Newcomer / Intro Understanding The Throttle Display & "6 Second Rule".

[withnail67]

There's a couple of things about the ship's throttle that I can't quite wrap my head around.

1. Looking at the throttle/speed display to the right of the sensor display, I understand that the left most blue section shows the throttle range where your ship is at its most maneuverable and the horizontal bar shows the current throttle setting. I assume the large arrows under that bar shows any difference between potential and current speed due to nearby gravity wells? But was is the thinner yellow gauge to the far right telling me?

2. The 6 second rule. If I reduce the throttle to 75% at 6 or 7 seconds away from my destination, the speed will decrease, keeping the ETA at 6 seconds. But, if I set the throttle to 0 at 5 seconds from my destination, I shoot past and have to loop back. Does setting the throttle to 75% at 6 seconds ETA engage a particular fly-by-wire routine, or is there another explanation?

Cheers,
Withnail67

 

[Thwarptide]

Are you talking about throttle in supercruise?

 

[Maenden]

You'll notice that as you set off on a journey the speed will increase and then start to decrease as you approach your destination - all without you doing anything - because the system programs the journey timing to accelerate and decelerate.
So in simple terms it accelerates at full power for the first half of the journey then decelerates at full power for the second half.
Dropping the power input to 75% - or less- gives you the time to react as you close on your destination because you're basically reprogramming the slowing down half at the end.

 

[MishaTX]

But, if I set the throttle to 0 at 5 seconds from my destination, I shoot past and have to loop back. Does setting the throttle to 75% at 6 seconds ETA engage a particular fly-by-wire routine, or is there another explanation?

Not exactly, though it's useful to think of it that way. Setting it at 75% at 6 seconds or higher gives the onboard computer plenty of time to decelerate for a safe exit while still going as fast as you can. At 5 seconds or below the ship will still decelerate if you throttle down, but it's too late for it to actually get all the way down to a safe exit speed in time.

 

[aRJay]

There's a couple of things about the ship's throttle that I can't quite wrap my head around.

1. Looking at the throttle/speed display to the right of the sensor display, I understand that the left most blue section shows the throttle range where your ship is at its most maneuverable and the horizontal bar shows the current throttle setting. I assume the large arrows under that bar shows any difference between potential and current speed due to nearby gravity wells? But was is the thinner yellow gauge to the far right telling me?

2. The 6 second rule. If I reduce the throttle to 75% at 6 or 7 seconds away from my destination, the speed will decrease, keeping the ETA at 6 seconds. But, if I set the throttle to 0 at 5 seconds from my destination, I shoot past and have to loop back. Does setting the throttle to 75% at 6 seconds ETA engage a particular fly-by-wire routine, or is there another explanation?

Cheers,
Withnail67

1 The large yellow arrows under the blue used to just be yellow blocks but were cosmetically changed a while ago, if they indicate anything it is just whether you speed is forward or reverse which is also shown by the speed indicators building from the top of the display.

2 The 75% throttle is effectively a basic auto throttle that reduces power to hold a 6 seconds to drop at target and can be engaged at any time if you do that a long time before you reach the six seconds point the trip takes longer as you are only at 75% if you engage after the six second point it doesn’t work because it is too basic to compensate for times shorter than 6 seconds. I tend to engage it at about 12 seconds to allow myself a second chance if the command wasn’t recognised first time.
If you don’t have a binding for 75% then setting the throttle to the middle of the blue should work.

 

[Chris Simon]

There's a couple of things about the ship's throttle that I can't quite wrap my head around.

1. Looking at the throttle/speed display to the right of the sensor display, I understand that the left most blue section shows the throttle range where your ship is at its most maneuverable and the horizontal bar shows the current throttle setting. I assume the large arrows under that bar shows any difference between potential and current speed due to nearby gravity wells? But was is the thinner yellow gauge to the far right telling me?

2. The 6 second rule. If I reduce the throttle to 75% at 6 or 7 seconds away from my destination, the speed will decrease, keeping the ETA at 6 seconds. But, if I set the throttle to 0 at 5 seconds from my destination, I shoot past and have to loop back. Does setting the throttle to 75% at 6 seconds ETA engage a particular fly-by-wire routine, or is there another explanation?

Cheers,
Withnail67

Ad 1) The horizontal bar is your throttle position, the thick bar is your "speed" (it's more complicated than that) and the thin bar is basically your thruster output (i.e. how hard and in which direction your thrusters are firing - notice that the bar fills up either from the bottom up or from the top to bottom, depending on which direction you're going)

Ad 2) Others basically said it all but to put it into simpler terms, your ship can only brake so hard, if you start braking too late, you will overshoot. At 6s ETA the thrusters are braking at their max capacity and it so happens that they brake at the same rate as you are approaching your target, so the ETA stays the same.
As a metaphore, you can look at it as the Falcon 9's suicide burn - the goal is to start braking at an exact point so you end up with 0 velocity at 0 altitude. For supercruise braking that point is 6-7s away from the target.

 

[Ashnak]

If you want my explanation for 2):
In supercruise, the FSD needs flat space (i.e. no gradient in gravity) for optimum performance. The steeper the gravity gradient, the slower the SC speed.
When accelerating, that's not an issue apart from limiting your speed. When you want to decelerate, though, a too steep gradient will let your FSD loose traction and you will fly faster than your FSD is able to control - if this is due to a gravity well, you'll then get the SLOW DOWN warning.
When approaching a station (signal source, whatever), your FSD can only brake so hard - at 6 seconds, you're riding the brakes all the way down to safe exit speed without (so to speak) locking the wheels.
The ship itself is capable of braking harder - there are a few tricks you can pull off with circling around, using gravity wells or (de)selecting SC assist - but the 6-second-rule is he easiest safe approch technique (apart from just tsicking the throttle to 75% all the way).

 

[CptArcher]

You'll notice that as you set off on a journey the speed will increase and then start to decrease as you approach your destination - all without you doing anything - because the system programs the journey timing to accelerate and decelerate.
So in simple terms it accelerates at full power for the first half of the journey then decelerates at full power for the second half.
Dropping the power input to 75% - or less- gives you the time to react as you close on your destination because you're basically reprogramming the slowing down half at the end.

Not exactly. The frame shift drive's acceleration profile and max speed is a function of distance to nearby mass. If one is traveling in deep space at 1000c and needs to stop, the deceleration to 0 m/s is very fast. Likewise, to speed back up 1000c is very fast. If near a massive object, the frame shift drive will accelerate very slowly and not achieve 1000c at all.

 

[Chris Simon]

Not exactly. The frame shift drive's acceleration profile and max speed is a function of distance to nearby mass. If one is traveling in deep space at 1000c and needs to stop, the deceleration to 0 m/s is very fast. Likewise, to speed back up 1000c is very fast. If near a massive object, the frame shift drive will accelerate very slowly and not achieve 1000c at all.

That is true. This is also why when traveling through a system with a large number of bodies, an arcing trajectory that takes you away from the ecliptic can be faster than slogging through the shipping lane.

 

[aRJay]

Not exactly. The frame shift drive's acceleration profile and max speed is a function of distance to nearby mass. If one is traveling in deep space at 1000c and needs to stop, the deceleration to 0 m/s is very fast. Likewise, to speed back up 1000c is very fast. If near a massive object, the frame shift drive will accelerate very slowly and not achieve 1000c at all.

You can show the effect on max speed by travelling away from a system in cruise or in a less pointless way by visiting Hutton Orbital from the Alpha Centauri arrival point once you get far enough away your speed at full throttle will increase to 2001c and will reduce again as you approach another mass.

A related effect is dropping distance to stations, outposts etc. usually we get the disengage message about 1000 km from the destination but for stations a long way from a gravity well that distance increases up to about 15,000 km for targets that are really isolated.

 

[withnail67]

Been away for a few days, but thanks for the fascinating discussion!