They See Me Rolling: A Rover Discussion

[Pezzhippo]

Indeed! That is absolutely gargantuan! Was it merely a balloon-assisted launch (going by the potent envelopes I can see in the background), or was something more complicated involved? O:

Edit: Also Wayfare, the way you've angled your wheels on the smaller craft, how does that affect steering or handling?

Edited August 26, 2013 by Pezzhippo

[Wayfare]

Why didn't I think of that? This would have saved a lot of my rovers.

I wish I could take credit for that little stroke of genius but it was suggested to me as a workaround when I suggested adding a "disable brakes" toggle to the game. Works like a charm!

Wayfare, the way you've angled your wheels on the smaller craft, how does that affect steering or handling?

It works really well but you'll need to test out a few different angles to find the right one for your rover. I use 35 degrees (seven "clicks") off vertical. At some point, the angle becomes either too steep or too shallow and the rover will violently shake itself apart and explode.

The main benefit of those angled wheels is that they spread our your wheelbase a bit and lower the rover's center of gravity. Of course this comes at the cost of some ground clearance, but the small wheels (and the huge ones) have plenty of that for their size. This results in a much more stable ride. It does increase the turn radius a bit, but that too can prevent you from flipping the rover by turning too sharply at speed. I've noticed no problems with traction (other than the general traction problems that plague KSP) as long as the axles are horizontal.

I originally used the angled wheel trick on my old Mun Mammoth heavy rover:

Didn't prevent this though - there's only so much abuse any vehicle will take in low gravity:

[NGTOne]

How, in gods name did you get that into orbit around kerbin!

Lots of rockets. My payload to LKO was something like 2800 tons.

Indeed! That is absolutely gargantuan! Was it merely a balloon-assisted launch (going by the potent envelopes I can see in the background), or was something more complicated involved? O:

The balloons were only for landing - it was a conventional rocket launch. I didn't want to try a balloon-assisted launch, because it a) would throw off my ascent profile, and might have ended up tearing the whole thing apart (the whole package weighed around 16 thousand tons at liftoff, if memory serves), because it was decided to redistribute force upwards, not down. When you're building something this ridiculously big in KSP, real structural engineering principles apply - strut spam doesn't get you very far, because you end up connecting pieces that don't need it, and not connecting pieces that do, and by the time you're done, your vehicle is 20 thousand parts, 19 thousand of which are struts - rather counterproductive, in my personal opinion.

[shamelesspromotion]There's a whole thread for it here, with lots of pictures[/shamelesspromotion]

Edited August 27, 2013 by NGTOne

[DChurchill]

I generally use this rover for everything unmanned.

And this is the kerbalfied version:

[Kunschner]

My rovers tend to come out looking like dune buggies, with RCS to help with getting up and down slopes.

http://i.imgur.com/eAC6GQa.png/QUOTE]

CAN I HAZ CRAFT FILE!?

[Fiddlestyx]

You know what this thread is missing?

.craft files

[Boomerang]

This is the one rover design that I've had widespread success with and that I've been the happiest with from an aesthetic point of view. I've found that it works well just about anywhere. Having the battery, probe core, and RCS tanks below the structural plate/wheel mounts helps keep the center of gravity reasonably low. That, plus the torque from the probe core and RCS if needed, generally keeps it from flipping over at speed. And should it flip over, the RCS is strong enough to right it upon the Mun or any other body with similar/less gravity.

I used to be paranoid that with everything in the undercarriage like that, at least the battery would get knocked off on some bit of topography, but with plenty of time on Kerbin, Mun, Minmus, and Duna, as well as limited experience on Eve and the Joolian moons, that's never happened. Wheel mounts give plenty of clearance

As far as placement of the wheels, I used to have them anchored closer to the center line of the rover and further fore and aft. But I've found a slightly shorter but wider wheel base is more stable. And disabling the motors on the back wheels helps to moderate acceleration and some of the instability that occurs when you want to make a sharp turn shortly after getting under motion. I find that experimenting with disabling the steering and/or motors on either end of a rover that's already fairly stable can make it even more so.

And while it's not a terribly useful feature with this design, you can use the RCS docking controls to thrust in only one plane, which is nice for an extra boost of speed or slowing without locking up the breaks.

Might not be terribly useful for mining or refueling or moving Kerbals about, but I'm fond of it.

P.S. I used to have a third pair of wheels in the middle of the rover, but with something this small, that did nothing to improve speed or stability. Just upped the mass and electrical consumption.

Edited May 7, 2014 by Boomerang

[Sof]

The main point I would make regarding rovers is to remap the controls to a different set of keys if you want to use a capsule as a base or install an SAS unit. (you can always just disable torque now, but that isn't always what you want. Also make sure the SAS unit is pointed in the direction of travel)

The default controls for steering right or left are also the torque controls for rolling right or left. As kerbal kars are notoriously unstable at the best of times, actively rolling your vehicle when turning just guarantees you'll explode whenever you make sharp turns.

Also worth noting is that you'll often find you roll head over heels under heavy braking. Or even the opposite and you do a backflip when trying to accelerate up a hill. Disable the brakes for the front wheels and have the motors for them on a toggle. Disable the steering for the back wheels helps with control, although you won't turn as fast.

I remap the steering controls to the RCS translation controls (ijkl). This way, if I turn on the RCS whilst driving, it tends to helps me. "I" pushes the rover down keeping grip. "J" and "L" also push against the roll when turning left or right. This way also leaves enough room for 2 handed driving with the left hand on the rotation controls for a bit of extra stability when turning at high speed in low gravity.

[Othuyeg]

For low gravity bodies RCS is very very beneficial. You can flip your rovers, climb hills etc. with the aid of RCS.

[stevism]

i like rovers for roleplaying but tbh i think a good hopper is more fun

if you could set waypoints for rovers (combined with timewarp) it would be a really nice feature. yeah sure i know "well what if your rover can't go over the terrain" yeah but idk i hate sitting there and driving and driving only to realize i haven't really gone anywhere

bu that's just me...definitely not knocking on anyone that enjoys that.

[Duke23]

I agree with Stevism. I like rovers, but a lot of times they're just not practical if you're trying to hit a couple biomes. For my last Mun mission I built a rocket powered rover... Mostly because I'm still kinda low tech and didn't yet have powered wheels, but also because it's freaking fun. It can run along the surface at about 20m/s with no problems but if you really want to cover some distance just tip the nose up with SAS and roll on the throttle. It also solves those pesky crater problems where you just can't get up the lip of it. Just remember to set 'er down easy, ~40m/s surface speed and ~5-7m/s vertical is fine as long as you're braced for impact on a reasonably flat surface where you can feather out the brakes and not tip it over. I think it would be a blast to take one of these to Minmus. Hopefully I'll have the external seat by the time I get done scraping the Mun for science.

Edited May 8, 2014 by Duke23

[timsfitz]

For hunting easter eggs I've used this large rover several times. It's kinda slow, but the great thing is, there's a ship on top that can blast you back to orbit for the return trip after you plant your flag.

[katateochi]

I like building rovers, but they can be a bit annoying for not as much gain as a simple hopper. That being said, my main goal with rovers is speed and stability; a quest that has resulted in the loss of lives of many Kerbals!

One key thing is to have a wide wheel base to height ratio and to drive in docking mode (which I think is less hassle than rebinding keys). Another trick I recently found is to use both turn and tilt when cornering at speed. ie; hold both A and Q to turn left; the left tilt force from Q counter acts the rovers tendency to roll right when turning left. But in low gravity environments that can be too much force, so I have several SAS units that can be switched on/off to vary the power from the reaction wheels. Also for low grav environments I put a load of linear RCS ports that face straight up, in docking mode they can be triggered with Ctrl, and they help keep traction and prevent rolling.

I also put several facing forwards to act as brakes and in docking mode they fire when you hit S (reverse). But I disable the brake on the front wheels as they can make you to somersaults.

But in the end you have to accept that rovers will roll over. So I either put additional reaction wheels that can be switched on to give them enough force to get them back on their wheels, or use an infernal robotic system to right the rover. The other thing is to make them tough enough to withstand damage from rolling, some form of structural roll cage to protect the weaker parts.

This is one of my better recent rovers (still working on it thou). It can tumble down a hill and survive a 30-40ms crash without it loosing any parts and it can corner pretty well at 30-40ms.

This one has rear wheel steering which seems to be more stable than front wheel steering at speed. At low speeds I can switch the front steering on for making tight turns.

I've also recently started using Kethane power instead of solar panels or RTGs. This rover gets all its power from its kethane generator, which does mean I have to fuel it with kethane, but two small tanks lasts a pretty long time and it has the added bonus is that it kicks off exhaust smoke when its in motion (which I think is really cool).

[Remkeau]

I shamelessly took inspiration from Levelords bike design earlier in this thread to create this:

Enough torque to flip itself upright, (also used to bank into corners) and the sidewheels prevent damage when taking sharp corners.

I just can't get it to go faster than 25m/s in a straight line, is the 60 m/s advertised in the wheels description just theoretical?

[Sof]

I just can't get it to go faster than 25m/s in a straight line, is the 60 m/s advertised in the wheels description just theoretical?

The speed listed in the description is the surface velocity at which the wheels will explode and probably kill your Kerbals.

[Geschosskopf]

So, how would you folks go about designing rovers for these environments? For example, what kind of footprint do your rovers generally posses, how do you cope with various inclines or rough terrain, and how do you go about designing something for a given task, such as Kethane mining, or moving other objects over the surface of a given celestial body? Go nuts, be as detailed as you like, I most certainly look forward to your replies! c:

Weeeelllllll.........

To be honest, I have found only 1 practical use for rovers. That is being a being a Kethane drill/refiner in a situation where high efficiency is necessary. In such a case, you want a Kethane shuttle/lander that does nothing but haul raw Kethane from the surface to an orbital refinery, without it having to lift any hardware. So this thing lands somewhere in the Kethane deposit. Once it's down, the rover goes over to it, drills Kethane right there, and pumps it straight into the shuttle/lander. The rover also has a refinery to refuel the shuttle for the trip back up.

Such a Kethane drill/refinery rover can be pretty small. It only needs the small drills, the small refinery, and 1 each of the smallest tanks for Kethane, LFO, and mono. Plus the power to run the equipment and move itself, a box for KAS pipe parts, and a lawn chair for the Kerbal who's been condemned to pump gas on Vall for all eternity. There is no need for anything huge in this application because all the volume goes into the tanks on the shuttle/lander.

I also have a few impractical/unnecessary uses for rovers. I like to have a hearse to drive from the runway to the flagpole to plant a flag when I kill a Kerbal. I sometimes put 3.75m microwave reactor/generator units on wheels and move them more than 2.5km from KSC so as not to cause loading lag in the immediate KSC area. I sometimes like to build rocket-powered dragsters, and a bulldozer to clear the debris for the next run. And I have the dream of one day jumping the canyon on Dres .

But otherwise, I find rovers pretty much a waste of time, energy, and money. If you want to get around on the surface of a planet, it's almost always faster, safer, more practical, and more fun to fly (whether with wings or rockets) than to drive. The only place where driving is really superior to flying is Tylo.

[Blind Dead McJones]

Weeeelllllll.........

In such a case, you want a Kethane shuttle/lander that does nothing but haul raw Kethane from the surface to an orbital refinery, without it having to lift any hardware. So this thing lands somewhere in the Kethane deposit.

Really? I've heard that the efficiency between refining in orbit and refining on site is about the same. That's what Scott Manley decided, anyway.

On subject: My rovers have been so far:

Small, unmanned rovers which are usually the first thing I ever land on a planet. These are so I can see firsthand what the surface is like. Since I installed Kethane I've sent a few to find a good spot for a surface base.

I've made a few medium sized rovers for Kerbals to ride. I'm having a hard time making one that both works well and looks good, though.

Then I made this:

This is a gigantic rover that I put on the mun which holds eighteen Kerbals and is essentially a nomadic base. It's all stock, but I can't give the craft file because I accidentally deleted it. That's okay, though. It was horribly designed, really ugly, and had something like 268 parts in the VAB (over 400 for the rocket that got it to Mün). I wanna try to remake it, hopefully better, and I don't mind if someone else tries.

That thing was surprisingly sturdy. It never flipped over even if it reached 30 m/s (on Mün). It also killed my framerate. I've tried to make something smaller with fewer parts, but besides lag nothing has been as reliable as that.

Edited July 26, 2014 by Blind Dead McJones

[Kasuha]

Mun hopper (version 3) I finished today. It has everything (except science tools):

- rover wheels -> no limit on ground distance, also useful to pass the "last mile" after a hop

- nuclear power, lots of lights -> independent on daylight

- airplane gear for horizontal landing/liftoff and fast transport (powered by engine)

- main nuclear engine, allows reach orbit and land again three times without refueling (on Mun)

- VTOL engines at the bottom for easier liftoff or landing

- braking engines at the front

- all engines draw fuel evenly from all (five) tanks

- landing struts and landing lights at the back for vertical landing using main engine

- RCS system, docking port and docking lights for refueling (preferably in orbit, RCS is not strong enough to lift it on Mun)

- reasonably sturdy

- 3 seats, decent crash protection

- probe core for autonomous operation

- prepared as subassembly, attachable by docking port

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[Spartwo]

I have the one which I use for everything. There is a standard docking port on the top which allows for trailers as large as 2.5m and various landing setups and other augments.

All purpose landing stage testing.

[magnemoe]

Unmanned landers are always rovers unless inpractical like Eve and Laythe splashdown science probes or Jool atmospheric ones.

This is an typical design at Duna north pole, probe, 2 oscar tank and here a life belt tank , 48-7S, struts out to place the wheels, solar cells on top of struts.

If I require more dV like landing on Tylo I put an drop tank on top. Very lightweight design only downside is all the struts increase part count.

Small and medium rovers are used to move kerbals and science equipment around.

Laythe

Eve, both was to pick up data from splash down probes for ocean measurements.

A better view of the Eve rover, this was destructive testing as an mission extension after the kerbal had returned to orbit.

Landed on the highest point of Eve and traveled the mountain down to sea level to get the measurements.

The kas winch is to pull the splashdown probe into water if it landed on shore, it was a problem on Laythe.

And 0.22 mobile munar lab, it could be docked to lander and moved to new locations.

Not used larger rovers much, for kethane I prefer to use large landers for mining, convert to fuel on site and return to orbit and the ship who need fuel.

if you want reliable and fast rovers my advice is to cut weight as much as possible.

Rovers like the Laythe and Eve one was landed desperately, it simplify landers a lot.

[samstarman5]

They see me rollin' They hatin'

http://i.imgur.com/wQVAh6Z.jpg

Mad Max Kerman to keep the kerbal bandits at bay!

[Esme]

Despite having played for a few months, I've only successfully landed kerbals on Minmus and the Mun so far - and have only successfully returned them from Minmus - but then I'm in no hurry with this wonderful game. Anyway, my Minmus rovers (produced by the Bannister and Moore Engineering Works) so far have been based around a Mk1 cockpit, with a monopropellant tank behind that, followed by an FL-T400 fuel tank, and finally an inline reaction wheel. To this I add four undercarriage wheels , two almost as far back as they'll go without poking beyond the reaction wheel, and two as far forward as they'll go without poking beyond the monoprop tank. A fifth wheel is then added under the nose of the cockpit, with the light shining forwards (so that the three foremost wheels make a sort of tripod). Add small engines and thrusters plus other equipment to suit. Finally put one or two landing legs on the top back of the rover.

You land this like you would a normal lander - onto the landing leg or legs - but then you simply pitch the nose down and get it onto its wheels. Most of my rovers have also had ladder rungs added to the monoprop tank, too. then, when the rover stops, retract the undercarriage, and when your Kerbonaut EVA's, they can simply climb back on top of the rover and back into the cockpit - handy until you get the hang of the jetpacks. Because I haven't got around to learning how to use action groups yet, every time I halt a rover for some exploration and retract the undercarriage, it gives the whole thing something of the appearance of a dog lying down. So much so that I have named the ones currently in use at my Minmus base 'Rover', 'Spot', 'Fido' and the extended twin-cockpit version (has a Mk2 cockpit at the rear, but still only 5 wheels) 'Cerberus'. Then when they are boarded and the pilot deploys the undercarriage, it looks like a dog standing up raising it's tail eager to be off..

On the flat icy Mare of Minmus, this design works very well, and once you have set the rover in motion at over about 2m/s-1, it will continue without further use of fuel until it hits something or encounters a slope. I sometimes set one going at 10ms-1 (about 36kph) and leave it whilst I do something else for a bit as it traverses the ice. Of course, if you use it on uneven terrain, and particularly when ascending or descending slopes or mountain sides, you need to be at the controls all the time, but it WILL happily cope with such terrain, provided you don't go too fast. And if you can't be bothered with that amount of driving? Point your Rover in the direction that you want to go, and tell it to 'sit' (retract the rear two undercarriage wheels), then just use its rocket engine(s) to put it into a sub-orbital hop, landing on its tail (landing leg(s)) exactly as you landed it on Minmus in the first place. If you have sufficient parachutes in place, this Rover can easily make it back to Kerbin, provided it is sufficiently fuelled, too.

My original designs lacked the nosewheel, but did have a slight tendency to nose over on rough terrain. I have tried a three-wheeled design, as per the five-wheel design but with the paired forward wheels removed. This works fine on the flat, but unsurprisingly isn't so good on undulating terrain. The reaction wheel should not be kept on constantly whilst gliding over the surface, as it will, within a few minutes, tend to cause the nose to lift and the back wheels to dig in, and you will slow down.

Also, I discovered that one should never ever create a twin cockpit rover/ship with the cockpits facing in opposite directions (because the reaction wheels in the cockpits will be fighting each other). I did this once, and whilst I did manage to land the rover, it was so troublesome to handle both in space and on the ground that I sent a rescue ship to bring the crew home in. :-}

Edited May 9, 2014 by Esme
correction of typos

[firegeek83]

Also, I discovered that one should never ever create a twin cockpit rover/ship with the cockpits facing in opposite directions (because the reaction wheels in the cockpits will be fighting each other). I did this once, and whilst I did manage to land the rover, it was so troublesome to handle both in space and on the ground that I sent a rescue ship to bring the crew home in. :-}

Had no problem with that here on the Mun (total trip mileage @ 37km+)

[HafCoJoe]

Watch my KSP stream "Flight of the Gekko" for a Kerbin super fast heavy rover. 100+ m/s and mountain climbing xD. The real key is "tons" of weight, landing gear, jets, and a wide wheel base.

[Esme]

Firegeek, I did say 'cockpit' Those command chairs don't have reaction wheels built in. You try putting a Mk1 cockpit on one end and a Mk2 cockpit on the other end facing in the opposite direction of a 10-ton ship/rover. 'Awkward' isn't even close.. :-}