The HELO challenge

[Fengist]

What about the HELO Model A? That was the one I really wanted on the Leaderboard right now- it already made 4 of the awards... (Precision, Eggington, and both the altitude challenges)

Done!

About the desire for MechJeb on the cargo run- I should explain: I'm not using physics warp, because I'm afraid it would probably break the KAS winch (which is very close to breaking with that cargo load), and I'm also experiencing VERY low FPS due to ocean-lag (surprisingly, the helicopter itself is no laggier than the Model A- probably because there is no lift to simulate anywhere on it)

Regards,

Northstar

Because... Jeb makes it too easy. As you pointed out, you're learning how to manage that helo without Jeb. Every aircraft flies differently. Learning how to handle them is half the fun. Think about it this way. You're having fun now. Once you get da Vinci you'll probably never fly this helo again. How would you like to remember the experience? As a challenge to your skills or as another boring MechJeb flight?

[Northstar1989]

Almost there...

And NOOOO!

The helicopter came down a bit too quickly on the final landing (10 m/s), and the (extremely fragile) fuel tank exploded!

The copter itself touched down perfectly fine though (except for the inch, which either came off when the tank exploded or with the legs clipping into the ground- I can't tell)

So, I'm at least halfway to the Bell Ranger Award (the return flight should be a cake-walk). And I more than proved capability for the Kolenchenko Award. Any chance I could get that one- or am I going to be made to do it all over again? (in that case GIVE ME MECHJEB OR GIVE ME DEATH! Hey, I'm from Boston )

Regards,

Northstar

Edited February 1, 2014 by Northstar1989

[Northstar1989]

Done!

Because... Jeb makes it too easy. As you pointed out, you're learning how to manage that helo without Jeb. Every aircraft flies differently. Learning how to handle them is half the fun. Think about it this way. You're having fun now. Once you get da Vinci you'll probably never fly this helo again. How would you like to remember the experience? As a challenge to your skills or as another boring MechJeb flight?

I believe, right now, you have me remembering it as a boring and extremely, painfully tedious manual flight.

And no, MechJeb *DOESN'T* make it any easier. There's really no difference between setting angle of attack to 20 degrees with MechJEb ASAS, and waiting and holding the W key hard for 60 minutes (that's how long my 30-minute game time flight took, with FPS-slowdown). Except that one way I get Carpal Tunnel, and the other way I get to snack on a piece of fruit I've been dying to pull out of the fridge...

I already know exactly how to pilot these things- it only takes a minute or two to learn. The only problem is that if I get bored/tired enough, I make stupid mistakes (like coming down too hard near the runway with the cargo) *BECAUSE* I'm bored/tired. That's precisely why in REAL LIFE, they use autopilots for long, slow flights- because otherwise the human pilots will get bored, and eventually mess up.

It's not like I can walk away too long from it on MechJeb, anyways. It's not perfect, and it still sometimes screws up. The most it lets me do is grab something from the fridge, or maybe (if I want to risk it) take a super-quick shower...

Stop ruining my fun, and let me use MechJeb. It doesn't make the challenge any easier- it's not fair to impose YOUR style of play on other players.

Regards,

Northstar

[Northstar1989]

That's... a lot of rotors. Leaderboard updated for Model B. You may want to do the 40 tons the way I did. If you'll notice on the first post, I just used a decoupler from Anvil. I understand why you're trying it with KAS and hope you succeed. But it'll be wobbly.

Also, how in the heck am I supposed to strap a 40-ton payload on the bottom of the thing with a decoupler? (and if I could- would that count as making modifications to the copter, since I would need to put it in the place of the KAS winch?) I tried starting with a payload already attached to the KAS winch in lock-mode (as good as a decoupler) initially, and the copter bugged out, exploded, and flew 150 meters up in the air from the force, in that order...

[Northstar1989]

Taking off for a return flight to the KSC for the finish on the Bell Ranger Award. I don't know if you can see them clearly in the dusk light, but there are two Kerbals left behind at the island runway (so long, suckers!)

Except, because I was bored and impatient after that run on the Kolonchnko Award, and I didn't want to land in darkness; I decided to make the Eggington Award on the way back too... I actually hit over 150 m/s in that Eggington run. And YES, the copter *IS* still gaining altitude at that angle of attack on maximum Cargo Throttle... (GIMME THAT AWARD!)

And here I am, having just landed safely at the KSC after the Eggington and Bell Ranger Awards:

Regards,

Northstar

Edited February 1, 2014 by Northstar1989

[Northstar1989]

Meet my new 40-ton cargo (40.27 tons, to be precise)

Learning from my last cargo haul, this time I'm moving it as a paradrop. The fuel load is partial because if it was full, the whole thing would weigh nearly 60 tons instead of close to 40 (if I were setting up operations at the island runway, I would start off by sending over a larger, partially-empty tank anyways). The probe core is there solely to deploy the 'chutes.

I examined the rules carefully, and there was no rule against probe cores- only against having them control the helicopter itself instead of a pilot. In real life, drops are rigged all the time so the chutes are deployed as soon as they are released- unfortunately, KAS offers no means of doing this without attaching the winch in "docked" mode- which messes up the view by centering it on a calculated Center of Mass *BETWEEN* the 'copter and the cargo, making the 'copter impossible to see and *very* difficult to fly... (and the variation of cockpit I used in the HELO has no internals- meaning I get the default view of the inside of an opaque metal box, so flying from the internal isn't an option either)

I'm posting this now so I can hear any objections right away- but I don't appreciate any. This is a perfectly legit strategy, and saves me another hour of tedious, manual flying only to possibly drop the tank a bit too hard again (although this one is a bit less fragile- the tank itself can sustain over 100 m/s on the bottom piece, and 12 m/s on the top connector. The RTG's can only take 7 m/s, but I will consider it a successful drop unless the top connector breaks- as the cargo still weighs over 40 tons without the RTG's- which I need for a night paradrop...)

Edited April 17, 2014 by Northstar1989

[Northstar1989]

Oh, and another award...

The Boulet Award:

Edited February 1, 2014 by Northstar1989

[Fengist]

Meet my new 40-ton cargo (20.27 tons, to be precise)

Learning from my last cargo haul, this time I'm moving it as a paradrop. The fuel load is partial because if it was full, the whole thing would weigh nearly 60 tons instead of close to 40 (if I were setting up operations at the island runway, I would start off by sending over a larger, partially-empty tank anyways). The probe core is there solely to deploy the 'chutes.

I examined the rules carefully, and there was no rule against probe cores- only against having them control the helicopter itself instead of a pilot. In real life, drops are rigged all the time so the chutes are deployed as soon as they are released- unfortunately, KAS offers no means of doing this without attaching the winch in "docked" mode- which messes up the view by centering it on a calculated Center of Mass *BETWEEN* the 'copter and the cargo, making the 'copter impossible to see and *very* difficult to fly... (and the variation of cockpit I used in the HELO has no internals- meaning I get the default view of the inside of an opaque metal box, so flying from the internal isn't an option either)

I'm posting this now so I can hear any objections right away- but I don't appreciate any. This is a perfectly legit strategy, and saves me another hour of tedious, manual flying only to possibly drop the tank a bit too hard again (although this one is a bit less fragile- the tank itself can sustain over 100 m/s on the bottom piece, and 12 m/s on the top connector. The RTG's can only take 7 m/s, but I will consider it a successful drop unless the top connector breaks- as the cargo still weighs over 40 tons without the RTG's- which I need for a night paradrop...)

No objections. I've even suggested parachutes in previous posts and fully understand about the probe core, no problem there. BTW, I just bragged on you in the VTOL challenge. You realize if you pull this 40 tons off with KAS you'll have a craft capable of moving most anything on any planet with an atmosphere.

[Fengist]

Taking off for a return flight to the KSC for the finish on the Bell Ranger Award. I don't know if you can see them clearly in the dusk light, but there are two Kerbals left behind at the island runway (so long, suckers!)

Except, because I was bored and impatient after that run on the Kolonchnko Award, and I didn't want to land in darkness; I decided to make the Eggington Award on the way back too... I actually hit over 150 m/s in that Eggington run. And YES, the copter *IS* still gaining altitude at that angle of attack on maximum Cargo Throttle... (GIMME THAT AWARD!)

Regards,

Northstar

The Eddington is 400m/s not 100. And you CAN modify it. Read the rules. And then, take a break dood, you're getting pissy.

[Northstar1989]

And the Church Award: this took longer than I thought- the HELO B barely makes it...

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The Eddington is 400m/s not 100. And you CAN modify it. Read the rules. And then, take a break dood, you're getting pissy.

The Award says 400.87 km/h, not m/s. Units are important!

400.87 km/h equates to 111.35 m/s- much different than 400 m/s! (which would be, frankly, impossible without jet engines)

The historical speed record, set by John Trevor Egginton, is 400.87 km/h, so you did have it right in the OP: http://en.wikipedia.org/wiki/Helicopter

That means, I won the Egginton Award fair and square...

Regards,

Northstar

P.S. Sorry if I'm getting a little edgy- I don't like being deprived of MechJeb for long/slow flights- which I find insanely boring...

P.P.S. The "fly-anywhere" capability was kind of the reason I chose electrics. The HELO A won't do me much good off-planet due to its limited lifting capacity and stability problems, but the HELO B would make an excellent heavy-lifter on Duna...

Edited April 17, 2014 by Northstar1989

[Northstar1989]

The Eddington is 400m/s not 100. And you CAN modify it. Read the rules. And then, take a break dood, you're getting pissy.

WAIT, so if I'm reading you correctly, are you saying that modifications wouldn't DQ the craft from the Da Vinci award?

More importantly, I think you need to also take a look at your criteria for "The Kasprowicz Distinction". As it happens, 136.7 km/h is only about 38 m/s. To circumnavigate Kerbin at that speed would take 27.56 hours, not 6 hours.

6 hours means an average speed of 174.53 m/s for the whole flight, which, frankly, is impossible with electric-only craft (if jets are banned). And, it equates to an average speed of 628.32 km/h- more than three and a half times (3.60 to be precise) the average speed that Kasprowicz circumnavigated the Earth...

It *APPEARS* that you got the records off Wikipedia (you list almost exactly the same records, in a similar order, and even have a Da Vinci image straight off the page), but made the MAJOR mistake of confusing km/h with m/s. They're two entirely different units of speed- and as I said, some of the distinctions are nearly impossible with m/s...

Regards,

Northstar

Edited February 1, 2014 by Northstar1989

[Fengist]

WAIT, so if I'm reading you correctly, are you saying that modifications wouldn't DQ the craft from the Da Vinci award?

Correct.

More importantly, I think you need to also take a look at your criteria for "The Kasprowicz Distinction". As it happens, 136.7 km/h is only about 38 m/s. To circumnavigate Kerbin at that speed would take 27.56 hours, not 6 hours.

6 hours means an average speed of 174.53 m/s for the whole flight, which, frankly, is impossible with electric-only craft (if jets are banned). And, it equates to an average speed of 628.32 km/h- more than three and a half times (3.60 to be precise) the average speed that Kasprowicz circumnavigated the Earth...

Fine, you're in on a technicality. Everyone else, m/s. I think everyone who's done this so far knew what I meant. Kerbals fly faster by nature.

It *APPEARS* that you got the records off Wikipedia (you list almost exactly the same records, in a similar order, and even have a Da Vinci image straight off the page), but made the MAJOR mistake of confusing km/h with m/s. They're two entirely different units of speed- and as I said, some of the distinctions are nearly impossible with m/s...

Of course I got them off wikipedia. If you LOOK in my OP, I even LINK to that page. And yes, that image is from wikimedia meaning... it's not copyright and legal to put on these forums.

Let me know when you're done which you qualify for. I'll be off for a couple of days and will get them all when I'm back.

[Northstar1989]

Fine, you're in on a technicality. Everyone else, m/s. I think everyone who's done this so far knew what I meant. Kerbals fly faster by nature.

Believe it or not, I actually read to OP to mean what it said. Parts in the Kerbal universe are higher-thrust at times, but not by that large of a difference: the difference between m/s and km/h is roughly 7:25, that is, a craft flying 7 m/s is flying 25 km/h. And I can tell you, Kerbal parts DO NOT produce more than 3x the thrust of their real-life counterparts, and DO often have less ISP than irl... (meaning a given Delta-V requires a larger fuel tank, or powering a given # of electric rotors a larger reactor. You think nuclear reactors are OP'd now- see them if the rotors required even 10 or 20% less electricity per kN thrust...)

Anyways, sorry again for getting edgy before... I tried to do all these challenges in one play session- and seriously needed a break...

Regards,

Northstar

Edited February 1, 2014 by Northstar1989

[Northstar1989]

The Kasprowicz distinction - Complete a circumnavigation in less than 6 hours. (In honor of Scott Kasprowicz who completed a circumnavigation of the Earth with an average speed of 136.7 m/s. Yes, he landed numerous times and so can you if you need.)

Also, err, you can specify that Kerbals need to do it is m/s instead of km/h, but you ought not to re-write Earth history...

Scott Kasprowicz circled the Earth at an average speed of 38 m/s (136.7 km/h), not 136.7 m/s- and saying otherwise is incorrect.

You ought to clarify that *HE* did it at an average speed of 38 m/s (or 136.7 km/h), but *YOU* expect players to do it at 136.7 m/s... (once again, a 7:25 difference in speed)

By the way, if you see this before leaving town or whatever- am I allowed to add small wings as a "minor" modification? That is physically the only way to achieve speeds over about 150-160 m/s with an all-electric helicopter using the Electric Helicopter blades (unless you literally vertically spam them until the point where something like 80-90% of vessel weight is in blades- but that feels like an exploit)... You saw how many rotors the HELO: B had relative to its size- its TWR st sea-level is around 7.5 or 8 or with Cargo Throttle, and the rotors make up more than 40% of vessel-mass, and yet its top sustainable speed is only around 135 m/s, and it physically can't fly faster than 150-154 m/s (for the record, doubling the TWR won't double the top-speed- it'll increase it maybe 40-50%, since helicopter rotors work best near sea-level, where you get a lot of drag- which increases exponentially, eventually forcing you to fly higher-up, where rotors have much lower TWR...)

I COULD do it with jets, or I could do it with wings- the issue that must be overcome is a helicopter rotor's velocity-curve (which is so limited as to make achieving an 175 m/s circumnavigation with electric rotors alone impossible).

Wings have no velocity-curve, in fact they work better at higher speeds. Jets have a much more favorable velocity-curve than propellers and rotors (in fact, props/rotors use basically the same velocity curve- which is why I used props as smaller, better-TWR rotors on my 'Hornet' design- as smaller rotors/props generally get better TWR due to the way angular momentum and lift works- that is, the bigger the rotor, the exponentially more energy you need to maintain the same tip blade-speed, and lift increases exponentially with tip blade-speed...)

I could also do it with roughly 72 of the larger electric plane propellers (incorporating additional attachment mass to the estimate) mounted vertically on the HELO: B instead of Electric Helicopter rotors (of which, it currently has 22), so that I'm basically just using a lot more small rotors instead of fewer big ones, for the smaller rotors' greatly improved TWR- but that would create a lag machine of death that would, frankly, fly at like 2-3 FPS or even crash my computer...

Regards,

Northstar

P.S. For those curious how the 'Hornet' achieved 240 m/s, but conventional electric helicopters can't, there were 3 reasons: (1) It utilized jet plane propellers mounted vertically instead of much lower-TWR helicopter rotors. Basically, just smaller, and thus more mass-efficient, rotors. (2) It had a small rocket on the rear. That only provided 0.4 kN of thrust- but that would be the equivalent of 2-3 kN of thrust with my much larger HELO: B, and it was subject to no velocity-curve. (3) Most importantly, it had significant wing area relative to its mass. Those wings were oriented such as to push it further down in a dive, keeping the helicopter low to the ground where props work best even when the props were throttled up to insane TWR (more than 10). Even so, the wings were oriented such as to work best in a dive, and its speed of 240 m/s was in a dive- it could only sustain MAYBE 160-170 m/s in sustained 60-70 degree flight... (wings mounted closer to perpendicular to the rotors work much better for level flight at angles of attack more than 20 degrees below the horizon- but it was designed for the much thinner atmosphere of Duna, where any angle of attack more than 12-15 degrees below the horizon would produce insufficient vertical "thrust" to avoid a crash...)

Edited February 2, 2014 by Northstar1989

[Northstar1989]

OK, so I made a little light modification to the HELO: Model B, and switched the two 6m Structural Fuselages for 6m Cargo Bays. Here she is lifting off the runway with just over 40 tons of metal canisters:

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The cargo bays are exactly the same length, diameter, weight and weight distribution, and drag- so they change the base performance in no way- and I've decided to make this the permanent base design to avoid the hassle of ever needing to do it again.

And, here the HELO: Model B is on approach to the runway with the 40-ton cargo. I believe I've beat the Earth record for highest altitude lifting a 40-ton cargo as well (2,255 m)

By quite a lot...

Regards,

Northstar

Edited February 2, 2014 by Northstar1989

[Northstar1989]

All went smoothly, and I believe I now have every right to collect the Kolochenko Award- putting my one step closer to the Da Vinci...

The dropoff went without a hitch:

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And, on the return trip, I pushed the HELO:B, and by connection all wingless electric-rotor helicopters (seeing as it has an insanely high TWR) to its limits...

The landing went smoothly as well.

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The observant among you might have noticed I included two pictures that examine the thrust of the electric rotors. Their base thrust is 80 kN, and 120 kN on full Cargo Throttle- like I had them in those screenshots. However, due to rotors having very velocity curves, their thrust tends to fall off very quickly when reaching high speeds- as is clearly demonstrated here, where the thrust is quite a bit greater at the *higher* altitude due to the somewhat lower craft velocity.

It's for this reason that circumnavigating Kerbin in 6 hours (requiring an AVERAGE speed of 175 m/s) is *absolutely impossible* for an electric helicopter without either including vertical wings in the design and tipping the craft over so it flies like a plane; or utilizing jet, thermal turbojet, rocket, or ion/plasmodynamic/ATILA engines (all essentially versions of the ion engine concept- listed in order of increasing thrust). The design doesn't have room for sufficiently large vertical wings (I tried finding a good place for them)- so I'm either going to have to spam a ton of small wing pieces (which have less lift relative to their mass), or get a rules change to allow some kind of non-propeller engine...

Perhaps an allowance could be made for use fission-powered thermal turbojets- which have rather anemic thrust, extremely high mass relative to that thrust (over 2 tons for about 40-60 kN, with a reduced nuclear fuel load, including the weight of both a reactor and a TTJ nozzle) and burn no fuel? (they rely on reactor heat instead) I already have a place for one on the back of the helicopter (the reactor is in the perfect position- I need only slap on a TTJ nozzle and an air intake- though the turbojet nozzle would compete with my electric generator for reactor output...) Their main (only) advantage for me over props would be their superior altitude and velocity curves (they behave similarly to stock turbojets in terms of ISP and thrust with speed and altitude), which would allow me to mount a nozzle (like I said, it would use the existing reactor) on the back of my helicopter, and perhaps some small horizontal winglets for control/stability and a bit of lift, and be able to probably hit speeds of about 200-250 m/s (enough to circumnavigate Kerbin in under 6 hours).

And, to repeat myself- if I added only 1 nozzle, it would simply be fully utilizing the existing reactor- passing air over it to make use of the leftover ThermalPower that the generator doesn't need... And no fuel would be consumed, in fact nothing would be consumed but spare reactor heat- so technically the rules allow it, if you read jets to mean the standard (fuel-burning jets) and gasses to mean what they were obviously targeted at: Xenon, and perhaps also ArgonGas and HydrogenGas resources in NearFuture mod and Argon in KSP-Interstellar...

I think it's fair enough that if I'm expected to circumnavigate the globe more than 3 times faster than the real-life world record holder did in a helicopter, I should at least be able to pass a little hot air over my reactor?

Otherwise, minus basically cheating and turning your helicopter into a VTOL propeller plane (adding vertical wings, and switching to a horizontal flight regimen after takeoff), there's no physically possible way to build a helicopter that can fly fast enough without massively spamming the smaller (and much higher-TWR) electric plane propellers as a a sort of smaller and more efficient helicopter rotor...

Regards,

Northstar

P.S. When I say MASSIVELY spamming, I mean *MASSIVELY*. My 'Hornet' design, which weighed in at just over 2 tons, and had a maximum TWR in excess of 10 with Cargo Throttle engaged, had 4 of them, and still couldn't sustain 175 m/s in level flight, only in a dive... The HELO:B weighs a bit over 30.5 tons- so you do the math...

Edited February 2, 2014 by Northstar1989

[Northstar1989]

http://imgur.com/a/91h5P

With this little tilting blade design I've been on the VAB, at 774Km/h in level flight, 11582m forward flight altitude and delivered 2 Kerbals to the dirt runway. Oh, and the blades never clip anything

The Jet Ranger distinction

Precision award

The Eggington award

The Church award

I'm considering a nuclear-electric multi-prop heavy lifter - would that be considered as an infinite fuel?

Interesting design- if you see this Darren, how did you get the blades to tilt? Did you use Infernal Robotics? I tried installing that mod- but it was the straw that broke the camel's back- it was just one mod too many for my computer to handle on top of everything else.

Also, I feel the need to point out that Darren also, like me, understood the Egginton Award (no third g in the spelling) to mean 400 kh/h, like the historical record and the challenge originally stated- his pics show his chopper moving at 215.5 m/s, which comes out to roughly 774 km/h- the top speed he stated he reached.

Anyways, I have need of a high-speed scout aircraft that can land on a mountainside in my career game (helicopters, especially with the restrictions placed on electrics here, do NOT count as high-speed), so I'm going to go take a look at the VTOL challenge...

Regards,

Northstar

[Darren9]

^ Yes Northstar, the blades tilt with Infernal Robotics, you just need the Rotatrons, you could try deleting all other parts from the pack (I also didn't update to the latest version, it's had issues with the toolbar from reading the thread).

And, unfortunately my "Kerbvinci Nuclear Electric Turbo Jet Copter" was the catalyst for some rule changes that made "Da-Vinci" pretty much totally out of range for a nuclear powered device. I have a tilting 8 blade design that can achieve around 220m/s (has a small amount of lift cleverly disguised as structural supports) so it's fast enough for a lap of Kerbin but getting to 400m/s at an altitude where the blades function at all is impossible even with FAR. How much thrust can you get from a thermal jet on air? I haven't tried that yet, I could realistically add up to 40T more of reactors and jets as an allowable base design modification.

[Northstar1989]

By the way- I know this particular thing isn't technically one of the challenge requirements; but I thought it might be interesting to see I actually found real, non-challenge uses for the HELO: B. Namely, attempting to deliver a launchpad to the mountains west of KSC (to save fuel on future rocket launches)

Sorry the images are so dark: this mission was performed somewhat after midnight in Kerbal (and real-life) time:

Too bad attempting to fly it without MechJeb's built-in altimeter functionality resulted in losing the payload by crashing it into the mountainside (TWICE- the panels from the bottom of the thing fell off in the first crash, and can be see in the background) when I couldn't see how far it was to the ground:

I'd install a plugin giving night vision view (like LAZOR)- but my computer is already overburdened with the # of mods I'm running...

Regards,

Northstar

[Northstar1989]

^ Yes Northstar, the blades tilt with Infernal Robotics, you just need the Rotatrons, you could try deleting all other parts from the pack (I also didn't update to the latest version, it's had issues with the toolbar from reading the thread).

And, unfortunately my "Kerbvinci Nuclear Electric Turbo Jet Copter" was the catalyst for some rule changes that made "Da-Vinci" pretty much totally out of range for a nuclear powered device. I have a tilting 8 blade design that can achieve around 220m/s (has a small amount of lift cleverly disguised as structural supports) so it's fast enough for a lap of Kerbin but getting to 400m/s at an altitude where the blades function at all is impossible even with FAR. How much thrust can you get from a thermal jet on air? I haven't tried that yet, I could realistically add up to 40T more of reactors and jets as an allowable base design modification.

Oh, if TTJ's are allowed, then its really no problem. Even a small amount of forward thrust that doesn't fall off with altitude like rotors do, near max altitude, would be more than enough to achieve 400 m/s- especially with a little bit of lift to help keep it aloft as well. For TTJ power and weight, though, it really varies a lot by the type of reactor you use...

The thermal turbojets have a velocity curve that really only starts falling off after about 800 m/s (that's about 95% of orbital velocity on Duna- falsely leading a player who used them on the Flying Duna Challenge to conclude that they have no velocity curve, getting ALL KSP-Interstellar put in a separate category as a result, similar to all nuclear craft here... This is even though theirs is in fact a significantly less generous velocity curve than stock turbojets), and hit a peak ISP at around 5000-6000 m.

Their maximum rated thrust of the jets is 300 kN- but you'll only ever achieve that with antimatter reactors (which it's difficult to obtain enough antimatter for to last more than a few minutes...) With the lowest-level standard fission reactors, they obtain about 35-45 kN with Uranium and 50-60 kN with Thorium. KSP-Interstellar just introduced a new reactor, however, which might be more powerful under certain operating conditions and with certain designs (you might have to keep the throttle down a bit, counter intuitively, to obtain maximum thrust- for instance...), and that is also a bit lighter.

The KSP-Interstellar reactors are based on real-world designs (or proposed designs) and operating statistics, adjusted a bit for KSP-scale, but the basic 1.25m Uranium reactors with a full nuclear fuel load weigh 2.5 tons (the Thermal Turbojets themselves an additional 0.4 tons)- with a 10% fuel load you can get it down to 1.6 tons of weight with Uranium. I don't know how much the upgraded reactors weigh. Thorium weighs a bit less, but uses the same basic or upgraded reactor, yet I don't know how much Thorium weighs on reduced fuel load (which I highly recommend- the default, full fuel load of a uranium reactor is enough to last around a game-year on idle or over 7 months on full power- though thorium burns through a good bit quicker). You can adjust reactor loading via tweakables, or using a plugin like TAC Fuel Balancer after launch.

Nice call using the Infernal Robotics part to rotate the rotors, by the way. Although, I'm curious though- did your rotors clip through the craft when you did that? Except for slightly-overlapping wing segments, I consider part-clipping anathema, and strongly avoid it at all costs- as I consider it to be "cheating". Even the HELO-B, if you look closely at a few of the close-up pics (I intentionally took some of the pictures to show this), doesn't have *ANY* part-clipping. I was particularly careful to make sure the rotors had clearance with everything in their path, including other rotors- if only a few centimeters' worth.

Regards,

Northstar

Edited February 4, 2014 by Northstar1989

[Darren9]

^ The blades don't touch anything as they spin (at any angle on the rotatron) - I always stick to that rule, the surface attach rules on the rotors base though would require additional spacers not to have slight clipping of the rotor base into the rotatron. I could of added some virtually weightless parts (62.5cm circular battery for instance) but then be left with joint strength issues and visible gaps opening up between parts at full throttle and closing again at idle.

It depends what I'm building and what parts, the rotors for example can't be mounted upside down and have thrust reversed but every other propeller/blade in Firespitter can. I did some bad clipping to have an "under/over" twin rotor (one above and one below a narrow wing that rotated on a rotatron, instead of a rotor stuck to a wing and another rotor stuck on top of the first rotor).

I haven't got around to trying the thermal jet yet, I needed the high core temp of anti-matter reactors to get useable thrust from the plasma thrusters but I was able to get a VTOL to orbit and Mun - it did have wings to help though.

[Northstar1989]

I haven't got around to trying the thermal jet yet, I needed the high core temp of anti-matter reactors to get useable thrust from the plasma thrusters but I was able to get a VTOL to orbit and Mun - it did have wings to help though.

Wait, Plasma Thrusters- where did you use those? I missed that somehow- all I saw were your rotor-based designs...

Plasma Thruster thrust isn't based on the core temperature of the reactor though. They don't even require reactors, technically. It's based on the availability of the electricity supply- the more electricity available to them, the higher their thrust (the fuel type determines their ISP). You can easily get insane amounts of thrust through a Beamed Microwave Power Receiver and a very large nuclear or dozens of *HUGE* solar power transmission stations. Theoretically, you could even strap a ton of solar panels to the thing and get a bit of thrust- though not much without an enormous mass of solar panels...

Regards,

Northstar

[Darren9]

^ I couldn't say I've fully appraised that mod, I initially only installed it to get more electric at a lower mass specifically for this challenge. I did lift off at KSP, go to orbit and onto Mun landing with just 3T of RCS fuel, 8 folding electric props and 4 small plasma's on a 1.25m anti-matter reactor. It would of been for the closely related VTOL challenge, if I'd finished it and if a plasma drive was considered equal to ion. It takes an amount of time to complete all the challenges though and I've already completed them all with various craft.

[dacamp66]

Got a k-mail from Jeb, said he found the perfect mood music for this topic on youtube:

Enjoy!

[Fengist]

All went smoothly, and I believe I now have every right to collect the Kolochenko Award- putting my one step closer to the Da Vinci...

The dropoff went without a hitch:

http://imgur.com/a/Hm7tg

And, on the return trip, I pushed the HELO:B, and by connection all wingless electric-rotor helicopters (seeing as it has an insanely high TWR) to its limits...

The landing went smoothly as well.

http://imgur.com/a/Ih60c

The observant among you might have noticed I included two pictures that examine the thrust of the electric rotors. Their base thrust is 80 kN, and 120 kN on full Cargo Throttle- like I had them in those screenshots. However, due to rotors having very velocity curves, their thrust tends to fall off very quickly when reaching high speeds- as is clearly demonstrated here, where the thrust is quite a bit greater at the *higher* altitude due to the somewhat lower craft velocity.

It's for this reason that circumnavigating Kerbin in 6 hours (requiring an AVERAGE speed of 175 m/s) is *absolutely impossible* for an electric helicopter without either including vertical wings in the design and tipping the craft over so it flies like a plane; or utilizing jet, thermal turbojet, rocket, or ion/plasmodynamic/ATILA engines (all essentially versions of the ion engine concept- listed in order of increasing thrust). The design doesn't have room for sufficiently large vertical wings (I tried finding a good place for them)- so I'm either going to have to spam a ton of small wing pieces (which have less lift relative to their mass), or get a rules change to allow some kind of non-propeller engine...

Perhaps an allowance could be made for use fission-powered thermal turbojets- which have rather anemic thrust, extremely high mass relative to that thrust (over 2 tons for about 40-60 kN, with a reduced nuclear fuel load, including the weight of both a reactor and a TTJ nozzle) and burn no fuel? (they rely on reactor heat instead) I already have a place for one on the back of the helicopter (the reactor is in the perfect position- I need only slap on a TTJ nozzle and an air intake- though the turbojet nozzle would compete with my electric generator for reactor output...) Their main (only) advantage for me over props would be their superior altitude and velocity curves (they behave similarly to stock turbojets in terms of ISP and thrust with speed and altitude), which would allow me to mount a nozzle (like I said, it would use the existing reactor) on the back of my helicopter, and perhaps some small horizontal winglets for control/stability and a bit of lift, and be able to probably hit speeds of about 200-250 m/s (enough to circumnavigate Kerbin in under 6 hours).

And, to repeat myself- if I added only 1 nozzle, it would simply be fully utilizing the existing reactor- passing air over it to make use of the leftover ThermalPower that the generator doesn't need... And no fuel would be consumed, in fact nothing would be consumed but spare reactor heat- so technically the rules allow it, if you read jets to mean the standard (fuel-burning jets) and gasses to mean what they were obviously targeted at: Xenon, and perhaps also ArgonGas and HydrogenGas resources in NearFuture mod and Argon in KSP-Interstellar...

I think it's fair enough that if I'm expected to circumnavigate the globe more than 3 times faster than the real-life world record holder did in a helicopter, I should at least be able to pass a little hot air over my reactor?

Otherwise, minus basically cheating and turning your helicopter into a VTOL propeller plane (adding vertical wings, and switching to a horizontal flight regimen after takeoff), there's no physically possible way to build a helicopter that can fly fast enough without massively spamming the smaller (and much higher-TWR) electric plane propellers as a a sort of smaller and more efficient helicopter rotor...

Regards,

Northstar

P.S. When I say MASSIVELY spamming, I mean *MASSIVELY*. My 'Hornet' design, which weighed in at just over 2 tons, and had a maximum TWR in excess of 10 with Cargo Throttle engaged, had 4 of them, and still couldn't sustain 175 m/s in level flight, only in a dive... The HELO:B weighs a bit over 30.5 tons- so you do the math...

Give the turbojets a shot. Let's see what you come up with.