Why do my Rover wheels go all wonky between saves / returning to vehicle?

[JoeSchmuckatelli]

This is happening more often lately - and it's highly frustrating.

I build a rover and test it on Kebin, making sure that all the wheels work the way I want them to (whether in the VAB or SPH) - then I launch and land (Mun/Minmus).  Initially, everything is fine.

Then - when I return to the vehicle after doing something else for a while; they've lost their minds.  The front wheels pigeon-toe, one of the back wheels decides it needs to go the other way under power from its neighbor... brakes don't work... etc.  Even after spending a few minutes trying to get the wheels to work correctly - something is never quite right.

Is it just because?  Known bug?

[paul_c]

It does the same for me. It doesn't help either, docking/undocking components (with more wheels), when you want a slightly different steering configuration for each combination of vehicles etc...

[bewing]

Generally, it's because your control point for the rover got reset. The control point has to be pointing in the "forward" direction. If it's pointing up or down or some other stupid direction, your rover will have steering issues.

You can tell what direction your control point is facing by looking at your navball. The center of your navball should be pointing at the horizon, in your direction of travel.

 

[JoeSchmuckatelli]

1 hour ago, bewing said:

Generally, it's because your control point for the rover got reset. The control point has to be pointing in the "forward" direction. If it's pointing up or down or some other stupid direction, your rover will have steering issues.

You can tell what direction your control point is facing by looking at your navball. The center of your navball should be pointing at the horizon, in your direction of travel.

 

I'll check this out.  Thanks for the tip!

 

Edit: Hmmm...  I think @bewing is on to something; but the problem is I can't change navball facing because of the way I built this rover.  It's a standard craft, except it had wheels on one side, and I tipped it over using landing gear and reaction wheels (turning a rocket into a truck).  I'll have to check out whether this fix works on other non-truck lander/rovers.

 

As of now -- his is the best answer (but it is yet incomplete)

 

Edited December 16, 2020 by JoeSchmuckatelli

[AHHans]

11 hours ago, JoeSchmuckatelli said:

Hmmm...  I think @bewing is on to something; but the problem is I can't change navball facing because of the way I built this rover. 

Hmmm... The common solution to this would be to build the rover differently. (SCNR! )

When you press the "drive forward" button, then the wheels try to rotate in a way that will propel your craft into the direction that is considered "forward" (i.e. the direction in the center of the navball). Similar for turning the rover. If the wheels are placed in a way that these directions are not well defined then - well - the results are not well defined either.

12 hours ago, JoeSchmuckatelli said:

As of now -- his is the best answer (but it is yet incomplete)

If you want a more specific answer then it would help to have a screenshot of the rover.

[18Watt]

Which probe core and/or command module are on your rover?  Some of them can change their reference direction, even after launch.   That feature is accessible from the part action window (PAW), for some parts anyway.

Edit: The PAW button you are looking for is "Control Point:"  Some probe cores and command modules have only "Up" or "Default" and "Reverse".  Some however have "Up/Default",  "Reverse", and "Forward".  The cores and command modules with this option are in my opinion ones more likely to be used for rovers.

Examples are Mk-1 Lander Can, Mk-2 Lander Can, OKTO2.  That list is not exhaustive.

Edited December 16, 2020 by 18Watt

[vv3k70r]

On 12/15/2020 at 11:00 PM, JoeSchmuckatelli said:

Is it just because?  Known bug?

Check control point.

Quite often You have to select a guidance unit (if any or cabin) for rover to get all properties back. Especialy if it were docked.

[king of nowhere]

i had a similar bug strike yesterday, after i've been using rovers extensively for months without seeing this. i would suspect the new version, if the original question wasn't older