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Rover Tips


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So I've been working on some Rover missions, and I'm having real trouble with designing an easily drivable manned rover. Does such a thing exist?

Basically, my designs drive (mostly) fine on Kerbin, but once I get them on the lower Mun gravity they become unstable death traps. Get them up to speed and the slightest bump will send it careening off with parts flying in every direction. My most recent design I tried to give a very wide, bottom heavy design, and while it does drive better, it is still only a matter of time before I send it into a death-bounce.

In particular I'm looking to design a manned vehicle that deorbits, drives around, and then re-enters orbit from wherever it happens to be.

Any tips for building big rovers that either don't easily flip, or can survive flips intact? I tried youtubing, but I didn't find much of any help.

Here's a pic of my most recent attempt, the Iktomi I:

szdhm.png

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One thing that really helped me was installing a reaction wheel module. Anytime it looked like I was going to be airborne or flip, I'd just turn on the SAS. Survived some very hairy launches down slopes at 40m/s+ on Moho. Well, except for the last one... Anyway, they really help.

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What the previous two posters said, and also just drive carefully. Blazing along at 20 m/s may not seem too fast, but when you realize that it is 72 km/h (45mph for you Liberians, Myanmarians, and Americans), or highway speeds. I wouldn't be surprised if I flipped my car while attempting to some maneuvers in KSP at those speeds.

For low-gravity worlds, drive slowly. However, for ultra-low gravity worlds (like Minmus), you might want to make a super low-riding rover which is packed full of RCS and has many linear thrusters on top. I haven't had the chance to try one out yet, but theoretically whenever you want more traction you could simply blast downwards using the RCS.

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For low gravity worlds you could also remap your rover keys so they don't overlap with attitude controls(as normally pressing W makes your rover pick up speed but also try to backflip, similar with every other wsadqe key). Either that, or turn SAS on after landing and then switch to docking mode; that way SAS will keep you straight and you still can drive around. This way can make turning a bit harder on really low gravity ground, but in case you bump into something and go flying, you will still land on wheels, not side or back.

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Survive flips intact? well, below are example of "flips proof"..

http://www./view/x9cbaigb736jcv3/004-Ultimate_Rover_F.craft

And Fort...put more strut..

http://www./view/ws9bwxa3i9bm1pb/004-Ultimate_Rover_J.craft

And if you are looking for anomalies at Mun, you better change from Rover to something such as rocket type VTOL shuttle craft.

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Design: Have a wide wheel base. A long one would be good too, but as long as the width is the greater of the two in size. Low center of gravity. The lower the better. Use high impact tollerant parts as a makeshift rollcage if you must, the cubic struts help with that, so do radial air intakes.

Driving: Switch to docking mode when driving. Sudden turns are discouraged. Be aware of the speed at which your tires pop. DO NOT BRAKE SUDDENLY! This will cause you to frontflip. Gradually tap the brakes until you slow down enough to where that isn't an issue.

Also. when driving downhill, ride the brakes. Your rover will require constant attention.

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Thanks for all these tips guys! I'll fiddle around with my next design, and hopefully I can use some of your driving tips with my current rover on Mun. I like the idea to drive in docking mode and/or remap the vehicle keys. Gonna give those a try.

And yeah, that thing does clip a long at a very fast pace on Mun, 30 m/s actually. Once it gets up to that speed it is basically impossible to stop safely unfortunately :confused:

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Pretty much been covered - design the rover with a wide axle track and a low center of mass, include a reaction wheel, drive around in docking mode or remap the keys for translation instead of rotation, and don't go much past twenty m/s. Only thing I'll add is to encase your critical hardware in parts with high impact tolerance - structural panels and modular girders in particular. If it's a probe-rover, you want to sandwich the probe core, battery packs and/or RTGs between a pair of structural panels. That way if it does flip over, nothing blows up and all you have to worry about is righting the rover again.

If you need downforce (i.e. if you have a high center of gravity and narrow axle track), I've heard of folks using ion engines for great effect. They won't run out of juice as quickly as an RCS-based system will, though keeping them running will add mass.

Obligatory screenshots of the Hellhound 7:

Edited by capi3101
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And yeah, that thing does clip a long at a very fast pace on Mun, 30 m/s actually. Once it gets up to that speed it is basically impossible to stop safely unfortunately :confused:
I think anything above 20 m/s is considered a huge success. Add low gravity to the mix ... well, you can see where this is going. If you manage to hit 40 m/s in a rover, you are going back to the future.

I think the actual lunar rover for the Apollo missions, the Moon Buggy, maxxed out at about 10 mph, which would be about 5 m/s. Most of my rovers tend to max out about 10m/s for safe driving.

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Make the rovers the same wheelbase/chassis dimensions/ratio as a supercar in real life. While the aerodynamics may not accurately represent reality, the gravity and momentum and center-of-mass physics are pretty much spot on..

This baby goes 20m/s no problem:

Drives horribly on Kerbin, but really shines on the Mun..

Mm3gdSJ.jpg

How did I get it there? Well, I don't have any pictures of the launcher, but imagine this:

TjXzH50.jpg

With even bigger 3.75m stacks on each corner.

As for the actual landing...Also note the center of mass...

5YhoEzC.jpg

And safe on the Mun, with 16 Kerbs inside. Left some space so they got some room to move around.

tMb6Su2.jpg

God, I got so much air..erm..vacuum in that thing..

Seriously, if you can handle the lag, a gigantic rover like that is a ton of fun, especially just watching it jumping over things, leaping and bounding over foothills without a care in the world. Just be careful. If your tires start to pop, HIT THE BRAKES IMMEDIATELY, otherwise, you will skid for miles. Speaking from experience. Somehow nothing got broken other than the wheels, which were able to be repaired...

Edited by M5000
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Another thing that might help, especially with those high-traction wheels on relatively light rovers: Make your rover front-wheel drive as opposed to all-wheel drive. Disable the motors and steering on your rearmost wheels and do all of your active driving with the front set. Otherwise, you'll end up popping several wheelies without even trying, which looks cool and all but isn't really ideal for controlling your rovers. The only real downsides are that you have to be careful when backing up if you want to keep most of your tires on the ground at all times and that you'll have a fairly wide turning radius, but these can be compensated for via other means (usually a set of reaction wheels).

Also: At high speeds, rely more on the reverse gear than you do on the brakes. Brakes always stop the wheels cold, and those high-traction tires really do grip the ground, but your rover's momentum has to go somewhere, and if it can't go forward, it'll try to go up, essentially turning your rover into a giant lever with the wheels acting as the fulcrum. If you still want to kill your speed fairly quickly with brakes don't hold them; tap them periodically, and watch that back end.

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Hellhound = Like !

It's a good design and I've put it through some serious hell.

First time I tried to launch one the launch failed and I wound up dropping one from something like 2000 meters up; hit the ground at 70 m/s and survived (some popped tires; that was it). Was still drive-able afterwards.

Put a couple of BACC SRBs on it once just to see if I could get it to fly (for a challenge, of course). Nearly ripped it in half, but it was still drive-able afterwards.

Malaise and Lack of Prospects - the two I landed on Duna - leapfrogged each other for over 100 kilometers from their landing site to get to the SSTO anomaly; my longest ever rove. Did something similar on Minmus just before that mission.

I always bring it up when folks ask about rovers because it's everybody's suggestions in action - wide axle track, low center of mass, includes a reaction wheel, sandwiched critical bits, etc. Hauls two Kerbals and includes a couple of science instruments. As a bonus, it's pretty easy to modify; the original didn't come with deployable science probes.

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I managed to hit 25 m/s on minmus ( no flipping and rolling ).

I got help from some guys on this forum, I used this method:

1. design your rover ( any rover, big, small or large )

2. After you chose how it will 'look' make it WIDER and LOWER.

That way, u wont even face a single problem, also try to make the center of mass closer to the ground, specially if you are going on low gravity moon/planet.

Add some structures to it ( make it look cool, also making it more un-breakable, just in case if something happened. )

So yea, try these tips and tell as what happened!

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