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

[The_Rocketeer]

Just now, Azimech said:

Very nice! I'd like to test it!

Craft here.

Instructions:

NB: requires the infinite fuel cheat - she has some fuel tanks (and will fly with them empty or full), but I haven't taken the time yet to put in the necessary fuel hoses.

Take-Off:

1. Launch vessel.
2. Apply brakes.
3. Set elevator trim up (alt+S) about 1/3 to max.
4. Set roll trim left (alt+Q) just a little nudge
5. Stage to separate propshafts
6. Stage to start Junos.
7. Wait until engines spin up to >35 rads (they max out a little over 40 rads).
8. Release brakes
9. Keep her straight down the runway
10. Pull up once speed hits about 70m/s, or when she runs off the end of the runway.

Once flying:

• Cycle thru propellor crafts & increase input authority to maximum (stabilises propshafts by reducing rads slightly, and boosts thrust for better cruising speed).
• Avoid exceeding 120m/s in a dive as engines may fail.
• Avoid exceeding climbrates of 5m/s as you will likely stall.

[Azimech]

I'll test it tomorrow, off to bed.

[Teirusu]

So, by mucking around with the new floaty nodes on the fairing bases, I came up with this work-in-progress co-axial copter with a hybrid rotor design.

 

Definitely need to work on the bearings a bit, but seems to fly reasonably okay.  Certainly more fuel efficient then the quad I came up with.    

[Azimech]

1 hour ago, Teirusu said:

So, by mucking around with the new floaty nodes on the fairing bases, I came up with this work-in-progress co-axial copter with a hybrid rotor design.

 

Definitely need to work on the bearings a bit, but seems to fly reasonably okay.  Certainly more fuel efficient then the quad I came up with.    

Kudos for the coaxial but ... rockets/jets on the tips of rotors is exactly the reason I invented the turboshaft. So I'm more interested if you can create a pure one instead of hybrid ;-)

The MK3 cockpit is not going to help though.

[The_Rocketeer]

 

[Teirusu]

6 hours ago, Azimech said:

Kudos for the coaxial but ... rockets/jets on the tips of rotors is exactly the reason I invented the turboshaft. So I'm more interested if you can create a pure one instead of hybrid ;-)

The MK3 cockpit is not going to help though.

Ahh!  Well, I was aiming for  efficiency on that one.  Wanted to see if I could make something that could fly around for a good long while and the MK3 was to mostly test how much weight it could carry.  On the other hand..

After a quick edit for more blades, it can -just- barely get off the ground with only the 4 panthers.  Woooo

[EpicSpaceTroll139]

I can confirm as @Azimech mentioned earlier that the rpm limit boost allows turbos (or at least this heli) to work straight out of the box.

Until you do this, that is:

http://imgur.com/a/SXnX0

Which is interesting because I was expecting the new breakability on the antennas would make the antenna bearings snap.

Edited September 20, 2016 by EpicSpaceTroll139

[Majorjim!]

20 minutes ago, EpicSpaceTroll139 said:

I can confirm as @Azimech

Which is interesting because I was expecting the new breakability on the antennas would make the antenna bearings snap.

I think the antennas will only break at high atmospheric speeds/pressures and only when extended. 

[EpicSpaceTroll139]

So I've been trying to see how fast I can make something spin, and I keep seeming to get blocked at 60rad/sec despite having my angular velocity limit at 100rad/sec. Didn't someone say he/she'd had something reliably do 80rad/sec before? Also:

http://imgur.com/a/Wznzy

Edited September 22, 2016 by EpicSpaceTroll139

[Gman_builder]

17 hours ago, EpicSpaceTroll139 said:

So I've been trying to see how fast I can make something spin, and I keep seeming to get blocked at 60rad/sec despite having my angular velocity limit at 100rad/sec. Didn't someone say he/she'd had something reliably do 80rad/sec before? Also:

 

Yeah that tends to happen. I am not exactly sure how it works in 1.2 but previously the game would bug at really high RPM and give a miss-reading. I was testing a engine and a turbine blade flew off at exactly 100.0 rad/s, but i dont know how accurate that reading was because it was so precise.

[Azimech]

Great news everyone!

 

[comradephil]

New to the whole bearing and turboprop thing, but here's my very first attempt!

 

http://imgur.com/a/Hd576

 

She's a hybrid stayputnik and wheel bearing engine with 16 blowers. I'll let the album speak for itself

Edited October 18, 2016 by comradephil

[Azimech]

47 minutes ago, comradephil said:

New to the whole bearing and turboprop thing, but here's my very first attempt!

 

http://imgur.com/a/Hd576

 

She's a hybrid stayputnik and wheel bearing engine with 16 blowers. I'll let the album speak for itself

Great first attempt! Don't give up. Turboprops are harder than helicopters for learning about bearings: they're great for learning you the basics. After that there's a whole lot of simple science about blower/propeller blade stuff we can help you with.

[Pds314]

2 minutes ago, Azimech said:

Great first attempt! Don't give up. Turboprops are harder than helicopters for learning about bearings: they're great for learning you the basics. After that there's a whole lot of simple science about blower/propeller blade stuff we can help you with.

This is true, although I would have to say that simple helicopters are much less easy to make than practical helicopters. Trying to make choppers go fast is hard due to differential lift.

[Pds314]

Alright. What is even happening?

I've developed a new 1.2 Turbo, 42 blowers in a 2.5m form factor, external turbine blades, pretty typical style of construction for me, just quite a bit longer than normal.

The ENGINE MOUNTS are exploding. I've tried autostruts, real struts, rigidity, and more. I wonder if there is just so much torque on them that they come off their mounts?

Maybe I should keep the struts but get rid of the rigidity?

or maybe move it forward so it doesn't interfere with the wing?

EDIT: hmm.. maybe they can't stand being at the rev limit and generate spontaneous torque? EDIT2: I should note that this is with completely stock aero, no base drag reduction.

Edited October 18, 2016 by Pds314

[Azimech]

Good question. Does it happen when the plane is fixed to the ground with launch clamps? Is there a lot of vibration? I believe the rigidity can wreak havoc on things, yes.

[comradephil]

Turns out my bearing design is rock solid. I tested it in various high G situations (spins on the tarmac, crash landings in water at 30m/s) and it simply will not break. Even after removing one of the two stayputniks. I improved both the bearing and shaft rigidity by playing with the suspension settings on the wheels and adding struts to the shaft itself, as well as repositioning some wheels for a tighter fit. The axle hardly wobbles at all now.

I have sixteen blowers and have angled the blades at 60° towards the them, which seems to have increased torque no end. With a short wingspanned plane I've reached 50m/s on engine power alone, and with a high aspect ratio wing I've had it airborne for 30-40 seconds (45m/s) before stalling out into the sea. I also lengthened the prop, reasoning that a bigger prop means higher velocities at the tip thereof, therefore it'd provide more thrust.

What I'm wondering now is how you guys get to 80m/s and more. I seem to have enough power to go places, but not enough to really take off.

Can anyone take a look and tell me what I'm doing wrong? Craft file 

 

EDIT: I DID IT!

 

With the addition of eight extra blowers she'll now perform full aerobatic manoevres

Edited October 18, 2016 by comradephil

[Gman_builder]

@comradephil Nice job! I was testing it today and determined that the shaft stability needs some improvement. It kinda wobbles back and forth during spool up and take off which affects the aerodynamics in a strange oscillating pattern. It doesn't seem to really affect the performance but its just something to consider. If you add more blowers in the future it might shake itself apart. On that note, it needs more blowers. A lot more. For reference, my fastest plane exceeds 230 m/s in 1.2 but it has something like 72 blowers. I'll count later. @Azimech @Pds314 Yall should test your fastest planes in 1.2. I want to see how the new aero affected them too, because mine got a 20 m/s speed reduction.

[Azimech]

Indeed, the changes in the aero system are obvious.

[Pds314]

9 hours ago, Gman_builder said:

@comradephil Nice job! I was testing it today and determined that the shaft stability needs some improvement. It kinda wobbles back and forth during spool up and take off which affects the aerodynamics in a strange oscillating pattern. It doesn't seem to really affect the performance but its just something to consider. If you add more blowers in the future it might shake itself apart. On that note, it needs more blowers. A lot more. For reference, my fastest plane exceeds 230 m/s in 1.2 but it has something like 72 blowers. I'll count later. @Azimech @Pds314 Yall should test your fastest planes in 1.2. I want to see how the new aero affected them too, because mine got a 20 m/s speed reduction.

Is this with or without base drag reduction? I've mostly been trying to work on building craft that can deal with stock base drag since 1.2 The whole idea of "build wide" has problems here, since wide engines have higher drag.

So for example:

6 blowers in Mk1 with 0.3125m effective radius has a base drag of 1 unit and a torque of 1.875 blower-meters. Power/drag ratio of 1.875.
12 blowers in a Mk2 with 0.9375m effective radius has a base drag of 4 units and a torque of 11.25 blower-meters. Power/drag ratio of 2.8125
18 blowers in a Mk3 with 1.5625m effective radius has a base drag of 9 units and a torque of  28.125 blower-meters. Power/drag ratio of 3.125.

Etc, etc. Eventually you realize that acheiving more than 0.625 power/drag/engine/nodeSize^2 is impossible. Thus, with a given density of engines around the outer edge, asymptotic performance is achieved by increasing radius.

The problem is, you need a high power/drag ratio in order to achieve high speeds.

So you make your engines longer, less efficient, heavier, less powerful, but less draggy.

So for example, you make a Mk2 engine with 27 blowers instead of 12, so that it is equal in torque to a Mk3 engine with 18 blowers with much lower drag.

This is where I'm at. My current Mk2 engines have 42 blowers, but there seem to be serious structural issues with them. I did build a massively powerful 120-blower Mk3, but the sheer impracticality of putting a pair of them in an aircraft makes me wonder if super-efficient super-sized engines are worth making at all. With my construction techniques, an engine of that scale requires like 180-300 parts and like 35 tonnes. That means 70 tonnes of engines and 500 or so engine parts.

So I think it makes sense if I want full-aero flight capabilties, to focus on Mk2 form factor engines with rows upon rows of blowers. As it is, having 42 engines on a Mk2 decoupler causes an unbelievable amount of problems in terms of ripping the plane apart.

Edited October 19, 2016 by Pds314

[Pds314]

Tried bringing a rusty old bomber out of retirement, giving it some new(er) engines and flying in stock drag. Part count reduced by 84, engine power increased by at least 122% per engine. Weight increased by 11%.



This is under fully stock drag. Note that it is climbing and at altitude.

I just realized. My older-but-still-new engine is actually better than my new problem child engine from a size and part count perspective. With some minor KSP 1.2-related improvements, a modernization program is probably better than a new design. 95% the power for 80% the part count.

In any case, what's the full-drag airspeed record? My plane so far manages about 103 m/s in level flight.

One thing I notice is that Base drag is more than double lift-induced drag even while climbing. This is... inefficient. I think probably the thing to do is build a 2-engine pusher prop flying wing like my MASSIVE Archelon (400 parts) and Archelon XA2 (540 parts), which are much larger and more failure-prone.

An alternative idea is to design a new engine with a coaxial pusher prop, thus hopefully reducing drag tremendously.

Edited October 19, 2016 by Pds314

[Pds314]

First engine test of the Talon Double PX. Definitely needs work on structural reinforcement, but it spins in both directions and it is only about 160 parts with rotors.

80 blowers. 40 in each direction.

157 parts, but it's got some problems for now. For one, it does not seem to be stable enough for prolonged static tests, let alone the rigors of flight.

It managed 40 rads/s in each direction for about 30 seconds before something broke. This means that if, for ex, one external turbine wheel hits the other one, the impact velocity will be about 100 m/s. Splat.

Edited October 19, 2016 by Pds314

[Gman_builder]

@Pds314Thats a whole lot of numbers that i really dont understand but it seems interesting. Anywho, i appreciate your work in smaller engines but i would still like to know your top speed. I'm talking exact same parameters as we used previously for our speed runs. I will also test my plane under completely stock conditions however its a lot harder now to accurately get good info because VOID isn't updated yet.

Edited October 20, 2016 by Gman_builder

[Gman_builder]

Update, i cannot get my plane to fly in any conditions let alone stock. KSP is being very unpredictable where sometimes the plane has enough power and sometimes it doesn't and sometimes it just explodes. This game will be the death of me.

[EpicSpaceTroll139]

4 minutes ago, Gman_builder said:

 ...sometimes it just explodes...

KSP at its finest