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### Dark Physics & Dark A.I. & Dark Dynamix / [dark dynamix] how to set the hardness of the hinge

Message
Posted: 19th Nov 2012 00:58
Hi all,
I am doing really a lot of different experiments with the joints.
I did a lot of practice in this complex matter and now I have my flaps that can rotating using JointRevolute and I have my tail moving surfaces that can rotating using JointSpherical.

I have 2 way to move flaps and my tail surfaces :

1) The stop_block_object method, as Fallout advice (perfectly working If my airplane is not in accelleration).
Using a stop_block_object and an external force too and I can obtain my flap stopped in a precise position. But when the airplane getting an accelleration (not a speed but an accelleration) so the stop_block_object loosing its correct position from the flap and the airplane. Using or not KINEMATIC command don't solve this problem.

You can notice the same thing in the flap when it is getting an accelleration and you can see the flap waving in the hinge as the wind make it flying (it not flying away just cause it is linked in the hinges)
Test and test and I can't to reach to obtain the mechanism stable and in a PERFECT XYZ coordination with the airplane. This mean that if my airplane getting 2 or 3 seconds of accelleration so the mechanism changing its position. So I tried another method.

2) The equal and opposite forces method.
I using 2 equal and opposite forces to let my flaps to stay in a precise position. When I want to move the flaps UP so I just slightly reduce the downward force. In this way I obtain a perfect rotation in the hine and when the flap reach the target position so the forces back to be equal and opposite and I back obtained my flap stopped.

In this method I obtain my flap waving but I reach with no too many problems to stabilize it in accelleration just making the 2 forces more big.
Using this method I obtain a good stability model and I can move airplane flaps and airplane tail surfaces in a really easy way!
But when my airplane is in accelleration so I always obtain a bit of drive in the joints hinges and I see my 2 forces making some differences and I can obtain not precise position or movement of my flaps and tail surfaces.

So I think about the chance to set the hardness of the hinges!
If I can set my hinges very hard so I can obtain my flaps and tail surfaces with less chance to lost their perfect position and stability!

You can open and close this door using little force but If you open your windows and some air start to flow so you risk to see your door slamming hard.

Now think about a door with hard and not oiled hinges:
You can open and close this door using big force and if you open your window so the wind can't make the door slam hard 'cause the hinges are doing physical resistance.

Ok, I would to obtain my joint hinges like the second example! (the hard hinges door) In this way I can obtain more stable position and less chances to obtain error when I moving my flaps and tail surfaces.

I tried to use DYN JOINT DESC SET SWING DRIVE, DYN JOINT DESC SET MAX FORCE, and other commands but since now I just can set the rotation limits of the SWING and TWIST and what DOF I can make free to work or locked.

But I can't get the hardness of the joint!
moreover If I try to use DYN JOINT DESC SET MAX FORCE I obtain "parameter mismatch error" but I am using the correct parameters... (If I use DYN JOINT DESC SET MAX TORQUE so I obtain no errors)

I hope you can help me!