Servos HELP!

[Guest MikePowell]

I can't give you a definitive answer, but I would not be surprised at a very shortened life for a wiper motor operated at stall for extended periods.DC servo motors are designed to move heat out of the motor through conduction. Servo motors that have brushes use large copper-graphite ones that conduct heat well.Consumer grade motors use lighter brush-commutator assemblies. Brushes are more likely to be only graphite which does not conduct heat as well. Air circulation through the motor, or at least within the motor if it's a sealed unit, is a significant cooling factor. If the motor is stalled, there is little to move the air.On a more positive aspect, wiper motors are designed to operate in a hot, hostile environment. Of any DC motor you might choose short of an actual DC servo motor, a wiper motor is probably your "best" choice. Whether or not it will turn out to be a good choice, I really don't know.The factor that will most degrade the motor's lifetime is long periods of high torque demand when the motor is stalled. You could extend the motor's life by using the motor to set the tension of a spring, and let the spring supply the control loading.Mikewww.mikesflightdeckbooks.com

[Guest SHORT360]

Hello Mike,Many thanks for the reply, indeed. Is in the book I ordered some schematics as regards that kind of servos applications ???If not could you make a little schematics about your idea with the spring loaded by the wiper motor?? Would be great. ThanksRoger

[Guest SHORT360]

I can imagine it like that, and not sure at all if it works, but there must be a way using only one motor??http://forums.avsim.net/user_files/91398.jpg

[Guest MikePowell]

Roger,Your drawing is fundamentally what I had in mind. There are differences in implementation details (I would probably use a lead screw and traveling nut), but the concept is the same.You could make do with a single motor if you a torsion spring centered on the column's pivot point center of rotation. The simulated instrument book does not have full circuitry for large servo systems like this, though it does have some general information for motor drivers.Mikewww.mikesflightdeck.com

[Guest SHORT360]

Mike,I understand what you mean. Nevertheless, your idea using using a lead screw and a travelling nut would need something more like an stepper motor rather than a servo. Having all the stuff needed to drive servos I prefer the simplest way and so I adapted your idea as you can see on the sketch below.It is right so ??CheersRogerhttp://forums.avsim.net/user_files/91467.jpg

[Guest Stephan Haas]

Roger,This looks like a good desigh I would like to use too.However, I have still stil question nagging me: What will happe to the servo when I move the yoke manually?Kind regards,Stephan Haaswww.lemont.nl/b767flightdeckhttp://www.pic767flyingclub.com/images/sas544.jpg

[Guest SHORT360]

Stephan,Two thing may happen, depending on how you will electronically feed your motor.1. My solution - slaved to the trim output value given by FSUIPC. The servo will move in the same range as the trim what means it will move as soon as you move the trim.Slaved to the trim output is a an easy solution and simulates at 70% what happens in the reality.2. More complex solution - slaved to the aerodynamical force applied to the control surfaces. In that case the servo would move in the opposite way you are applying a given pressure on the controls.That's real force feedback, but as far as I know it not really modelled with FS2004. May be in future version. The force feedback outputs generated by FS2004 are kind of gimmicks.Cheers,Roger

[Guest Stephan Haas]

Roger,Perhaps I did not formulate my question correct.It's my plan to connect the servo throuhg the trim output. That wil probably work.What I was referring to: usually a change in the airflow is initiated with pushing/pulling the yoke. Once the aircraft is in the right attitude I start trimming to relieve the forces on the yoke.So, when I pull the yoke without touching the trim will it be able to move freely from the servo?Kind regards,Stephan Haaswww.lemont.nl/b767flightdeckhttp://www.pic767flyingclub.com/images/sas544.jpg

[Guest SHORT360]

>>So, when I pull the yoke without touching the trim will it be able to move freely from the servo?>>Stephan,Yes of course. While pulling the yoke, you act against the torque of both the spring and the motor. So the spring and the motor will bring your yoke back to the initial trim setting. So once you on autopilot, you will see the yoke travelling back and forth as trimmed by the autopilot. But anyway it will be an experiment, because the right thing would be to slave the servo to the aerodynamical forces which as I said are not output by MSFS. And in that case a real actuator motor would be the finest, but we would then have a commercial simulator.GreetingsRoger

[Guest SHORT360]

Mike,I find an interesting internet site with different kind of industrial servos - actuators - motors ....available onlineand it is in Europe, what seems interestingHere the linkhttp://nanotec.com/page_servo_dcservo_en.htmlSo my question:What would be your suggestion lets say, you best choice. CheersRoger

[Guest mbessler]

>Mike,>>I find an interesting internet site with different kind of>industrial servos - actuators - motors ....available online>and it is in Europe, what seems interesting>>Here the link>http://nanotec.com/page_servo_dcservo_en.html>>So my question:>>What would be your suggestion lets say, you best choice. The peak torque for the last one in the list is in the range of common steppers.The rated torque of 37Ncm is not a whole lot for our purposes, I think.Look at some of these RC servos:http://www.gmmodels.co.uk/acatalog/Multiplex_Servos.htmlThey even have more torque than those from nanotec.Just checked my cheapo rc-servo we use for instruments... it has 31 Ncm.Thats just a bit less than nanotec's biggest DC servo, but a standard RC servo draws a lot less amps....looking at the sizes of the servos from nanotec, I understand, they are small. (From the company name, I guess they are specialized in small motors...)Manuel

[Guest SHORT360]

And what about those actuators. Should be ideal, but dont know how to drive them. Stepper controller ???RegardsRoger

[Guest SHORT360]

Sorry thats the link to the actuatorshttp://nanotec.com/media/l4257_en.pdfBetter than the actuators, I find that geared motors which would make the job I guess.http://nanotec.com/media/planetengetriebe_en.pdfI think about the PLE 80But finally that motor is similar to a wiper motor which may used be less expensive.

[Guest Stephan Haas]

Roger,Yes, I guess it will be experimenting. This part of my sim is not right away on mu planning, but it's always good to think ahead.Thanks for your input.Kind regards,Stephan Haaswww.lemont.nl/b767flightdeckhttp://www.pic767flyingclub.com/images/sas544.jpg

[Guest MikePowell]

Hi Roger,I think Manuel is correct. Those motors produce too little torque. The geared motors might work better, but it depends on how robust the gear head assembly is. If movement of the column can overpower the motor, it may over stress the gears.Mikewww.mikesflightdeck.com