Dear Friends,
Running MSFS2020, PMDG 737 and an old Cockpitsonic motorized throttle quadrant.
I rewired the full device, via Teensy, Arduino Mega and Mobiflight all switches and axis are now visible in Windows and MSFS. Hurra!
The tricky part is the automated move of the speed brake lever, which should deploy if the spoilers are deployed automatically in the sim (during RTO or after landing).
Two nights with Gemini were not successful in identifying the correct dependencies for the Spoiler Servo output: I want it to read and follow the generic ‘Spoiler handle position’ if the spoilers deploy in the sim.
How to set the independency up for this logic?
Thanks a lot for any advice,
Georg
#B737 motorized throttle quadrant – speed brake lever
glacial osprey
spare fractal
Do you already have a working motorized lever, which Mobiflight can move in test mode to the expected positions??
(A:SPOILERS HANDLE POSITION, PERCENT)
Should return a value from 0 to 100
Representing the position of the lever at any given time
Is the servo connected to the Arduino Mega running Mobiflight firmware?
glacial osprey
Do you already have a working motorized lever, which Mobiflight can move in test...
Yes, the lever is fully accessable and moves under mobiflight commands. Connection is via Arduino Mega/Mobiflight firmware.
spare fractal
Ok, what is the percent rotation of the servo necessary to move the lever to the max position
glacial osprey
Ok, what is the percent rotation of the servo necessary to move the lever to the...
88% from 10 to 180.
The problem I am running into is the dependency of deployment.
spare fractal
what do you mean?
glacial osprey
what do you mean?
I mean to make the servo only taking control over the 'handle position' of the lever if the speed brakes are deployed in the sim (because otherwise I want to move them manually).
spare fractal
how will the servo disengage from the lever? Because you can't really move a servo by hand.
glacial osprey
how will the servo disengage from the lever? Because you can't really move a se...
That's exactly my problem, Jaime )))
In the ideal world the servo takes over control if the speed brakes are deployed automatically (RTO, after landing) and release again if lever touched physically.
But all trys and errors I had with different status dependencies led to the fact, that those servos grab the lever and block them.
Thanks for your replies and help on this server, btw...!
spare fractal
That's exactly my problem, Jaime )))
In the ideal world the servo takes over con...
but that is a mechanical problem, not a Mobiflight configuration issue.
A servo will not allow movement of anything attached to it while powered. I think you need to physically detach the servo from the lever, in order to be able to move it manually.
glacial osprey
A servo will not allow movement of anything attached to it while powered. I thi...
I thought I can tell the servo ooutput to follow the handle position only if ... and otherwise not, so servo would go limp.
spare fractal
Even unpowered it is hard to move a servo because of its internal gear reduction.
glacial osprey
Even unpowered it is hard to move a servo because of its internal gear reduction...
That is clear. I dont want to override it.
spare fractal
The servo will on its own try to hold its position. There is no limp instruction. Like I said, even without power is not so easy to overcome the gear mechanism. I mean, it can be done, I would suspect, at the risk of damaging the gears.
glacial osprey
The servo will on its own try to hold its position. There is no limp instructio...
Yes, those servos are a strong hold. The previous logic of Cockpitsonic (old platine was not visible by Windows anymore, so I had to rewire everything) understood the logic. So the servo of the speed brakes only were activating the speedbrake lever if the spoilers were deployed automatically. Same with the throttle levers: if A/T active, the servos move the levers, if inactive the servos go 'off' and you can move them manually.
Therefore I was looking for a condition to take control as output only in these dependencies.
But maybe a dream of hot icecream...
spare fractal
does this TQ have relays for the servos that maybe you can control from Mobiflight?
I have only dealt with very small servos, which would not be suitable for a TQ. When I made an autothrottle lever, I used Nema17 stepper motors, not servos.
When you say the servos go off, how do they go off? If you move the throttle levers manually, what happens to the servos?
I am thinking you either overcome their gears, or somehow they are mechanically decoupled.
glacial osprey
I have only dealt with very small servos, which would not be suitable for a TQ. ...
The old logic was: If A/T off, levers move freely manually. If A/T on, the servos take control and the levers move automatically until I switch A/T off again. So inside there must be some kind of clutch.
And no, relais I don't have. At the moment. But that is what Gemini suggests to build in between and let the Arduino/Mobiflight switch them on/off.
spare fractal
how would the servo know the lever position if a clutch allowed you to move the lever without the servo knowing?
glacial osprey
Potentiomenters build in on all axis as well. So the position of the levers is known to Arduino.
spare fractal
Do the levers move the servos when in manual mode?
glacial osprey
Yes, looks like. I can hear the gear moving. But actually I did not take apart these elements never.
spare fractal
I have zero knowledge of how your TQ is designed. It seems clear that there must be a way in this design to allow movement of the levers manually. The easy way would be to cut power to the motors, and overcome the gear mechanism, if these servos can take it.
glacial osprey
Yes, that is for sure a way. Maybe going for relais. Until then flying manually 🙂
spare fractal
the other thing that I would worry about is that upon restoring power, the servos I have used always go back to the zero position. I don't think that would be any good in mid flight.