Xeldrak

What did you do in KSP today?

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No pics on this one, but while on lunch today, I flipped a rover upside down for the 988th time. This time, instead of disaster and a revert, for the first time I flipped it back over upright with the robotic arm mounted on the roof.

O.M.G. I already love Breaking Ground.

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Posted (edited)

I finally have it back... a working Duna VTOL SSTO... and this time it is made of stock parts only.

On final approach:

i60X9Ge.png

Landing configuration:

1Nl5jfX.png

Touchdown!!!:

TX45b5l.png

...and retro-configuration for deorbiting, without turning the plane around:

omCGSNE.png

 

Thank you @SQUAD, for all these new options and possibilities. I especially like the way, one can control single robotic parts in multiple ways, using more than one controller.

Edited by Frank_G

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@Frank_G That´s a very nice looking lander you got there.  I´ve got a payload for you:

sSDxPmW.png

Curiosity Rover with fully functional rocker-bogie suspension. And it can climb stuff :o. Suspension also works with normal wheels now. Aaaawesome!

Has anybody figured out what damping on the rotation servos does?

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I think damping does what it says on the box, adds... damping to the rotation. 

Man this rotary wing craft are different than airplanes. I tried to make a conventional single-rotor helicopter but I failed either at engineering or at piloting, either way it was borderline uncontrollable. I suspect though that until someone figures out how to implement cyclic control they're going to be fundamentally unsatisfactory.

I've made a lot of progress with contrarotating twin rotors however. My basic testbench is by now pretty manageable, and I made an experiment with the big motors which made it very manageable... for a very short time, until it ran out of battery. Currently working on figuring out the best mix/setup of reaction wheels; at least at this point trying to make a fully aerodynamically controlled chopper is way beyond my abilities.

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3 hours ago, Shadowmage said:

.... Waiting for someone to make a full collective pitch helo using the new robotic parts.

Could someone sequence/construct a swashplate using the servo axis controls?   https://en.wikipedia.org/wiki/Swashplate_(aeronautics)

Likely that there is a simpler method though for CCPM, considering all of the functions available in KSP with reaction wheels/etc.

No need... there is a very simple way.  Make your rotor/s from control surfaces, then enable pitch and roll controls, disable yaw.  KSP just figures it out.

So far I've found one really simple way to make coaxial helos - surface attach one rotor above the CoM.  Then rather than node-attach a second counter-rotating one, surface attach it as well and gizmo it coaxial with the first.  Sorta cheaty, but it avoids the various problems of motor-on-motor.

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Today I did an experiment with throttling back during launch and got an unexpected result. I used this simple setup:

 

Stayputnik

1.25m fairing

3x FL-T440 fuel tanks

Reliant engine

 

The fairing was shaped to a simple cone about as long as one of the fuel tanks.

 

The first run I throttled back and held at 300-350 m/sec, avoiding supersonic shock waves, and throttled up as soon as possible. The trajectory peaked halfway to the Mun.

Second run, I throttled back when flames appeared. Trajectory peaked well past Minmus.

Third run I went full Kerbal, max throttle all the way. I wound up escaping Kerbin and orbiting the Sun.

 

So it looks like the idea of throttling back to avoid wasting fuel fighting aerodynamics is completely wrong! If you can fly without exploding, go max throttle for max results.

 

Anyone want to try to replicate this?

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2 minutes ago, fourfa said:

No need... there is a very simple way.  Make your rotor/s from control surfaces, then enable pitch and roll controls, disable yaw.  KSP just figures it out.

 So far I've found one really simple way to make coaxial helos - surface attach one rotor above the CoM.  Then rather than node-attach a second counter-rotating one, surface attach it as well and gizmo it coaxial with the first.  Sorta cheaty, but it avoids the various problems of motor-on-motor.

Really? I'll have to try that. That should help a lot with controllability. That sounds more like cyclic than collective though -- collective can't be automatically figured out as it controls how much lift the rotor produces. I did implement it with servos and it works really well. Didn't try it with automatic pitch and roll though.

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3 minutes ago, Brikoleur said:

I think damping does what it says on the box, adds... damping to the rotation. 

Thanks for the reply mate. You´re probably right, I just haven´t observed any effect yet.

 I haven´t tried helicopters today. Just wanted to say helicopters are rockhard. It will take some time till we learn how to build and control them sufficently. Don´t worry, you´ll get there :)

Currently I´m slowly figuring out how to use KAL 1000 with very simple tasks. Not easy, but it´s robotics, it´s not supposed to be.

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2 minutes ago, Brikoleur said:

Really? I'll have to try that. That should help a lot with controllability. That sounds more like cyclic than collective though -- collective can't be automatically figured out as it controls how much lift the rotor produces. I did implement it with servos and it works really well. Didn't try it with automatic pitch and roll though.

Oops yeah, pitch and roll is cyclic.  I'm doing collective with servos set to rotate between 0 and ~20 deg (it's important to limit this so you don't accidentally increase pitch into stall - then control gets real hairy!).  The servos are also tricky - do not autostrut across them, and I haven't figured out why node-attaching things is sometimes weird.

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Posted (edited)

I spent a lot of time making a sidewheeler paddle boat (most of which was figuring out how to control the rotary motors) that went exactly NOWHERE once in the water because apparently water only pushes against your ship, but your ship can't push against the water.

f9kGjlr.jpg

With the paddlewheels turning at a slightly faster-than-realistic 70rpm, max speed was MAYBE 0.1m/s, which could well have just been residual momentum from rolling down the hill.  Increasing the paddle RPM to the max of 460 got the thing up to 0.7m/s, reduced the game to a 0.001 fps state, and ultimately crashed it.

So, paddlewheel boats don't work... yet

Edited by Geschosskopf

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Umm, I may have....umm....killed Valentina.

She rode our shiny new quadcopter, courtesy of Breaking Ground, up to about 5km before the batteries died (got plenty of lift after tweaking the blades, but those new motors eat up charge fast). She ejected on the way down, and deployed her parachute....

Then the pilotless screaming, whirring mass of blades caught some wind and changed direction, barreling down behind her and ripping her parachute to shreds before a rotor blade, still spinning pretty fast on inertia, caught her helmet and just *flicked* her toward the ground at 100m/s.

Poof.

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1 hour ago, Opus_723 said:

Umm, I may have....umm....killed Valentina.

A more glorious death than the last time BARIS killed her in my game :D

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From yesterday, posted in one of the breaking ground specific threads:

qVJjDmD.png

9UcqOuT.png

6 hours ago, fourfa said:

No need... there is a very simple way.  Make your rotor/s from control surfaces, then enable pitch and roll controls, disable yaw.  KSP just figures it out.

So far I've found one really simple way to make coaxial helos - surface attach one rotor above the CoM.  Then rather than node-attach a second counter-rotating one, surface attach it as well and gizmo it coaxial with the first.  Sorta cheaty, but it avoids the various problems of motor-on-motor.

My solution is for 1 set of blades to be mounted to the top of the rotor, and another set mounted to the bottom (or in this case, an I beam attached to the bottom). Then I put the smallest rotor size underneath that, and set it to spin freely (not motorized), preventing torque from going to the body of the craft. The two blade sets spin opposite directions, and torque cancels out.

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Posted (edited)
8 hours ago, KerrMü said:

@Frank_G That´s a very nice looking lander you got there.  I´ve got a payload for you:

sSDxPmW.png

Curiosity Rover with fully functional rocker-bogie suspension. And it can climb stuff :o. Suspension also works with normal wheels now. Aaaawesome!

Has anybody figured out what damping on the rotation servos does?

Thank you very much! A cool rover - like this specimen here - is next on the agenda :) - I havent found out what damping is, but my guess is, that its the time they need to decelerate, when you cut the power.

Edit: and wow... it took me a while to notice, that those wheels are actually stock parts... incredible cool work!

Edited by Frank_G

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Posted (edited)

So summary of my findings of last night's into-the-small-hours helicopter research.

  • The most promising layout from a handling PoV is Kamov-50 style stacked contra-rotating rotors. A conventional main + tail rotor setup should be doable but my first attempts were almost uncontrollable. I did manage to take off and land but mostly just lurched around in the interim. 
  • The simplest motor for a Ka-50 dual rotor involves a bit of gizmoing. I made a module of it by taking an I-beam, surface attaching two motors to it, then sliding them into place. 
  • Once I figured out how servos work (and when they have problems), using them to make a collective control was easy and works really well. It needs tuning. I've been experimenting with a range of +/- 15 to 25 degrees.
  • SAS does not play well with rotors. At least on my small experimental craft, it introduces uncomfortable judders. On the other hand it flies kind of nicely on all manual control.
  • As a bonus, I've solved airline carbon emissions, just stick a couple of solar panels on an electric-powered propeller airplane and only fly in the daytime, voilà, zero emissions. Can't believe nobody's thought of this before. 

Current challenges:

  • Much tuning is needed regarding rotor diameter and number of blades. The BAK-50 improved a lot when I lengthened them. I've been using 3-blade rotors with the medium motors. I made one experiment with the large motors and 6-blade rotors, and it flew really nicely for a very short while until the batteries ran out. I will experiment with even larger 2-blade ones, I suspect lower RPMs are good.
  • Roll control is hard. Enabling pitch and roll on my rotor blades gives me more of it but only with SAS engaged; with it off my chopper really doesn't like to roll but does like go into a tilt and I don't know why.
  • I'm still working on the optimal set of reaction wheels for control of rotorcraft. How many and where do you put them?

Edit @KerrMü that is an awesome rover, now I want to make one too, all we need is some really rough terrain for it to climb over...

Edited by Brikoleur

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8 hours ago, Ron Devu said:

So it looks like the idea of throttling back to avoid wasting fuel fighting aerodynamics is completely wrong! If you can fly without exploding, go max throttle for max results.

Anyone want to try to replicate this?

I think someone did some testing on this a while back. The upshot was that gravity losses outweigh drag losses by a large margin, so you should go for maximum throttle (subject to aero forces and not killing the crew) and adjust pitch over rather than throttling back.

Maybe I'll get my launch simulator going again and have a look.

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1 minute ago, Flibble said:

I think someone did some testing on this a while back. The upshot was that gravity losses outweigh drag losses by a large margin, so you should go for maximum throttle (subject to aero forces and not killing the crew) and adjust pitch over rather than throttling back.

Maybe I'll get my launch simulator going again and have a look.

Thanks for the reply, I think I'll take that as a confirmation. I figure this is part of the reason Scott Manley does so much with so little rocket, the other part is (I think) he knows how to set up the classic elliptical transfer orbit so the transfer is exactly tangent at both ends. If I'm not mistaken, being ten degrees off at the destination end can add 1500-2000 m/sec to your insertion burn. (Kerbin to Duna transfer).

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Posted (edited)
8 hours ago, Geschosskopf said:

I spent a lot of time making a sidewheeler paddle boat (most of which was figuring out how to control the rotary motors) that went exactly NOWHERE once in the water because apparently water only pushes against your ship, but your ship can't push against the water.

f9kGjlr.jpg

With the paddlewheels turning at a slightly faster-than-realistic 70rpm, max speed was MAYBE 0.1m/s, which could well have just been residual momentum from rolling down the hill.  Increasing the paddle RPM to the max of 460 got the thing up to 0.7m/s, reduced the game to a 0.001 fps state, and ultimately crashed it.

So, paddlewheel boats don't work... yet

Oh yeah?  With a blistering top speed of 2/s, MY boat will dust you in a race.    :sticktongue:    (I think a race between 2 mobility scooters would actually be more exciting.)

G23OocN.png

 

 

Edited by Klapaucius

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5 minutes ago, Klapaucius said:

Oh yeah?  With a blistering top speed of 2/s, MY boat will dust you in a race.    :sticktongue:    (I think a race between 2 mobility scooters would actually be more exciting.)

 

 

Is it possible that the program is calculating the thrust for these boats as if the propellers were in air and not water? If so, those props need to go a LOT faster.

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2 minutes ago, Ron Devu said:

 

 

Is it possible that the program is calculating the thrust for these boats as if the propellers were in air and not water? If so, those props need to go a LOT faster.

Not sure, but I also tried a sub and got it to a blistering 4.  To be honest, I cannot get my airplane to taxi faster than 25 m/s with twin props set to full rpm.  So far, I am not having much luck.

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So last night I installed Breaking Ground ... ... ... Then spent the next hour trying to work out why none of my rovers worked any more! :0.0:

 

At the end of the day "Have you tried turning it off and on again" seemed to solve the problem; and I now have Minmas covered with 8 different designs of mining rover in various experiments. 

This frees me up to try my mission I've been planning for weeks and diverting a *Huge* asteroid. I wonder if 24 Nervas will have enough thrust to actually perform the capture in time :-)

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All right, I think I've got the BAK-50 series tamed. Rotor tuning discovered that slightly larger four-bladers work best. I also remapped the controls for easier flying -- now I/K controls collective much like W/S controls pitch, which is more intuitive. I also mapped the engine power/clutch to the Lights group so you can see if it's on or not -- now landing is much easier as you can simply switch off the engine and once touched down, brake the rotors to a stop (I tuned that too so that it's not too abrupt). And I added some solar panels for unlimited (daytime) endurance. I also added a control for collective pitch limit for more athletic flying.

I very much like it now and I think I'll move on to something different. Maybe a bigger version.

Updated craft is here: https://kerbalx.com/Brikoleur/BAK-50-x2

Anybody figured out yet how the custom axis groups work? What do you do to activate custom axis group 01 for example?

Pic related:

jaWVGIP.png

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y4mgL-xb_w7vLRGTYiG1WeeI5F6Akj0DmX1f8rGt

I made a small chopper drone with robotic arm, the small electric motors are enough to make it fly. Now I have to learn to land it gently...

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Today I came back to KSP after a break of a few weeks, and you all know why I've returned... :D

Very basic design but it was a nice test of the new rotation parts.

eixxEZq.png

0IXErWn.png

I love this update!!

 

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