FFB Physics calculation error found

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Emmerich
Posts: 87
Joined: 21 Feb 2021 09:58

FFB Physics calculation error found

#1 Post by Emmerich » 21 Oct 2021 17:34

I love the idea of realistic wheel feeling but there is a small error in your calculations:
In a normal vehicle the mass of the car adds to the tension turning the steering wheel to the CENTER..in your physics they adds to the tension driving the steering wheel out of the center..I think the error in your calculations is based on the fact that the thought line added to the axle to turn the front wheels into driving direction is in FRONT of the point where the wheel touches the surface..you need to shift the axle point past the point of the street contact then it will give us more fun :-) I am not sure how to say in english..in german is that the "negativer lenkrollenradius"

Best regards
a adicted home truck driver ;-)
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Reinhard
Posts: 4709
Joined: 20 Dec 2012 16:46
Location: Berlin, Germany

Re: FFB Physics calculation error found

#2 Post by Reinhard » 21 Oct 2021 17:41

Emmerich wrote: 21 Oct 2021 17:34 I am not sure how to say in english..in german is that the "negativer lenkrollenradius"
"Negative scrub radius".
Emmerich
Posts: 87
Joined: 21 Feb 2021 09:58

Re: FFB Physics calculation error found

#3 Post by Emmerich » 21 Oct 2021 17:50

oh right thanks for the help
SJ_Stein
Posts: 4
Joined: 13 Feb 2016 15:58

Re: FFB Physics calculation error found

#4 Post by SJ_Stein » 21 Oct 2021 20:05

That sounds about right. The FFB is way off... normally, the harder you push the truck, the tougher the FFB should get.... it just wont load up in time for the weight of the truck and the force of the tires on the road to feed back into the steeringwheel. it way out of alignment. SO, yeah, calculating the force feedback is way off. Also the centering force is nearly non existing now, whereas one should feel just a bit of centering spring.
Emmerich
Posts: 87
Joined: 21 Feb 2021 09:58

Re: FFB Physics calculation error found

#5 Post by Emmerich » 22 Oct 2021 03:12

Thats all because of the wrong scrub radius...you can see it driving backwards because then you have the right centering forces :-)
Seelenkrank
Posts: 441
Joined: 16 May 2018 13:04

Re: FFB Physics calculation error found

#6 Post by Seelenkrank » 22 Oct 2021 18:12

i did a testdrive on my yard backwards and cant share your experience...
when driving backwards and steering the truck/ffb moves like a drunken sailor and the wheels feels like a rubber band with changing forces.
Eewec
Posts: 50
Joined: 19 Apr 2021 13:00

Re: FFB Physics calculation error found

#7 Post by Eewec » 22 Oct 2021 18:19

Centering force? I was driving in ETS2 last night, getting the wheel centered was a constant struggle. I'd turn, then have to force the wheel to go back to center and heaven help me trying to take a roundabout and actually want to reverse the turn direction to leave the roundabout... Judder, trying to overcome the force-feedback to turn the wheel from one direction to the other and sudden points of drop off and I'm amazed I didn't crash... more often. It actively felt like it was pushing against me trying to center my wheel on multiple occasions.

EDIT: Ok, so I figured I'd check everything with a fine toothed comb. Seems Thrustmaster released some firmware/driver updates last month. Went through and installed both on my wheel and it's like night and day different... they only came out last month with the update and I was otherwise up-to-date so... yeah. Didn't have a long drive before dinner was ready, but the difference was immediately apparent. One thing is certainly worth checking; Did your own wheels get any driver/firmware updates released recently?

Side note: Only found out by pure chance: last few (3 for me) force feedback options are greyed out in the main game but are editable from the launchpad.
SJ_Stein
Posts: 4
Joined: 13 Feb 2016 15:58

Re: FFB Physics calculation error found

#8 Post by SJ_Stein » 31 Oct 2021 18:55

Oh boys, have you actually followed the SCS instructions, as with the new 1.42, you NEED to reset your ffb settings to default, as they changed quite a bit... mine was misaligned at first because it was still using the old settings from before this update. So first default, then first thing i do is turn the engine ffb to 0, it should add rumble, but it makes most wheels go berserk. When y ou adjust the ffb in the profile manager, you can actually set everything to zero and start from scratch... i only have the gain and the centering forces enabled and up pretty high, and the terrain and collision sliders way low... as i'm running an OSW Direct drive wheel set at about 10nm (of 20)... this powerful wheel will rip yer thumbs off when in the wheel and the engine stalls in a turn... So good ffb settings is key, i can feel EVERYTHING, the wheel is just thát sensitive in portraying ffb.
Emmerich wrote: 22 Oct 2021 03:12 Thats all because of the wrong scrub radius...you can see it driving backwards because then you have the right centering forces :-)

After horsing around for over a week, trying to get some decent force Feedback settings in, it turns out you are absolutely, positivily, completely right.... I tried driving backwards (in outside view) and Onto a roundabout... then i floored it and the forces did Add up, there was more friction the faster i went, until my truck fell over from the centrifugal forces.... in forwards motion there was this sort of Saw-tooth where the forces had to get over upon turning the wheel at speed, as soon as i steer over that sawtooth/spike, the FFB drops down, then loads up again... very anoying.

So yeah here we go:


Dear SCS Dev's, your FFB calculations are indeed backwards. Try driving backwards and feel the difference in ffb forces. See first post for a more detailed explanation by Emmerich.


who can bump this message up to the devs?

Woof ~ Woof & Salute to Emmerich


Steiny
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