Got some tips on designing rovers?

[TehUndeadMerc]

So I just managed to land my first successful Rover it worked well on kerbin, very stable and all. However once on Minmus (Skipped Mun because after 3 attempts the hilly terrain causes the rovers to blow up upon landing) I noticed that they are... Problematic.

They are slow to start moving, slow to stop, bounce all over, skid (a lot) and well they think they're fighter jets needing to perform an aileron roll (More commonly though erroneously known as a barrel roll)

Do you have any tips? Bellow is a 1.25 min video of said rover doing said things so you can help me with my design

http://www.youtube.com/watch?v=QACnC2v4baU&feature=youtu.be

(in case embed doesn't work http://www.youtube.com/watch?v=QACnC2v4baU&feature=youtu.be )

[DrMonte]

- too high center of mass;

- might be wider rover;

- lock steering of middle wheels;

- use capslock for slow steering;

- drive slow;

- use physic time warp to go fast;

drive safe

p.s.

In such design you could put all rover parts below deck. This way you would have low center of mass and plain deck for some cargo (or 20 kerbals )

Edited November 19, 2013 by DrMonte

[TehUndeadMerc]

Well if I put the solar panels under the rover they won't receive sunlight. Though I like the idea of a Kerbal Bus

[Tex_NL]

You are clearly controlling your rover in flight mode. Switch to docking mode or even better re-map your rover controls to something like IJKL .Doing so will control the wheels but not the SAS.

Edited November 19, 2013 by Tex_NL

[TehUndeadMerc]

Oh? I'll try that then thanks for the tip

[Starwhip]

I think it's all of the above, combined with the low gravity (If you call it gravity, it's so low it could be static electricity!) of Minmus. All rovers will slide around, as far as I know. I've launched several, and they always skid and move slowly.

[TehUndeadMerc]

Yeah I managed to get a kerbal in orbit around the sun from Minmus.... I do rescue him just to then run out of fuel and have a crew of three stranded....

[celem]

Some good tips here.

Will add that it's usually worth de-activating torque on the probe part you have fitted. Let the wheels do the work (or switch to dock mode).

Minmus is always a tricky one to drive on. You do seem a little slow to launch,this is probably over-power (over-torque from the wheels), as seen by the little wheelies you pop, I find shifting the CoM forward a little helps with the start. (while you only have 2 wheels actually in contact with the ground you obviously cant accelerate much, but doing so would be dangerous anyway as it increases the wheelie and can lead to flip-on-launch) Have to just keep tweaking the design to get them as responsive as possible. And remember that a design is usually tailored to a specific body (or more accurately it's gravity).

Some folks like to build very light rovers with a lot of drive power for low-gravity worlds, then add a downforce ion engine to keep it on the ground, not experimented with this myself

Edited November 19, 2013 by celem

[Panzerbeard]

I've never successfully built a minmus rover, the gravity is just too low; you might be better off making some sort of flying rescue craft/rover for it, it'll go through fuel quickly but it'll be much easier to use than a rover.

[Starwhip]

Actually, probes are sometimes more rewarding than rovers. I stuck one in an orbit around Minmus about 100 meters from the surface. Seeing mountains and boulders rushing by at over 100 m/s never gets old.

[capi3101]

Basic tips for rovers - build them wide, build them low, incorporate a reaction wheel somewhere into the design, drive around in docking mode (or remap your keys so that you use translational controls instead of rotational controls - which is what you're doing while in staging mode). Encase the critical hardware (command pod, batteries, etc.) in parts with high impact tolerance (e.g. structural panels and girders). If you need additional downforce, try ion thrusters or RCS (ion thrusters have the advantage that you can leave them on without constantly thrusting and they'll last longer, though the weight of the necessary equipment will be significant).

Obligatory, now dated screenshots of the Hellhound on Minmus:

[Xiphos]

Check out the post I made here. http://forum.kerbalspaceprogram.com/threads/54504-Turns-out-the-Mun-is-quite-large-or-getting-around-on-the-Mun-how?p=719634#post719634

The Rover doesn't use the new rover wheels (For Low-G, they cause too much problems). This is by far the best design I've come up with. Also, by the time the new update comes, we will have tweakable parts(steerable landing gear) so this model can be used then in higher G worlds with a better turning radius. The RCS turns it quite well on minimus. Also, the RCS helps control it while it's airborne. (It's easy to drive this thing really fast) PM me if you would like to try it I'll send you the craft file.

Edited November 19, 2013 by Xiphos

[Deadweasel]

One thing that can help abate roll-overs:

Disable steering on any rearward (beyond the mid-body) wheels. Turning too tight at speed will make it flip every time. Your turning radius will increase of course, but it will help keep the thing from going steamroller on you.

[Franklin]

Like everyone else has been saying: design them wide, and design them flat. And I recommend equipping a small set of RCS thrusters on the corners so if worst comes to worst you can RCS yourself back on all fours. I've used RCS as a reliable/constant downward-pushing force on some rovers to simulate stronger gravity.

But like some have noted, rovers can be finicky and teetery and I usually just make a super tiny probe and toss an ion unit or a block of RCS thrusters and use that to fly around. I'm far more inclined to deal with easy travel and attempt an awkward landing than a slow, sliding, rocky, anxious roadtrip.

[Tank Buddy]

Minmus has exceptionally low gravity, so you will get little to no traction. The most efficient way for wheeled transport on Minmus is with an Ion or RCS powered rover on Landing gear, like they did before rover wheels were introduced.

Also, add reaction wheels on your Minmus rovers so you have better control and can right a flipped rover.

Or you could just go to the Mun. There are plenty of flat spots. You will want a smaller rover for the Mun, without reaction wheels.

[700NitroXpress]

Another good thing to do is put some single direction RCS ports on the top of the rover. Also have RCS fuel. Then when the rover is on a planet with low gravity, push the translation control buttons, it should be I,K,H,N see which one makes the RCS fire. This will push the rover into the ground. You're essentially creating down-force on the tires. You could also get the same result with Ion engines although it may not work as well. When you push the wheels into the ground, you won't bounce as much and the tires will get better traction for turning, stopping, and going. Since Minmus gravity is so low, you could also get the rover back into orbit with vertical take off engines and refuel it once it runs out of RCS.

[TehUndeadMerc]

Well I do pretty much everything using Mechjeb since it's consistent and so allows me to pinpoint problems, though everytime I try landing on the mun using that it blows up my rover.

Also I land a lander with the rover attached, it's not an atmospheric drop, I've no idea how that'd work