Double Yoke for C172 Pit

[wody]

Hello,

I was searching a lot for a good sturdy solution to have a dual yoke in my planned double seater C172 pit. Has anybody made such a construction?

I tend do have a box behind the MIP running on rails for the pitch axis. In this movable box is a linkage for the 2 yokes onm a common roll axis. Springs, dampers and potentiometers to be added accordingly.

Is this a good approach?

BTW: what are the movements of the yoke? I heared about 90 mm for and 90mm back. The roll is 180°. Is that right? What is the distance between both yokes?

Thanks for any help/advise!

Peter

[hyamesto]

Peter:

80 mm for and 80 mm back (last week measurements from a real C-172). and a little more than 180º, maybe 200º, but 180 is a good approach.
In my pit, the distance between yokes are 482,42 mm.
Anyway, ever exist a little diference between measurements of same model of plane.

Some dimensions graphics (not mine)



Your approach (the box) is good, and i can add another. (look the link below)

http://b58.svglobe.com/controls.html

But, if you want to add a trim system, look this photos and study.



Regards.
Horacio.

[wody]

Horacio,

many thanks for all this information!

The link to the Baron is perfect. Good idea. Looks like I will do it that way.

I did not think about electric trim yet, but is worth to consider. The problem is always with trimm after switching off the AP. Will think about.

Thanks also for the cockpit dimensions from B. McMullon. I had them already, but.....
the dimensions in length I could not find anywhere, like Angle of window, distance to the MIP, distance yoke to MIP, location of the doors, ....
A similar drawing with a crosssection over the length of the cockpit would be great. Unfortunately I have no access to areal C172, I would have measured already. Accuracy to the mm is not necessary.

Thanks a lot,
Peter

[hyamesto]

Peter:
Maybe this can help...
You can use a drawing program to scale an measure angles, etc... all real C-172 drawings.
The second and third images are captured from Pilot´s Operating Handbook. If you need more resolution, i can send you the originals PDF files.

Distance between yokes: 476,42 mm or 482,42 mm (different MIP)
Minimal distance between yoke and MIP : 155 mm (see drawing)




and some other drawings to compare:


About the trim system, what sim and hardware are you using?
With an encoder, and FSUIPC registered, you can do a motorized trim without problems with the autopilot.

Regards.
Horacio.

[geneb]

You might be better served in replicating the "Y" yoke in the real aircraft. That's how the two flight control yokes are linked. There's a gent on this forum that's building a sim from a 172 cockpit section that is re-using the original flight control hardware exactly this way. g.

[wody]

Thankks for the hint. I considered this already when I saw a picture of the 172 front without engine. Should be easier to build. It would be a quieter solution also.

Still dual rudder are open. Do you have any suggestion?

Thanks,
Peter

[hyamesto]

The "U" system.

[Zlatko]

For the dual rudder please take a look at the following pictures :



The rope in the middle drives the pulley for the actual rudder surface ( in our case it could be a potentiometer ). Two parts going under floor drive nose wheel steering mechanism.
And i can't really find out how differential brake cylinders are actuated , if you find that out , please let me know, to preserve me some headache.

[hyamesto]

Zlatko:

For the differential brake cylinders, you can see the next image and you can understand how it´s work....

Regards.
Horacio.

[Zlatko]

Thank You , Horacio. You are the best. The pictures you provided undoubtedly confirmed my suspicion -there is an inner shaft within the outer tube , moved when the upper part of the pedal is pressed.
Still i can't figure it out though, how that movement is passed on the cylinders - are the cylinders hidden behind those green brackets from the picture above or they are in some way linked to the inner shaft. One more time - thank you for your good heart to share knowledge and for your patience.
Best Regards
Zlatko