Small rovers, and not capsizing them...

[capi3101]

I'd honestly rather not irradiate the crew, tbh.

Why not? If you get the Kerbals glowing bright enough, you wouldn't have to put any headlights on the rover......

[Lazro]

But in all reality, RTGs don't emit significant radiation-if it did, they would have never included one on the Apollo LM.

[Skorpychan]

I'm sure a structural panel will make sufficient shielding, though. Have to see if things settle into the rocket well, though.

While I'm at it, anyone got a similar design for one of the small Rockomax fuel tanks used as a base?

I'm tempted to just turn the entire damned lander into a rover.

[capi3101]

Built one of the RTG-powered OKTO-2 core SAS-chassis rovers last night with the ruggedized wheels. Put a quad of Z-100 battery packs on the SAS and the lights on the cubic struts, put my "self-righting system (SRS)" - a toroidal fuel tank on the bottom with two 24-77s aimed upwards - on the bottom of the SAS, slapped a big strutural panel on top and one on the bottom, stuck four chairs on top of the dorsal structural panel and took it out for a test flip. SAS on, had to get it up past 20 m/s before it would flip. Even then, it was still useable; aside from the seats breaking off. SRS righted it and off I flipped again. Had to stop when the SRS ran out of fuel...

Tweaked it a little to include a roll cage; put a modular girder adapter in the center of the dorsal panel and connected it to struts on the panel's four corners. It let me put a ladder on the rover, which in that permutation was the only thing that broke off when I flipped it.

I need to get on imgur so I can show this stuff to y'all...

I don't see why you couldn't use an X200-8 as the chassis. Same general principle; you could still add the SAS for stability, even. You'd probably want eight PB-NUKs so you'd have mounting points for more wheels, I'd imagine.

Something else to try out...

[UtopiaV1]

I love threads like this, great for new rover ideas! I'm rubbish at building rovers, always unstable or too heavy, but the ones posted here are fantastic! And mostly automated as well, so no need to strand anymore Kerbals on other worlds now! Just wish I could play KSP at work...

[capi3101]

Been reading up on rollover accidents. Apparently the U.S. government says a vehicle is relatively safe if it merely slides (i.e. two wheels don't leave the ground) when the vehicle is being fish-hooked (rapidly turned left-to-right-to-left etc.) at 50 mph (22.35 m/s). Wikipedia says "Generally, the higher the center of mass, the narrower the axle track, the more sensitive the steering, and the higher the speed, the more likely a vehicle is to roll over." So in KSP, the way you make a rover more stable is to keep the center of mass low, increase the distance between the tires, and lock the steering on at least one set of wheels.

Occurs to me that an X200-8 tank weighs 4.5 tonnes on its own...

Looking that stuff up has given me some other ideas to try out...trying to emulate a sway bar, for one thing. Seat belts for another (thinking a small lander leg might work; yes I know it's not the Kerbal way, I'm just thinking about how I might do something like that).

Also been thinking about how I might improve the roll cage design. Apparently I made an awesome choice with the Modular Girder Adapter...has an impact tolerance of 80 m/s. I'm looking at replacing the struts with I-beams; same reason - higher impact tolerance.

[Skorpychan]

I love threads like this, great for new rover ideas! I'm rubbish at building rovers, always unstable or too heavy, but the ones posted here are fantastic! And mostly automated as well, so no need to strand anymore Kerbals on other worlds now! Just wish I could play KSP at work...

You're welcome. I'm just trying to get input on what's stymieing me, and get my brain working on how to fix it.

I'm SERIOUSLY tempted to start nailing wheels to my landers now I've started dropping hab units on the mun, though. My aim needs improvement, since the first two are 70km apart.

Adding wheels WOULD make the whole affair more viable, but runs the risk of them sliding down a hill and overturning and exploding. Like my rovers have done.

What I really want is to have a nice big stable land-train that I can assemble on the ground to move kerbs about in complete safety. I can't manage to land anything more than about 5 tons on the surface yet, but that should be a couple of hab units with wheels on.

I'd probably have to find a way around my ubiquitous ASAS units, though.

[MBobrik]

SAS on, had to get it up past 20 m/s before it would flip.

Just tried the nuclear version on Moho.Drove downhill, jumped over ridges, landed, jumped, landed, jumped... all the way to 60m/s downhill, at which point the rover landed after the next jump so hard that the kerbals fell off. But the rover still didn't flip and stopped after a few hundred meters safely.

.

[Skorpychan]

Interesting. How do you get things to go out at the right angle?

I tried adding wheels to a couple of hitchhiker containers connected with a 6-way core. It needs more stability. Horrible habit of exploding when it flips.

Also, most of my issues are lack of brake authority. Are RCS brakes viable, at all?

[Ketsa]

My first thought when faced with the problem : reversible rover.

http://www.youtube.com/watch?v=If9f3XkF-jI

might not be the right solution

[Skorpychan]

My first thought when faced with the problem : reversible rover.

http://www.youtube.com/watch?v=If9f3XkF-jI

might not be the right solution

I considered that, but the containers are big and round. Maybe I can get away with anti-flip wheels on outriggers, though.

[capi3101]

SAS-core design again, I tried locking the steering on the back wheels. That's pretty much all I could do at that point to make it rollover safe but it worked: even at 20 m/s, it wouldn't flip over. Took it out to the shoreline to get a few extra m/s from the slope to the water; still wouldn't flip (though driving it into the water proved to be a bad idea).

Did the first manned run near KSC over the weekend. With SAS and docking controls on and the back wheel steering locked, the only way I could get it to flip was to slam on the brakes and put it in reverse. Ejected two Kerbals and broke off the SRS; none of the Kerbals died, but obviously my roll cage design isn't foolproof. And when I tried adding lander legs for use as safety restraints, I found they were likely to be the part that broke off first when the rover rolled. Still trying to figure out what I might try next. Don't know if a restraint system is necessary at this point, though; the rover itself seems stable.

Of course, I haven't gotten it up to sixty on Moho, either......

My next problem: figuring out how I'm going to get it deployed anywhere. The obvious attachment point (the top of the Modular Girder Adapter) has part of a ladder sticking through it, and so far I haven't been able to get anything else to attach to the node. Might have to resort to part clipping.

Occurs to me I might try attaching something to the underside panel...

Tried out the X200-8 design; had a tendency to blow up on rollover. Of course, fuel tanks have a very low impact tolerance in general, so that might be why. Rollovers also had a tendency to break at least one of the wheels. At least, I think it was the rollovers doing that; it could've just as easily been the weight of the tank.

[Skorpychan]

I finally got my big base-rover onto a rocket, beefed up the lift stage, and set off for the mun.

Didn't have enough deltaV on the descent stage for the weight, so I had to dump the rover to save the kerbals in the lander can.

Next attempt will be a robot descent stage with twice the number of engines, about 3 tons less mass, using the descent stage as a disposable skycrane, and saving the last of the Mun transfer stage's fuel for final braking. I hope to hell this works; I don't know how else to land that much weight.

I used XL girders for the axles, and that seemed to work okay. Only really dangerous on braking or >20m/s turns, but it's not going to be allowed to go fast at all.

FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF

FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF

FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF

It fracking got there. Onto the surface. It moved, albeit a little scary with the pitches. Skycrane gone with the last skotch of fuel. AND THEN MY GAME LOCKED UP.

Edited July 15, 2013 by Skorpychan

[capi3101]

That sucks about as much as my computer spontaneously shutting down when I'm five meters away from docking....

[Skorpychan]

I finally got it down in one piece. Sort of. Half the wheels broke, and the skycrane was going to come crashing down on top of it.

I think I need to send another couple up, maybe with a bit more fuel on the crane.

EDIT:

Some brainstorming later. Two of the big radials instead of eight small ones. More thrust, less drag, but more weight. Bigger tank on the upper stage, with some separatrons to make sure there's some oomph there to get out the way of the rover. Maybe some ON the rover for final braking of the thing, but that'd be problematic, and risk it accelerating up with the descent stage.

Some extra boosters on the lifter stage to move the extra fuel up, too. Long Small tanks with bi-coupled engines under.

And see about giving the rover a bit of a diet.

Edited July 15, 2013 by Skorpychan