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

[EpicSpaceTroll139]

@_Rade I can confirm that autostruts do affect rotor/prop performance, at least in some cases. I've been working on that fenestron rotor I showed earlier, and I had both rigid attachment and autostrut on the blades to keep them from over-expanding. I noticed that I didn't need the autostruts, and when I removed them, the rotor spun up by an additional 100deg/sec or so. When I put them back on it slowed back down again. Rigid attachment did too.

Edit: Update on that fenestron rotor.

I'm currently getting about 26kN from this 15 bladed rotor with one Juno blower.

I was getting 19.1kN with a 10 bladed setup earlier. I'm going to do testing with different numbers of blades, as well as experiment with slightly different pitch angles, though I think I've got the latter pretty close to the optimum. Unfortunately the rpm is currently limited to some degree by rigid attachment, which is required to keep the rotor from over-expanding and coming in contact with the blower. I will also add a second blower, because even if it is efficient compared to other tail rotors I've made, 26kN is rather pitiful for a device this large.

Edit 2: Unfortunately it would seem the most effective blades are also the ugliest.

Edit 3:

I've made a fantastically efficient tale rotor of this type and I'm testing it on Azi's Selene heli. It is able to provide adequate antitorque with one Juno blower limited to 75% on the maximum main rotor power setting.

I might try changing making a few more changes though. I'd like to decrease the susceptibility to over speed (stay above 90% blower power for more than a few seconds and the outer blades hit the duct*), and if at all possible I want to add a system to vary the output via yaw control in a manner similar to the relatively weak rotor I showed a month or two back.

*Interestingly the inner blades are able to keep up enough antitorque by spinning at 50rad/sec to keep the heli flying for a short period of time, but they then develop a "whirl" oscillation which feeds back on itself until the rotor assembly is ejected)

Edited December 14, 2017 by EpicSpaceTroll139

[Krog34]

@EpicSpaceTroll139 what a beautiful tail. I can't wait to see it in action!

 

Far from being a production piece, I thought I'd show off my progress on the Kermansky Osprey knock-off!

 

Spoiler

 

Edited December 15, 2017 by Krog34

[EpicSpaceTroll139]

@Krog34 Thanks! Good luck with your tiltrotor endeavor. I should probably continue work on mine at some point.

Might I advise changing the mechanism that locks the rotors horizontally to have the claws offset further along in the rotation so they grab a wing panel situated horizontally just behind the main wing, about where the innermost flaps/ailerons are now? The current setup with the near-vertical panels looks rather draggy. Alternatively you could swap with the half sized panels or, after a lot of trial and error, something small like a cubic strut.

 

Anyways, this is what I've got currently going on with my fan-tail.

Next time I load up KSP I'll probably do this with the aero force display on, but between the two pics you may notice that the diameter of the fan changes. This is due to a sort of "yaw brake" thing I added. The design pushes to the left to counteract the counterclockwise torqe produced by the clockwise spinning main rotor. You can see there is an airbrake next to the fan, and when the pilot or SAS gives a yaw-left input, this airbrake actuates a few degrees and presses against the grey adapter which is connected to the rotor, acting kind kind of like a one-sided disk brake, thus slowing the rotor, causing it to produce less thrust, and allowing the torque of the main rotor to yaw the thing to the left.

Current plans are to make some modifications to reduce spool-up time, and set it up so that it will normally produce a little more thrust than needed, so it can yaw the heli to the right, and to hold constant heading, SAS will apply a slight pressure on the brake to moderate the thrust. The trick is going to be making sure the thing doesn't overspeed and explode while still being able to return from the slower, braked rpm in a reasonable timeframe.

If I get everything working right I also might try making the thing smaller, because it's kind of bulky, and hardly looks comparable to what you see on a real heli. 

Spoiler

Not sure I can get it to look right at any size though

Edited December 15, 2017 by EpicSpaceTroll139

[Azimech]

Most impressive, @EpicSpaceTroll139!

[EpicSpaceTroll139]

The success of the use basic fin blades on the fenestron convinced me to try a new main rotor design.

While at the moment it's not working quite how I had hoped, the flex made it occur to me that a short section of basic winglets at the blade root could be used as elastomeric flap/lead-lag hinges for a larger helicopter rotor. Perhaps @Azimech might want to experiment with this?

[Azimech]

Anyone else experiencing problems with the 1.4 update?

[EpicSpaceTroll139]

6 hours ago, Azimech said:

Anyone else experiencing problems with the 1.4 update?

I haven't downloaded it yet, but I plan to soon. Is it causing problems with bearings?

[Azimech]

45 minutes ago, EpicSpaceTroll139 said:

I haven't downloaded it yet, but I plan to soon. Is it causing problems with bearings?

Yes, multiple designs seem to have issues, not just mine.

[qzgy]

Have not used it yet. All bearings though?

[EpicSpaceTroll139]

I need to do more extensive testing, but I was just doing some flight testing of my E-50.

It took off fine

But then after about 25 seconds of flight something locked up in the lower rotor, and it came back down. Luckily it was at fairly low altitude, and the kerbals were fine.

(Note the top rotor blades deflecting up under high power, while the lower ones rest in their built-in pre-flight droop.)

 

Update: There is definitely something wrong with the bearings now

E-50 will take off, but breaks shortly thereafter.

E-23 will not even take off. The bearings act like they're they're filled with rocks, making the rotors move like they're in soup when at low power, and break out at high power.

Hoping Collide-o-scope gets updated soon so I can see if there's anything changed about the collision meshes. This is all very strange.

It seems likely all my helicopters are broken, but some will be more broken than others, for reasons unknown

Edited March 11, 2018 by EpicSpaceTroll139

[qzgy]

32 minutes ago, EpicSpaceTroll139 said:

Hoping Collide-o-scope gets updated soon so I can see if there's anything changed about the collision meshes. This is all very strange.

Think it is already updated.....

Or at least works with 1.4. Saw someone use it on the new decouplers.

[Azimech]

Correct, Collide-o-scope works in 1.4, no update needed.

Interestingly enough: my V8 and Curious Chakora are doing fine.

[Azimech]

Some of the problems can be solved.

[klond]

 I am not @ 1.4 yet, but I wanna try the new parachutes very badly.

 Is the new tank (dumpling) truly round (hint hint)?

[EpicSpaceTroll139]

I can confirm that both the Dumpling and Baguette tanks are truly round.

I forget if it had been exploited before (wasn't there a combination lock?), but the Doughnut no longer has that slot in one side.

Edit: on an unrelated note, the Dumpling has an absolutely abysmal fuel/mass ratio, with less than 25% of the wet mass being fuel.

Edited March 10, 2018 by EpicSpaceTroll139

[Azimech]

Those tanks really have a very low impact rating though ... the RCS tanks can withstand more than double the punishment and have spherical/cylindrical colliders as well.

[klond]

 Yeah, but it's nice to have something new and round, even if low impact.  I'm sure we'll find a use for it, like in ball joints or maybe even just for ammo  

[EpicSpaceTroll139]

I just noticed something. Kerbal helmets are spherical. And you know how tough those kerbal noggins are...

(jk please don't use kerbals as bearings)

Edited March 10, 2018 by EpicSpaceTroll139

[qzgy]

1 hour ago, EpicSpaceTroll139 said:

(wasn't there a combination lock?)

Yes, there was a slot and yes someone made a combo lock (klond I think...)

[klond]

1 hour ago, qzgy said:

Yes, there was a slot and yes someone made a combo lock (klond I think...)

 I did a combo lock, but not with the toroidal(sp) tank.  I do remember experiencing wierdness with that tank tho.  It has a gauge sticking out one side - is that where the slot was?

 

[qzgy]

2 minutes ago, klond said:

 I did a combo lock, but not with the toroidal(sp) tank.  I do remember experiencing wierdness with that tank tho.  It has a gauge sticking out one side - is that where the slot was?

Hmmm.

Opposite of the gauge.

 

I know I started one a combo lock with these. Never finished it though.....

I honestly don't remember.

[Castille7]

2 hours ago, klond said:

 Yeah, but it's nice to have something new and round, even if low impact.  I'm sure we'll find a use for it, like in ball joints or maybe even just for ammo  

It's still a useful life ring! 

[klond]

20 hours ago, Castille7 said:

It's still a useful life ring! 

 The toroid?  Yeah, totally a naval life preserver or life raft.

The new donut is hollow.

[qzgy]

1 hour ago, klond said:

The new donut is hollow.

New exploits/things coming then probably, right?

OH WAIT WE CAN MAKE HOOP THING CARNIVAL GAMES

 

Or tubes.

[klond]

Aw, it don't quite fit.

 

 This is getting off-topic, but all my dudes are here.  They did fix a Grabber issue.  Now you can steer on grabbed-craft, free pivot or not.  Opens up the building of flexible rovers.