Hello Pedro, Building motion into your flight simulator is a nice idea, just not the way you're thinking. Technically speaking, I'm sure it would be feasible. But in terms of realism, negative for your sim. No matter what the airplane flies through, the seat must stay put in reference to the airframe. Some vibration, or even small ups and downs would make it real, since it sounds like similar to what you actually feel in turbulence. But do not rotate the seat while the rest of the cockpit stays still, or you'll get undesired results. That does not happen in the airplane.Just my 2 cents.Regards,Rafa.

>Hello Pedro,>> Building motion into your flight simulator is a nice idea,>just not the way you're thinking.>> Technically speaking, I'm sure it would be feasible. But in>terms of realism, negative for your sim. No matter what the>airplane flies through, the seat must stay put in reference to>the airframe. Some vibration, or even small ups and downs>would make it real, since it sounds like similar to what you>actually feel in turbulence. But do not rotate the seat while>the rest of the cockpit stays still, or you'll get undesired>results. That does not happen in the airplane.>>Just my 2 cents.>>Regards,>>Rafa.I've to say it again: I don't want to rotate the seat like the plane does, I'm only after a bit of movement to simulate turbulence!A bit means 1-2

Hello,Here is a link that has many useful solitions may help for building custom size motion platforms.http://www.servos.com/products.htmHas anyone tried theese so far?Best regards,Cesurkanat

we know, we get it .. small movements to simulate turbulence..if you're ok with the idea and spending your money on this, pls go right ahead. and if it turns out like you wished, let us know.only it seems that most of us are not so fond of this idea. i'm sure most think that it'll cost you more than you'll ever get from it.maybe tying a subwoofer to the back of your chair like we did c here some day to make your chair vibrate is a better thing and much less expencive.and as for my 2 cents ... i think that even with 2

>we know, we get it .. small movements to simulate>turbulence..AT LAST... ;)>>if you're ok with the idea and spending your money on this,>pls go right ahead. and if it turns out like you wished, let>us know.>>only it seems that most of us are not so fond of this idea. >i'm sure most think that it'll cost you more than you'll ever>get from it.I't seems to me that most of the replies were intended for a cockpit movement rather than a seat simulating turbulence.But that's just my 2 cents...Thanks to everyone that replied sofar.Keep the ideas coming.Best regards,Pedro

I know...I got the idea at the beginning. Turning your chair with the airplane's yawing, rolling and pitching would be ridiculous. We're talking about what you said at first.it's just not gonna cause the effect you are looking for. It'll be weird.Reproducing turbulence is not a joke.

Ok I get the picture :)Was just an idea.Thanks for the input on this.Best regards,Pedro

Hi Pedro,I agree with those who say perhaps just a speaker or two might be a good cheap start. There are commercial speaker seats that do this. And something that probably uses magnetic speaker parts:http://ivibe.comI think I've heard of people doing feedback seats with pneumatics as well. Little bladders in the seat and its back. Air blows up and releases each bladder to give you a "seat of the pants" sensation.In real flying, being a little uncoordinated in a turn means you should be able to feel a little more pressure on one side of your buttocks. Acceleration could be both blowing up quickly. Decel the opposite. Etc. I've been wanting to try this... it should prevent having to put the whole sim rig on a gimbal :)Good luck!Kev

Hi Kev,The pneumatic idea is bit over my head :) but is good nevertheless.I was thinking in adding just the up/down movement for starters and see what goes from there.Now I need more info on motors to experiment this.Best regards,Pedro

One bit of advice: Before starting to build the mechanics, servo drive etc, first figure out the way to bring the required parameters from the sim to the outside as useable voltages to drive servo systems or something like that. You'll need things like:a. Longitudinal accelerations (surge)b. Sideways accelerations (sway)c. Vertical accelerations (heave)d. Pitch angle velocities e. Roll angle velocitiesDepending on the degrees of freedom of your platform, the above parameters need to be manipulated to get something useful, including washout back to neutral. In order to simulate turbulence, the response needs to be fast. Update rates of 50Hz as used by X-plane seems to be the best available in the consumer market at present. As posted some time ago (search for my name), I had build a simple pitch/roll platform, which held the seat, controls and display. It was fun, but I stranded at the point where I needed to get the flight parameters to drive the platform powerservo systems. Building a motion platform requires multi-disciplinary skills, where writing custom software plays a major part.I planned a writeup, but due to the lack on the software part and the international move, it is far from finishedRoland

>I't seems to me that most of the replies were intended for a cockpit >movement rather than a seat simulating turbulence.The point that i think many of us is trying to make here, is that simulation turbulence is hard... You wont feel anything in common with real turbulence by rocking the chair back and forth 1-2 degrees...Simulating turbulence, that FEELS like turbulence is a rather complicated mechanic/algorithm. In a 6DOF simulator, it is done by accelerating the sim platform straight up or down, with the force needed, and then fast and smooth get the platform back to zero position without the pilot knowing, to be able to do an new "bump" without reaching the movement limit of the mechanics.Again, from my own flying experience, turbulence does feel like quick alternations of gravity, 2Gs one second, weightless or negative Gs the next 10th of a second. If thats what you want to simulate, you need to come up with a better solution that rocking the chair.My 2 cents: If you want turbulence, you'll need up/down acceleration. If you build that into the seat in your cockpit, you will soon hit the roof, literally. Cheers/ Olle

Hi Roland! Good to see you back. I really enjoyed your "DIY Cockpit Controls." I consider it a seminal white paper for the hobby. Every would be sim builder should read it completely.As a real world pilot, turbulence is an almost instantaneous multi

Hi Roland, thanks for stepping in .>One bit of advice: >>Before starting to build the mechanics, servo drive etc, first>figure out the way to bring the required parameters from the>sim to the outside as useable voltages to drive servo systems>or something like that. You'll need things like:>>a. Longitudinal accelerations (surge)>b. Sideways accelerations (sway)>c. Vertical accelerations (heave)>d. Pitch angle velocities >e. Roll angle velocities>Here's what we can get from FS with FSUIPC:OFFSET SIZE DESCRIPTION3178 8 Z (longitudinal, or forward/backward) TAS-velocity in ft/sec relative to the body axes. This is in double floating point format (FLOAT64). [FS2k/CFS2/FS2002 only]3180 8 X (lateral, or left/right) TAS-velocity in ft/sec relative to the body axes (see Note at end of table). This is in double floating point format (FLOAT64). [FS2k/CFS2/FS2002 only]3188 8 Y (vertical, or up/down) TAS-velocity in ft/sec relative to the body axes (see Note at end of table). This is in double floating point format (FLOAT64). [FS2k/CFS2/FS2002 only]3190 8 Z (longitudinal, or forward/backward) GS-velocity in ft/sec relative to world axes (see Note at end of table). This is in double floating point format (FLOAT64). [FS2k/CFS2/FS2002 only]3198 8 X (lateral, or left/right) GS-velocity in ft/sec relative to world axes (see Note at end of table). This is in double floating point format (FLOAT64). [FS2k/CFS2/FS2002 only]N.B. The sign may be reversed in FS2002.31A0 8 Y (vertical, or up/down) GS-velocity in ft/sec relative to world axes (see Note at end of table). This is in double floating point format (FLOAT64). [FS2k/CFS2/FS2002 only]31A8 8 Pitch velocity in rads/sec relative to world axes (see Note at end of table). This is in double floating point format (FLOAT64). [FS2k/CFS2/FS2002 only]31B0 8 Roll velocity in rads/sec relative to world axes (see Note at end of table). This is in double floating point format (FLOAT64). [FS2k/CFS2/FS2002 only] N.B. In FS2002 the sign may be reversed, and the units may be 16x31B8 8 Yaw velocity in rads/sec relative to world axes (see Note at end of table). This is in double floating point format (FLOAT64). [FS2k/CFS2/FS2002 only] N.B. In FS2002 the sign may be reversed, and the units may be 16x31C0 8 X (lateral, or left/right) acceleration in ft/sec/sec relative to the world axes (see Note at end of table). This is in double floating point format (FLOAT64). [FS2002 only]31C8 8 Y (vertical, or up/down) acceleration in ft/sec/sec relative to the world axes (see Note at end of table). This is in double floating point format (FLOAT64). [FS2002 only]31D0 8 Z (longitudinal, or forward/backward) acceleration in ft/sec/sec relative to the world axes (see Note at end of table). This is in double floating point format (FLOAT64). [FS2002 only]31D8 16 Reserved>Depending on the degrees of freedom of your platform, the>above parameters need to be manipulated to get something>useful, including washout back to neutral. Yes. There's has to be a program to control and convert those values. >>In order to simulate turbulence, the response needs to be>fast. Update rates of 50Hz as used by X-plane seems to be the>best available in the consumer market at present. >Can you explain this 50HZ???>As posted some time ago (search for my name), I had build a>simple pitch/roll platform, which held the seat, controls and>display. It was fun, but I stranded at the point where I>needed to get the flight parameters to drive the platform>powerservo systems. Building a motion platform requires>multi-disciplinary skills, where writing custom software plays>a major part.>I recall seeing your thread. I'll check it out again.Thanks,Pedro

Thanks for your input John.I understand that this is more complicated than I was thinking to do it right.Are servos so expensive to try it???Basically what I would need is rapid up/down movement in a small range of , say 1 or 2 inches.Do you think that this is enough?Best regards,Pedro

>Thanks for your input John.>I understand that this is more complicated than I was thinking>to do it right.>Are servos so expensive to try it???>Basically what I would need is rapid up/down movement in a>small range of , say 1 or 2 inches.>Do you think that this is enough?The simple way to try it out is to build a mechanical "mockup" where you make some kind of a platform for your chair that can rock around and have a friend "simulate" the turbulence for you while you fly by shakibng the chair. That should tell you pretty quickly whether the idea works or not. I'm not joking, that is a good way to check if something really works, and avoid wasting time on something that, at the end, does not fill your expectations. And if it does work, then it's fine to build it since you know there are better changes for it to work.In turbulence the whole panel and glareshield shakes like crazy though.I am still thinking that "no motion" is a lot better than "bad motion system" - your brain is too good to figure out it's fake and you just get motion sickness in the worst case. And we got the idea this is not a "motion system" :) The subwoofer-under-your-butt (or one of those sonic transducers even, shaking without the excess noise) sounds like an idea that would give better feeling of realism.Tuomas