View Full Version : Spring VS DCmotor when the plane turns

03-04-2008, 10:31 AM
Hi to all.

In the next days i start the construction of my yokes.
I have a query in a issue.

When the plane makes a turn under of A/P command (with LNAV or with HDG SEL) the 2 yokes turns too.

Have someone construct it this.?

When the A/P is not engage and you make a turn with the yoke ,and you stop the force in the yoke when you are happy with the turn the springs they go in natural position the yoke (to center).

BUT what happen when the A/P is engage?
The DC motor they make the yoke to turn (left or right).
So far so good.
BUT if need the yoke to stay for 5 -6 seconds or more to left or right position what will happen?
Can keep the dc motor and hold the yoke to the left or right position as long need to be hold.?
Because the springs they force the yoke the center.
It will be like a fight springs with dc motor.?
Sorry for my bad English.


03-19-2008, 03:30 AM
Lambi's question is : How the DC-Motor works ? It still has power/force to remain in the position commanded or it just move to one position and then remain idle?

The question has to do with the command for a turn into yoke. When autopilot starts a turn the yoke has to turn also.
So with an interface card we can send a command to DC-Motor to move to the yoke to a certain position so we will have the requested angle.
BUT as we have also a spring to keep the yoke in center position, there is another opposite force trying to move the yoke again into the center.

So........ the DC-Motor continues to have power after the requested action by keeping it position or returns on idle and the spring wons by taking the yoke on center? Or there is a coninues fight between them?

Exept DC-Motros, is there another way like big Servos or something else ?

Has anyone made a moving yoke?

Best regards


03-19-2008, 07:26 AM
Simple solution, Buy some AP servo's used in GA aircraft from a scrapyard. They are dc motors with small chain and a clutch system. Motor will hold yoke in in position but when ap disconnects, the clutch will release and you regain control, or you can overide it just like in real life using a strong force. I have one i have been testing it should work well.

03-19-2008, 12:23 PM

thanks for reply, but here in Greece we can not find a scrapyard :sad:
Not only in the small country Greece, but maybe also in the other European countris, we donīt have such large areas with scrap aircraft & parts, like in US.

Any other idea ? What other people do? They donīt have the movement?



03-19-2008, 03:28 PM
I got mine off of ebay for 9.99!! Shipping would be about 20-30 more to greece.

03-19-2008, 04:34 PM
Controlling a yoke movement with DC motors is described here: http://www.simprojects.nl/adding_force_feedback.htm The power very much depends on the yoke construction. Cables and pulley system works best I believe.
If you have a correct yoke position signal from FS, then all you need to do is build a servo position feedback system, where the motor overrides the springs to meet the postion demand.

03-19-2008, 05:30 PM
Thanks both for your replies captains!!