Some rover questions.

[Fenris]

I guess the first question is, are small rovers even possible on Minmus? I remember trying years ago and would just end up with a rover launching itself on every small bump, or gaining zero traction and going nowhere because of the reduced gravity. And yeah I know hopping to different biomes on Minmus would be much faster, I just felt like playing with rovers. So I made this one I'm thinking about taking there.

So as you can see, I tried to make it wide and low to the ground to be more stable on a low gravity body, but still not sure if it is worth a try. I suppose if Minmus is out, I could try the Mun.

And the second question (not really rover related), once I suck the science up into the Experimental Storage Unit is it then possible to dock and transfer the science through the Clamp O-Tron to a return vessel with another Experimental Science Unit?

[DeadJohn]

49 minutes ago, Fenris said:

are small rovers even possible on Minmus?

Yes, but as you already found out they are likely to leap after small bumps. Workarounds include roll cages so you don't break parts if you flip, upside down pistons or landing gear to get back on your wheels after a flip, emergency RCS to maintain control during leaps. Or just drive carefully but that's less fun

50 minutes ago, Fenris said:

And the second question (not really rover related), once I suck the science up into the Experimental Storage Unit is it then possible to dock and transfer the science through the Clamp O-Tron to a return vessel with another Experimental Science Unit?

Yes. After you've docked, right-click the desired Experiment Storage Unit and pick "Collect All".

An alternate way to do that is EVA construction mode. An engineer can move a Unit from one ship to another with no docking required. Make a new save file before doing that and make sure the science is still held within after moving the part, though, because construction mode can be glitchy.

[Zacspace]

As someone who builds a lot of rovers, I usually send landers and dropships with high RCS thrust when I want to move things around the surface of a place like Minmus, Rovers are obviously doable, but the low gravity means that your performance is severely limited, probably beyond the point that they'd be any fun to drive. At least I don't find it fun, you do you.

Related to that, some combination of the third person view, the low detail terrain, and the fact that your speedometer reads out in m/s makes KSP rovers seem like they're quite a lot slower than they actually are, so it's extra painful when you hit a bump at only 15m/s (54km/h , 33mph) and get flung into the nonexistent stratosphere.

[Fenris]

Thanks for the answers. I think I'll skip rovers on Minmus and stick to higher G bodies for rovers. I did test it out later by using the hack gravity cheat and getting the gravity as close to Minmus as I could ..... and well it was no fun

[king of nowhere]

7 hours ago, Fenris said:

I guess the first question is, are small rovers even possible on Minmus? I remember trying years ago and would just end up with a rover launching itself on every small bump, or gaining zero traction and going nowhere because of the reduced gravity. And yeah I know hopping to different biomes on Minmus would be much faster, I just felt like playing with rovers. So I made this one I'm thinking about taking there.

So as you can see, I tried to make it wide and low to the ground to be more stable on a low gravity body, but still not sure if it is worth a try. I suppose if Minmus is out, I could try the Mun.

And the second question (not really rover related), once I suck the science up into the Experimental Storage Unit is it then possible to dock and transfer the science through the Clamp O-Tron to a return vessel with another Experimental Science Unit?

the best way is to have reaction wheels on your rover, that can be toggled on and off by pressing 1.

when you drive, you keep reaction wheels deactivated, else they will capsize your rover.

when you stumble, you quickly activate them, and use them to fall on your feet.

if you look at the Bolt mission linked in my signature, where I did drive a rover on every planet, you will find tips. I did drive a rover with success even on gilly, which has a much lower gravity even than minmus. but i was limited to 2 m/s top speed.

[miklkit]

Rovers on Minmus?  Not a problem.  In 1.12, right click on the rover and select "friction" and turn it up until the rover is controllable.  They turned down the friction to help with roll overs and now they slide around too much.  Also, at least for me, if you leave the rovers there they will explode.   I had to build carports to protect them.

[Snark]

Moving to Gameplay Questions.

On 6/10/2022 at 10:44 PM, Fenris said:

I guess the first question is, are small rovers even possible on Minmus?

Sure, they work just fine.  It's just a different experience from driving on a body with higher gravity, is all.

On 6/10/2022 at 10:44 PM, Fenris said:

I remember trying years ago and would just end up with a rover launching itself on every small bump, or gaining zero traction and going nowhere because of the reduced gravity.

Launching from bumps, absolutely, yes... but how is that a problem?  It'll come back down soon enough, it's not as though you're going at orbital speeds.  In the meantime, wheeeee! 

Slipping and sliding can be an issue, sure, but that just means you need to be patient for it to get going.  (Minmus has some pretty steep slopes, so those can be an issue if you don't have enough traction to stop from sliding downhill faster-and-faster.  When I'm roving on Minmus, I generally avoid the steeper slopes, or else put some RCS thrusters on for assistance in case of need.)

On 6/10/2022 at 10:44 PM, Fenris said:

So as you can see, I tried to make it wide and low to the ground to be more stable on a low gravity body

Stability's not much of an issue-- just make sure you've got a reaction wheel on there (which I see that you do).  Reaction wheels are super effective on Minmus, precisely because the gravity is so low-- they can muscle the rover around to any orientation you want, and with SAS activated, they absolutely prevent any flipping over.  (And even if you did somehow flip over, they could flip you right back again.)

On 6/10/2022 at 11:45 PM, DeadJohn said:

Workarounds include roll cages so you don't break parts if you flip, upside down pistons or landing gear to get back on your wheels after a flip

Just put a reaction wheel on the rover and flipping's not a thing.  Rock solid stable.

On 6/11/2022 at 6:12 AM, king of nowhere said:

when you drive, you keep reaction wheels deactivated, else they will capsize your rover.

Hm?  I would say precisely the opposite:  always keep them running, so that you cannot possibly capsize.  If they're off, then you'll rapidly flip if you hit the smallest bump, which requires quick reaction to turn them on before you clobber yourself upside-down on terrain.  Just leave them on all the time so you're always stable.

 

[king of nowhere]

46 minutes ago, Snark said:

Hm?  I would say precisely the opposite:  always keep them running, so that you cannot possibly capsize.  If they're off, then you'll rapidly flip if you hit the smallest bump, which requires quick reaction to turn them on before you clobber yourself upside-down on terrain.  Just leave them on all the time so you're always stable.

 

that is also possible, leaving the reaction wheel setting on SAS only.*

however, I don't like it, because a reaction wheel set to SAS only will not correct roll. You are fine for small bumps, but you take a hard bump and you are now landing on your roof, and the reaction wheels are still making sure your rover is pointing prograde, so they won't fix it, and you can't give commands to reaction wheels, and you crash.

I much prefer to have the reaction wheels be activated/deactivated by a quick command. If I flip, I activate the wheels and turn the rover upright. The key thing about driving in low gravity is that it takes a very long time to fall, and so you can recover at leisure. In fact, moderate gravity worlds  (duna-sized) are far more difficult to drive on, because the gravity is still low enough that you flip easily, but it's also strong enough that you will crash down before you have time to recover. For those situations, I recommend either a combination of stronger reaction wheels and reflexes, or some kind of roller cage or protection against crashes, or driving more carefully.

 

* Note: I am assuming here that one uses the default commands, where the commands for the rover wheels are the same as for the reaction wheels, and so telling your rover to move forward will also tell it to point the nose downwards. if one changes commands so that they use different keys one is also fine, but I am just too used to the wasd keys. And I find quickly pressing 1 with my little finger (EDIT: after actually paying attention to the movement, it seems I am pressing  with my ring finger instead) to be much easier than having four separate keys to control for the reaction wheels.

Edited June 14, 2022 by king of nowhere

[Snark]

7 minutes ago, king of nowhere said:

that is also possible, leaving the reaction wheel setting on SAS only.*

No, I leave them on standard mode, otherwise I can't use them to help with things like yaw-steering and it makes the rover difficult to steer.

8 minutes ago, king of nowhere said:

however, I don't like it, because a reaction wheel set to SAS only will not correct roll. You are fine for small bumps, but you take a hard bump and you are now landing on your roof, and the reaction wheels are still making sure your rover is pointing prograde, so they won't fix it, and you can't give commands to reaction wheels, and you crash.

No no, don't set SAS to hold , just set it to hold orientation (i.e. the default mode).  That way it basically can't roll.  Even the hardest bump will only knock it slightly off-kilter, which you can easily correct by hitting the roll key a bit.

 

9 minutes ago, king of nowhere said:

* Note: I am assuming here that one uses the default commands, where the commands for the rover wheels are the same as for the reaction wheels, and so telling your rover to move forward will also tell it to point the nose downwards.

Well, yes, but leaving those as the default commands makes steering rovers practically impossible by having the reaction wheels do counterintuitive and unhelpful things every time you need to steer. 

Absolutely remap the rover controls to something else, otherwise all is confusion and madness.    I like to use the numpad keys, myself, since they're not otherwise used for anything else.

[Zacspace]

1 hour ago, king of nowhere said:

that is also possible, leaving the reaction wheel setting on SAS only.*

I think what you're asking for is effectively this:

1 hour ago, Snark said:

Absolutely remap the rover controls to something else, otherwise all is confusion and madness.    I like to use the numpad keys, myself, since they're not otherwise used for anything else.

Which I gotta agree with in a big way. I personally use the arrow keys for rovers, but regardless having strong SAS on your rover becomes much more useful when you can control it independently from steering. It also lets accelerate without doing a front flip or losing rear wheel traction

Makes driving a two-handed experience, but realistically your other hand was hovering over f9 anyway.

Oh! and while I'm at it, I'm going to advocate for putting landing thrusters on your rovers. Makes it way easier to survive high jumps and falls. They don't need enough dV to actually land from orbit, just enough to get control in the air and land softly.

Edited June 14, 2022 by Zacspace

[king of nowhere]

2 hours ago, Snark said:

Absolutely remap the rover controls to something else, otherwise all is confusion and madness.    I like to use the numpad keys, myself, since they're not otherwise used for anything else.

 

55 minutes ago, Zacspace said:

Which I gotta agree with in a big way.

Makes driving a two-handed experience, but realistically your other hand was hovering over f9 anyway.

I see where you're coming from, but using my two hands to do different things at once is not for me.

And I assure you, it drives very easily anyway. As I said, I did drive rovers very extensively, on every single stock body (except eve, where i used planes) and my latest rovers had all been designed to be driven with reaction wheels, and I just find the single-handed drive to be the most comfortable for me. At most, I use the second hand on the mouse to press the brake button on top of the screen when needed.

From my perspective it is "confusion and madness" to drive with two hands, but to everyone its own.

P.S.

Quote

No no, don't set SAS to hold , just set it to hold orientation (i.e. the default mode).  That way it basically can't roll.  Even the hardest bump will only knock it slightly off-kilter, which you can easily correct by hitting the roll key a bit.

this comment make me thing you don't have so much driving experience on hard terrains at high speed. Because I can guarantee you, with SAS on you still roll, you can get a lot off-kilter, you will start tumbling; if you don't, then you're not going fast. when going downhill I don't need to tell the rover to go forward, and I generally tell it to hold prograde. it's more efficient than me at high speed. I only control roll and braking.

Edited June 14, 2022 by king of nowhere

[Snark]

1 hour ago, king of nowhere said:

this comment make me thing you don't have so much driving experience on hard terrains at high speed.

Well, as high a speed as I can make it go in a really low-g environment like Minmus (which is what we're talking about here)-- traction's somewhat limited.  With a good strong reaction wheel set to hold orientation, tumbling basically isn't a thing, at all; doesn't matter how hard you hit it, the rotation stops almost instantly as soon as the rover is out of physical contact with the obstacle. 

This can leave the rover in a somewhat off-kilter attitude (for example, leading back on the rear wheels, or leaning left and driving just on the left wheels)... but that doesn't hurt it right away, as it can drive along just fine indefinitely at that attitude.  So at my leisure I just pitch or roll it back to flat again.

(Plus, any high-speed jolt that's strong enough to push it seriously out of true will launch it off the surface with some serious hang-time, on Minmus, which gives plenty of time to reorient it a bit if I need to.)

Here's another example of using strong reaction wheels for a rover.  This unicycle works fine in Dres gravity (substantially stronger than Minmus) at pretty high speed (as high as that motorized wheel will go, anyway).

https://imgur.com/a/cptXT
(The ion drive is just there for purposes of interplanetary flight, capture, and landing.  Once landed, the vehicle gets along fine on the surface without it.)

Another option, I suppose, for someone who wanted true "keep it right-side up" stability, would be to mount a probe core on the rover that's pointing up, set "control from here" to that, and then set SAS to hold .  With the navball in surface mode, this means pointing straight towards the zenith, regardless of the rover's motion.  That would auto-correct for both roll and pitch.  (It would also have the side effect of making the navball basically useless for navigation, which is why I generally don't use this mechanism myself, but tastes vary and I mention it just in case someone else might find it more appealing than I do.) 

[Zacspace]

26 minutes ago, king of nowhere said:

And I assure you, it drives very easily anyway.

I'm definitely not trying to offend or tell you what you're doing is wrong. I'm just trying to leave some extra rover wisdom in the rover questions thread for passers by. I meant my "you" to be more the royal you than you specifically but that's just poor communication on my part.

I also appear to have overstated the degree to which having separate controls requires two hands. It mostly just lets the player leave SAS on all the time while driving normally. For me it solved the problem of tipping while accelerating or driving up steep hills on low gravity planets like the Mun. I guess you solve that by turning the reaction wheels off, but I find it helpful to have them help me keep my rover pointed true while I'm sliding around trying to find grip. I also have at least one useful rover that just can't be driven on a lot of planets with the controls bound together because it'll just flip over forward.

[dci]

Reaction wheels can be tuned in some ways. One of them is their reaction to WSAD keys. If you switch RW mode to "SAS only", it will not react to WSAD, but keeps orientation. "Pilot only" mode turns off torque and acts like SAS is off. Third option is "Normal" and, yes, RW is acting as you know.

When I build a rover for low gravity environments, I always use RW with AG1 to turn it on/off and RCS AG (if not RCS attched) to cycle through RW modes. If you go weeeeee, simply cycle through modes to normal and turn SAS on, you will be able to control rover orientation. If you stick to the ground, let RW be on, just switch to "SAS only" mode.

[18Watt]

As someone who has completed the Elcano challenge on every stock celestial body, I feel somewhat qualified to weigh in on which SAS mode works well.

First, use whatever mode is most convenient for you.  There are a lot of ways to address the problem.

Personally, I activate SAS in normal mode, locked to pro-grade.  I remap the rover controls so that the rover controls don’t also activate the reaction wheels.   I re-map the rover controls to the translation controls- HWIJKL, which I normally don’t need while rovering.  Works well for me.  I’ve used the other methods described, they also work well, but for me I find remapping the rover controls is the most effective.

One advantage to having prograde locked is that when you take a nasty tumble, your rover will at least automatically point itself prograde.  Then all you need to correct is roll, and possibly pitch if you end up on a high-arc trajectory.

I also ended up connecting a pair of old PlayStation 2 controllers to my computer, and also use them for rover controls.  In that case, I do the same thing- lock SAS to prograde, and have the rover controls mapped to different buttons or joysticks than the attitude controls.  For long drives, it was definitely worth the work of figuring out how to connect PS 2 joysticks..

[Snark]

4 hours ago, 18Watt said:

As someone who has completed the Elcano challenge on every stock celestial body, I feel somewhat qualified

A friendly PSA for anyone who's relatively new to the forums and isn't aware of the context of the Elcano challenge, the above quote perhaps qualifies for "understatement of the year".

By which I mean: I would advise listening to this person, they know what they're talking about. Completing that challenge is basically the definition of "have done all the roving that there is to be done", and involves several orders of magnitude more roving than most KSP players ever do.

[18Watt]

1 hour ago, Snark said:

Completing that challenge is basically the definition of "have done all the roving that there is to be done", and involves several orders of magnitude more roving than most KSP players ever do.

Well, thank you for the kind words!

Just guessing, but I think if you looked at players who have completed say 3 or more Elcano runs, you’ll find a pretty good mix of ways to control rovers.

I do think a lot of players eventually gravitate to the method I prefer- using SAS and remapping the rover controls.  But I know several players still prefer something similar to what @king of nowhere described- only turning on SAS when needed.  I’ve seen some other interesting approaches as well.  It all boils down to what works for you.

I would emphasize that if you plan on rovering for considerable distances, it would be worth at least trying a few methods out, to see what method works best- for you.

I have also seen a player do an Elcano run with no reaction wheels and no RCS.  That was a bold move..

On 6/10/2022 at 9:44 PM, Fenris said:

I guess the first question is, are small rovers even possible on Minmus? I remember trying years ago and would just end up with a rover launching itself on every small bump, or gaining zero traction and going nowhere because of the reduced gravity.

Honestly, the size of the rover isn’t going to make much difference.  Doesn’t matter if it’s a big rover or a small rover, if they both hit a bump at the same speed, they will both get bounced airborne for the same distance, regardless of mass.  

 

On 6/10/2022 at 9:44 PM, Fenris said:

And yeah I know hopping to different biomes on Minmus would be much faster,

But rovering is much more fun!