Wheel brakes and symmetric braking

[outbaxx]

I don’t know if this is just me but I have a really hard time using the wheel brakes symmetric.

As soon as I start applying brakes the aircraft starts to steer left or right and I try to compensate by either lift or press one one brake pedal and it ends by me flapping and flopping the brakes and steering the nose wheel left and right to try not to skid.

And of course I skid...

 

I using the Saitek combat rudder pedals and there aren’t much feedback in the brake pedals so it’s probably easy to brake asymmetrical and therefore start steering left or right.

 

Is it possible to make the brakes brake symmetric if My brake pedals are in let’s say within 5% or degrees from each other?

 

Regards

F

 

 

It’s never too late to give up

[Goblin]

You sure there are no double commands mapped to the brakes?

Did you try setting some deadzones in the axis adjustment, in DCS?

[outbaxx]

Wheel brakes and symmetric braking

 

It’s not double assigned and the dead zone does not do the trick here.

I’ve done some testing and the issue is that the physical travel on the brake pedals are short so even if the difference between the pedals are very small, the difference in values in the sim get large and I end up having one brake brake harder than the other even if I think I brake them evenly.

And when I try to adjust I press just a little harder on one pedal but that gives a high change in the sim and the aircraft steers hard.

 

Maybe its time to see if I can change the spring in the brake pedals so it takes a lot more effort to move them?

 

 

 

 

It’s never too late to give up

[Elor]

It's also next to impossible now to brake with a button. I don't have pedals and use a joystick button for my wheel brakes. It used to work just fine but after some update it has become a skid fest which makes road base landings virtually impossible. Maybe I should play around with the dead zone a bit more as I haven't really done that yet and see what happens but as is I only land on normal bases and use the reverse thrust for all my high speed braking.

[MYSE1234]

Adding a curve to the breaks helped reducing instability when breaking for me.

Edited December 7, 2019 by MYSE1234

[Katj]

You really don't need asymmetric breaking in the Viggen, so you could just bind one of your axis to symmetric braking and leave the other unbound.

 

I don't have pedals (yet), so I have brakes bound to a key, and they are all but unusable. As soon as you touch them you will start slipping, even in dry conditions. I usually just use reverse for slowing down.

[RagnarDa]

SOP is to pull back on the stick when braking or using reverser. I find it helps a lot.

[outbaxx]

SOP is to pull back on the stick when braking or using reverser. I find it helps a lot.

 

 

I’ve haven’t read that you should pull aft stick while braking, only when using thrust reverser, more thrust = more stick aft.

 

It says that you should brake with even pressure and steer with the rudder pedals and only use asymmetrical braking if that isn’t enough.

(My issue is that I always seem to brake asymmetrical due to the reason about the small physical range on my pedals I described above)

 

But if guys start to skid using keyboard there must be something wrong?

Different values on left/right brakes? Or why would they skid?

 

 

It’s never too late to give up

[RagnarDa]

Outbaxx what happens if you assign the symmetric braking to both pedals?

[Bagpipe]

I've always just seen this as a quirk of the viggen (using keyboard braking here) tbh.

It only happens when you apply the brakes too early without using other methods i.e. reverser to slow adequately before applying them

[outbaxx]

Outbaxx what happens if you assign the symmetric braking to both pedals?

 

 

 

I assigned the symmetric wheel brake to my right pedal.

It is better and it it brakes symmetric if I apply low to moderate brake pressure but something happens when the aircraft is about to stop, then it start to yaw left or right and trying to steer makes it skid.

Applying hard brakes seem to speed up the yaw and skid.

 

So, low to moderate brake pressure and it brakes symmetrical down to, I would guess 100kmph, and then it start to steer away by its own, not a very high steer but enough so that I have to try to steer it straight and then it starts to skid.

 

But why would it start to steer when the speed is low? Could the rudder have too much authority at low speeds?

 

 

 

 

 

It’s never too late to give up

[outbaxx]

Wheel brakes and symmetric braking

 

No, it’s the brakes, I did some more testing, just speeding up on the runway and braking.

 

The issue is when I brake too hard, the wheels lock and it comes fast to a unrecoverable skid.

And it’s very easy to apply too much pressure, the difference between low pressure braking to locking the wheels is very fine.

 

And that’s probably why I had that weird skid when I was low speed as I began pressing more on the brakes (and they locked).

 

As they lock, the brakes does not brake evenly and the aircraft yaws and start to skid.

 

So the main issue seem to be that the wheels lock while braking.

And what I’ve read is that they shouldn’t lock at all on the Viggen?

 

 

It’s never too late to give up

Edited December 8, 2019 by outbaxx

[RagnarDa]

Apart from simulation of the boogey wheels, all ground-wheel interaction simulations is using DCS standard system. Despite what it might appear these simulations are non-trivial. It's configurable in Suspension.lua so you can check it out for yourself and experiment. DCSs anti-skid system is enabled.

[Katj]

But if guys start to skid using keyboard there must be something wrong?

Different values on left/right brakes? Or why would they skid?

The brakes are so powerful that the wheels lock, and any perturbation will then make you skid sideways.

 

There is no ABS on the Viggen, so the solution for you is probably to be more gentle on the brakes. Since I have brakes bound to a button I can't do that.

 

I don't know if the Viggens brakes are too strong, but I know that they are enormously more effective than the Fighting Falcon brakes.

[outbaxx]

The brakes are so powerful that the wheels lock, and any perturbation will then make you skid sideways.

 

There is no ABS on the Viggen, so the solution for you is probably to be more gentle on the brakes. Since I have brakes bound to a button I can't do that.

 

I don't know if the Viggens brakes are too strong, but I know that they are enormously more effective than the Fighting Falcon brakes.

 

 

 

There are brake-regulators and a modulator that see that the wheels don’t lock, perhaps not ABS but nevertheless a “anti lock system”

@RagnarDa I’ll check that out :)

 

 

It’s never too late to give up

[RagnarDa]

Wheel brakes and symmetric braking

 

I should add that max brake power needs to be pretty strong, you should be able to stand still with Zone 2 engaged IIRC. IIRC I added a delay for the brakes to fully engage (like 1 sec or so) to make it more gentle. This means that if you are using keyboard you can engage the brakes halfway by holding the key for half a second and release for half a second or less.

Edited December 8, 2019 by RagnarDa

[Katj]

There are brake-regulators and a modulator that see that the wheels don’t lock, perhaps not ABS but nevertheless a “anti lock system”

@RagnarDa I’ll check that out :)

 

 

It’s never too late to give up

I see, I've been told that it doesn't have abs before, something I've always found a bit odd, but perhaps the one who said it was referring to the effectiveness of the system or something.

 

Does it have anti-skid on the front wheel?

 

@RagnarDa, I do pump the brakes like you propose when I really need to stop quickly and it works fairly well, but I rarely need it because she stops so quickly anyway.

 

I haven't done so many road landings, though. But I do use brakes when I land on the Stennis, for instance.

[Elor]

Does it have anti-skid on the front wheel?

As far as I know no nose wheel has brakes on any plane. Just the main gear (but I might be wrong there...happened before....).

[RagnarDa]

There’s a break on the nose wheel when the suspension is depressed

[outbaxx]

There’s a break on the nose wheel when the suspension is depressed

 

 

Are you sure you’re not mixing up the front boogie wheels with the nose wheel?

The front wheels in the main gears brakes don’t work unless the nose gear suspension is depressed.

 

 

 

 

It’s never too late to give up

[Jonne]

As far as I know no nose wheel has brakes on any plane. Just the main gear (but I might be wrong there...happened before....).

 

Yes you are wrong ;)

 

Small hint: There are even DCS modules with nose wheel brakes, and those do have an anti-skid system.

[outbaxx]

After some testing I came up with this solution for me:

Saturation Y to 50

 

-I can still hold the ac still up to max Zone1.

- As long as I don’t floor it during the whole brake I have a really steady yaw. If I floor the brake it will eventually start to slide but not as bad as it did whit default settings.

 

I have only had time to test with “symmetric brake” -> only one pedal assigned for the brakes. Will try to assign both pedals left and right some other time.

 

 

It’s never too late to give up

[Elor]

Yes you are wrong ;)

Well, at least I'm consistent then.:D

[Uriah_]

Thanks outbaxx for the hint on the saturation Y to 50. However, I am trying to use the breaks on the BF 109 and the Spit. It seams that touching the breaks locks them up. And nothing seems to unlock the breaks. Is there a solution to this or is it just me?

[MBot]

I think this needs to be looked into again. According to the manual, the aircraft is supposed to be equipped with anti-skid.