28 minutes ago, Pds314 said:

But it isn't?! The wheesley masses in at 1.5 tonnes =O
Panther is 1.2. Wheesley has the best dry static sealevel TWR I suppose.

On the other hand, I bet the Panther has a better TWR at 8000 meters or so.

Also, I guess in part count, 120 Junos is worse than 20 Wheesleys..

I just tested that, both have ~25% thrust left at 10km altitude when flying at minimal speed, so the Wheesley still beats the Panther. The Panther improves over the Wheesley when speed goes past ~150m/s.

Edited April 22, 2016 by Azimech

[Pds314]

1 hour ago, Azimech said:

I just tested that, both have ~25% thrust left at 10km altitude when flying at minimal speed, so the Wheesley still beats the Panther. The Panther improves over the Wheesley when speed goes past ~150m/s.

Lol. Good luck getting over 150 m/s, at least in stock drag, especially with low blower density achieved by the Panther. I wonder if there is any use for the Panther's generous gimballing abilities?

Edited April 22, 2016 by Pds314

[Pds314]

 

On 11/23/2015 at 7:43 AM, Azimech said:

And while you're correct, they're essentially waterwheels.

I'm SOOO going to make a boat powered by these. It might involve messy gearing to increase torque and avoid submerging the rotor though, or it could be powered by a paddle wheel, but again, still needs gearing.

Edited April 22, 2016 by Pds314

[Azimech]

1 minute ago, Pds314 said:

 

I'm SOOO going to make a boat powered by these. It might involve messy gearing to increase torque and avoid submerging the rotor though.

Try it, when I ditched my airplane in the water the turbine was running fine while semi-submerged!

[Pds314]

1 minute ago, Azimech said:

Try it, when I ditched my airplane in the water the turbine was running fine while semi-submerged!

Reminds my of my failed attempt to make a nuclear electric submarine using a massive pile of RTGs and wheels in 1.0.5.