Got a question for you sim folks

[727737Nut]

I am having a hard time with this set-up on my new sim I am building.  Here is the deal, the motion base system I am using has pitch, roll, and yaw.  The Yaw/heading axis spins the base 360 degrees.
I am not sure whether to use the yaw or just make it a 2-DOF sim.

Pro's with:
Accurate butt feeling/flight feel when using rudder, like slipping and uncoordinated turns etc
Heading gauge and compass read and react 100% correctly and easy to interface

Pro's w/o:
Much easier to set-up because power supplies, PC, and Display can all be separate
Spare motor in case one of the others break
Can use PJ for a large front display.

Con's
Everything must be attached to sim like PC, power supply's etc , Space is very limited
Can't use projector
Have to mount 32" TV to front of sim
Heading Indicator and compass much harder to interface

I am really struggling to finalize this question and am looking for input.  Good, bad, ugly don't care

What would you do?
Thanks,
Rob

[fordgt40]

Rob

From articles I have read it is the initial "cue motion" that is important on motion platforms. Would it be possible to limit the slew to say 45deg in total? That way you could connect to the sim via an umbilical power/data cord. Cannot quite get my head around whether you could still use a PJ though

Regards

David

[727737Nut]

It's possible and that could be a compromise between no yaw at all and full 360deg.   Would be nice to have on landing.  The PJ would have to rotate as well though which again can be done but you are adding complexity.
Keep the ideas coming.

Rob

[Trevor Hale]

Rob,

I would say you have it, so use it.  When I think of the motion you feel, and the motion you see the platform make, they rarily are the same thing.  I have seen a lot of people do a lot of research on this matter.  Remember the movement of the platform isn`t going to follow the movement of the airplane or the flight controls.  In a small example, braking on the runway will cause the platform to `Dive`making you feel like the aircraft is slowing..  when in level flight, the `windsheer`may cause the uncommanded yaw of the aircraft.  With that all being said, the guys who have written software for the 6d0f platforms, or 3dof platforms integrate several different combinations of motions depending on the `feeling they are trying to achieve`rather then the movement the aircraft makes.

Keeping this in mind, you will logistically spend a lot of time perfecting this, or you can refer to the many individuals whom have already done this and utilize their software/formulas.  Just a thought, but I know that if you are that far, why take the easy route..  Many would suggest you getting the thing into your house was the hardest part, not to mention convincing the wife to let you tear the side of the house out to do it LMFAO.

This probably doesn;t help you though, but thought I would contribute anyway.

Trev

[MLeavy737]

 I would say having the sim spin 360deg is worthless.. Do full Hydraulic/Elec flight sims spin? i dont think so.. When your talking about the feeling of yaw you want to bank the sim or lean it over. like Trev said, how the sim moves and what the visuals are showing are two different things. I would stick with sim pitch for accelerate/decel and bank for the feeling of yaw.
  Not sure your up to the software yet however i believe Xplane has Datarefs/Offsets for use with motion platforms.

Mike L

[727737Nut]

I just took a test flight on the stock original GAT-1 I have and tried with yaw/heading on then off.  I tell you it is pretty convincing.  With yaw on it feels pretty realistic.  Mike, from what i read, the reason the big stuff doesn't spin is due to the complexity and size.  See all the wiring and computers would have to be self contained on the sim and that would make it way to big and heavy. The engineers said 360deg movement was best but not feasible. 

As for the movement, i am not fully understanding.  I know the car guys tilt their chairs opposite of the turn direction and that I understand but in planes, we have bank angle, side slip, and gravity in 3 dimensions.  If the plane banks left, the cockpit tilts left, turn right , tilt right.  Pitch up, nose raises.   I don't understand where opposite movement would be correct in my simple little motion base.  Now in a 6-dof you have sway, heave and the other 4 forces it can simulate.   My pit will follow the pitch and bank angle outputs from the sim offsets.    With yaw turned on, i can tell the difference when i make a coordinated turn and not.     

Still at a loss on what to do after that test flight today.  Another thought I had was I could fully enclose it with the TV mounted on the front and MAN you talking about full immersion.    Barf bags ready. LOL

[iwik]

Rob,
Why dont you have a look at Ian Hoopers site
http://buggies.builtforfun.co.uk/Sim/

He has software available which others have used with their own hardware. Discuss the pro's and con's with someone who has done quite extensive research and is very approachable. Ive completed
his mini 3dof (bank,Pitch and Heave) sim and also the Force Feedback Yoke. He has provided me with some great articles relating specially to Real life Feedback.
Motion Sim are great,ive only had small play with my one but sure one hell of a fun.
P.S to anyone reading this Ian's  FFB unit can be easily configured for Heavy Iron.
Please take a look at what he's up to.
Regards
Les

[mikeh]

HAVING PLAYED WITH THE gat1 i would suggest that 360 degree motion in an airliner type is unimportant.
much more important is the 'turbulant air' effect. that feedback (even mimiced by Link in his 1940's ANT-18 simulator
is really noticable.
Even the pitch and Yaw motion only has to be small to kid the brain into thinking its on the move.
it is the initial movement that can be slightly exadurated that get the adrenalin rushing.
The body/ brain quickly forgets about continued movement other than tight spins because it figures it into its calculations for near future expectations
So I would say LEAVE IT OUT and get the best out of the visual displays
Mike