Motorized speedbrake

Question

Hi Vlad, hope you are well.
I have just finished making a set of motorised throttles, I have the throttle working fine using servos but i also designed the speedbrake to run from a servo using the same setup as the throttles with a mosfet. I saw that you answered a similar question but suggested a dc motor is used, At the bottom of that answer you said that if the lever moves easily with the servo off then it could be used and to assign 0 - 1 in the gauge config. I have my mosfet running from the digital out on the master card, but i can't find a way to assign my servo to the speedbrake on the servo card

Answer 1

Ian,
In the SimVim you need to use the simple DC motor with gears to move the AB lever on touchdown.
It can be a relay or FET.

Another topic
Vlad

Comments

Ian,
OK I will test it as select a time.
Please remind me if I don't answer too long (too many work, and I can't keep all...)
Vlad

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appreciated Vald, would really like to get this throttle finished and installed

Ian

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I have removed the laminar reassignment for the SB Armed LED, only our SimVim custom left.
You can try to use it in update (later today will be uploaded.)

"I have a dc motor running through a FET but in the default 737 upon touchdown the fet is recieving the signal but only for about half a second so not enough to get my lever quarter of the way to the rear."
 

The logic of SimVim function:

- the LED "ARMED"  is lit  when 1) the plane is in air, 2) the VS is less than 100, 3) the SB lever is in arm position.

- the Output "Speed_Brake_Motor" is active ("1") when (and):
    1) ARMED is ON,  2) wheel on the ground, 3) Speed is more than 80, 4) Throttle is in Ydle position

Then the MOTOR is active (1) and turned OFF either after 2,5 seconds, or if the SB lever is in full up position.

So, in the Laminar the model moves the lever momentary on touchdown, and your motor gears don't follow this such quickly.

Of course, as you understand the plane model may not have any SB function because you control it with hardware. If you have a hardware cockpit with real lever, the model ideally shouldn't have the virtual lever movement on the touch, the hardware lever should work as usual with your hand, but using the motor.


Vlad

 

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excellent vlad thankyou, I'll try it later and let you know

in the default 737 the fet was getting the signal on touchdown and my physical lever started to move then then the signal to the fet was killed by hcsci after only half a second or so, so my physical lever only managed to get quarter of the way. In the zibo the fet wasn’t receiving any signal at all from hcsci on touchdown.

Ian

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The plugin 1.0.71 is released, you can try it.

"the signal to the fet was killed by hcsci " 
It's because the virtual lever is moving  to the full up position too quickly. 
The lever position is precaution for the hardware lever to stop it  not only by the time 2 seconds.

We could remove this precaution, but in this can I would recomment to use the "end-switch" in the lever max point to prevent it from braking the mechanics...

Vlad

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Hi Vlad, I've just tried it again with the new version and still getting no signal to the fet on touch down with both default and zibo 737. Without changing the wiring, I changed the config to be AT_CONTROL_ON. The fet opens fine and the motor spins up when the auto throttle is armed and N1 is pressed. I did this to prove to myself that the fet and motor are operating correctly when it recieves the signal from the Mega.

If you removed the precaution, would the motor try to work again as soon as the lever is pushed away from the kill switch? Even with the precaution in place I think it's wise to still fit a push to break switch at the end of travel for the lever.

I have an led on my fet that illuminates when signal is being recieved from the mega, On landing the led doesn't even blip at all at any time.

I just tried something different and took the mosfet out completly and instead swapped it with a simple led, wired to the signal line through a resistor and to ground, again i tried the auto throttle config listed above and the led illuminates when auto throttle is armed and N1 is pressed, proving the mega is sending the same signal that spun my motor up. Changed the config to SPEED_BRAKE_MOTOR, took off flew a circuit, armed spedbrake and checked for armed light in cockpit, landed while keeping an eye on my led and it did not illuminate, The sims speed brake deployed without issue but no signal was sent to my led.

Ian

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Ian, strange, I have tested too - everything works with any plane (even for Baron 58, he-he... if  landed on speed more than 80), because it's  universal program, not depending on the virtual model.

Have you all these conditions?:
- the Output "Speed_Brake_Motor" is active ("1") when (and):

1) ARMED LED is ON,  ( the real, HCSCI LED),  Aircraft was in air (descending)
2) Wheels touched the ground,
3) Landing Speed is more than 80,
4) Throttle is in IDLE position

"If you removed the precaution, would the motor try to work again as soon as the lever is pushed away from the kill switch?"

NO, it's activated only ONCE. And deactivates after 2.5 seconds (in feature we can add the changeable timing)
Vlad

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Thanks Vlad much appreciated, Also whats the purpose of the throttle having to be idle in order for the speedbrake to arm? Arming of the speedbrake is done during the approach when generally the 737 is still on auto throttle, hence idle is not possible.

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The idle condition is not for to arm, it's for speed brake to activate on landing.
Vlad

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ah ok all good then, was thinking it was a bit strange haha! Did you remove the condition of the lever reaching full travel like we said? What triggers hcsci's speedbrake? is it when the main gear touches the ground or nose gear?