rover won't go uphill; suggestions?

[king of nowhere]

I have a massive beast of a 48-ton rover, with eight TR-2L wheels, designed for exploration and fuel transfer (hence the mass: it's a Jumbo-64 fuel tank on wheels) on small moons 1.

the rover performs very well in all the many things i want it to accomplish, except for this problem. it can't go uphill when fully loaded. In mun gravity it cannot climb a slope steeper than 10 degrees. on minmus, it barely makes it to 15. Even dry (just shy of 20 tons) it barely climbs 20 degrees on mun. which is a huge problem when you want to explore with your rover.

it seems clear that the wheels aren't powerful enough to propel the rover. I am looking for solutions.

- i could use the massive XL3 model, but it seems overkill. even using only 4, it would add 4 tons of dry weight. now, this rover is also designed to fly 2 on planets with small gravity, i'm not excited at the prospect of adding 4 tons. perhaps worse, they have a top speed of only 15 m/s, against the TR-2L cruise of 30 m/s. i plan to drive around the small planets with this rover, i'd rather have a fast one (i am aware of the glitch that lets accelerate much faster with the XL3, but i dislike using it; feels too much like bug abuse)

- i can put some hinges to orient the rockets backwards and give it a push. it can work as a backup solution, and i won't run out of fuel because i have a small ISRU facility on board 3. At least, as long as i am in a biome with more than 2.5% ore. and i'm not excited at the prospect of using fuel every single time i have to go uphill. not to mention that the more hinges i add to the rockets, the more they shake and vibrate, creating all manners of problems during flight

- i can put more wheels? say, double theirs number? would that even work?

- i can use the very neat trick that i was suggested in the forum. please tell me there is a neat trick to get the desired power/grip for my rover that would not feel like bug exploiting.

- I canNOT make my rover lighter. even at 20 tonnes, it's still barely acceptable in mun gravity. and i'd have to give up on the fuel tank, or reduce some of the other functionalities.

 

so, any advice?

 

1: it started as a fuel transfer rover to get fuel from mining operations to landed ships. then i realized, science equipment is light anyway, instead of having one mining rover and one science rover i could send one single rover to do the exploring between one refueling trip and the other. but a mining rover is fine moving only a few kilometers on mostly flat ground, an exploration rover needs to be able to go far on rugged terrain.

2: i already had a big fuel tank for fuel transfer. and i had one engine on a side to rotate it in case it capsized. as i was studying solutions to drop it on mun, i suddenly realized what the hell, it has a tank, it has an engine, i just need another engine on the other side and then this thing can fly on its own.

3: i already had a 45+ton vehicle designed to be adept at a lot of different tasks. adding ISRU was only 1.5 extra tonnes, why not?

[bewing]

The most important first thing to try is turn off traction control on all your wheels. Traction control automatically applies the brakes to your wheels when they slip. And on a low-G world, your wheels are always slipping. All the auto-braking can easily destroy 90% of your propulsion.

 

[king of nowhere]

1 hour ago, bewing said:

The most important first thing to try is turn off traction control on all your wheels. Traction control automatically applies the brakes to your wheels when they slip. And on a low-G world, your wheels are always slipping. All the auto-braking can easily destroy 90% of your propulsion.

 

well, as i hoped, there was some trick.

it definitely improves traction. not as much as i was hoping, but at least i can climb a 15 degrees slope on mun, and i can even go a long way up at 20 degrees if i have a bit of starting velocity. It drains battery like crazy, though - my 5000 starting battery, that with similar rovers would last me through 10 km of night driving, were depleted in minutes. but it's a function i can turn on and off, so it's ok. i will activate it if i need to climb.

furthermore, i realized that i can increase my grip by using my rockets to puch me downwards (they are mounted to push downwards because, if the rover is flipped, they can spin it in the air again). which i want to kick myself for not realizing earlier. it still takes fuel, but much less than trying a suborbital trajectory on a rover with poor manueverability. i accelerated up a 30 degrees slope, and with enough starting speed i even managed to overcome the 50 degrees slope and get out of the crater i was using as testing ground. though using my rockets so long costed me 300 m/s, it may have been cheaper to go for parabolic flight.

well, at least my rover is now usable. not optimal, but usable.

anything more i can try? next thing i will attempt is putthing hinges to fire the rockets backwards and see how that goes. or maybe i'll try extra wheels.

 

by the way, what does "friction control" do (i'm translating it back from my italian game, name could be a bit different. anyway, it's the option next to traction control)? i tried to set it to ignore and then pump it to the max manually, without seeing any difference.

[bewing]

1 hour ago, king of nowhere said:

by the way, what does "friction control" do

If you set it to "manual" and then set it to zero, it will act like you are on ice and not able to go anywhere. If you set it really high, then your wheels will always have perfect grip on the ground.

[Reactordrone]

You can also try going up hills in a zig zag. It reduces the effective incline by increasing the distance travelled for the altitude gain.

[Tonka Crash]

@king of nowhere I modified the Torque curves of all the wheels. I used go 4x4ing in a Nissan Xterra and it could climb a 60 deg slope, so getting stuck on a 10 degree incline really annoyed me.  The way squad has the wheels set up the torque tapers off pretty rapidly as speed increases.  This is not how electric motors generally work in the real world.  They usually have a flat torque output until the fall off at their peak speed.  This is what I use for the TR-2L, you might give it a try:  

@PART[wheelMed] {	// RoveMax TR-2L
    @MODULE[ModuleWheelMotor] {
	-torqueCurve {}
	torqueCurve
	{
	    key = 0 2.1 0 0
	    key = 5 2.1 0 0
	    key = 15 2.1 0 0
	    key = 25 2.1 0 0
	    key = 52 0.5 0 0
	    key = 58 0 0 0
	}
    }
    @MODULE[ModuleWheelBrakes] 
    {
	@maxBrakeTorque = 2.1
    }

}

I just got done Baja racing a rover 170km across the Mun and was getting 100m+ in the air after running 30m/s up some crater rims. With MechJeb SAS the thing handled acted like a cat to keep the wheels pointed at the ground. 

[king of nowhere]

17 minutes ago, Tonka Crash said:

@king of nowhere I modified the Torque curves of all the wheels. I used go 4x4ing in a Nissan Xterra and it could climb a 60 deg slope, so getting stuck on a 10 degree incline really annoyed me.  The way squad has the wheels set up the torque tapers off pretty rapidly as speed increases.  This is not how electric motors generally work in the real world.  They usually have a flat torque output until the fall off at their peak speed.  This is what I use for the TR-2L, you might give it a try:  

@PART[wheelMed] {	// RoveMax TR-2L
    @MODULE[ModuleWheelMotor] {
	-torqueCurve {}
	torqueCurve
	{
	    key = 0 2.1 0 0
	    key = 5 2.1 0 0
	    key = 15 2.1 0 0
	    key = 25 2.1 0 0
	    key = 52 0.5 0 0
	    key = 58 0 0 0
	}
    }
    @MODULE[ModuleWheelBrakes] 
    {
	@maxBrakeTorque = 2.1
    }

}

I just got done Baja racing a rover 170km across the Mun and was getting 100m+ in the air after running 30m/s up some crater rims. With MechJeb SAS the thing handled acted like a cat to keep the wheels pointed at the ground. 

 

thanks, but modifying the files really would feel like cheating. i would like to publish this rover when i'm done working on it, i can't have it work only on a modded pc.

 

but hey, good news. i did manage it putting two G-00 hinges on two of the engines. now i can turn them backwards and fire to help me uphill. the good part is, the rover wheels mostly keep up speed, only losing slowly against the slope. so i can give myself a quick rocket push, and then just cruise for a while. i got out of the test crater with less than 100 m/s.

and they cause no stability problems in flight that i could determine.

and i only added 40 kg of extra weight.

Edited July 13, 2020 by king of nowhere

[Spricigo]

20 hours ago, king of nowhere said:

 

thanks, but modifying the files really would feel like cheating. i would like to publish this rover when i'm done working on it, i can't have it work only on a modded pc.

Just for clarification: when people post config like the one above they are not telling you to modify the original files but to use a mod called Module Manager that allows loading custom configs.

In any case, that means the rover will have modded wheels if the config is used. You are correct that it can be a issue if you plan to publish (amenable, but still). As for the feeling of cheating, that is up to the player to decide, since it's a single player game.

 

 

[king of nowhere]

and now that i really used the rover outside of testing ground, i found an even simpler solution: delay refueling

see, the rover is supposed to land on rockets, refuel with a small drill, explore around, and take off again, to visit another low-gravity moon. with a full tank it is very heavy, and sluggish to drive. but i am on mun with one third of my maximum fuel, which is more than enough to straighten the rover when it capsizes (the original purpose of the rockets, before i realized i was already halfway to making a flying car), or to save me in case of whacky accidents, like accidentally plunging over the edge of a crater at full speed (Iwhich i just did). but still, the rover has a lot of acceleration and manueverability.

I'll just have to stop and make fuel before i leave mun. at worst i may found a biome too low on ore to make fuel, in which case i'll just have to move around a bit.