Trouble with Throttles and FSUIPC

[Michael Carter]

I am using five identical professional grade 100mm Panasonic linear slide pots for all axis.

The flaps and speedbrake are working fine. I've never had trouble with either of those two axis.

The three throttle pots refuse to cooperate with FSUIPC. During some programming attempts the throttle pots aren't even recognized as being hooked up. FS and the input card sees them just fine.

Other attempts have had one, two, and sometimes all three being recognized, but still unable to calibrate correctly one or more throttles. I've been using the program long enough to know how to calibrate an axis, including how to avoid a reverse thrust setting at the idle stops.

I've also tried copying one good throttle configuration from the .ini file to the other two throttles with no better luck than trying to perform a manual calibration through the GUI.

[XOrionFE]

The calibration is prohibited from having those out of order. The "minimum" or "max reverse" setting must be lower (or more negative if it goes negative -- not all axes do) than either of the centre or "idle" zone settings which must in turn be lower than the max (max thrust) setting.

That is the only imposition. It will not allow you to violate that rule (if it did it would really mess up the interpolation computations like crazy!).

So, if you somehow got a negative value in the max position, or a big positive value in the rev thrust or minimum position, you have to correct those first.

That is all. there are NO OTHER RULES there, only the imposition of order, low on left to high on right. The middle two have to be between the other two but themselves may be in either order. they just define the idle zone -- and it must be a zone, not just a "point". (There's really no such thing as a single selectable point on an analogue axis, even with detentes).

If your levers are acting in reverse, then you should select the REV option BEFORE doing the calibration. Otherwise the interpolations will be wrong. Reversing after calibrating is not good unless the axis is truly symmetrical, like aileron, elevator and rudder. Obviously for symmetrical axes the reversal is simple. For centres which are not truly central it gets the ranges into a real mess. So calibrate AFTER getting the direction correct.



I just can't imagine how it can take more than a couple of minutes at most. It is so stark-ravingly simple! What you see is exactly what you get. There's nothing hidden, nothing clever. It's just saying "my axis runs from here, which is where I want reverse, to here which is where I want idle to start, to here, which is the end of the idle zone, to here, where I want max thrust. That's it. Dead simple, nothing hidden, no magic.

I always advise making the two extremes a little away from your real extreme values, so you can be sure of always reaching them even with expected variations in the pot readings -- and you do get those. They vary with humidity, temperature, dirt, and so on.

The documentation only says the same. But mostly it is entirely intuitive and 99% of users find it so. I don't understand why some don't -- must be some sort of number blindness. Some folks are more graphically minded instead I assume. I prefer numerical precision.



Well, the whole system is really designed to provide a nice reverse thrust capability, that's why it was done, but you should be able to achieve that by making the one of the two centre/idle values as close as possible to the minimum value. Ideally the minimum value should be below the lowest negative number you can achieve, but of course you can't set that with the axis as it won't get there. You might be able to improve it by editing the numbers in the INI file afterwards. But you have to make the whole area, from just above your idle detente (to allow for variation as i said) to as close as you can get to the minimum, all part of the idle zone -- i.e. the two centre values.

That's all. It's much easier to do than describe.



Well, in the 10+ years FSUIPC has featured this facility I've only had about three requests asking how to remove the reverse zone, and my answer above has worked for those users. If there were a general clamour for it I would have added another set of 4 throttles with no reverse zone, or simply put such an option on that page, but it didn't seem to be needed and so would just make things more complex than necessary.

But please yourself. Use FS assignments if you really find this so so difficult. I just don't understand why.

Pete

It may be nothing wrong with your program and I am pretty certain I understand how it is SUPPOSED to work. Bottom line is that on one of my throttles the values go from being positive at low throttle position to Negative at high. And because the REV checkbox has NO effect on this (yes I set it before calibrating) I am unable to set it properly (Rev, Idle, Max) because as you said the program is designed to have values go from negative to positive (which makes sense). What you are saying about right now about getting rid of the reverse thrust zone now makes sense to me (if it was stated that way in your docs it would be helpful probably for others that want to do this in the future).

I am going to go mess with the wires and if I can get the values to work in the right direction I should be able to do what you said and remove the reverse.

[Tomlin]

Scott-

Hang in there. For some reason things dont always work the way that we assume that they will and when that happens, we sometimes get stuck in a rut expecting one result and getting another, and of course frustration insues and we make no progress. Keep your chin up- what you need to do is very possible using FSUIPC but maybe step back and take a break for a while and give it another try later. I have had this happen on numerous issues before, and a break is almost always a good temp solution.

[XOrionFE]

Thanks Eric,

I just figured out part of the issue and that is that by reversing the wiring on the pot I took care of my problem with low being positive and high being negative. So it is not FSUIPC but I got fixated on that damned REV checkbox and kept thinking it should be managing the direction of the values. The reality is that only the wiring could do that. (Pete - I am going to read your doc again but perhaps putting something in there that says if your values are not going from negative to positive you have to reverse your wires...etc).

Anyway, it is working now. I am still fighting a little with getting rid of the reverse thrust zone but not because FSUIPC but because my pot values fluctuate and so sometimes it is working and sometimes not. I did try editing the .ini file but it didnt seem to stick or work as I still get the reverse now and then. This is a cool feature (reverse thrust zone) for throttles without reverse thrust levers but of course that is not the case with the learjet.

Now I just need to get it to be consistant (maybe better pots...) and I will also have to put some switches on the back side that can be activated by pulling the levers all the way back to stops and thus make them activate the cutoffs.

Thank you for your help Pete. Remember, you wrote the program so of course it is simple in your mind. For the rest of us we may not always see the obvious. And by the way, I am a numerical thinker also.....

Scott

[XOrionFE]

Thank you Jack and Ian for helping by pointing out the wiring of the pots. That did it.

[Peter Dowson]

Pete - I am going to read your doc again but perhaps putting something in there that says if your values are not going from negative to positive you have to reverse your wires...etc).

That really should be completely unnecessary. I cannot imagine what you were doing, but all the REV button does is active a little line in the code which inverts the input it is receiving BEFORE passing it on for calibration. In other words it simply does "N = -N". That should be enough. It works here, as it always has worked. It is effectively the same as the Reverse facility in FS itself. It isn't complicated, it is simply that.

You should NEVER have to reverse the input, and I really cannot advise that in the documentation. You forget that 99.99% of FSUIPC users use ready-made joysticks and throttles, not home made gear.

my pot values fluctuate and so sometimes it is working and sometimes not.

The more the values vary the greater the dead zones need to be on the calibration. It is a shame. You start losing too much movement.

I did try editing the .ini file but it didnt seem to stick

INI values remain in use and unchanged unless you go into the calibration tabs and change them. They are only ever written there or by your own editing.

This is a cool feature (reverse thrust zone) for throttles without reverse thrust levers but of course that is not the case with the learjet.

The usual way to deal with this is surely to have the thruster and reverser pots in series. Then the thruster pot gets part of the range, and you calibrate it with idle zone and max thrust zones, and calibrate the reverser part (in the same FSUIPC section) with the reverser lever.

Now I just need to get it to be consistant (maybe better pots...) and I will also have to put some switches on the back side that can be activated by pulling the levers all the way back to stops and thus make them activate the cutoffs.

Cutoffs are operated by the thrust levers on a Learjet, not separate levers? Does that work the other way too (to start)? Sounds a bit dodgy.

Regards

Pete

[XOrionFE]

That really should be completely unnecessary. I cannot imagine what you were doing, but all the REV button does is active a little line in the code which inverts the input it is receiving BEFORE passing it on for calibration. In other words it simply does "N = -N". That should be enough. It works here, as it always has worked. It is effectively the same as the Reverse facility in FS itself. It isn't complicated, it is simply that.

You should NEVER have to reverse the input, and I really cannot advise that in the documentation. You forget that 99.99% of FSUIPC users use ready-made joysticks and throttles, not home made gear.

The more the values vary the greater the dead zones need to be on the calibration. It is a shame. You start losing too much m


INI values remain in use and unchanged unless you go into the calibration tabs and change them. They are only ever written there or by your own editing.



The usual way to deal with this is surely to have the thruster and reverser pots in series. Then the thruster pot gets part of the range, and you calibrate it with idle zone and max thrust zones, and calibrate the reverser part (in the same FSUIPC section) with the reverser lever.



Cutoffs are operated by the thrust levers on a Learjet, not separate levers? Does that work the other way too (to start)? Sounds a bit dodgy.

Regards

Pete

Not sure about 99% of users but in my case the rev didnt do the job but changing the wiring did.

As for cutoffs, on the learjet the thrust levers do handle the cutoff. Cutoff is achieved by overcoming the Idle dentent and pulling th ethrottles all the way back to the stops. So right now I set the bottom most Travel point of the levers in Reverse Zone. Then I set the Low end of Idle to the same value and the high end of Idle to just forward of the Idle detent/stop. I shut down FSX and went into the .ini file and edited the second value on each line (Idle Min) to be about 100 more negative then the Reverse Value (I am assuming the values are Reverse, Idle Min, Idle Max, Max. Does this sound like what you were intending?
As for cutoff then, not sure how I could setup other than using a switch that would get engaged by pulling the handles all the way back then mapping the switch to the cutoff command with my encoder.
I did see that you can map a key to a zone in the axis assignment tab. havent tried that though yet. Might that work for this if I set the bottom range (Reverse to Idle Low for instance) to assign Throttle Cutoff command?

Thanks Pete

[Peter Dowson]

Not sure about 99% of users but in my case the rev didnt do the job but changing the wiring did.

Yes, but it isn't logical ("it does not compute") because the REV button simply changes the sign. It can't fail to reverse the direction, so it is very very puzzling. As I cannot see your PC and you using it from here I don't know what exactly you are doing to get this to happen. Shame. Maybe if i saw what you were doing it would be immediately obvious.

As for cutoffs, on the learjet the thrust levers do handle the cutoff. Cutoff is achieved by overcoming the Idle dentent and pulling th ethrottles all the way back to the stops.

Yes, you said that already. What I asked was does it do the reverse, i.e. automatically enable the fuel when you push the levers off the stops? As I said, it seems a bit dodgy to me if it does.

right now I set the bottom most Travel point of the levers in Reverse Zone. Then I set the Low end of Idle to the same value and the high end of Idle to just forward of the Idle detent/stop.

Sounds good.

I shut down FSX and went into the .ini file and edited the second value on each line (Idle Min) to be about 100 more negative then the Reverse Value

Interesting. I'd have to look at the code to see what that might actually do. Does it work?

(I am assuming the values are Reverse, Idle Min, Idle Max, Max. Does this sound like what you were intending?

Not really. I think it should work if the values are the same. That's what most folks do. I'd need to work through the code to check exactly.

As for cutoff then, not sure how I could setup other than using a switch that would get engaged by pulling the handles all the way back then mapping the switch to the cutoff command with my encoder.

Well a button or microswitch would work. Not sure why you'd need any encoder. Can't you feed buttons/switches through your controller board as joystick button presses? Then simply program it in FSUIPC or FS.

I did see that you can map a key to a zone in the axis assignment tab. havent tried that though yet. Might that work for this if I set the bottom range (Reverse to Idle Low for instance) to assign Throttle Cutoff command?

Yes, you can do that. However you've got no range from reverse to idle low and if you had any it would activate reverse because of the axis arrangement, notwithstanding any control assignments on the right-hand side.

BTW FS doesn't sport a control known as "throttle cut-off". You have to use Mixture Lean.

Regards

Pete

[XOrionFE]

Yes, but it isn't logical ("it does not compute") because the REV button simply changes the sign. It can't fail to reverse the direction, so it is very very puzzling. As I cannot see your PC and you using it from here I don't know what exactly you are doing to get this to happen. Shame. Maybe if i saw what you were doing it would be immediately obvious.

Yes, you said that already. What I asked was does it do the reverse, i.e. automatically enable the fuel when you push the levers off the stops? As I said, it seems a bit dodgy to me if it does.

Not sure but I will check. I am still trying to learn how they really are supposed to work. Your assumption is probably correct. I will check with Mr. Learjet...Eric Tomlin
Sounds good.

Interesting. I'd have to look at the code to see what that might actually do. Does it work?

Didnt seem to matter. The best result I got was just having the Reverse and low Idle values be the same like you said setting them through the interface. I know that if I changed the value in the .ini and then went back to the interface, it was not reflected in the interface.
Not really. I think it should work if the values are the same. That's what most folks do. I'd need to work through the code to check exactly.

Yes, that is what I did and where I left it for now.
Well a button or microswitch would work. Not sure why you'd need any encoder. Can't you feed buttons/switches through your controller board as joystick button presses? Then simply program it in FSUIPC or FS.

Yes, that is what I meant. I will feed it through my Hagestrom controller board.
Yes, you can do that. However you've got no range from reverse to idle low and if you had any it would activate reverse because of the axis arrangement, notwithstanding any control assignments on the right-hand side.

oops, yes you are righht and I didnt think of that. I will just use microswitches.
BTW FS doesn't sport a control known as "throttle cut-off". You have to use Mixture Lean.

Didnt realize that. Thank you as I probaby would have been going nuts looking for a throttle cut-off function.
BTW - I think your software is great and apologize for fumbling through it but I can say that most of what we do probably wouldnt be possible where it not for your software so I appreciate it and your help.
Regards
Pete

Thank you,
Scott

[Tomlin]

Yes, you said that already. What I asked was does it do the reverse, i.e. automatically enable the fuel when you push the levers off the stops? As I said, it seems a bit dodgy to me if it does...

BTW FS doesn't sport a control known as "throttle cut-off". You have to use Mixture Lean.

Regards

Pete

Pete, just for clarification since there are lots of new LJ45 projects that are springing up-

The Learjet 45 and 40 have the same TQ/Lever system. Scott was correct in the fuel cutoff and enable but maybe this will clarify just a bit since it works quite well in the real world and is very simple.

When ready for engine start, the crew simply push the levers forward and the cutoff pins drop into the idle spot. At that point the crew press the desired engine switch and start either 1 or 2.

When ready for shutdown, the levers are brought to idle, and then you pull up on the idle cutoff levers, located under the lever knobs. Then the levers are brought back to Cutoff and they shut down.

For those interested...



BTW Pete, thanks for the reminder about 'Mixture Lean' for all the folks- that one got me about a while back.