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

[Azimech]

4 minutes ago, selfish_meme said:

He was using the same method I was, but instead of putting the thermometers around the mk0 tank he puts nosecones on the tank and forms the thermometers into caps, it is very smooth. With two mk0 tanks end to end there is enough room for 4 blowers length, plus if you stick the end out you can attach the props directly to the nosecones as well, saving parts and suspended bits hanging way forward.

It is also slim enough to fit inside a structural fuselage instead of a cargo bay if you don't use blades.

I love this solution. Low part count and light. I'm actually experiencing difficulties with this setup. And I don't believe it's capable of handling the power I want from it.

[selfish_meme]

7 minutes ago, Azimech said:

I love this solution. Low part count and light. I'm actually experiencing difficulties with this setup. And I don't believe it's capable of handling the power I want from it.

I haven't gone beyond 6 junos in total using this and the tank glows red, so it's getting quite hot. I was going to try 8 junos in the next engine.

I guess thats why I am looking at multiple power plants rather than trying to build a bigger engine. It's quite easy to move the jets from one side to the other to reverse the rotation and you can also set the propeller pitch exactly. A s my other craft showed 2 engines allowed a much more practical plane than one engine.

Edited June 18, 2016 by selfish_meme

[Gman_builder]

I did some testing of this the Skipper Corsair and the engine did 45 rad/s and was extremely stable. 46 and it blew up. Very promising design. Not super fast but definitely promising.

[Gman_builder]

@Azimech I had a engine failure but this part of my prop went spinning off at 60 rad/s without any problems with my physics. I don't know what this means for turboprops in the future but it seems like 50 rad/s isn't the limit.

[Azimech]

3 hours ago, Gman_builder said:

@Azimech I had a engine failure but this part of my prop went spinning off at 60 rad/s without any problems with my physics. I don't know what this means for turboprops in the future but it seems like 50 rad/s isn't the limit.

Like I said, 50 rad/s isn't the absolute limit ... on my machine it's when PhysX goes gaga <-- I should explain this: joints become unstable and the construction starts to look very weird. Try it yourself: fixed setup on the runway, a shaft with a bunch of 2.5m SAS modules and rev it up.

Actually I might start a separate topic for this test.

Edited June 18, 2016 by Azimech

[Azimech]

7 hours ago, selfish_meme said:

I haven't gone beyond 6 junos in total using this and the tank glows red, so it's getting quite hot. I was going to try 8 junos in the next engine.

I guess thats why I am looking at multiple power plants rather than trying to build a bigger engine. It's quite easy to move the jets from one side to the other to reverse the rotation and you can also set the propeller pitch exactly. A s my other craft showed 2 engines allowed a much more practical plane than one engine.

Yes, multiple engines can be a joy. If they're more practical ... I think that's a matter of taste. Having to switch focus to adjust the prop pitch is already a nuisance with one engine. I don't have control issues with longitudinal torque anymore because I just stack multiple ailerons, depending on the engine setup 3 to 5 sets, change control authority and/or use bigger ones. Excessive tendency to roll can be a sign of a lot of internal friction and at least during Errordynamics depended on prop pitch as well: low prop pitch - much torque, high prop pitch - little torque. Haven't done aerobatics recently nor have I tested it in NeoAero. And naturally, higher speed results in more control authority.

Edited June 18, 2016 by Azimech

[Gman_builder]

Uhhhg. Whenever I try to solve problems with my engines it just leads to more, bigger problems.

 

Edited June 20, 2016 by Gman_builder

[Gman_builder]

This thread has been empty for almost a month omg

[Gman_builder]

@AzimechWhy do some engines only produce thrust on one side of the prop?

 

[TheDestroyer111]

How to make a good hinge? Even if I tighten the hinge milimeters close to part clipping, the axis inside is very jumpy. If the hinge is very close to part clipping, the axis even clips itself into the hinge for short moments! I tried several techniques, nothing works.

[Pds314]

5 hours ago, TheDestroyer111 said:

How to make a good hinge? Even if I tighten the hinge milimeters close to part clipping, the axis inside is very jumpy. If the hinge is very close to part clipping, the axis even clips itself into the hinge for short moments! I tried several techniques, nothing works.

Using the right part is key. I know for certain that atmospheric scoops work without issue, and so do cubic and octagonal struts. Make sure it is on the avionics cone's antenna, not the cone itself. Static solar panels also work if you don't intend to take it to ludicrous speeds.

Edited July 12, 2016 by Pds314

[Pds314]

Built a 65-tonne twin-engined bomber. The engines it uses are unfortunately extremely finicky during turns, very much unlike my previous design, which was free to do crazy spins at 100 m/s. I shall have to figure out some way to reinforce them. Each has 18 junos for blowers around a wheelless bearing. Design speed is 34 radians/sec, fails at 36. Will upload images and craft once I have access to my pc.

The engines each have something like 250 kN*m of torque, so at 34 radians/sec, each engine is producing around 8.5 Megawatts, or about 11400 hp.

EDIT: actual torque as measured is 226 kN*m, meaning it's more like 7.7 Megawatts or 10300 hp.

Edited July 12, 2016 by Pds314

[TheDestroyer111]

4 hours ago, Pds314 said:

Using the right part is key. I know for certain that atmospheric scoops work without issue, and so do cubic and octagonal struts. Make sure it is on the avionics cone's antenna, not the cone itself. Static solar panels also work if you don't intend to take it to ludicrous speeds.

What do you mean by "atmospheric scoops"? And how do you ever make a hinge from an avionics cone? Cubic and octagonal struts, I-beams, modular girders and structural panels all failed me (They were either very jumpy or very clippy, depending on how tight the hinge was made). Solar panels are gonna be a terrible choice for propellers due to the ridiculously high rotational speeds required to generate significant thrust, and solar panels (even static ones) are easily breakable. Also, why would using the right part be key at all ?

Edited July 12, 2016 by TheDestroyer111

[Pds314]

1 hour ago, TheDestroyer111 said:

What do you mean by "atmospheric scoops"? And how do you ever make a hinge from an avionics cone? Cubic and octagonal struts, I-beams, modular girders and structural panels all failed me (They were either very jumpy or very clippy, depending on how tight the hinge was made). Solar panels are gonna be a terrible choice for propellers due to the ridiculously high rotational speeds required to generate significant thrust, and solar panels (even static ones) are easily breakable. Also, why would using the right part be key at all ?

I'm not sure why some parts work well and other parts are jumpy and jittery, but I know the ones I mentioned work well.

[Pds314]

2 hours ago, TheDestroyer111 said:

What do you mean by "atmospheric scoops"? And how do you ever make a hinge from an avionics cone? Cubic and octagonal struts, I-beams, modular girders and structural panels all failed me (They were either very jumpy or very clippy, depending on how tight the hinge was made). Solar panels are gonna be a terrible choice for propellers due to the ridiculously high rotational speeds required to generate significant thrust, and solar panels (even static ones) are easily breakable. Also, why would using the right part be key at all ?

I have an engine that does like 40 rad/s pushing on solar panels, up to 42 before things go wrong.


Flying pushing on solar panels. They are connected to a central shaft of the type I mentioned, held by cubic struts:

Edited July 12, 2016 by Pds314

[Pds314]

THIS is the kind of insanity that you deal with in a 50 rad/s prop:



That probe core is still attached in this image. The engine is in fact working. The probe core, attached perfectly centered, is merely spinning out of control.

As a side note, does anyone still doubt the efficacy of solar panels as turbine blades?

Edited July 12, 2016 by Pds314

[Azimech]

This text applies to bearing technology and KSP physics in general.

One of the things I've discovered in my studies with piston engines is that part mass directly influences collider integrity. When designing cogs & pistons for building a 4 stroke engine I experienced that low mass means parts are able to ghost through other parts when a force is acting upon them, while a high mass means they don't. While I'm not able to give any formula (I didn't finish school), I can say this is ridiculous because collider integrity should be based on material type. What it should be: either the part breaks connection to it's parent or child in the Unity part tree (and/or) disintegrates or it doesn't.
Modifying breaking force and breaking torque does something else that's unintuitive: instead of parts breaking loose it just influences joint flexibility.

Another interesting fact: parts can radiate heat but this won't influence parts not connected to the tree. Explanation: My piston engines have cylinders as a separate entity confined in a cradle (to prevent them from ghosting through). While cylinder heads, pistons and all connected parts quickly heat up, the cylinders remain at ambient temperature.

Stock KSP is an underdeveloped compromise and totally immature for anyone wanting to explore the wonderful world of engineering. I'm just stating facts and don't complain, what we're trying to do is a small niche. But ... I would like to see a branch develop in a different direction and would like to invite @NathanKell and @ferram4 for some discussion. The competition is not idling. The whole space game is nice but ... in the long run people will recognize the editor as the main selling point. Even if it's crude, it's the best on the market.

[SpannerMonkey(smce)]

40 minutes ago, Azimech said:

This text applies to bearing technology and KSP physics in general.

One of the things I've discovered in my studies with piston engines is that part mass directly influences collider integrity. When designing cogs & pistons for building a 4 stroke engine I experienced that low mass means parts are able to ghost through other parts when a force is acting upon them, while a high mass means they don't. While I'm not able to give any formula (I didn't finish school), I can say this is ridiculous because collider integrity should be based on material type.

I've noticed this as well, I have  made a two part turbo shaft {inspired by one of your many other posts ), literally just a cowl with thrust transforms and a turbine shaft complete with vanes, decouple  and thrust bearings and this does exactly what you describe, after reading your post I'm going to add mass and see what happens, as ALL my tshafts fail in exactly the same way,  the front end of the shaft drifts through the collider in a way that makes no sense to me, I'm with you on materials, whats the point of a metal material that has the same integrity as a cloud

[Pds314]

Hmm.. So I've made a rather interesting discovery. Adding a third avionics cone vs. Just 2 facing into each other DRAMATICALLY improves shaft stability. I made a modified version of the bomber engines that's slightly longer, but it maintains much better rpm. I also made a real-sized fighter with the small engine that is designed to operate at 46-51 rads/s. Takeoffs are finicky, but the flight characteristics are great above 50 m/s. Of course, real engines got ~3x that rpm, and were geared DOWN.

5 minutes ago, SpannerMonkey(smce) said:

I've noticed this as well, I have  made a two part turbo shaft {inspired by one of your many other posts ), literally just a cowl with thrust transforms and a turbine shaft complete with vanes, decouple  and thrust bearings and this does exactly what you describe, after reading your post I'm going to add mass and see what happens, as ALL my tshafts fail in exactly the same way,  the front end of the shaft drifts through the collider in a way that makes no sense to me, I'm with you on materials, whats the point of a metal material that has the same integrity as a cloud

This most-likely has a lot to do with the timestep. 25 fps is really not good enough to support high rotation rates. It's astounding we're managing to churn out engines that get 2 radians per physics step without blowing up.

[Pds314]

Something I've noticed is that, since blowers are big and solar panels are small, having the blowers on the inside seems to give you a better tangent radius, and therefore more torque and a more efficient engine, as well as reducing turbine blade collisions. On the flipside, putting the blowers externally allows room for more blowers, at the cost of efficiency and the ease with which the turbine blades overheat, as well as the cost of a more structurally complex system required to hold the shaft in place.

IMHO this works out to make inside out engines the better option in most situations, since improving blower density is almost always less useful than improving tangent radius when it comes to things like torque/weight ratio, fuel efficiency, and structural integrity.

Maybe I'll build a 12x panther engine or something to see how well it scales up.

Edited July 12, 2016 by Pds314

[Gman_builder]

17 minutes ago, Pds314 said:

Something I've noticed is that, since blowers are big and solar panels are small, having the blowers on the inside seems to give you a better tangent radius, and therefore more torque and a more efficient engine, as well as reducing turbine blade collisions. On the flipside, putting the blowers externally allows room for more blowers, at the cost of efficiency and the ease with which the turbine blades overheat, as well as the cost of a more structurally complex system required to hold the shaft in place.

IMHO this works out to make inside out engines the better option in most situations, since improving blower density is almost always less useful than improving tangent radius when it comes to things like torque/weight ratio, fuel efficiency, and structural integrity.

Maybe I'll build a 12x panther engine or something to see how well it scales up.

I had not previously tested panthers before last night and I have found that engines utilizing them have significantly lower part count and are much easier on your computer. My latest engine has the lowest part count and highest thrust and RPM I have made yet. Toping out at 45 rad/s. It is only powered by 8 panthers as well. I get around 40 FPS with that engine with the smoke effects turned off. A Juno powered engine with comparable performance takes me down to around 20-25 FPS so panther engines are WAY better. They also weigh a lot less because of the low part count. My engine is 4.5 meters in diameter and only has 178 parts. So its a win win in power to weigh ratio and low part count and low engine count to keep your computer happy. One thing however is that my engine can barely lift off the ground without afterburners on. So I usually turn them on when I get to high enough RPM. Therefore it consumes fuel around twice as fast which succs.

Edited July 12, 2016 by Gman_builder

[quasarrgames]

Hey guys! I know you've probably seen this picture way too many times before, but i've discovered a secret:

You see how the propeller is a bunch of wings clipped together? Well, for some reason that increases the lift massively. I'm not really sure how to measure it in a propeller plane, but for comparison, i used it to make a barebones helicopter which could lift 7x its body weight and still have a TWR if about 2.

Edited July 12, 2016 by quasarrgames

[Gman_builder]

As you may know, wing surfaces have vastly increased lift over elevens and other control surfaces. So here is my prop design. It covers almost the entire range of prop angle from almost horizontal to almost vertical. It cannot be manually controlled in flight so it can still put the engine into over-speed. but it gets the job done. Far better than I expected actually. Acceleration is amazing and it has a very high max RPM.

 

[SpannerMonkey(smce)]

Hey, well adding mass has certainly helped, the noobshaft  managed to knock on the door of a whole 20 rads, this is a major triumph and i permitted myself a small woop I know it's not at all stock, so some evidence may be required so here's a few pics of noobshaft,  note at present it's only running 85kn so potential for a bit more yet

Spoiler

 

Edited July 12, 2016 by SpannerMonkey(smce)

[Gman_builder]

25 minutes ago, SpannerMonkey(smce) said:

Hey, well adding mass has certainly helped, the noobshaft  managed to knock on the door of a whole 20 rads, this is a major triumph and i permitted myself a small woop I know it's not at all stock, so some evidence may be required so here's a few pics of noobshaft,  note at present it's only running 85kn so potential for a bit more yet

 

Previously I used the "free moving docking washer" from infernal robotics to mate my drive shaft to the aircraft. It worked decently well but it is registered as one craft and there are no part collisions between parts of the same craft so the stability of your driveshaft is at the mercy of the strength of the joint of the washer,