Motion Platform Profile for FSX - X-Sim

[toktiny]

Hi Pete

It must be ten years since I sent you an E-Mail with a FS problem. Hope you are keeping well . I have been a registered FSUIPC customer down through the years. I am using Version 4.53.

Now my problem this time is that I have just completed building myself a 2DOF Motion Platform with SCN5 actuators for FSX using X-Sim for a driver and the problem is that I can not select a suitable effect for Banking and Pitching. I have tried ( as far as I can select ) all the X and Y acceeration effects and also any roll efffects but I am afraid that despite the fact that I can get very good movement I find it impossible to syncronize screen with platform.

They have been most helpful in X-sim Forum regarding SCN5’s and FSX profiles but the main interest seems to be in car racing so there is not one FSX profile available that one could use as a model to work from . One of the lads , Bernard , whom I have the highest of faith in but unfortunatly is not a flightsimmer, has said that the type of effect we should be looking for is one without acceleration as this tends to introduce problems.

Pete I would be most grateful if you would , being the guru of flightsimming over the years, which I would vouch for, suggest the best effect to use.

Kind regards

Toni

[Pete Dowson]

... the problem is that I can not select a suitable effect for Banking and Pitching. I have tried ( as far as I can select ) all the X and Y acceeration effects and also any roll efffects but I am afraid that despite the fact that I can get very good movement I find it impossible to syncronize screen with platform.

I'm no expert on such matters, but surely there's no way, and no reason, to match pitch bank and yaw with the simulated aircraft. Apart from the crazy positions you might try to get into, I didn't think that was the point of motion platforms. Surely you are just after the "feel", so only accelerations are of use -- apart from vision and sound, which of course you have, it is really only the accelerations give any sense of change to the body. And then, to keep the platform from crazy attitudes you do a thing called wash-out (I think) which slowly returns the platform at constant speed so it is ready to move again.

They have been most helpful in X-sim Forum regarding SCN5’s and FSX profiles but the main interest seems to be in car racing so there is not one FSX profile available that one could use as a model to work from . One of the lads , Bernard , whom I have the highest of faith in but unfortunatly is not a flightsimmer, has said that the type of effect we should be looking for is one without acceleration as this tends to introduce problems.

Really? I don't think there's anything but accelerations which would be useful at all. Trying to do any sort of match of actual pitch, bank, heading, and their rotations would simply be doomed as far as I can see, and not justified in the first place. The orientations and speeds of the aircraft aren't relevant if they aren't changing.

How you program that, scale it, whatever, and then do the wash-out part, I've no idea. Although I've found it an interesting proposition in the past I've really never had the hardware to do anything with, and whilst I'd love it for my 737NG cockpit I don't think the floorboards will take the strain of a 2000 lb bulk moving about! ;-)

Regards

Pete

[toktiny]

Hi Pete

Many thanks for your prompt reply.

I think I did not make it too clear what I have here. Let me explain, over the years I have built a cockpit and I was looking around for a type of motion platform that would more or less just fit in nicely in front of all my controls and five monitors. I came across the seat type platform worked from two SCN5 actuators which I was able to build with a front frame which really replaced my origional cabin seat. This means that the whole cabin is not included in the motion, just the seat. I wondered what you meant when you said "2000 lb bulk moving about" !!

I will try to explain the problem in more detail. I have created several profiles for various planes which have got completely different characteristics and I have adjusted the combinations of values which suit each plane individually and the planes are all corrusponding very much the same. As far as I can follow in the tweaking of the profiles a lot depends on the cruising speed of the aircraft. I am at the moment getting approx 20 degree full forward and backward movements, I am also getting full 20 degree left and right banking movements, I am also getting where you have a combination of lets say a forward pitch and a left bank a movement which I would say could be better but this is due I feel to more improvment needed to the profile.

Now you might say how can I be sure of all this, I will tell you, I take my B737 up to lets say 5000 ft. at a speed of 200 and use my AP to hold her at this, this leaves that the only manual control available is to bank her at whatever degree I want. Now I have my X-SIM ForceProfiler operating on my fourth monitor at the side wall of my cabin and it is on Math Input selection which enables me to watch the analyzer. This enables me as I fly to feel the movement and also to watch and check the actual movement on the monitor which is recording. I do exactly the same with appropriate settings to check all other movements e.g pitch etc.etc.

The strange thing that happens and I can not understand it , I will try to outline it. If you imagine you are flying at a given fixed altitude in a straight line and you turn the Yoke to bank lets say 50 degrees to the left, the motion platform will lean to the left until it gets to approx 20 degrees fairly following the angle of the plane but when it gets to the end of its full span it does not hold in that position but then starts to return to its center position even though the plane may not have accomplished its full desired 50 degrees direction and is still on a bank. Why is the seat dictating the movement direction after it reaches its maximum reach and returning to center while the plane is still turning on its selected course and I have the yoke still held in the same position ? If I can describe a simular situaton with a car at very slow speed. You turn the steering wheel to turn a long slow bend , half way round the bend the seat starts to return to center position while you still have a lock on the wheel to finish getting round the rest of the bend. Please excuse my simple way of explaining .

Now I have found a way around this which may indicate something but it not the right way to correct the problem. If the initial speed that you allocate is in accordance with the amount of change of direction that you request the motion platform movement will syncronize perfectly with the planes movement, i.e. Initial Speed 100 : 25 Degree turn or Initial Speed 150 : 50 Degree turn, in other words the greater the turn the greater the initial speed required to keep the two in unison, the acceleration can remain the same. I realise that this is an impossable way to get proper sync..The profile has to be adjusted to syncronize properly but I am afraid I have not found the answer.

What I meant in my first post was that acceleration in the effect seems to return the platform to center after it has completed and come to the end of its its designated span which is not in sync. with the rest of the bank that remains for the plane. I should also explain that my main aircraft that I use is a B737-800 or a twin prop Beech Baron which does not require very fast movements.This is why I dont understand when you say that the orientations of the plane would not be changing when the plane banks or pitches . Surely when the plane banks or pitches this will provide movement ? As I explained earlier I have tried the acceleration effects and they all seem to return to center when they dictate which I dont want them to do. I want the effect to follow the movement of the plane.

Hope this might explain my problem a bit better.

Kind regards

Toni

[Pete Dowson]

I wondered what you meant when you said "2000 lb bulk moving about" !!

That's what would be necessary in my case. I was only explaining why i had never followed it up.

I am at the moment getting approx 20 degree full forward and backward movements

Sorry, I don't understand how an angle applies to moving forward and backward, Are you perhaps referring to pitch, controlled by elevator?

I am also getting full 20 degree left and right banking movements, I am also getting where you have a combination of lets say a forward pitch and a left bank a movement which I would say could be better but this is due I feel to more improvment needed to the profile.

So you just have a seat swinging about but the scenery view and instruments remaining static? I must admit i cannot imagine what you are doing, it makes no sense to me. If you cannot stop FS also displaying the pitch and bank in the scenery view, and the instruments are going up and down and left and right in front of you (relative to you and your seat), how can that be any sort of flight simulation?

Now you might say how can I be sure of all this, I will tell you, I take my B737 up to lets say 5000 ft. at a speed of 200 and use my AP to hold her at this, this leaves that the only manual control available is to bank her at whatever degree I want. Now I have my X-SIM ForceProfiler operating on my fourth monitor at the side wall of my cabin and it is on Math Input selection which enables me to watch the analyzer. This enables me as I fly to feel the movement and also to watch and check the actual movement on the monitor which is recording. I do exactly the same with appropriate settings to check all other movements e.g pitch etc.etc.

Sorry, I don't understand any of that. I cannot relate at all to wehat you are trying to do.

The strange thing that happens and I can not understand it , I will try to outline it. If you imagine you are flying at a given fixed altitude in a straight line and you turn the Yoke to bank lets say 50 degrees to the left, the motion platform will lean to the left until it gets to approx 20 degrees fairly following the angle of the plane but when it gets to the end of its full span it does not hold in that position but then starts to return to its center position

50 degrees of bank seems enormously out of any range I know for any sort of platform. Is your seat mounted on some sort of universal joint? How is it you don't fall out?

If I can describe a simular situaton with a car at very slow speed. You turn the steering wheel to turn a long slow bend , half way round the bend the seat starts to return to center position while you still have a lock on the wheel to finish getting round the rest of the bend.

I've never had any experience of a car with tilting seats, and i would worry that if it tilted as much even as 20% i would not be able to easily read the instruments nor see where I was going!

Surely when the plane banks or pitches this will provide movement ?

No, only when it STARTS banking or pitching. If an aircraft continues banking or pitching at a fixed rate you do not feel the effect. Only accelerations are felt.

It sounds as if you are getting the wash-out I mentioned, even if you didn't program it. You should surely be using accelerations, and once those settle, so then should the platform, move back to straight and level ready for the next effect. I am certain that all of the good motion platforms I have experienced are based on acceleration effects. That seems to be the whole point -- it is the ILLUSION you are after, not the real pitch or bank in your home. After all the instrumentation must remain static in front of you -- your chair swivelling about in front of everything really does seem ludicrous to me. I'm not trying to be insulting here, and maybe it is just that I don't understand what you are trying to achieve. It all sounds completely wrong to me.

Regards

Pete

[toktiny]

Hi Pete

I feel that we have now reached a point in our post where the preference of different types of platforms is being expressed fairly strongly, however, as I see it everyone is entitled to there own choice and I will take some comments to be meant more in humour than for real.

The truth of the matter is that you obviously dont have a preference for the type of platform that I have built and you would only consider one of these enclosed cabins mounted on a 6DOF platform and operated with six large motors weighing 2000 lbs.as being the real experiance.Well so be it Pete ,I am not in that league and am very happy with what I have and can afford in my computer room. When you say I am after an "ILLUSION" I would say that whether you are sitting on a seat that provides motion in sync. with what you are looking at on a screen or if you are sitting in an enclosed container and getting a good tumble drier experiance it is all an illusion , just a different form of same to whatever extent that satisfies you.

I have used FSUIPC down through the years and have always respected the tremendous benefit it has provided to us flightsimmers and you being what I consider to be an authority on FSX commands and effects I am asking you purely and simply for your opinion as to what FSX command or effect you would consider best to use through FSUIPC for best results for my setup. As explained without getting back into it again ,I have tried the acceleration effects without acceptable success and am looking for an effect that will just the current bank, roll or pitch position of the aircraft.

Many thanks Pete

Toni

[Pete Dowson]

I feel that we have now reached a point in our post where the preference of different types of platforms is being expressed fairly strongly, however, as I see it everyone is entitled to there own choice and I will take some comments to be meant more in humour than for real.

Hmm. not sure what you mean there, sorry.

I am really at a loss to understand what it is you want to do, as nothing accords with my understanding of what a motion platform is all about. I'm sorry I do not understand you, but perhaps you will forgive me for not being able to help at all with something i don't understand. I have not included any humour or criticism, only emphasising again and again what I understand and what i do not.

The truth of the matter is that you obviously dont have a preference for the type of platform that I have built and you would only consider one of these enclosed cabins mounted on a 6DOF platform and operated with six large motors weighing 2000 lbs.as being the real experiance.

No, that is absolutely not so. One of the most effective small platforms I have tried was a small D-Box supported one as supplied by RC Simulations in England and demonstrated at a Birmingham show earlier this year. It did just support a seat, but again it was the acceleration effects which it reproduced, and very effectively even though no part of it ever rose or fell by more than a few inches. So the screen and controls always remained in the correct place relative to the pilot. I have seen and tried others, such as those at the Lelystad weekend in the Netherlands, which moved a little more, but carried the screens and cockpit controls with it. There are many ingenious solutions, but all of them that I have seen seem to be of the acceleration, and so "seat of the pants", variety.

Sorry, it is obvious now that you do not understand my words as much as I don't understand your intentions.

I am asking you purely and simply for your opinion as to what FSX command or effect you would consider best to use through FSUIPC for best results for my setup. As explained without getting back into it again ,I have tried the acceleration effects without acceptable success and am looking for an effect that will just the current bank, roll or pitch position of the aircraft.

The current pitch, roll, bank and other parameters are clearly listed and available, if you wish to use them. What is the problem? How can I advise you on something different if that is what you think you need? Or I you merely asking for me to search my documents as you yourself could do so? If that is all you wish, just look at offsets 0578 - 0580.

Regards

Pete

[toktiny]

Hi Pete,

Many thanks for your suggestion.

Regards

Toni