How do I... make a rover- any rover- that won't FLIP

[Tassyr]

So, the title. I want to make a simple rover, that can support at least one (possibly more) kerbals. Catch is, I can't seem to do it without making some sort of deathtrap that sends them into the stratosphere the second it hits something bigger than a BB, or I try to turn. As in, at all. Help?

[Kimberly]

Tip: in the lower-left corner, select "docking mode" instead of staging mode. The controls will now turn the rover, instead of pitching it.

That aside, you want to have a very low center of mass to maintain stability, and you want the wheels far away from the center mass. So try to keep your rover flat and the wheels low.

[Tassyr]

I've tried docking mode- and I've tried spreading the wheels out. Is there a guide somewhere, perhaps...?

[stupid_chris]

not going 80km/h usually helps with the previous guidelines.

[Skorpychan]

Currently, I have a couple of Hitchhiker storage containers held together with a 6-way connector in the middle, and with four of the ruggedised wheels per can, on the big cubic girders.

Disabling the motors on the rearmost pair of wheels, and the steering on the rear container completely makes the whole thing quite stable, until the brakes are used.

Also, it uses a LOT of rocket to get to the Mun, a very carefully built skycrane to land it, and about a week of learning and redesign to get it mounted to a rocket and out there.

[Tassyr]

not going 80km/h usually helps with the previous guidelines.

try 8m/s. That's slow enough to get a ticket for obstructing traffic! And it still flips like it's trying to catapult kerbals. XD

Edited July 25, 2013 by Tassyr

[AnalogAddict]

Have you tried disabling the rear wheel's steering ability? That might assist you in "not-flipping", also having a low CoM will help your stabililty

[WhiteWeasel]

What wheels do you use?

[Flixxbeatz]

Widen the base. And try not to make it very tall.

[capi3101]

Include a SA......what's this "Inline Reaction Wheel" crap? That's a mouthful...

No, seriously. Put a Reaction Wheel on your rover and make sure it's on when you drive. You can make it the core piece of your design; slap some of the large structural panels on the bottom for impact protection. You can then use modular girder segments to build out the rest of your chassis - a stable rover will have a long wheelbase (distance between the front and back wheels) and a long axle track (you want this to be not quite as long as the wheelbase, but out there a bit). When you're out driving, lock the steering on the back wheels, turn SAS on and switch over to the docking controls (or remap the controls for rover steering, whichever floats your boat). Should be able to get up to the maximum speed of the wheels on level grade without flipping.

I'd also recommend structural panels or a modular girder adapter on top of your rover. Again, that's for impact protection; structural panels and modular girder segments have an impact tolerance of 80 m/s, which is beyond the speed you're going to be able to travel with any set of stock wheels. Makes a skycrane drop a lot safer too. That way if the rover does roll over, it's still intact - and then the trick becomes righting it again. I usually include two or three 24-77s pointed upwards with toroidal fuel tanks for this purpose. Be careful where you put them, though; they're no good to you if they're the first thing that breaks off when your rover flips.

I know of one guy who added ion engines to his rover design to provide downward force. Actually worked, though that's got its own can of worms.

Good luck; let us know how it turns out.

[WhiteWeasel]

If you're using these wheels, they have a lot of torque and will flip lighter rovers when turning. Don't use them for anything light.

[troyn123]

I've had really good experiences with my latest rover design... I was using the TR-2L Ruggedized Vehicular Wheel (WhiteWeasel's picture), since they have a lot of torque and really good traction (they start and stop really well)... BUT that also means no drift at all when turning at higher speeds, so easier to flip.

The RoveMax Model 1 on a low and wide vehicle seems to work really well. I added some RCS to mine so I can flip it back over if necessary, put the tanks really low, the power comes from two PB-NUKs on top of a battery that's also low and center, and a small docking port so I can easily stick it to a lander for delivery. And it carries two Kerbals or drives remotely!

I lock the steering on the rear wheels when driving fast, and unlock when I need precision steering (bind "toggle steering" to an action group). When on a planet(oid) with low gravity, I remove the front wheels from the "Brake" action group, so less likely to do a front-flip when hitting the parking brake at speed too. All in all, it works really well, and driven in docking mode, even better.

*edit: The navball is 90 degrees off in the picture as it was built in the VAB. If you right click and "control from here" on either of the command chairs, that fixes it.

Edited July 25, 2013 by troyn123