6DOF Project, design considerations

If you have a heavy pedal and wheel set for racing, be careful that your actuators at the back can handle a centre of gravity that is forwards from your midpoint. Love the cardboard test model!

I think the pedals don't matter much but the screens will be heavy. So yes, I can move the joints forward (from orange to the yellow triangle in the picture) to better match the center of the nacelle to the center of the hexapod.

For the motion kinematics this won't make much difference. I'd gain a bit pitch angle range because the front doesn't reach that far out as before. But this will be mostly cancelled out because I need more surge to keep the COR near the pilot's head.

I know that I will almost surely have to bolt the base plate to the ground or use lots of sandbags or other heavy weights to keep it from jumping. Rigs with the actuators placed around the rig have a bigger base so it's less likely to tilt or jump. But don't worry, I have a friend who is a stonemason. He can get used gravestones for free.

I did some more research about the screens. There are LCDisplays available for advertisment walls that are much better than standard TVs. They have very little bevels, something as low as 1.7mm is claimed. But they also bring some serious problems:

• shipping from China won't be cheap
• ~20kg weight per screen means >100kg for the whole structure
• glass is fragile, too much vibration or hitting the ceiling could be expensive

So I'm re-thinking about the projector solution. This video about the warthog project shows how to make a curved screen quite easily out of MDF sheets. The warthog is no motion rig but has a stationary cockpit. Although it will be much harder to move the curved screen around together with the rig it's still lighter and less fragile than the LCD screens. And there are new projectors available with wide angle optics that allow shorter throw distances. I ordered one to check that out.

Have you looked at a program like INFUSE VR on Steam ?
Maybe you could transfer the physical cockpit to VR ?

The warthog project is really good.

I reckon projectors are the wat to go. I saw a glider sim with 360 degree projection ! It was very immersive

Yes, this looks interesting. But I already said that many times before: I just don't like VR. There are black shadows around the "amputated" hands. Laser pointers to menus floating around in space. That looks cool like science fiction movies but it's more virtual than reality. I don't want that. I prefer a real cockpit with a simulated landscape outside the windows, being able to manupulate the gadgets on the dashboard with my real hands instead of a simulation inside the simulation like floating "gloves".

I know, many times people have tried to convince me. I have to admit that VR is the "path of the least resistance" and it would save me a lot of work. Maybe I'll use it as a temporary patch as long as the whole cockpit isn't finished. But for me, it remains a patch or crutch.

@GRAP What happened to your project with the U-shaped canvas and the 3 projectors? I saw some updates for the instruments, lately. But is the display/projection already working?

Hello
I m working on the sim pit and the real instruments.
For the 3 projectors, i change a little my mind and i test a new idea.

I have é configurations now
- one with only 1 projector for fast game and video etc ...
- one with VR for long play

For informations, i need to explain you that i use now a VR quest 3 but with passthroug.

the cameras from the VR head set add the true cockpit in the eyes and the a my all body too. i havent shadow or simulate gloves.
You add 3D VR on real cockpit.
You can see your true body and you can use true papers, real maps, write and read on it.
you can read your phone SMS etc .....
With quest 3 it s working good but not perfect pictures at all.

Quest 3 is the cheapest VR with passthough. The best is Somium vr1 but near 5000e
Im waiting the pimax super crystal with outside camera too. i hope soon.

With VR and big motion rig you need motion compensation too

something like this.
I cant record on my computer.
You draw a border and you have VR 3d up and cockip with hands down

Thanks @GRAP . I have to say I don't own a VR headset and I have no clue at all, yet. But I also found this: Open Kneeboard

Yes, you have 3 program like this.
With quest 3 on amazon, you can test it 30 days and give back at the end.

I've drawn the most important parts in the CAD.

To save some headroom to my low ceiling I've attached the upper U-joints as high as possible inside the boxes under the seats.

This requires some funny cut-outs, especially for the motors that are mounted at the upper side of the actuators.
I think I have to build the support structure in the real world before before making a decision about the final position of the dashboard. The collective has to fit between the seats and the dashboard while still having easy access to all switches.
But the CAD model is important to check for collisions of the actuators with the rig. I'll make most of the bigger parts out of plywood so changes and additional cut-outs are much easier than with a welded steel structure. Only the areas with higher loads are reinforces with metal plates.

OMG, I have to limit pitch and roll in software. That's definitely too much!

And I think it's a good idea to install runners. They not only can be used as steps to enter the cockpit but they also act as stoppers and hit the ground or the bigger tubes of the actuators in the case the software fails or if the rig drops in an uncontrolled way due to a power or servo failure. This should protect the ball screws from bending.

If I use a horseshoe shaped canvas and beamers it has to be at least 2m in diameter.

There are almost no gaps from the pilots point of view and I think I can cover the whole area with 4 projectors. But this thing will be HUGE. And the planar part at least on one side has to swing together with the door to get access to the cockpit.

Hi
Your floor rig must be very heavy or your rig can collapse or move.
Or you can bolt it on the floor.
You check it ?

With my 6 motors 750w, i can jump at full power.
To enjoy , i need to add spike filters and half power on PtFlyer

Yes, I know (see end of post #22). I've visited @PeterW lately. His base plate is made from cast concrete, quite clever. In the CAD pictures above I was lazy and have drawn a 19mm board, only. But adding weight is easy. I could add a stack of sidewalk tiles onto the base plate.

The thing I'm worried the most about is still my very limited vertical space. Limiting heave, roll and pitch seperately won't be enough. There are cases where the combined effect of all of them together could cause collisions. I think I need either a bigger house or a clever software.

I came up with some theory about solving the collision problem in software. Because I don't know if it's a good idea that will eventually be implemented in FlyPT Mover or my own controller or just a "brain fart" nobody else cares about I started a new thread.

Do you know theese moments when you think you have a brilliant idea but as soon as you try it out in the real world you immediately realise that it doesn't work at all?

I thought I could hide the projectors behind the instrument console or below the footwell and put a mirror behind the dashboard to "fold" the projection beam and save space. But with a projection angle close to 90° there is no way to place the mirror and the projector without conflicts. Either the mirror has to be so large that the pilot's view to the screen would be totally obstructed or the projector has to be inside the "fan" range creating a large shadow. In the picture above you can see my "wishful imagination" but the reflection angles are obviously wrong.

Next try was to find a configuration with the projectors mounted behind the dashboard without mirrors.

This is a little bit "less impossible" but there are still lots of problems. The front screens have to be far away from the pilot's head and the required area for the side screens becomes quite large. The projection beams would cross the pilot's line of view and when leaning forward would flash into his eyes. And fitting the two front projectors into the instrument console would still be quite hard.

The reason why I experimentd with such a complex screen arrangement was because I wished to create a sort of immersive dome display for a helicopter with glass dome cockpit like the R22 where you can look to the ground even between your feet. This would have been very cool (see post #18). But I think I have to finally accept that this is only possible with VR.

But no reason to dispair. If I decide to make a helicopter cockpit with a classical nose bulge like @GettinBetter shows here things look much more promising.

I can place the projectors on top of the overhead panel. This adds a bit to the total height of the rig but the critical dimensions for possible collisions with the ceiling is not the height in the center but at the edges of the screens at extreme roll or pitch angles.

So I'm quite optimistic and I think I'll order three more of those projectors.