Wooden 2 DOF Sim with integrated G-Seat, Fans, and Vibration

That would have been wise, especially when considering how many changes I made up to now.
Fortunately everything on my rig is screwed (in the technical sense of this word ), and I was able to move the pivot by 4 cm backward with nearly no effort. This was possible because accidentally two of the four screws fixing the universal joint are still matching:

I will probably drill 2 more holes for the remaining 2 screws, but for a first test it is ok.

Then I mounted the surge flaps for testing the balance after moving the pivot. This is how it looks:


The result of my balance test was that I need to change the pitch angle backward by 5 degrees in order to have it balanced.
That means, the surge flaps with their weight of 7.6 kg don't have such a strong effect on the pivot.

Thus, I changed the pivot back to its original position, and even with the surge flaps mounted, the balance is still perfect with about 0 degreed pitch angle. I'm really glad about this result.

Tonight I will connect the motor with the already installed JRK board (the one that is currently controlling the fans and the vibration motors), and I hope to get the missing joints soon.

Mates, I tell you what: I love my local DIY market! It contains so many simulator stuff; you just need to see them with the right eyes.

Here is a perfect example:

As I mentioned earlier, I use bungee cords for supporting the motor that moves my heave flaps, because it is not able to lift the flaps with my 90 kg on them. But I did not like the bungee approach and planned to replace the cords with springs.

But where to find suitable springs? Of course there are specialized spring shops, but you need to know the exact parameters you need, and there are plenty of them.

So I started thinking around, came to the springs of a bicycle rack, and finally I found my solution:


Just these minor modifications were needed:


I first did this with 2 of these clamps and mounted them below one of my heave flaps.


Then I connected a scale and measured the force needed for pushing the flap down.

With the flap in horizontal orientation, 8 to 10 kg were needed for holding it down.
This needed to be increased, and so I mounted two more clamps, resulting in a needed weight of about 18 to 20 kg for holding the flap in horizontal position.


Here is the completed flap module. The chains are needed for holding the flaps back, because otherwise the springs would relax completely, resulting in a too large angle.


After mounting the flaps on my rig and doing a first test with the JRK utility, I can confirm success: Now the motor lifts me without any problems.
(Now it has some problems without my weight, but that's ok because usually I don't let my rig move without myself seated.)

And yet another improvement is done: My surge flaps are working.

Yesterday the joints arrived, and since everything was already prepared, it was just little effort to use them for connecting the flaps with the axis.


Then I mounted them on the seat again and wired the motor.


And here you can see them moving:


A minute ago I did a test with FSX, and it is as I hoped: Separating pitch and surge in a flight simulator is a great improvement.

Time for changing the title of my thread due to all the stuff that has changed since I started it.

Just made a little addon today:
I added a second lever to the axis of my surge flaps. This lever has an angle of 90 degrees to the first lever which pulls & pushes the flaps.
Then I connected the shoulder belts of my harness to this second lever, resulting in a simple harness tensioner.


When the motor now pushes the flaps forward (meaning positive acceleration), the harness is released a bit, and when the motor pulls the flaps backwards (meaning negative acceleration or braking), the harness is tightened.

A first check with the JRK configuration utility has shown that the tensioner has a noticeable effect when the flap is completely released.
Of course it is not an optimal harness tensioner solution, because the moving flaps reduce the tensioning effect. Thus, @SeatTime's approach of building a tensioner with an extra motor that is completely decoupled from the G-Seat flaps is much better.

However, I got this one nearly for free with only 20 minutes of work, and so I will give it a try.

Next thing will be to add some of my spring clamps to the surge flaps, because the motor does not manage to push them forward completely. Only when I lean forward, the flaps manage the last centimeters.

And I also had a downer yesterday: The JRK that was previously driving my fans (and that I now wanted to use for the surge flaps) seems to have a defect: The potentiometer curve jitters, which makes the board unusable. I made sure that the pot is ok by driving the surge flaps with a different JRK. This one works correctly.