Hi Mike,>>>I too have been looking into using magnetic actuators for control loading. It was, in fact, the low cost of neodymium magnetic that caused me to pursue the approach.>>>Is funny is'nt it ?? Anyway It was your idea using the neodynium and I followed it. Just "Magic">>>The "magic" relationship is: a one tesla field acting on one meter of wire carrying one amp will impart one newton of force.>>>>Thanks a lot. That's the equation I was looking for>>>>Building a magnetic actuator for a columm mounted yoke is possible, but large, if one wants to deliver relatively large forces (say, around 40 pounds) to the yoke that have significant range of motion.>>>>>>That's the goal.>>>Turns out that there are commerical units called magnetic linear actuators that can be used in this application. I looked briefly at them, and actually saw one on Ebay.>>>I have seen some too and do not have yet a precise design to use them.May be do you have one ??CheersRoger

No designs as yet, Roger.

Just a note:You can't wind the wire in the field into a coil. The current through the entire length of the wire has to be in the same direction through the field. Remember the right hand rule with the thumb, index finger and middle finger all at right angles to each other (to represent the x, y & z axis). Thumb is direction of current flow, index finger is the direction of the field and the index finger shows the direction of force. If you wind the wire into a coil, when the direction of current flow changes through the field (as it will when you wind the coil), so will the direction of force..... you just made 1/2 of a DC motor.

Somewhere in this thread, you are speaking about "really centering" the yoke.Are you planning not to use ANY autopilot at all?Because if you do, all your system can be thrown in the wastebin.FS autopilot vertical trim requires the control system to be centered.It would be easier to just let the trim wheel operate the FS trim, and then "move" the physical yoke center position.

Claudio,As far as I am concerned, I personally really DO NOT understand the use of an AP on a flight simulator.When I was flying for real, I loved the AP, because the workload is really heavy when on IMC in a crowded area.But on the simulator, I do not use it at all, or then just when I want to take a cup of tea, or when the phone rings rather to put the sim on hold.I think that Tuomas shares my position.CheersRoger

>I think that Tuomas shares my position.Yeah, I might as well watch a cockpit DVD instead of using autopilot.Sure it is a great help when flying for real. But for the sim I dont see much of an advantage - I want the sweat - that's why I am building the Cessna 310 - a lot of switches, knobs and levers to tweak..Then again, if I was training for IFR certificate, I would probably make a basic autopilot for my sim to get routine familiarity with it as well. Then I'd need to figure out something.Anyway, personally I value the possibility to trim off control forces WAY WAY higher than the possibility to use an autopilot. The trim stuff is one of the very very basic things I want to try and get right on my sim. If that makes autopilot impossible, so be it, I dont give much.. :) It is one of the essential things in flying that you use the stick/yoke to keep certain attitude (you need to use force to maintain it, of course) - then use the trim until the force becomes zero and the control stick stays there by itself. FS gets it all wrong (understandably because people use joysticks with fixed centering) and that is the issue. Either way will be a compromise, I choose the control forces.I heard from a friend that even the Precision Flight Controls jetliner yoke does not center itself, can someone verify? I think their tabletop yoke consoles DO implement the trim adjustment though. But those, while look very high quality, are also very expensive.But I must say: I do understand the importance of an autopilot/autothrottle/whatever for a jetliner simulator, since the flying procedures for those planes are completely based around using the avionics and systems.. But one would then need to make moving throttles for autothrottle and also simulate an autopilot system that moves the actual flight controls (or do they move in real life?)//Tuomas

>>>simulate an autopilot system that moves the actual flight controls (or do they move in real life?)>>>Yes they do, indeed.Roger

Yep, and so I had to do it.. The hinge was just flexing too much sideways.Now, here's some yoke.. :)So I used a 8mm bolt and lock nut with a pair of inline skate bearings (I drilled a fitting hole halfway into a "bread cutting board" block so the bearing has a nice "slot" to stick into - and the yoke pivots on the bearing - very smooth and solid (those screws holding it together are just temporary, 4 bolts do the job now each side..http://tigert.gimp.org/aviation/vatsim/coc...vator-pivot.jpgBelow the floor, there's even heavier stuff :) 12mm bolt, and a rear suspension from a VW Beetle (the cheapest one there was in the car parts store :) Now, this should stop all the oscillations.. The problem is, I am very interested to see if the centering can fight this as well :)http://tigert.gimp.org/aviation/vatsim/coc...suspension1.jpghttp://tigert.gimp.org/aviation/vatsim/coc...suspension2.jpgAll in all, it starts to look nice again.http://tigert.gimp.org/aviation/vatsim/coc...iew-kokkari.jpgNext job is to implement the centering pendulum thingy.. Wish me luck =)//Tuomas

Tuomas,You don't need luck. You've got skill and talent!Mikewww.mikesflightdeck.com

>Tuomas,>>You don't need luck. You've got skill and talent!Thanks :)But it's like climbing a mountain: Just when you think you reach the top, you see there's still another higher pile of rocks ahead :)I just hope I can figure out the aileron centering stuff in a sensible way.. Anyone got a PFC jetliner who has looked inside? :-)//Tuomas

Has anyone thought about using the mechanical components from a car power window to "move" the centering position???Gus

I made a test using a windscreen wiper 12VCC motor.The motor itself has enough torque to managed it.Unfortunately, the only electronic driver available in order to change such motor into a heavy servomotor is not powerfull enough.I have here the wipermotor and the electronics available for anybodywilling to make some experiments.The elecronics came from: http://www.oatleyelectronics.com/kits/k098.html CheersRoger

If the only issue was one of power at the output of the "motor driver", I'd think that it could be solved with a couple of FET's and perhaps a simple PWM motor drive circuit. Gus

>>>f the only issue was one of power at the output of the "motor driver", I'd think that it could be solved with a couple of FET's and perhaps a simple PWM motor drive circuit.>>>>Probably, but the only one available is the one by Oakley. And I am not qualified to design one.Roger

Ok, some slight progress.. :)So I was looking for something to use as the weight, to attach to the pendulum arm.. I pondered blocks of lead etc.. while looking at the toolbox.. while this idea popped up.. :)http://tigert.gimp.org/aviation/vatsim/coc...ringhammer.jpegThis must be the craziest thing so far.. :) :) :) We'll see how this works out in practice.. I need to make the suspension a bit lighter though (the washing machine one sounds better for this since I am not building a 757 :))But hopefully this works. The bolt holes have brass tubing inside the drilled holes for "bearings" for this test setup, if this works, maybe ball bearings will be in order for the next version.. The metal part on the right will be fixed to the yoke pole.But we'll see. At least the weight is rather small and fixed well at the end of the arm. All I have to say my sim firewall is not going to be happy :) I better cut a hole in it for the hammer to go through..//Tuomas