Flight Sim Motion Platform, ideas and suggestions please!

Hello all,

I'm a long time flight simulator fan looking to start building my first motion platform for the A-10C Warthog module in DCS World. I've already built a home cockpit for it, and would like to have something similar, but with added motion of course, also incorporating tactile transducers... I've read in these forums that 3dof is the most immersive for flight sims, and I think that's the way I'd like to go. I'm not even sure where to start, really... I've been lurking in these forums for a while now, trying to get ideas, and as helpful as they are, it's almost too much information!

• What's the best design for a 3dof motion flight simulator? It's important to me that I can mount all of my toggle switches and the monitor I use for my Helios gauges into the frame.
• Not sure what to do with the projector? Leave it static, or is there a better option?
• Right now my tactile transducer just runs through the normal audio of the game, is it possible to use Simtools to make it more interactive with what's actually happening in the sim?
• I have an Arduino Uno, but very limited programming experience, it looks like the JRKs are the way to go, right?

I'm proficient in sketch-up, and have a ton of experience building RC planes, so designing or customizing an existing design is possible for me, and I'd like to build a small prototype with RC servos first. From what I've read in here, seems like all the issues with Helios and Simtools have been worked out, right? I feel like with the info in these forums, I can start to get a good parts list going, I just need a direction to go in, before I start spending money. Any and all help would be greatly appreciated. Looking forward to getting started and sharing my progress as I go. Doesn't seem to let me upload pics from my iPad, I'll post some pics of my existing cockpit a little later once I get to my PC.
Thanks again, Hori

Hello Hori.
A suggestion for a flight sim frame would be build one of these
http://www.acesim.com/main.html
Granted its 2 DOF, but has a great range of movement.
Its just a matter of motoring it.
If you want 3 DOF lift, that can get expensive. As you are lifting an entire structure.
Aldoz did it ages ago with boat winch motors and JRKS, with a costly calculated spring under neath to support it http://www.xsimulator.net/community/threads/my-3dof-project-is-born.3096/page-15#post-39894
@BlazinH has a 3 DOF lift with 800 watt DC motors and runs an arduino or Kangaroo controller, not sure what.
If you cannot code, best use JRKS, but it does restrict the motor size to 250 watts max. Considering they are overdriven 2.5 times the rated power.
But using such a 250 watt motor, say on DIY actuators http://bffsimulation.com/linear-act.php you could lift a heck of a lot of weight.
Hopefully that helps a bit.
Dave.

Thanks for the replies, guys... I'll definately be doing some more research. Here's a couple of pics of my current 'pit. Nothing too special, a slightly modified Akers/Barnes set-up.

To which I've also added an X-55 Rhino HOTAS.

I have developed a motion platform which works well with 5 dof using 3 pneumatic rams which give several inches of vertical heave motion and roll and pitch motions. This is all mounted on two sets of drawer runners at 90 degrees to each other which provide sway and surge motions. The air valves are driven by servomotors controlled by an Arduino Uno. The supported sim cockpit is a skeleton cockpit based loosely on a Spitfire. If you are interested I can post further details and some photos. It does get quite complicated I am afraid.

Wow, Hugso, that sounds incredible! Definitely interested to see what you've done. I'd like to start out on the simpler side of things at first, though. I'm thinking about now going for a joyrider style frame at first, modified to fit a more complete cockpit. 2dof, pitch and roll of course, at first with maybe adding surge once I figure out what I'm doing.

Thanks @noorbeast,

The intention of simplicity and the inevitability of complexity, it's pretty much the story of my life... I know that 2dof will be awesome, but I feel like it won't be enough, and if I'm going to do it, might as well go for it...

I believe the essential motions for flight sims are Heave (ie g force) and roll. The others are icing on the cake. My first (non motion platform) attempts used inflatable bladders (bicycle inner tubes) under my thighs which inflated with increased g. Sounds really rubbish, but actually felt surprisingly good. I also had the left and right sides inflating separately which was a proxy for roll. The straight g effect is so good that I have retained it with my motion platform. This means that in a long tight turn I feel the cue of the seat moving upwards and then the sustained pressure from the bladders combined with the visual effects maintains the illusion of continuing high g as the rams stop and washout back to centre.

Using compressed air for motion means I do not need noisy high current motors and linkages. It just needs a silent compressor, which is as quiet as a normal domestic refrigerator, that can produce about 2 cu ft per minute. I will try and post some pictures and schematics over the next few days I'd I can remember how to do it.

Hugso,

I'm super intrigued by your idea with the bicycle inner tubes and compressed air. Are you using an Arduino? What flight sim do you fly with it?

You're right, I am extremely fascinated by the G-Seat... I especially like the GS-105 by Geko Systems. That looks like a little more than a G-Seat they have going there, though... I'm curious, has anyone done a DIY approach to the GS-105?

I used tubes about one and a quarter inches across flat and bound them with tape so that they inflated hard rather than just blowing up like a balloon. I placed them on my (fairly hard) chair so they went under the centre of my thighs. I could email a photo of the tubes in my present motion sim to you directly if you like. The maximum pressure involved is only about 5 psi and you will need to use flow restrictors to give the nice steady increase in the pressure which you want to feel. If you have never used compressed air before you will be pleased to find how easy it is to use with push-in connectors.

As I am very into WW2 stuff I use IL-2 Cliffs of Dover. There is a plugin which does works with with DCS world, but it does not yet implement airspeed, which is a shame as it is very useful for several functions.

I use an Arduino Uno to drive up to 6 servo motors using a sketch provided by eaorobbie. This links the servomotors to the plugin. The most most important motion is Heave. I would suggest for Roll you use a motion derived directly from the position of the joystick, as using the Roll from the plugin does not feel right at all. It is much too slow to give to required movement and when you go upside down over the top of a roll it goes bananas as it flips over the other way.

Thanks @hugso, I PMed you my email address.

I'd like to get started on a small scale prototype using RC servos. Curious what I need to do this. I have the servos already, and I'm planning on using JKRS, does anyone have any advice where to start? I'm planning on doing a dual PC setup, using an older laptop I have to run Game Engine, while Game Manager and the sim run on my main PC, and will try to work on that this evening. So... What's next? Order the JKRS? Is that how the RC servos are run? Do they connect right to it? Like I said earlier, I have an Arduino Uno, but if I'm planning on JKRS, I think I'd like to just go that route from the get go. Thanks again...

Again, it will depend of the frame design you would like to move.
JRKS are restricted to 12-16 volts 250 watt motor, but that doesnt mean that you are stuck with a certain frame. if you needed actuators, you could build BFF (buggies built for fun) actuators and have a full lift frame.
Back to Rc servos, email pololu and ask how to hook them up to the JRK.
Theres has been a few GS4 seats in development here, have a dig through the threads.

The Maestro requires coding . The JRK does not.
Email pololu and get an answer first before you end up taking up to much time with something you may have to change later.

Thanks for the quick responses, @bsft and @noorbeast, will do ASAP.

So... I seem to be having trouble getting telemetry from my sim, and my virtual dashboard running Helios on a second monitor has stopped working. Using a dual PC setup. I have an Arduino Uno on com 5 hooked up to 2 RC servos. Using RC Model Code For Arduino Uno-2DOF, by @eaorobbie. Game Manager says "connected" then "running game" once I start my DCS. In Game Engine, running on my laptop, under axis testing, I can turn that on and all the servos are moving the way they should according to my profile when I move the sliders. It switches and says "game on" once the sim starts up. However, with the virtual axis turned on, no sliders are moving, in the tuning center, with DCS selected, nothing is happening. I've tried this with the original .LUA export and the Combined Helios/Simtools Export by @Macka. Any help would be greatly appreciated...