Engine start and idle detent question
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if the engine isn’t starting you’re doing it wrong.
possibilities:
your throttle isn’t bound
you’re not doing it quickly/slowly enough
you rebound idle detent
you don’t have idle detent and are using the non software thing but doing it incorrectly somehowdon’t you think everyone would kind of notice that they can’t start the jet since 4.33 u1
i mean you do that every mission after all unless you’re a filthy casual
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@Red:
Nope, the idle cutoff option from BMS config is 100% realistic, if set correctly. But to be able to use it you need strong physical detents to be sure that you don’t inadvertently go past the detent as you’re reducing throttle in flight. With the option enabled and going past the detent you will shut the engine off.
Well…more like 80% realistic…
In a real jet(s), the detent/latch/lock/lever, etc is actuated first, then the pilot pulls the lever aft WELL PAST the detent to engine cut off to shut down the engine. In BMS with Engine Idle Cutoff enabled in Config, the detent and the engine cutoff are located in the same part of the throttle stroke which is not realistic. Even with a rock solid detent (9mm shell casing in my case), the idle detent setting in setup/controllers can still drift a little bit eventually causing inadvertent inflight engine cutoff (or engine that won’t spool down completely to idle RPM) when pulling the throttle to idle against the hard detent. As currently modeled, there is virtually no margin for error between “idle detent” and engine cutoff. To add a small margin of error against inadvertent inflight engine shutdown for sim pilots using a hard detent throttle, I posted the following suggestion in joysticks/CH forum (note step 3):
The combined “engine idle detent/cutoff” as currently modeled in the sim needs to be corrected by separating these two functions into two different settings. One for the detent/latch/lock/lever, etc. (essentially idle RPM) and one for the cutoff of the engine. I posted a more detailed explanation here.
F1
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I’m a little puzzled by idle detent and throttle inputs, and I’m not sure whether this is normal behaviour or it indicates an issue of some kind.
I select JFS2 and RPM rises to 20%. I set throttle to approximately 50% and press Alt+i. The SEC light illuminates briefly and then goes out. RPM does not rise. I then reduce throttle to idle and then return it to 50%. RPM then rises.
It doesn’t seem to come out of idle detent without significant throttle input.
Try this or similar instead of Alt i (how to push throttle forward to light off the engine):
F1
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I created a video showing the procedure with idle cutoff first unchecked and then checked.
Note that with it unchecked I advance the throttle, Alt-i, then when RPM doesn’t rise above 20% I return throttle to idle and advance it again to approximately 50%, at which point it does rise.
Then in the second example with idle cutoff checked I do no more than select JFS 2.
MS Sidewinder FFB.
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Checking Idle cutoff in the config is, if performed as the only step, a simple case of misconfiguring the software and blaming it on the software.
You also need to set the position of the detent, and by default it is positioned at the very back of the throttle movement. Which means the software considers you already to have advanced the throttle over the detent.
If you want it to work you need to also set the detent position in setup, by positioning the throttle just aft of the detent position and right clicking the set AB button. Left clicking sets the green AB line, right clicking the red IDLE line.
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I would expect Alt+i to work without throttle movement.
That’s the key word, expect. BMS doesn’t function how one expects. The user can resolve this problem through patience in having the software change or by altering their understanding. I recommend the latter as it is more timely.
The idle detent logic is simple to grasp if the proper effort is put forth. There are only two elements at work: if the idle detent command is given and what is the throttle axis value at that time. The user has only these two inputs to concern himself with and in the proper order: axis first, command second.
At the moment the command is given, the program looks at the axis value. If the axis value is > X% then it will move the throttle to the working range. If the axis value is <y% then=“” it=“” will=“” move=“” the=“” throttle=“” to=“” off.=“” change=“” in=“” setting=“” depends=“” entirely=“” on=“” axis=“” value=“” <em=“”>at the time the idle detent command is given. In this way we can see that the idle detent command can do two actions (three if one includes doing nothing) and this decision is entirely depending on the throttle controller axis value which is set immediately before the command is given.
If the user wants to advance the throttle then he must set an axis value consistent with this desire first and issue the detent command second. (>X%)
If the user wants to reduce the throttle then he must set an axis value consistent with this desire first and issue the detent command second. ( <y%)<br>It would be nice for general information to have exact values of X and Y for completeness.</y%)<br></y%> -
I have 1 view on that video, which I think speaks for itself.
The video explains clearly the issue. I can’t do any more than put the time and effort in to create a video showing what the issue actually is. But I feel that no one is actually listening to what I’m saying, or, indeed, showing.
I don’t have a detent, I’m not enabling cutoff other that to demonstrate that the engine spools up without using Alt-i when I do have it enabled.
Without cutoff enabled in config I have to push the throttle forward, Alt-i, pull it back to idle and push it forward again.
Let me be absolutely clear, and, again, this is with a throttle without a detent:
Example A
- push throttle forward to 50%
- Alt-i
- back to idle
- push throttle forward to 50%
That is the only way I can increase RPM over 20%
Example B
- I don’t have to do a thing with throttle or Alt-i - RPM increases past 20% all by itself
I was told that’s incorrect, but if you watch the video, that’s exactly what happens.
I wanted to understand what exactly is happening. That was the purpose of opening this thread. I like to understand things. However I will just document it as I have experienced it, which is not optimal.
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I have 1 view on that video, which I think speaks for itself.
The video explains clearly the issue. I can’t do any more than put the time and effort in to create a video showing what the issue actually is. But I feel that no one is actually listening to what I’m saying, or, indeed, showing.
I don’t have a detent, I’m not enabling cutoff other that to demonstrate that the engine spools up without using Alt-i when I do have it enabled.
Without cutoff enabled in config I have to push the throttle forward, Alt-i, pull it back to idle and push it forward again.
Let me be absolutely clear, and, again, this is with a throttle without a detent:
Example A
- push throttle forward to 50%
- Alt-i
- back to idle
- push throttle forward to 50%
That is the only way I can increase RPM over 20%
Example B
- I don’t have to do a thing with throttle or Alt-i - RPM increases past 20% all by itself
I was told that’s incorrect, but if you watch the video, that’s exactly what happens.
I wanted to understand what exactly is happening. That was the purpose of opening this thread. I like to understand things. However I will just document it as I have experienced it, which is not optimal.
It’s private……
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I have 1 view on that video, which I think speaks for itself.
The video explains clearly the issue. I can’t do any more than put the time and effort in to create a video showing what the issue actually is. But I feel that no one is actually listening to what I’m saying, or, indeed, showing.
I don’t have a detent, I’m not enabling cutoff other that to demonstrate that the engine spools up without using Alt-i when I do have it enabled.
Without cutoff enabled in config I have to push the throttle forward, Alt-i, pull it back to idle and push it forward again.
Let me be absolutely clear, and, again, this is with a throttle without a detent:
Example A
- push throttle forward to 50%
- Alt-i
- back to idle
- push throttle forward to 50%
That is the only way I can increase RPM over 20%
Example B
- I don’t have to do a thing with throttle or Alt-i - RPM increases past 20% all by itself
I was told that’s incorrect, but if you watch the video, that’s exactly what happens.
I wanted to understand what exactly is happening. That was the purpose of opening this thread. I like to understand things. However I will just document it as I have experienced it, which is not optimal.
Just a guess…
Example A, #3, if not already done so, open Windows Joy Properties and confirm that the throttle axis graphic is not around 50% when the throttle lever is full aft. If not, fix issue then try again.Example B: as you have discovered, Alt I is not needed if Idle Detent is enabled in Config. However, “all by itself” (no throttle input) is definitely incorrect. If throttle not properly calibrated, engine may autostart with no additional input.
F1
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Well…more like 80% realistic…
Nope, I stand by what I said. The idle cutoff code in BMS config is made to accurately represent the very same way of the F-16. All cockpit builders here will tell you that.
You obviously (software options won’t get you a cutoff lever, throttle gate, …) need to have the hardware as I said earlierIn a real jet(s), the detent/latch/lock/lever, etc is actuated first, then the pilot pulls the lever aft WELL PAST the detent to engine cut off to shut down the engine
. Exactly how we pit builder do it, with the cutoff code
In BMS with Engine Idle Cutoff enabled in Config, the detent and the engine cutoff are located in the same part of the throttle stroke which is not realistic. Even with a rock solid detent (9mm shell casing in my case), the idle detent setting in setup/controllers can still drift a little bit eventually causing inadvertent inflight engine cutoff (or engine that won’t spool down completely to idle RPM) when pulling the throttle to idle against the hard detent. As currently modeled, there is virtually no margin for error between “idle detent” and engine cutoff. To add a small margin of error against inadvertent inflight engine shutdown for sim pilots using a hard detent throttle, I posted the following suggestion in joysticks/CH forum (note step 3):
Never happened to me in 10+ year of using BMS and my pit. You must have calibration issues (some using auto calibration for the Cougar might see that issue)
In that case, the problem is not the way BMS coded the cutoff, but rather the user way of calibrating his throttle, which is outside the scope of the BMS code -
@Red:
Nope, I stand by what I said. The idle cutoff code in BMS config is made to accurately represent the very same way of the F-16. All cockpit builders here will tell you that.
You obviously need to have the hardware as I said earliernot all… I can only conclude you did not read the post, and assumed it was the same issue as above (it is not).
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I quoted the part I’m replying to Bw (which was a reaction to a post of mine), isn’t that obvious enough?
I haven’t seen any VP member complaining about that bit of code. It does work beautifully if implemented correctly along suitable hardware -
Of course VP members are the only ones who count.
I would say it works 80% beautifully. It might be possible to set up 100% beautifully, with a modified curve on the cougar throttle, so that for the OFF-> IDLE transition where the BMS cutoff is set, the reported value to DX is constant (flat line on profile curve). Of course to be ideal, this would mean setting the cutoff value in a config file rather than clicking the (rather imprecise) slider in setup.
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Supanova, when you first enter the pit (cold), before you do anything, do you move the throttle up and down? I’ve found in BMS that every mission I load (when the jet is already in the air especially) that it won’t respond on the throttle until I’ve moved it all the way up and down again. So, say I join the 3D world and my physical throttle is midway, the games throttle won’t respond to my inputs until I’ve moved the physical throttle to the extremes.
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Sorry, replying here, definitely, yes. It’s nothing about the sim, but about recognizing your hardware, in my opinion, a sort of calibration or course range, if not one.
Supanova, when you first enter the pit (cold), before you do anything, do you move the throttle up and down? I’ve found in BMS that every mission I load (when the jet is already in the air especially) that it won’t respond on the throttle until I’ve moved it all the way up and down again. So, say I join the 3D world and my physical throttle is midway, the games throttle won’t respond to my inputs until I’ve moved the physical throttle to the extremes.
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Supanova, when you first enter the pit (cold), before you do anything, do you move the throttle up and down? I’ve found in BMS that every mission I load (when the jet is already in the air especially) that it won’t respond on the throttle until I’ve moved it all the way up and down again. So, say I join the 3D world and my physical throttle is midway, the games throttle won’t respond to my inputs until I’ve moved the physical throttle to the extremes.
I’ve seen this happen too, but not always…so as a rule I tend to include a throttle movement in my cockpit wipeout…even though that may not be strictly “checklist”.
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I’ve seen this happen too, but not always…so as a rule I tend to include a throttle movement in my cockpit wipeout…even though that may not be strictly “checklist”.
I’ve started doing so as well, as it happens 99% of the time for me. Like I said above, it happens mostly in training missions when the jet is already in the air.
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That always happens for me. The axis value is not used by the game until it moves “some amount” which I would guess is ~5% (haha, what a guess). In air start without touching the throttle axis there’s no way to keep flying as it initializes to idle. As you move the axis very slowly it is seen that it will “wake up” at a certain change of input.
Experiment #1: start -26213, wake up -4135.
Experiment #2: start 43161, wake up 7999.Delta: 22,078, 35,162
Fraction: 33.7%, 53.7%.Experiment #3: start 2, wake up 22124.
Delta, Fraction: 22122, 33.8%.
Experiment #4: start 24, wake up -21934.
Delta, Fraction: 21,910, 33.4%.I may have been sloppy on #2. Taking #1, #3, #4 and the theory of round numbers it appears that the throttle will wake up when it is moved through 33.3333333% of its range. For example if you start the session at 41% axis then the axis will wake up when leaving the range 8-74%. This also means that for some starting axis positions (<33%, >66%) that you cannot wake up the throttle by moving it in one of the two directions as it’s impossible to travel 33% before you reach the min/max value limit.
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I’ve started doing so as well, as it happens 99% of the time for me. Like I said above, it happens mostly in training missions when the jet is already in the air.
That sounds familiar too…
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That always happens for me. The axis value is not used by the game until it moves “some amount” which I would guess is ~5% (haha, what a guess). In air start without touching the throttle axis there’s no way to keep flying as it initializes to idle. As you move the axis very slowly it is seen that it will “wake up” at a certain change of input.
Experiment #1: start -26213, wake up -4135.
Experiment #2: start 43161, wake up 7999.Delta: 22,078, 35,162
Fraction: 33.7%, 53.7%.Experiment #3: start 2, wake up 22124.
Delta, Fraction: 22122, 33.8%.
Experiment #4: start 24, wake up -21934.
Delta, Fraction: 21,910, 33.4%.I may have been sloppy on #2. Taking #1, #3, #4 and the theory of round numbers it appears that the throttle will wake up when it is moved through 33.3333333% of its range. For example if you start the session at 41% axis then the axis will wake up when leaving the range 8-74%. This also means that for some starting axis positions (<33%, >66%) that you cannot wake up the throttle by moving it in one of the two directions as it’s impossible to travel 33% before you reach the min/max value limit.
This sounds “near” to consistent with moving a RL throttle out of it’s lift gate and into idle position - that first “near third” has no net effect other than to get fuel flowing…and what I was referring to when I mention I thought I’d read about this someplace; and also sounds like most of my TQS’s behave. I thought you could override this in setup/calibration somehow but I’ve not really delved into it as I’m working on a setup to do/use just this (building a full pit). Someplace I recall seeing calibration charts for doing realistic setups, but it was out on the web and not here.