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

Azimech

By Azimech
in KSP1 The Spacecraft Exchange

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Gman_builder

Gman_builder

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Posted
2 minutes ago, Majorjim said:

Well thanks man. 

 I would love to hae a go at rotor craft but I am focused 100% on my very tricky constellation build. When that is done I will have a look at these and my tank track craft. So for now I will just sit back and enjoy what you guys are making. 

Whats your constellation build? Sounds interesting.

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Gman_builder

Gman_builder

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Just now, Majorjim said:

Replicating the entire cancelled mars constellation mission. :)

Oh that shouldn't take TOOO long. I mean, space stuff requires less tweaking to make something work compared to a turboprop or the like. I mean don't get me wrong, i'm sure your thing is going to look amazing and have a ton of time put into it. I'm excited to see what it looks like.

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EpicSpaceTroll139

EpicSpaceTroll139

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Anyways, because I couldn't stay focused on making the ugly duckling engines work better, I've been working on making a compact swashplate mechanism. So far I've got this:... annnnd imgur isn't working so here's the link: http://imgur.com/a/KTNCq. Obviously it's not finished yet. It's only got the bottom part of the swashplate. But at least it works with the cockpit/control point pointed forward instead of up. So it uses pitch and roll controls. Also an action group can be used to perform collective...

Problem is the collective will be binary... it's either full up or some certain lower value... how are we going to work with that?
 

 
Edited by EpicSpaceTroll139
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Cunjo Carl

Cunjo Carl

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  Thanks, @Azimech, for directing me here! I developed a nice way to plot the physics curves for lifting surfaces -> propeller blades. The "lift" below correlates directly to the force of the turboprop, and the "drag" is one of the turboprop's key sources of friction.

   It turns out all the wings behave the same L/D-wise (much to my surprise), and are also the same lift/mass-wise. The only exception is the basic fins with 20% better lift/mass somehow. That said, longer propeller blades/wings will still catch more air, because their effective velocity is determined by its size (2pi*r*spin-speed). Other than that, a wing's a wing, which is nice to know.

  These values were plotted for a static (0m/s) test, but if people were interested, I could drum this up in a real program to include different velocities. I could also show how to turn these values directly into forces based on temp/altitude if that'd be handy.

412.png

Blue dots (upper line) is LIFT. Red dots (lower line) is DRAG. This takes into account that some of your lift is pointed counter-turn-wise and is actually acting as drag instead.

We can also take the ratio of these to obtain the commonly used L/D ratio for determining whether something is a good idea, or it'll get you stalled / make your turboprop spin too slow.

410.png

How charting KSP phsics works (my simple, homebrewed method).

Spoiler

1. Find the data

The data is written in config files using the following format

  key1   = X1  Y1  I1 O1
  key2   = X2  Y2  I2 O2
  key3   = X3  Y3  I3 O3
  key4   = X4  Y4  I4 O4

Where each key defines a point in terms of its x value, y value, incoming tangent (I), and outgoing tangent (O). A good example of these values might be mach values for x (the thing you know), drag coefficients for y (the thing you want to know), and the I and O tangents for how quickly drag coefficients change approaching and leaving this point.


2. Find some coefficients

We'll need some coefficients in a moment, so we plug in some numbers from key1 and some from key2.

  A =  2Y1 +  O1  - 2Y2 + I2
  B = -3Y1 - 2O1 + 3Y2  - I2
  C =    O1
  D =    Y1
 

3. Form the equation

We'll write an equation for the line that goes between the points of key1 and key2. We could try to make this equation in terms of x, but it would be really hard! So instead, first we'll make a convenience variable called u. The fancy term for it is a unitless transform, and it makes life soooooo much easier. Then we'll write an equation for y (the thing we want!) in terms of this u.

u = (x - X1)/( X2  - X1 )           Eq. 1

y = Au3 +Bu2 + Cu + D           Eq. 2

Cool, so if we make up an x value, and we want to know the corresponding y value we simply plug x into Eq 1, and then plug the resulting u into Eq 2 and we get our value! All's we need are those big letters A-D.
 

It's a little time consuming but pretty easy in practice. And if not, sorry I mathed all over the forum :blush:.


For actual application, it all boils down to trying things and seeing what works in the end anyways, but it can be nice to have charts like these to show you what to expect. I hope they help!

 

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Gman_builder

Gman_builder

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6 hours ago, EpicSpaceTroll139 said:

Anyways, because I couldn't stay focused on making the ugly duckling engines work better, I've been working on making a compact swashplate mechanism. So far I've got this:... annnnd imgur isn't working so here's the link: http://imgur.com/a/KTNCq. Obviously it's not finished yet. It's only got the bottom part of the swashplate. But at least it works with the cockpit/control point pointed forward instead of up. So it uses pitch and roll controls. Also an action group can be used to perform collective...

Problem is the collective will be binary... it's either full up or some certain lower value... how are we going to work with that?
 

 

Nice. Looks smoother than mine but a lot larger. Are you going to attach linkages and a rotor head?

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Azimech

Azimech

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soon on KerbalX: Curious Chakora v3.

Changelog:

  • Reduced part count from 416 to 340.
  • Reduced mass from 108 tons to 74 tons (tanks empty: 47 tons).
  • Dropped the external tanks. ;-P
  • New Chakora engine: S33B40R50L.
  • Reduced blower count from 72 to 40.
  • Increased max engine speed from 43 to 51 rad/s.
  • New propeller: 3 blades instead of 5. Changed standard blade angle from 45 to 55.
  • Improved thrust bearing capable of handling more stress. If bearing fails, no gigantic explosions, just loss of power.
  • Now fully capable of speed braking using propeller pitch.
  • Engine reliability improved dramatically, it's capable of aerobatics even at full speed (but huge bleed due to high mass/wing loading) without significant engine damage.
  • Can handle more damage, even flies with 7 out of 8 turbine blades missing.
  • Optimal power band: 48.5 - 49.9 rad/s.
  • Replaced extra large landing gear with large gear and moved them more to center to increase agility.
  • Max speed has dropped from 173 m/s to 162 m/s ... with all these improvements, small price to pay.

 

http://imgur.com/a/n699O

 

Also I'm redesigning the FW 190-A4 a bit. Wanted to show the cool effect of terrain shadows (Scatterer) with the old version.

http://imgur.com/UxoIFfF

 

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Majorjim!

Majorjim!

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Posted (edited)
14 hours ago, Gman_builder said:

Oh that shouldn't take TOOO long. I mean, space stuff requires less tweaking to make something work compared to a turboprop or the like.

LOL, try it. :D

 The amount of testing to get all the craft looking like, and working like the real craft together is hard in the extreme. Just have a look at the number of people who are trying it and how many have done it. It is probably one of the hardest full builds in KSP dude. I've been working on these crafts or variations of them for over a year. :wink:

 

 

Edited by Majorjim
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Gman_builder

Gman_builder

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5 hours ago, Majorjim said:

LOL, try it. :D

 The amount of testing to get all the craft looking like, and working like the real craft together is hard in the extreme. Just have a look at the number of people who are trying it and how many have done it. It is probably one of the hardest full builds in KSP dude. I've been working on these crafts or variations of them for over a year. :wink:

 

 

Oh wow nice. That's some serious dedication! I hope it turns out well!

3 hours ago, EpicSpaceTroll139 said:

@Azimechis that a person made of monopropellant tanks in that upgraded Chakora?

Except it's a Focke Wulf FW-190

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erasmusguy

erasmusguy

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On 22/07/2016 at 3:34 AM, Gman_builder said:

Alrighty, so what are you going to do with this new-found info and technology?

Will he build a car.....

Will he built a plane.....

Will he build a helicopter.....

The world may never know.....

 

I have been working on a silly little engine for about a month now I call the G-47-4F.  It makes 45 rad/s in a 1.8 meter diameter form factor(excluding prop). I was planning on using it for my endurance challenge for it's inherent efficiency(only 24 Juno's) but I might move the project over to the "Land vehicle Division" of my crazy KSP laboratory. I will be able to create much smaller and hopefully faster cars with the new engine.

 

I also had an genius idea for a super simple stock gear shifter. More on that later.

i built a train a while back

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Gman_builder

Gman_builder

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1 minute ago, erasmusguy said:

Ive got a little idea/challenge for you all. I was going to keep it to myself but I'm far too lazy to build it. How about building an ornithopter?  

heh. funny joke lol.

How would that even be possible in KSP? Maybe it was in 0.90 but I think not 1.1.3. Interesting idea though. How would the joint work?

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erasmusguy

erasmusguy

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On 25/07/2016 at 6:34 AM, Pds314 said:

Alright. I MAY have had a prop strike during taxi....

But I still managed to get inside the hanger!

The entire craft weighs a bit under 2 tonnes, plus 250 kg of liquid fuel (or 340 kg if the engine tank is used).

Maximum Ferry range is ~70 kilometers or thereabouts. Probably enough to land on the Island and return if flown right.

The Parakeet: my first Screacher 1x1 plane. 47 parts in total, lighter and simpler than some of my older "small" engines. A note on starting the engine: Set to about +20 +150 pitch, then wait for speed to exceed 15 rads/s. This could take a few seconds. Promptly reduce to about -60 and takeoff. Do not hold down S, but just try to be as level as possible without a prop strike until speed exceeds 25 m/s. Pull up and increase pitch until speed is at 60 m/s and pitch is at +90. It may be worth further increasing pitch from there at some point.

oSzolUq.png

https://kerbalx.com/pds314/Parakeet

pds314 you are my new hero. love your simple engine design :D

Just now, Gman_builder said:

heh. funny joke lol.

How would that even be possible in KSP? Maybe it was in 0.90 but I think not 1.1.3. Interesting idea though. How would the joint work?

 if a propeller is possible I'm sure this is. You might need two set of wings (one for height and one for thrust) but I think you could do it

 

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EpicSpaceTroll139

EpicSpaceTroll139

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2 minutes ago, Gman_builder said:

heh. funny joke lol.

How would that even be possible in KSP? Maybe it was in 0.90 but I think not 1.1.3. Interesting idea though. How would the joint work?

Lots of moving parts powered by a turboshaft motor which has a connecting rod to create reciprocating motion. It would probably require gears to get more power and less speed from a light motor. I've thought of building one at some point, but right now I'm also too lazy

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erasmusguy

erasmusguy

Posted
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1 minute ago, EpicSpaceTroll139 said:

Lots of moving parts powered by a turboshaft motor which has a connecting rod to create reciprocating motion. It would probably require gears to get more power and less speed from a light motor. I've thought of building one at some point, but right now I'm also too lazy

ive been experimenting on slower revving engines with high torque but so far had no luck. May be SAS driven would be better for something like this.

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Gman_builder

Gman_builder

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5 minutes ago, erasmusguy said:

pds314 you are my new hero. love your simple engine design :D

 if a propeller is possible I'm sure this is. You might need two set of wings (one for height and one for thrust) but I think you could do it

 

Thing with KSP aerodynamics though is this.

Wing pushes down, equals downward thrust.

Wing pushes back up, equals upward thrust.

Therefore you go nowhere. It's all but impossible to make a mechanic device that can replicate a dragonfly's flight pattern in real life let alone KSP. Especially when we could only dream of achieving the same speeds that a dragonfly's wings beat at.

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erasmusguy

erasmusguy

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2 minutes ago, Gman_builder said:

Thing with KSP aerodynamics though is this.

Wing pushes down, equals downward thrust.

Wing pushes back up, equals upward thrust.

Therefore you go nowhere. It's all but impossible to make a mechanic device that can replicate a dragonfly's flight pattern in real life let alone KSP. Especially when we could only dream of achieving the same speeds that a dragonfly's wings beat at.

the wings would have to turn.....like they do on a ornithopter :D

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