F1 like 3DOF Simulator with heave

Perfect, that was my idea as well, have them ready to be used. Especially on the parts that have to deal with movement I use self-locking nuts and loctite for the screws that go into threads.

@_cOdaC_
I might have gotten lost in translation, too, so please forgive me if I misunderstood something. To me it looks like you have not held on of those ball joints in your hand and you don't really know that the "inner" part (the "ball") of the ball joint can freely rotate around the axis if the hole. Please see the attached pictures.

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No lubricant is needed here. The screw doesn't turn inside the lever or inside of the "ball" part of the ball joint. Instead, the ball turns inside the joint. See section above and attached pics.

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Correct. I'm a little confused about the "only", though. What else could be done to secure a screw, besides tightening a nut? Are you talking about counter-nuts, self-locking nuts, loctite etc. or is this about something else?

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This shouldn't be much of an issue. You could use a threaded rod to connect the ball joint to the brackets (like I did) and use firmly tightened nuts to hold everything in place. The friction from the nuts should easily be strong enough to keep the rod in place, even though the hole is not circular.

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You correctly assumed that my screenshots were from using Simtools v2. If you want you can use that version too. As far as I know, the Simtools license allows you to use any version of simtools.

Lately I made the switch to Simtools v3. As I had some experience with v2 I had almost no trouble in dealing with the slightly different UI. But I understand that those small differences can turn into struggles if you are new to the topic.

I could provide screenshots of my settings for general aviation or combat flying games if that would help.

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Yes, I'm glad I could help!

Thank you for clarifying that (the screw rotation bit) @Sebastian2, Yes I havent had a ball joint in my hands yet, but now I do. I‘ve built a lot of other DIY lrojects but nothing compared to that, so I‘m a total novice.

By the way the „only“ was meant to be a „there is missing this and that“ it was more like a: „I would not habe thought that these bits are going to hold such a movement“, like being positively suprised.

I‘ve ordered the nuts with oval holes now.

Regarding the SimTools settings, I think I have some ressources now to test everything and come
up with questions later.

I was reading this tutorial the other day. They say it‘s optima to set the motors in a Y form with 120 degrees to each other. Should have read this before (although you mentioned it before as well @Sebastian2 ).
My idea so far was: The lower frame has the exact same size as the one above, which is 1200x500mm.
So I thought putting one motor on the back and sideways 500mm profile and the other two motors like one on the left 1200mm and one on the right 1200mm profile along the drivers view, watching from the driver seat, would be fine.
All with having CoG and CoM in mind.
But if the top and the bottom of the Y thing is all ball joints, the top mount would just flip forward or back, right, as the motors are all facing into the same direction, nothing would keep the ball joints from
moving even when the motors are switched off. To prevent that I could turn the left and right motor by a 90 degrees so that they are not following the drivers view but sideways.
Then, I thought about that Y-Form profiles that I would need to add to the lower frame and the 120 degrees between them. Unfortunately there is not many connectors for 120 degrees and then I saw @Sebastian2 rig, that uses 2 x 135 and 1x 90 degrees between the profiles with the motors mounted on top of them.
There are many 135 and 90 degree connectors available making the build much easier.
Anyhow, is the difference between mounting the motors on a square frame vs. 135/90 degree angle vs. 120 degree angles so different?

Correct, with concepts like the one in the tutorial you've mentioned or mine, it's imperative that not all 3 motor axis are parallel to each other. Otherwise the whole top platform will fall over. Thats the reason why most 3DOFs with heave are built that way. The exception are concepts with a central pillar, but those come with their own challenges.

To simplify things, I made a isosceles triangle using 45 and 90 degree corner brackets. I think a equilateral triangle would provide a little more stiffness around the vertical axis, but that would require 120 and/or 60 degree corner brackets. I have not seen those anywhere.
With the experience I have today, I would consider making those 120 (or 60) degree brackets myself. All those 90 degree L or T shaped brackets are simply aluminum sheets of 6 mm thickness with a couple of 8 mm holes in the right places. Aluminium is trivial to drill holes into with a electric drill and cutting with a electric hand saw is also very easy. Shouldn't be much more than an hour's work to make a handful of 120 or 60 degree brackets.
However, I don't regret the route I've went regarding the angles of my triangle. The stiffness around my vertical axis and against lateral and longitudinal movement is good enough.

In that case the kinematics will work out in principle. However, I'm not sure if the stiffness in lateral direction, preventing left/right movement, will be good enough. In your case, any sideways movement will have to be prevented by the axis bearings of one single motor. The resulting movement might be too big. Have you seen rigs built like this?

This will result in the maximum pitch angle being much smaller than the maximum roll angle. Are you aware of that?

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I'm a little worried about hearing that your bottom platform will be only 50 cm wide. Can you estimate how high up from the ground the surface of your seat will be? The top platform will throw you around quite a bit - aren't you worried that you and your whole rig are going to fall over sideways? Or will you bolt it to the ground or use heavy weights to keep it there?
While deciding on the width of my bottom platform, I took a look at my office chair. I noticed that the surface of the seat was about as high up from the ground as the bottom part (the star shaped structure with the wheels) is wide.
While constructing my rig in CAD I measured that the seat surface will be about 1m from the ground. That's why I made my bottom platform 1 m wide.

Have you seen other 3DOFs or 2DOFs with a similar angular travel that you are going for, that are only 50 cm in width? As far as I've understood you are aiming for the +/-20 degree ballpark which is much more than a lot of racing rigs do. So they might not be well suited to compare yourself to.