Logo 600sx OWB ;(
Posted by lukasdk
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January 09, 2020 10:58AM |
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January 09, 2020 11:30AM |
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January 09, 2020 12:07PM |
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January 09, 2020 02:10PM |
Hi again,
let the numbers speak for themselves (attachment).
The recommended max. head speed is 2,100 (with a margin, terminal velocity for some components could be as high as 4,800 1/min with 550 size blades ... don't try this at home).
If you put load on the system in 3D, the governor (ESC or VBar) will aggressively ramp up the power (and torque).
If you have very much head room and a strong enough motor, and high C rate batteries which can deliver high amps, the torque may exceed what components like main gear or OWB can sustain. Any powerful electric system will draw amps and output even higher power up to short circuit currents if loaded, and if the power supply can deliver.
And higher voltage means higher currents can be drawn, it's a myth that the currents decrease with voltage, this is only the case in the very simple equation where the output power P is constant, if you increase the voltage U, you need less current I to maintain P. Problem is, with higher voltage you can and will increase maximum P if you put load on the system. It does not know it's meant to be limited. This in turn will also increase the drawn current I no matter what, if you put load on the system. If the power or torque becomes too high, something will give way.
If you put load on the system aggressively, it becomes even worse.
If you do overspeeds with aggressive stops, same.
Nothing is indestructible.
If you use a motor with a sensible kV rating, you have a limiting factor, which is also a protecting factor to some degree. It's just as simple as that.
Even I, and I am not a very accomplished pilot, was able to strip the older (narrower) herring bone main gear with a hard cyclic and collective input on command, with 12s and 560 kV, 11 T pinion, at 12° collective, back in the day.
The thicker main gear can sustain more torque, now indeed the weakest point can be the OWB, so it's wear increases, and it's lifetime (number of flights it might sustain) decreases. And as being said, if the failure causes chatter marks on the main shaft, a replacement OWB will possibly fail even sooner.
This could be the reason why the flagship LOGO 600 comes with the double OWB, and it also has a higher recommended max. head speed.
We do not give our recommendations without a reason.
There are other such issues, granted. It just means, you are not alone.
My OWBs on the 600 and 600 SX have lastet 450-600 flights mtbc (mean time between crashes).
Even our team pilots who won competitions with the 600 did rarely if ever crash/lose/yellow card because of the OWB failing, and they did not nurse their equipment to the finals, either. But they were using our recommended equipment, maybe one or two teeth more on the pinion, but that's that.
This does not mean I'm trying to make you look like an idiot, and thanks for that, by the way.
I'll stop now, no worries.
Kind regards
Eddi
Born to fly ...
forced to work.
let the numbers speak for themselves (attachment).
The recommended max. head speed is 2,100 (with a margin, terminal velocity for some components could be as high as 4,800 1/min with 550 size blades ... don't try this at home).
If you put load on the system in 3D, the governor (ESC or VBar) will aggressively ramp up the power (and torque).
If you have very much head room and a strong enough motor, and high C rate batteries which can deliver high amps, the torque may exceed what components like main gear or OWB can sustain. Any powerful electric system will draw amps and output even higher power up to short circuit currents if loaded, and if the power supply can deliver.
And higher voltage means higher currents can be drawn, it's a myth that the currents decrease with voltage, this is only the case in the very simple equation where the output power P is constant, if you increase the voltage U, you need less current I to maintain P. Problem is, with higher voltage you can and will increase maximum P if you put load on the system. It does not know it's meant to be limited. This in turn will also increase the drawn current I no matter what, if you put load on the system. If the power or torque becomes too high, something will give way.
If you put load on the system aggressively, it becomes even worse.
If you do overspeeds with aggressive stops, same.
Nothing is indestructible.
If you use a motor with a sensible kV rating, you have a limiting factor, which is also a protecting factor to some degree. It's just as simple as that.
Even I, and I am not a very accomplished pilot, was able to strip the older (narrower) herring bone main gear with a hard cyclic and collective input on command, with 12s and 560 kV, 11 T pinion, at 12° collective, back in the day.
The thicker main gear can sustain more torque, now indeed the weakest point can be the OWB, so it's wear increases, and it's lifetime (number of flights it might sustain) decreases. And as being said, if the failure causes chatter marks on the main shaft, a replacement OWB will possibly fail even sooner.
This could be the reason why the flagship LOGO 600 comes with the double OWB, and it also has a higher recommended max. head speed.
We do not give our recommendations without a reason.
There are other such issues, granted. It just means, you are not alone.
My OWBs on the 600 and 600 SX have lastet 450-600 flights mtbc (mean time between crashes).
Even our team pilots who won competitions with the 600 did rarely if ever crash/lose/yellow card because of the OWB failing, and they did not nurse their equipment to the finals, either. But they were using our recommended equipment, maybe one or two teeth more on the pinion, but that's that.
This does not mean I'm trying to make you look like an idiot, and thanks for that, by the way.
I'll stop now, no worries.
Kind regards
Eddi
Born to fly ...
forced to work.
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January 29, 2020 12:06PM |
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