Mission idea: Kerbal Dakar 2017

[DrunkenKerbalnaut]

Shhh....! I just finished(tm) my tuning run on the FrogStomp. Your giving me ideas.  

 

 

Sigh...  I guess I'll be in blender making some BFG All-Terrains. If I'm gonna do it, I'm doing it right. What's a good size for a Dakar Jeep? 31x12.50?

 

EDIT: I blame myself, really:

http://www.bfgoodrichracing.com/desert-racing-bfgoodrich-baja-ta-15/

Edited December 21, 2016 by DrunkenKerbalnaut

[Azimech]

17 minutes ago, regex said:

It's kind of a point of pride for me, but it also serves two purposes:

1. Reduce electrical load so I have more running time during the day. Also reduced mass enough for a fifth solar panel. Since I have drivers there's no need for a probe core anyway.

2. Learn me how to tune in KSP. Friction settings have already been useful and I think softening the suspension will prevent the bounce that flipped the car.

Absolutely, I'm guessing a lot of people use damper and spring settings that are way too high for the mass of the vehicle.

Strong dampers prevent fast suspension travel, this may cause broken wheels after jumps or when driving over 1.2's terrain seams. Too weak dampers produce excessive body roll and pitching like a boat, constantly shifting the CoM and thus pressure on one or more tires. Unreliable roadholding and braking is what follows.

Spring settings: I usually set them so they're able to absorb most of the energy but able to hit the bump stops. The rest of the energy is then transmitted to the chassis, making it flex a little. A good measure is if the vehicle slightly has a tendency to rest somewhere at 4/5 or 3/4 of the total suspension travel.

Talking about chassis, that's the reason I don't use autostruts or normal struts with them, I'd rather have a bit of flexing bodywork than a breaking one. And of course when an impact is strong enough your chassis will deform just like in real life, past that threshold even struts don't help.

[mrmcp1]

I have had a go at creating an electric entry during the testing I found out the the alt+w to keep the car accelerating also works for whatever key is bound to accelerator so alt+i works for me

This means that for those using SAS you can keep in on and continue driving without having to press the same key for a few hours

Also the brakes and reverse overide this action and alt+x means the car will no longer accelerate

Hopefully someone will find this useful 

EDIT- put this in the wrong thread, sorry

Edited December 21, 2016 by mrmcp1
wrong thread

[DrunkenKerbalnaut]

Just now, mrmcp1 said:

I have had a go at creating an electric entry during the testing I found out the the alt+w to keep the car accelerating also works for whatever key is bound to accelerator so alt+i works for me

This means that for those using SAS you can keep in on and continue driving without having to press the same key for a few hours

Also the brakes and reverse overide this action and alt+x means the car will no longer accelerate

Hopefully someone will find this useful 

To add to this, some strange things can happen/be taken advantage of if your Kerbals seat is tilted back a few degrees   

[mrmcp1]

Just now, DrunkenKerbalnaut said:

To add to this, some strange things can happen/be taken advantage of if your Kerbals seat is tilted back a few degrees   

Hadn't thought of that 

My SAS is manly used to help with my self righting device 

[DrunkenKerbalnaut]

5 minutes ago, mrmcp1 said:

Hadn't thought of that 

My SAS is manly used to help with my self righting device 

My current design doesn't use the seat tilt, but one of my cage ones does. It opens strange options for cruise control, one of which allows you to set the ground-track angle when airborne, if you are targeting something that is -effectively- infinity meters away. Like a stage flag, at least until your right up on it. 

EDIT: I stopped using that particular feature, as it's really only helpful in the stages where start and finish are at near 0 degrees apart, elevation-wise, which is pretty much stage 1. And it can play havoc with stages that change elevation drastically, which is all except for maybe 1, 4, and 5, depending on how you approach them. 

Edited December 21, 2016 by DrunkenKerbalnaut

[Majorjim!]

4 hours ago, DrunkenKerbalnaut said:

Is "the way" a trade secret, @Azimech? I, too, would like to kick my SAS dependency.  Or are we just talking about a general stoicism?

LOL no. Elec cars just do not require SAS.

[DrunkenKerbalnaut]

Just now, Majorjim! said:

LOL no. Elec cars just do not require SAS.

Mine is electric. Unless you mean solar. I use a LF/Air generator. Or maybe you mean speed-wise? It's just as fast (slow?) as a battery-juiced rover. Or maybe you mean more like my driving technique must be weak. I'll give you that  .

[Majorjim!]

Just now, DrunkenKerbalnaut said:

Mine is electric. Unless you mean solar. I use a LF/Air generator. Or maybe you mean speed-wise? It's just as fast (slow?) as a battery-juiced rover. Or maybe you mean more like my driving technique must be weak. I'll give you that  .

Yeah the speed of them is usually too low to require SAS to hold the road, so to speak.

[DrunkenKerbalnaut]

I'll be posting a test video soon, to make sure I've got everything setup for Jan 1. I look forward to any critiques the competition has to offer! 

[Azimech]

1 hour ago, DrunkenKerbalnaut said:

To add to this, some strange things can happen/be taken advantage of if your Kerbals seat is tilted back a few degrees   

That's so 1970's! Creates back problems.

[regex]

8 hours ago, Azimech said:

.And of course when an impact is strong enough your chassis will deform just like in real life, past that threshold even struts don't help.

This surprised me on my second run, my car is basically a sand rail with an H-frame and four struts to hold everything more or less together. I caught terrain on two instances; after the first the car developed a noticeable pull to the right (no wheel damage) and after the second (which wrecked the car) the chassis was broken at the crossbar, one of the I-Beams was floating off the central cubic strut. Pretty cool to see that damage modeled rather than having parts "poof" away.

I'm now of a mind to build a support vehicle with some KAS or DMagic struts (and solar panels, because that's usually what breaks first during those sorts of crashes) so I can fix that kind of thing.

[mrmcp1]

3 minutes ago, regex said:

This surprised me on my second run, my car is basically a sand rail with an H-frame and four struts to hold everything more or less together. I caught terrain on two instances; after the first the car developed a noticeable pull to the right (no wheel damage) and after the second (which wrecked the car) the chassis was broken at the crossbar, one of the I-Beams was floating off the central cubic strut. Pretty cool to see that damage modeled rather than having parts "poof" away.

I'm now of a mind to build a support vehicle with some KAS or DMagic struts (and solar panels, because that's usually what breaks first during those sorts of crashes) so I can fix that kind of thing.

I find it can be a good idea to build into the rover sacrificial parts i.e. I would put a small part (like a cubic octagonal strut) so that it rests on top of the solar panel meaning that if you do roll over this part is destroyed but leaves the solar panel intact 

[regex]

 

5 minutes ago, mrmcp1 said:

I find it can be a good idea to build into the rover sacrificial parts i.e. I would put a small part (like a cubic octagonal strut) so that it rests on top of the solar panel meaning that if you do roll over this part is destroyed but leaves the solar panel intact 

I would prefer to not roll over at all but that's a good idea.

[katateochi]

Race side tickets are starting to sell out! 

(the things on the side detach and then can drive to the rover and lie flat so the rover can drive over the docking port and connect for refuelling).

 

So on the talk about SAS and rovers. In RL when jumping a vehicle it's v important to keep the revs up while airborne because the rotation of the engine acts as a gyroscope and will keep the vehicle from pitching down hard. Very important with front heavy things like pickup trucks. The spinning wheels also add some roll and yaw stability.  So real vehicles do have some SAS which is not modeled in KSP (or most games actually). 

I use SAS on my rovers but I drive in docking-linear mode (with a minor key setting adjustments) and set most of the SAS modules to pilot only. In docking-linear mode SAS doesn't respond to WASD input for pitch/yaw but does respond to Q/E input for roll so it can be used to right the rover after a roll but in regular driving the pilot-only modules won't be doing anything. I then have a couple SAS modules in normal mode which keep it from going crazy when jumping (provides the missing gyro forces that the engine and wheels would give).  

Leaving the RL and going Kebal, you can also just hit space and switch to docking-rotation mode and then WASD will control pitch/yaw and I'll admit I do use that off some jumps to adjust angle while airborne so it lands evenly. (I also just learnt something yesterday; if you double tap space when in docking mode it switches to "hold" mode, so rather than space acting to toggle between linear and rotation mode, it will only be in rotation mode while you are holding space and then reverts to linear mode when you let go. Can't get my brain to adjust to using it like that though!).

 

  

 

[regex]

4 minutes ago, katateochi said:

Look at you, hacker.

[Azimech]

12 minutes ago, katateochi said:

Race side tickets are starting to sell out! 

(the things on the side detach and then can drive to the rover and lie flat so the rover can drive over the docking port and connect for refuelling).

 

So on the talk about SAS and rovers. In RL when jumping a vehicle it's v important to keep the revs up while airborne because the rotation of the engine acts as a gyroscope and will keep the vehicle from pitching down hard. Very important with front heavy things like pickup trucks. The spinning wheels also add some roll and yaw stability.  So real vehicles do have some SAS which is not modeled in KSP (or most games actually). 

I use SAS on my rovers but I drive in docking-linear mode (with a minor key setting adjustments) and set most of the SAS modules to pilot only. In docking-linear mode SAS doesn't respond to WASD input for pitch/yaw but does respond to Q/E input for roll so it can be used to right the rover after a roll but in regular driving the pilot-only modules won't be doing anything. I then have a couple SAS modules in normal mode which keep it from going crazy when jumping (provides the missing gyro forces that the engine and wheels would give).  

Leaving the RL and going Kebal, you can also just hit space and switch to docking-rotation mode and then WASD will control pitch/yaw and I'll admit I do use that off some jumps to adjust angle while airborne so it lands evenly. (I also just learnt something yesterday; if you double tap space when in docking mode it switches to "hold" mode, so rather than space acting to toggle between linear and rotation mode, it will only be in rotation mode while you are holding space and then reverts to linear mode when you let go. Can't get my brain to adjust to using it like that though!).

 

  

 

A: What a terrific contarption! I'm just not so sure I'd want TriOptimum as sponsor.

B: What you said about the engine acting as a gyroscope is a very good insight but I believe partially true, it depends on the engine being mounted transversely or longitudinally. Engines produce torque while running and it depends if they are accelerating, maintaining speed or decelerating. It also depends on engine rotation. With a transverse mounted engine it could mean you need to decelerate or accelerate during a jump. And we all know the effect of someone blipping an old V8 in a muscle car, the whole body rolls.

[DrunkenKerbalnaut]

1 minute ago, Azimech said:

A: What a terrific contarption! I'm just not so sure I'd want TriOptimum as sponsor.

B: What you said about the engine acting as a gyroscope is a very good insight but I believe partially true, it depends on the engine being mounted transversely or longitudinally. Engines produce torque while running and it depends if they are accelerating, maintaining speed or decelerating. It also depends on engine rotation. With a transverse mounted engine it could mean you need to decelerate or accelerate during a jump. And we all know the effect of someone blipping an old V8 in a muscle car, the whole body rolls.

The pitch control effect comes from the rotating mass of the wheels and axles. Much more rotating mass there than in the motor. 

[katateochi]

39 minutes ago, Azimech said:

What a terrific contarption! I'm just not so sure I'd want TriOptimum as sponsor.

Thanks! but yeah good point....now where's my Weyland Yutani flag got to  Actually my whole space program flies under the flag of TriOptimum now, got plans for a big luxury cruise liner in the pipes....

44 minutes ago, Azimech said:

B: What you said about the engine acting as a gyroscope is a very good insight but I believe partially true, it depends on the engine being mounted transversely or longitudinally. Engines produce torque while running and it depends if they are accelerating, maintaining speed or decelerating. It also depends on engine rotation. With a transverse mounted engine it could mean you need to decelerate or accelerate during a jump. And we all know the effect of someone blipping an old V8 in a muscle car, the whole body rolls.

hmmm interesting point about how it's mounted. Keeping the revs up when jumping was something that I was taught by a guy who used to race quads back in the day when I used to derp around with quads and a pickup truck and it made a big difference. So both those would be longitudinally mounted engines. 

[DrunkenKerbalnaut]

For those using Junos, consider Nerteas VTOL jet (packaged with MkIV plane mod):

Spoiler

It's boost-flap compliant, but will start to burn your flaps when they are closed. I was able to static test one at 11.9kn for more than 30 seconds closed, heat meter hit 2/3. So very viable. Just scale it down a bit to meet Juno weight and you get a couple hundred ISP for free. Surface attachable. 

[Triop]

19 hours ago, Azimech said:

Some more greeble for the barren mountainside.

 

 

I love these side creations you guys are making, I'd like the idea that people can use them making the scene more interesting.

So I've opened this thread:

Hope you guys will upload your stuff there so we can decorate our tracks.

 

 

[Azimech]

13 hours ago, Triop said:

 

I love these side creations you guys are making, I'd like the idea that people can use them making the scene more interesting.

So I've opened this thread:

Hope you guys will upload your stuff there so we can decorate our tracks.

 

 

 

Seems that topic isn't steaming yet ... and I feel very comfortable with this one :-P

[Majorjim!]

22 hours ago, regex said:

This surprised me on my second run, my car is basically a sand rail with an H-frame and four struts to hold everything more or less together. I caught terrain on two instances; after the first the car developed a noticeable pull to the right (no wheel damage) and after the second (which wrecked the car) the chassis was broken at the crossbar, one of the I-Beams was floating off the central cubic strut. Pretty cool to see that damage modeled rather than having parts "poof" away.

I'm now of a mind to build a support vehicle with some KAS or DMagic struts (and solar panels, because that's usually what breaks first during those sorts of crashes) so I can fix that kind of thing.

It was discovered that time warping fixes those little offset node issues after a prang.

[Azimech]

Just now, Majorjim! said:

It was discovered that time warping fixes those little offset node issues after a prang.

Not always :-)

[liveinaboxkerbal]

I'm not to late to join the party am I? I've binge read about half the pages in this topic, and decided I have to try. It will be fun designing and testing a rover, and then trying to complete this course when I've never made a working rover before.

Any tips?