Supplier of Flight Control Springs

[emerydc8]

My PFC yoke takes about 1/3 the force of what is required for the real airplane.  I'm thinking of changing to stiffer springs. Has anyone experimented with beefing up the springs on an existing yoke and, if so, are there any good suppliers of springs out there for something like this?

Thanks,
Jon

[Hessel Oosten]

Hi Jon,

There are factories (online) where you can make choises about strength, wire thickness, material etc.
But extremely expensive for one piece....

So consider a local machineshop and let them make a few springs for you, with different forces to try.
It's easy for these people with a lathe.

See examples here:

https://www.youtube.com/results?search_query=making+springs+on+a+lathe

Hessel

[Jeroen Hoppenbrouwers]

I know, everybody has his trade... every time I see this kind of metal working, I drool and wish I had a workshop and could learn these things... either wood or metal. Sigh.

(looks at his 7.2V mini power screwdriver)


Hoppie

who has one light point in his quest for pretty metal... http://www.frontpanelexpress.com/

[emerydc8]

Thanks, Hessel. I didn't even think this was something a local machine shop could do. I don't really know if anyone makes a yoke that simulates the actual force of the real airplane. I just happened to fly the 767 within 24 hours of flying my sim and it dawned on me that there was a huge difference in force required between the two. This tweak is next on my to-do list for the sim.
Cheers,
Jon

[Hardy Heinlin]

How will you fix your hardware on the floor to withstand the enormous, increased force that the real yoke provides? And will the hardware structure survive the increased tensions in the long run?


Cheers,

|-|ardy

[Jeroen Hoppenbrouwers]

How will you fix your hardware on the floor to withstand the enormous, increased force that the real yoke provides?

Chemical Anchor

[Phil Bunch]

Will Boeing style high-force flight controls last indefinitely?  Will we ever see Airbus style joysticks on a Boeing aircraft? 

Interestingly, both Airbus style low-force joysticks and Boeing style controls seem to be accepted by their respective markets.

[Hardy Heinlin]

Airbus style low-force joysticks ...

The Airbus stick too incorporates pretty high forces and needs a robust fundament.

[emerydc8]

How will you fix your hardware on the floor to withstand the enormous, increased force that the real yoke provides?

I don't think increasing the springs by 300% will over-stress the existing PFC yoke. Even if it doesn't last as long, I don't really care because that will be a good excuse to scrap it and buy a yoke that can handle it or maybe one that has a more realistic feel to begin with. In any case, the existing PFC yoke is nowhere near the real aircraft, which makes me wonder why a company would go through the trouble of building a "Boeing" yoke that doesn't even come close to representing the real deal.

[Jeroen Hoppenbrouwers]

Will Boeing style high-force flight controls last indefinitely?  Will we ever see Airbus style joysticks on a Boeing aircraft? 

Interestingly, both Airbus style low-force joysticks and Boeing style controls seem to be accepted by their respective markets.

Boeing basically builds new aircraft that simulate old ones. Airbus just went with new.

I think we will see a convergence between the two, in that the obvious advantages of yokes (not only force feedback, but also motion feedback, from A/P and other pilot) can now be provided by sidesticks, too.
http://aviationweek.com/technology/active-sidestick-controls-make-commercial-debut

It then becomes a matter of cost... the large yoke installation will eventually be outcheaped by the sidesticks. I don't think there will ever be a customer option yoke/sidestick, though. Too different.

Hoppie
(putting crystall ball back in crate)

[torrence]

(putting crystall ball back in crate)

I know - saw you do it in my crystal ball.  We take this seriously in LA 

Cheers,
Torrence

[emerydc8]

I finally got some time to check my PFC yoke and look at the springs used for the elevator and ailerons.

As for the elevator, there are six springs per side and I was able to change out four of them (two on each side) with heavier springs and it seemed to help a bit, but I'll still have to get back to that when I find a source of stronger springs. Below is the elevator spring mechanism.



As for the ailerons, the stock spring requires about 10 pounds of yoke force at the outer edge to deflect it to the stop. The spring itself is fairly strong for its size. It's only about 1.5" long and 1/2" wide, but the pull force when moderately extended (as it is with full control in the picture below) is about 30 pounds, as tested with a scale normally used for testing fishing lines. The scale goes up to 50 pounds.

I bought some springs from the hardware store today, but none was even close to pulling 30 pounds and after testing them they were already deformed by just one pull. I'm thinking there is a big difference between run-of-the-mill hardware springs and what I need. I called a few machine shops and they don't make springs. Finding a source of commercial springs might be a challenge.

By the way, the spring PFC uses on the aileron appears to be the same as used on their Boeing-style rudder pedals. I've broken plenty of these already and they are a bit expensive ($20 each?).

Below is the aileron mechanism with the aileron at full stop.



And this is about the same extension of the spring, which takes about 30 pounds of tension.



Finding a spring this size that will do more than 60 pounds is going to be difficult if not impossible. I may have to modify the mechanism to fit a stronger spring. In any case, I don't think regular hardware store springs are going to do it for me.

[Hardy Heinlin]

The problem with these large yokes on small fundaments is that the column arm is so long and the counter arm so short. The ratio between the two lever forces is huge. To get 50 more pounds on the long lever, you need to add 500 pounds to the short lever, or something like that.

[emerydc8]

I'm afraid you're right, Hardy. I've been thinking that if I could just increase the break-away force for the ailerons it might help a lot. The initial movement in the real airplane is what I notice  most when comparing the two, probably  because once you get the airplane rolling it doesn't take much more aileron input. Now if I could just figure out how to connected some dampers to that aileron crank.