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Hi to all,

i finished building my 737 Yoke. The roll Axis works really well. I use a servo to simulate the A7P engaged movements. My problem now is how to motorize the nick axis.

First of all the nick axis is free to move even if the motor blocks the axis.
I started with 2 28BYJ-48 steppers. The movement is precice and smooth. But due to the weight of the Yoke these steppers are not working.
Then i tried 2 25kg servos. Basically working but the movement is rough and jittering
One option would be a linear DC motor. But i dont know how to control the movements in mobiflight. And the dc motor does not know its position when starting up.
Perfect would be if mobiflight could handle stronger steppers like nema 17.

Any help would be awsome. Thanks

Hi

Again a Topic i not can understand.
I really need a Brain Storming with the "electrical guys" how this ideas are possible!

From my point of view a "Stepper" can never be used in a system where the user make manual Inputs.
It´s true.... The Stepper "know" its own position..... But it do this by count the steps it was moved since startup.
If you touch the Yoke, and move it by hand, then the position change but the stepper can not know this ( cause this moving is NOT done by the stepper logic)
So Stepper "means" he is still on the position where it was before you touch the Yoke.

With DC it is possible and you can "copy" the Idea from the Throttle!
Technical we read the Poti Axis and the Sim Yoke axis and compare them together..... Simply Subtract one of the other.
If both are identical then the Motor must be OFF.....
If both are different the Motor must run .....
And the direction of the Motor is defined by the compared Value.... If its positive or negative.

Examples:
Sim 1000 - Poti 1000 ----> 1000-1000 = 0 .... So both are on same Spot cause result is "0" .... Motor can be OFF
Sim 1000 - Poti 800 ----> 1000-800 = 200 .... Poti is "below" its target position .... So in case Result is Positive we need to turn the Motor upwards.
Sim 1000 - Poti 1400 ----> 1000-1400 = -400 .... Poti is above the target .... Result is negative .... So we know Motor must tun now downwards.

Finally same Problem like in throttle.....
You need a System that disable the Poti Inputs to the Sim.... Cause else in Automatic Mode these Inputs override the Auto Steering.
Basically also no problem.... But then you can NOT make "interventions" by hand aslong AP is on.

So the finaly "key" is.... You need a indicator when you make a Input by hand. For example a Sensor or some MIcro Buttons.
OR
You accept this behavour and you disbale the AP before you start fly by hand again.

Hi,

thanks for that fast reply. Maybe you missunderstood. YES i know that this problem exists. But maybe cause of luck with the small steppers all worked. The steppers followed my manual inputs through the potis. On Hardware side the yoke is disconnected from the steppers due to construction of the mechanism ( see an example of a "clutch" https://www.737diysim.com/build-guides-1/boeing-737-single-control-column). Just cause of the weight and leverage law the steppers cant handle this.

Basically moving the yoke motorized is just a gimmick and nice to have. Will test out your solution for a dc motor. Thanks a lot for this