mystifeid

Yeah, I don't speak emoticon so you can forget about me even looking at them. If you are talking about real life then of course I agree with you, (I too am a survivor of an aquaplaning incident involving a full 360° spin down a hill at 80km/h - no damage!) but you may find the game engine is no respecter of real life - so... Go for it. Always willing to learn. But I will make this caveat - please, not on a high g world. On Kerbin I would never bother to change friction settings (and did I need to change friction settings on Eve? - well, yes, but not for any of the reasons we're talking about) but on lower g planets/moons where a more fleeting contact with the surface can play a pivotal role it is often a different story. Places where, without engines, it is possible to maintain speeds of 90-100m/s for long periods. Any faster and my wheels tend to explode and any slower and holy cow, it takes like twenty hours to drive around some of these places. (Eve is looking like about sixty hours and Eve's North Pole, though picturesque, has become my new least favorite place to drive a rover). In KSP we are lucky that we have reaction wheels and we do not need friction to give us yaw authority. While I use my alternate keys for forward/reverse, I always use "A" and "D" to turn. This is because, at high speed on lower g worlds, I am often not in contact with the surface and just beginning a turn can cause loss of contact. Losing contact often involves terrain induced yaw so I have to rely on the yaw control provided by my SAS anyway and using two different sets of keys to turn when things are happening fast is just not going to happen. When my front wheels hit the surface I don't want them making much of a contribution if I am yawed with respect to my direction of travel. Quite often a lot of time is spent above the surface and it's nice not to have to micromanage every landing. Losing steering authority provided by friction is the whole point of what I've been suggesting and yet by doing this in the simple example above, by preventing the roll it could be said that the steering has improved. Even using a rover with a very low CoM, the terrain or an overzealous turn can easily yaw and roll it in an instant. Was I going too fast? Obviously. Will I slow down? Of course not. Instead I look for a way to ameliorate the effect on the rover. Each world is different and I constantly change the setup until usually about three quarters of the way round I become confident that I've found the one that gives me the highest speed with the least mishaps. Does it really make that much difference? Probably not but even saving my rover once or twice per trip is worth the effort.

You'll notice that I included "generally" because I was thinking I could maybe build a rover for which that statement would not be applicable. But had you in fact increased friction on non-steering wheels and decreased it on steering wheels? If you had, are you blaming your loss of control on that setup? And are you basing your opinion on just one incident? Currently I am circumnavigating Eve. This is my last circumnavigation of all the planets/moons in the stock Kerbol system. I am the survivor/victim of countless incidents and over time I have become very good at regaining control in different types of rovers without damage. Loss of control is often caused by one or both of two things - terrain and aggressive course correction. Not much you can do about the terrain except anticipate the effect it will have on the rover and/or change the angle/speed at which you meet a feature. There are also bugs in the terrain. I have seen rips in the space-time continuum on Minmus and Ike, driven into bulldust on Gilly and on Eve I keep encountering invisible patches of quicksand which slow and slew the rover. This last one makes me wonder how many times I've encountered it before in other places without knowing it. The easiest way for me to cause loss of control is by changing course. Do it too fast and I'm going sideways. If a wheel catches I'm rolling one foot off the deck into the bargain. It is the roll which most often causes the destruction of the rover. The easiest way I've found to prevent the initial loss of control is to reduce friction progressively from the back to the front of the rover (my most used rover has 16 wheels - upgraded to 20 for Eve). This also helps to keep the rover pointed straight during aggressive braking. A simple test I use at KSC to help determine the worthiness of a rover is to take it to top or near top speed then hold down the left or right control key. If it rolls, I don't want it. But it can be interesting to see how much I have to change the friction settings to prevent the roll. In the following screenshots the rover is taken to 20.0m/s before holding down the left key (numpad 4). In the first the friction is left at the default 1.0/1.0 and a roll ensues. In the second the friction has been changed to 0.4/1.1 and no roll. I wouldn't advocate such drastic change for Kerbin but it does illustrate how the friction setting can influence loss of control. The 16 wheeler does about 75m/s at KSC with both Verniers burning. It doesn't even look like it is remotely close to rolling when I apply full lock but every now and then I get to see it suddenly flip upside down on some planet or moon so no matter the design or the setup, bad things will still happen. And I'm glad.

That's why reducing the friction on the (hopefully front) steering wheels is a good idea. You want them to be able to slide rather than dig in. Other than that make the rover very low and very wide. And even with the best designed rover, the snap barrel roll is still a possibility on low g moons/planets. Have a good lightweight rcs system and get used to flipping it on quickly in an emergency. You can also use Mechjeb's stability control if you get really fed up. Inertia is a b*tch though and really, the best way to improve turning at speed is to keep redesigning lower and wider.

It's actually generally a good thing to reduce the friction on steering wheels and increase friction on non-steering wheels.

So can you switch on the aerodynamic force overlay (F12) and post a screenshot of the lift being generated by your rover?

Test and test again. Two pairs of canards, a panther and 400 units of fuel gave this upside down rover a range of 300+km at 50m/s and with some more experimentation I'm sure I could have done better. (Check out the throttle position). Take the canards away and the range and speed become impossible. I've used also canards on other boats with good results. Try using the authority limiter of the canards to get the boat out of the water and then adjust for cruising trim. Further adjustment is necessary if the CoM moves as fuel is burnt.

Are you sure this is necessary? Try testing your design at KSC. Here is a Mk2 fuselage at 387m/s with aerodynamic forces shown and ... no lift.

Tried Alt+X to clear trim? (I could've sworn that besides negating trim settings SAS also stops the wheels from turning but I just tried it and it didn't.) And the steering issue sounds like an incorrectly oriented controlling part (eg probe core pointed upwards).

For initial forays, I'm with @bewing - LOS is fine. In a career though it pays to research the M700 survey scanner relatively quickly to enable finding the highest ore concentrations. This goes on a sat in polar orbit and it might as well have a relay antenna on it. Add another one in a polar orbit around Ike. When you get a contract for a station orbiting Duna it might as well have a relay antenna too. Add another one orbiting Ike. After researching the Sentinel Telescope contracts will be offered to place them in Kerbol orbit. Hey, throw relay antennae on all of them. Sooner or later you end up with more relays floating around than you can poke a stick at.

One or two (hundred) more attempts and I've reached 489.4m/s. In the absence of any more "motivation" this is my last submission. I've tried a lot of different things and have not limited myself to the one design but the same basic design has been the most successful. It would have been nice to get 500m/s but even risky drogues don't deploy at this speed so that other more extreme measures have to be considered. Today I have been lowering the wheel friction and attempting to slide. Sometimes I even get a wheel to blow out. But the turn at the end definitely helps. This time I have used three Vectors and Bill is a real hero for taking 20G's but stopping an extra 4 tons moving at nearly 500m/s is no fun.

Don't lose contact with the surface. If there is no impact the wheels stay intact. For stability keep it long, thin and low.

482m/s seems to be my limit with anything analogous to this design and don't ask me to do it again. Plenty of times I ended up past the end of the runway after going that fast. Risky chutes and engine cutoff are all tied into the brakes action key (as well as the air-brakes) and there's a very fine line between punching the "b" key too early or too late. (I also hold the reverse key for the placebo effect).

Yeah those ice sheets are great. Anyway - here is 435.4m/s. No problem with stability - just stopping - and I'm pretty sure it can go faster but I have to go out and am in a bit of a rush.

Wow - 403 is fast!!!

A little faster again - 265.2m/s

Just so there is something a bit higher than 104m/s to aim at ... here is 175.4m/s

It's probably not ideal due to the diameter but you could attach the Juno to an EP-18 engine plate (short variant) which will give you a coupling point beneath the Juno. Don't forget to rearrange the staging when you have finished attaching things.

Kerbin by (mainly) land - completed using a separate stock KSP 1.45 install - no added mods. Start and finish at the Dessert Launch Site. Wow. Second time around Kerbin - this time by land. I spent quite some time thinking about something I could take around Eve and Kerbin and finally came up with something that was hopeless for both. Nevertheless, over the course of the next few weeks I pushed it around Kerbin but I hated it so much that I would stop playing after driving for about a kilometer. Eventually I went back to the VAB and made something just for Kerbin, then started again. Four days later I finished the circumnavigation. Part of the problem lies in making a rover that is reasonably fast and durable on land yet economical on water while maintaining range and speed. Motorized wheels in water preclude economy and speed so I decided to place a couple of pairs of canards on top of the rover and on entering water I would flip it upside down so that the canards could act as hydrofoils. It made for a particularly ugly boat but 400 units of liquid fuel behind a Panther gave it a range of more than 300km at 50m/s. On land, for the most part the rover maintained 40-50m/s. I wanted to keep the route roughly circular with no spans of water greater than the range of the rover and the one that looked like it might suit was a polar route starting and finishing at the Dessert Launch Site. I crossed five major stretches of water. Four were unavoidable and the fifth was made mainly to keep the route circular. Likewise, if mountains were encountered on land, they were crossed and not skirted. This was my first major foray ever onto the Southern and Northern Ice Shelves. They are very big areas and perfectly flat. Eventually I began to wonder how fast I could go so I opened up the Panther and hit 160m/s. Great. Kicked in the afterburner and accelerated to around 230m/s. And held that speed all the way to the edge of the ice sheet. I have never approached the Ice Shelves by sea and didn't know about the 31m high ice cliff surrounding them. Fortunately, the Panther on full afterburner provided just enough power to inch up the 85° slope. Exiting from an ice shelf back to the sea required the same maneuver but this time in reverse. Estimated time to complete : 30-35 hours. Imgur album - https://imgur.com/a/52AuM7j

You could always go to either the Southern or Northern Ice Shelves which are perfectly flat and reasonably big. If you ever wondered about how fast a rover can go, they're not bad places. Here is a stock mining rover (with afterburner) at more than 200m/s.

Capital "A" for "Available" ?

My apologies - I can have an irascible nature before coffee in the morning. Might have to do something about that. I saw it! It really is a monster. Good luck with that. If going via the equator make sure it either carries a lot of fuel or can be refueled. It's a long way across the deGrasse Sea.

Which ISRU did you use?

As @4x4cheesecake has shown in this thread, it is possible to change inclination in LKO all the way from 0° to 180° for less than 1300m/s dV. So, if there is sufficient, maybe just keep the last ore from an asteroid to convert to fuel to intercept the next one.

Suborbital hops? Are you kidding? This challenge is about driving rovers around planets and moons - not flying rockets around them. Nowhere near ready? How hard is it to drop a rover on the Mun and start driving it? Not very. And after you've flown your rocket around the Mun, then what? Use bigger rockets to fly around Kerbin, Eve, Laythe, Vall, Tylo, Eeloo and Moho? Maybe we should get rid of the wheels in the badges and put rockets there instead. I get that you don't want to spend the time actually driving a rover around these places. It takes a heck of a long time. But that's the challenge.

Why not make a rover, put some engines on it if you like then transport it somewhere and try the circumnavigation. You might find that it is the jumps that cause you the most grief. All wheels have a maximum impact velocity. For the TR-2L Ruggedized Vehicular Wheel, that I tend to favor, it is 100m/s. On nearly any body you choose, you will find long downhill stretches that will want to accelerate you past this safe velocity and losing contact with the surface then accelerating more in freefall will be the last thing you want. Even when your route flattens out or turns into a climb, you will often find yourself maintaining an unsafe speed. You will want to be very sure before you take any jump and usually have little time to assess the situation. I would suggest that braking engines on the front of the rover would be of more use than any added to the rear. Also, all but the smallest engines add significant weight to the rover which not only increases the difficulty of transporting to and landing on your target but also increases the stresses on the wheels every time the rover lands. If engines are heavy then fuel is even more so and the difficulty of your task is increased again. Even the most parsimonious stock engine consumes fuel at such a rate that to be any help at all in speeding up your circumnavigation, you will have to refill your fuel tanks multiple times. This means carrying an ISRU, radiators, at least one mining excavator and at least one ore tank. Again, as the rover mass increases, so does the difficulty. At the same time the ability of the rover to cope with the stress of landing a jump decreases. After circumnavigating many places carrying all of the above on a rover I would advise you to only use engines on long very flat spaces or on uphill stretches. Rest assured that you will not need engines to make many jumps capable of destroying your rover. Before fitting engines and all the supporting paraphernalia it would be better to think about a decent rcs system. This is the thing that will really save you time because instead of repeatedly destroying your rover and having to reload your game, you will be able to slow descents and soften impacts. Also, even the best rover will spin out of control on occasion and being able to flip on a good rcs system will save your rover. On some of my circumnavigations, I didn't use engines at all and never filled up the fuel tanks. Frankly, I didn't want the extra speed and certainly not the extra weight. If you really want to circumnavigate somewhere while using engines try going to Tylo - you would be mad not to take them. Moho also has some excellent flats. And on Kerbin, Laythe and Eve you will require them. Of course if you are thinking of using engines on Gilly, then as far as I'm concerned, yes, that would make you a dirty cheating alpaca. But do what you want - you will feel proud or not proud of your achievement as the case may be.