control column pitch centering using gas struts

[Michael S]

@ak49er: I do not fully understand how this should work. But as you can see I have found the method probably working best for me. So I will try it the way I described above. Anyway thanks for your help. Sounds interesting too.

@spitfire9: Yes. Basicly it´s the same functional principle. Thanks for your help.

[verticallimit]

Have not even made control column yet, but have had these thoughts about the design.
If you connect the 2 rails together and mount them on a different track system, this system towed by a motor controlled by the autopilot.

[David Withers]

thats it Micheal s...as long as the struts are free to run when not being extended you will be fine. exactly the same principle we use down here but in reverse.

now you just need to mount pots.

[chris0518]

Hi Michael,
I just red your post about your centering issue. Maybe you want to take another approach on that. I am a real world aircraft technician working on commercial airliners. On almost every aircraft with a conventional hydraulic actuating system the flight controls are centered with a so- called feel and centering unit. The pilot input moves a cam. On that cam runs a roller which is attached to a link. The link is hinged to the fixed aircraft structure on one side and attached to a spring on the other side. The other end of the spring is also attached to the fixed structure. When the control collumn is moved, the spring will extend. That simulates a progressive force (depends on the shape of the cam) on the controls and also provides centering. In my opinion that would be an easier way to achive centering, than doing it with gas springs. The feeling should also be more realistic.

I attached a sketch to this post.
Should you decide to cosider this solution and should you need further information on that, just let me know.

Chris

Feel and centering.jpg

[Michael S]

Hi, Chris.

It´s very interesting to know how it´s done in real world´s airplanes. Now that I have the gas struts and also an almost finished control column, I will go with the gas struts as described. But it also might be of interest for a future version of my yoke. Who knows, maybe one day I will "upgrade" my project to a full size sim. Then I would have to build dual linked yokes so it´s very interesting anyways.

Thanks a lot.

[Westozy]

Great stuff guys, there are obviously "many ways to skin a cat"! Discussions like this where quite a few valid solutions are placed in view of the forum will be appreciated by many other builders. I think we need an 'ideas' gallery where everyone's sketches can be displayed, I'll talk to Matt Olieman about it.

Thanks guys,

Forum Manager

[spitfire9]

Very good idea Westozy,, I'll second that .

[Michael S]

Thanks to all who helped. Now I´ve got it working. I still need to add stop points for the forward and backward stop positions and I need to conect the pot. But - thanks to you guys - I´ve got a working elevator centering and let me say one thing: it really feels good. So thanks again. Here are a few pictures:







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Edit: As I originally planned the control column to be centered with halfway compressed gas struts, there was not enough space at my base plate. The piece of wood, that you can see in the front of the control column will be replaced with the base plate of my rudder pedals at a later point. I just wanted to add that.

[goof2092]

Hi Chris,

Old post here, but I guess this is the reason these things are documented to help newer builders

I am at the stage of constructing the dual linked columns for my B737. I have read your post and seen the sketch, but I am technically challenged to could not interpret other connections very well. Do you have more drawings I can look at to help with the fabrication?

Thanks

Anthony

[verticallimit]

Hi Here a little video from the project.

And yes... It's first this year i have build it in the cockpit. A long time under its way