Hello.Quiz time: We must have been thinking about the sim mechanics a lot, so I want some fresh water in my mill:How do you do the centering mechanism of your yoke or pedals?I have a mechanism for the aileron movement, but my problem is the elevator axis. I am currently thinking of the "cessna style" yoke construction where there is a pivoting point on the floor and a vertical column that tilts back and forth - much like a "airliner" yoke, but just behind the panel. Then the yoke "tube" connects to it through a hole in the panel. It will be something like this:http://tigert.gimp.org/vatsim/cockpit-stuff/kessnayoke.jpgBut how would you construct the centering mechanism for elevator? How do you center your airliner yokes, or what kind of constructions do you have for self-made yokes? I'd use gas springs, but those would probably just cancel each other out if you put one on both sides of the moving part.. Springs somewhat do the same. Bungee cord might work since you can just let the other one become loose when you stretch the other.. But none of those are particularly satisfying ways to do it.. Anyone got a clue?Looking forward for some new ideas.. :)Tuomas

Fairly simple with springs afterall.Only this time combined with none-strechable-rope.First you take center position at a certain height from your pivot point. There you measure +/- how much offset you'll have towards the front. (take same for backwards). This distance will be the length of the "none-strechable-rope" which will tie your string to your pole. This way, in centered position both ropes will be pulled tight but not streched. Once you push e.g. the rear spring will be stretched & the front spring will just start to hang down a bit. If the strings & ropes are attached with no hooks but like closed things they'll not detatch at any time.Hope you understand my explaining here.If you want a drawing, I'll get my 3DsMax up & runing for ya, no problem.

http://users.skynet.be/plipke/CenteringWeel_010001.jpghttp://users.skynet.be/plipke/CenteringWeel_010011.jpghttp://users.skynet.be/plipke/CenteringWeel_010021.jpghttp://users.skynet.be/plipke/CenteringWeel_010031.jpghttp://users.skynet.be/plipke/CenteringWeel_010041.jpghttp://users.skynet.be/plipke/CenteringWeel_010051.jpghttp://users.skynet.be/plipke/CenteringWeel_010061.jpghttp://users.skynet.be/plipke/CenteringWeel_010071.jpghttp://users.skynet.be/plipke/CenteringWeel_010081.jpghttp://users.skynet.be/plipke/CenteringWeel_010091.jpghttp://users.skynet.be/plipke/CenteringWeel_010101.jpgif you think of the yellow part to be a normal none-strechable-rope which won't be as stiff as in these pictures ;) you'll get the idea now for sure :)

Yea, or use bungee rope, that would work as well.On the other hand I wish there was a "nice and easy" way that doesnt take much supporting structures.Today I saw one of those ad stands shops put outside their door in the streets that can swing if there is a strong wind, they just bend but dont tip over. Those things have pretty strong springs vertically that act basically as a base for the whole thingy. Such a thing might work too as the pivot point.Any other ideas? I want to think this through first, then get the tools and do it :)Tuomas

That's indeed a very good one you got there.I'm all out of other ideas, but as I know from experiance ... people here tend to be more creative than I expect :(So lets just wait a little longer ..

Hi Tuomas,A pair of springs is the least expensive approach. One in front and one behind. They do indeed balance each other, but only at one location. The force exerted by a spring is modeled by F=kX where k is the spring constant and X is the extension of the spring. If you have one in front and an identical one in back, then F=kX1 - kX2 where X1 is the extensiion of the first spring while X2 is the extension of the second. So they are balanced when both springs are stretched the same amount. If you move the yoke one spring will stretch more while the other will be relaxed. The net change in force is 2k(delta X). The springs act together.The springs can be compression springs, extension springs, bungee cord, or gas springs. Gas springs will give you damping, which may give you a nicer feel.Now, if you're really clever, you'll figure out a way to move the point the springs tie to. Perhaps by using a threaded rod attached to a cheap electric screwdriver. (Actually, a pair of electric screwdrivers) The tighter the springs are, the firmer the yoke movement will be. If you put the spring tension adjustment under computer control, you will have variable control loading with electric trim thrown in for free. It won't be fast changing but you can at least soften the feel as air speed drops.Mikewww.mikesflightdeck.com

Yea, I just wanted to get some fresh water to the system since I have been thinking of my cockpit for a year now, and doing small things every now and then (and the still-very-nice console thingy). Thanks for those pics, looks pretty doable too.I just need to move ahead and finally do the yoke and pedals, so I need some "thinking outside the box" - there got to be things in real life that have some kind of a device to center a lever. Like those "saloon" doors some people have, that close automatically, such things might work too. But where to get them for a reasonable price? And are they strong enough. The elevator centering force doesnt need to be very strong since I am not thinking of implementing real trimming, that might be too hard technically in my current situation. And seriously off-trimmed plane needs your both hands and a lot of force to maintain attitude.But this is mostly just "thinking aloud" that hopefully creates useful ideas for everyone. So if you have ideas, even vague ones, let me know :)Tuomas

Very nice solution with the springs AND the rope.I experimented with gasspring for the centering of my yoke. But gasspring do not center (if you use 2 in opposite direction) they just hold the yoke were it is when you remove your hands of it.Instead of the rope, I extended the spring a bit so that it would be able to decrease and increase in size.For pictures:http://home.wanadoo.nl/norbert.bosch