737NG Yoke Forces?

[sagrada737]

Question:  What are considered realistic passive aileron/elevator yoke forces with the 737NG simulator?

I would like to make my own dual-yoke system for my 737NG simulator project.  I notice that some folks are using gas-shocks with a variety of pivots/linkages, etc.  It seems that each of these produces different simulated yoke effects.  The real Boeing 737 dual yoke system uses a fairly massive torque tube arrangement with internal/external linkage (simplified description).

I'm assuming that not many of these 737NG sim projects are incorporating any kind of active "force feedback".  That said, what are the typical push/pull/rotate forces (pounds or kilos) as measured for your yoke setups?  Any idea of what the actual "stick forces are in the real 737NG?  This information would be helpful as I consider my yoke design for my 737NG sim project.

Mike

[fordgt40]

Mike

I have it on good authority from David Allen who has built  a force feedback system using original Boeing hydraulic cam profiles that

The force required to hold 105 degrees of yoke rotation is 23 pounds, measured at a 6.5 inch radius from the center of the rotational axis of the yoke.

The force required to break-out from the neutral position is 4.5 pounds measured at a 6.5 inch radius.

The force at the rudder pedal when it starts to move (Breakout) it should be  no more than 18.0 pounds (80.0 newtons). Push the rudder pedal 3.6 inches forward from the neutral position, the force to hold the pedal should be between 51.0 to 82.0 pounds.

I also understand that full deflection up/down on the elevator requires a force of circa 40lbs

David

[Maurice]

  I notice that some folks are using gas-shocks with a variety of pivots/linkages, etc.  It seems that each of these produces different simulated yoke effects. 
Mike

I use gas springs for my rudder, elevator & yoke. I think they work great for the rudder & elevator but I almost hate them for the yoke. The reason is that when you are landing, you often need many lateral corrections to line up with the runway (much more than vertical corrections).

So with gas springs, there is a definite center point/catch which you feel very strongly when banking left then right or vice versa. That comes from the fact you need to start pushing against a different gas spring when you go from one side to the next. The initial force to overcome the spring and start the motion is the problem.  I think regular springs or elastic bands would make the transition much smoother and this is what I would do if I were to start over.

With rudders and elevators, the effect is much less bothersome because you have much more leverage and it is much easier to overcome the initial force required to compress the gas spring.

Maurice

[sagrada737]

Thanks David for the control force data references.  They seem reasonable, and I will factor this information into my own project. 

The Rudder and Yoke systems are something I would like to build myself, as it suits the capability in my small machine shop.  I will most likely try to buy the pilot/co-pilot wheels somewhere.  Any good sources for a set of  these for my 737NG project?

Thank you Maurice for the feedback on the gas springs.  Since these come in all kinds of sizes and forces, I think they are a good choice for the Rudder systems.  As you pointed out, there may be a better solution for the Yoke system.  I have seen a dual-screen door spring/gas system that looks promising, which seems to incorporate a centering function while providing for progressive control forces.

I appreciate the feedback.

Mike

[Joe Lavery]

Mike have a look at the Open Cockpits yokes, I have a set and they're pretty good.

http://www.opencockpits.com/catalog/mandos-moldeado-pintado-p-172.html?language=en&cPath=52_59

Also for the mechanics have a look at Gwyn's (Aerosim Solutions) video diary, he explains how he made his which look very nice.

Aerosim Solutions Boeing flight control columns

Cheers
Joe

[sagrada737]

Good information Joe.  Thank you. 

I have looked at AeroSim's design and it has some merits to be considered.  Those folks are quite innovative.

I'll check out the yoke link as well.

Mike

[steveeverson]

Have a look at simquip for the yokes as they make cast aluminium ones copied from the real item. I have them in my sim and I think the cold metal feel adds to the realism
Cheers
Steve

[mickc]

Have a look at simquip for the yokes as they make cast aluminium ones copied from the real item. I have them in my sim and I think the cold metal feel adds to the realism
Cheers
Steve

+1 for this
I ordered the yokes, rudder pedals and steering tiller, all in cast aluminum.