Differential brakes and brakes

[Masterius]

I currently have my left and right brakes set up independent of each other, functioning as differential brakes. For the most part this works great. I've a couple of issues, and a question, however.

Issue one is that, on random occasions, the brakes just stop braking. The popup flag [DIFFERENTIAL BRAKE] will disappear whilst braking, then reappear when the brake pressure is slightly altered. Issue two isn't, I suppose, as much an issue as an observation: when brakes are equally applied, or fully applied, it alters from [DIFFERENTIAL BRAKES] TO [BRAKES]. This is actually a good thing in its way, but leads to question one.

Getting the brakes to equally apply is terribly difficult unless fully applied. And it appears the differential application is 'all-or-nothing'. By that I mean it appears that if I'm applying pressure to both brakes, whichever one is seeing a higher pressure takes effect while the other brake is fully released. This results in rolling down the runway and the aircraft seesawing left and right as the brake pressure is altered to keep it heading straight. Is there any way of setting up differential braking so that if the brake pressures are within, say, 10% of each other [BRAKES]  are equally applied rather than just left or right brake?

[Pete Dowson]

1 hour ago, Masterius said:

Issue one is that, on random occasions, the brakes just stop braking. The popup flag [DIFFERENTIAL BRAKE] will disappear whilst braking, then reappear when the brake pressure is slightly altered.

Sounds like your differential ("toe" brakes normally described) aren't calibrated very smoothly.

1 hour ago, Masterius said:

when brakes are equally applied, or fully applied, it alters from [DIFFERENTIAL BRAKES] TO [BRAKES].

Yes, that is correct. They aren't applied differently when they are applied with the same pressure. Quite logical.

1 hour ago, Masterius said:

Getting the brakes to equally apply is terribly difficult unless fully applied. And it appears the differential application is 'all-or-nothing'. By that I mean it appears that if I'm applying pressure to both brakes, whichever one is seeing a higher pressure takes effect while the other brake is fully released.

Well in that case there's something either very wrong with whichever aircraft you are using, or with your brake pedals or calibration.  When you assign or calibrate do you see the values from the brake axes changing gradually, or do they jump from a low number to a high number? If the latter then it sounds as if they are either very badly calibrated, or are defined in the registry as "digital" (i.e only on or off).

1 hour ago, Masterius said:

Is there any way of setting up differential braking so that if the brake pressures are within, say, 10% of each other [BRAKES]  are equally applied rather than just left or right brake?

Normal use of toe brakes is to just balance them with your feet (toes really) to maintain your course along the taxiway or runway. You should be able to do that easily with a little practice. If not then your controls are probably very badly set up.

For more assistance you'll need to tell us more -- what simulator, what controls, how set up and calibrated? And if you are using FSUIPC, which version.

Pete

 

[Masterius]

1 hour ago, Pete Dowson said:

Sounds like your differential ("toe" brakes normally described) aren't calibrated very smoothly.

Since I use the joystick calibration function of FSUIPC, and set their Max/Min at the full range of travel, and since both brakes are -16384/+16383, and since their Flight Control Response curve are both zero, I'm at a loss at how they could be construed as being "aren't calibrated very smoothly".

1 hour ago, Pete Dowson said:

Yes, that is correct. They aren't applied differently when they are applied with the same pressure. Quite logical.

Yes, it is quite logical, and also what I would expect. I commented on that as an observation due to the fact that the flight sim recognizes that by altering from a [DIFFERENTIAL BRAKE] condition to a full, dual [BRAKE] condition, in case that was germane to the rest of my post.

1 hour ago, Pete Dowson said:

Well in that case there's something either very wrong with whichever aircraft you are using, or with your brake pedals or calibration.  When you assign or calibrate do you see the values from the brake axes changing gradually, or do they jump from a low number to a high number? If the latter then it sounds as if they are either very badly calibrated, or are defined in the registry as "digital" (i.e only on or off).

Normal use of toe brakes is to just balance them with your feet (toes really) to maintain your course along the taxiway or runway. You should be able to do that easily with a little practice. If not then your controls are probably very badly set up.

The aircraft I'm using is the A2A AccuSim B-17. The toe brakes are assigned using individual axis, and are calibrated using joystick calibration. During testing, each brake smoothly alters from -16384 to +16383 without a halt, skip, or bobble. Using Windows setup USB game controllers also shows a smooth, even progression from full off to full on.

1 hour ago, Pete Dowson said:

For more assistance you'll need to tell us more -- what simulator, what controls, how set up and calibrated? And if you are using FSUIPC, which version.

Pete

 

 

P3Dv5, version 5.1.12.26829

Saitek Pro Flight Rudder

FSUIPC 6.1.0

[Pete Dowson]

9 hours ago, Masterius said:

Since I use the joystick calibration function of FSUIPC, and set their Max/Min at the full range of travel, and since both brakes are -16384/+16383, and since their Flight Control Response curve are both zero, I'm at a loss at how they could be construed as being "aren't calibrated very smoothly".

Well, I can't see the values changing. Operate the brakes and observe how the numbers change. Some increase quite quickly with little pressure.

And leaving the calibrated values at -16384 to 16383, with no null zones at all and no slope considered, isn't really "smooth calibration" -- best to follow the numbered steps in the User Guide for good calibration. Toe brakes always need a healthy dead zone, and if you want more movement capability with more delicate braking, a slope with a flattened start.

All FSUIPC can do is transmit the values set by your choice of settings. The rest is up to P3D and the specific aircraft modelling. Maybe you can also adjust the "fierceness" of the brakes by values in the Aircraft.CFG file, but generally A2A are very fussy about their aircraft performance, so it would be better to adjust your controls to suit your needs.

Pete