slow tail wag
Posted by Marianovbar
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March 18, 2024 04:08PM |
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March 19, 2024 08:53AM |
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March 21, 2024 09:18AM |
Hi,
to be honest, no idea. The Wiehenstroth brothers are flying the 700 with KST servos, and definitely not material-friendly.
I must say I also never heard of broken belts, on the 700, yet.
Technically, I would say the motor by itself can not overspeed unless something is slipping.
On the other hand, your motor has nominally like 2.5 % higher kV (probably negilgible on it's own) but also like 15 % more continuous power so I _guess_, with the 14 T pinion, high collective angles and/or longer blades (710 instead of 690) you could be over stressing the mechanics, at least if you do most aggressive maneuvers without accommodating e.g. with collective management or going a tiny bit easier on the sticks.
It's not only that of course, but probably the combination, the servos driven harder, too, they just do, they don't ask or look left or right
The governor setup could also be a tell-tale, those high-bred electric motors, powerful ESCs and high-C batteries also simply deliver, if you let them, without much in the way of easing off the tiniest bit.
It's not that the 700 mechanics (mostly the same as the 800 mechanics, by the way) are weak, but there's certainly a point where too much is too much.
That being said, I'm only saying, I can not tell. Even if I had that model at hand, my flying would never bring it remotely to it's mechanical limits.
I'll try and put Alex on this topic, maybe he has some insights. He's maintaining the models also for his brother Marik, if anyone knows, it's him
—Eddi
Born to fly ...
forced to work.
to be honest, no idea. The Wiehenstroth brothers are flying the 700 with KST servos, and definitely not material-friendly.
I must say I also never heard of broken belts, on the 700, yet.
Technically, I would say the motor by itself can not overspeed unless something is slipping.
On the other hand, your motor has nominally like 2.5 % higher kV (probably negilgible on it's own) but also like 15 % more continuous power so I _guess_, with the 14 T pinion, high collective angles and/or longer blades (710 instead of 690) you could be over stressing the mechanics, at least if you do most aggressive maneuvers without accommodating e.g. with collective management or going a tiny bit easier on the sticks.
It's not only that of course, but probably the combination, the servos driven harder, too, they just do, they don't ask or look left or right
The governor setup could also be a tell-tale, those high-bred electric motors, powerful ESCs and high-C batteries also simply deliver, if you let them, without much in the way of easing off the tiniest bit.
It's not that the 700 mechanics (mostly the same as the 800 mechanics, by the way) are weak, but there's certainly a point where too much is too much.
That being said, I'm only saying, I can not tell. Even if I had that model at hand, my flying would never bring it remotely to it's mechanical limits.
I'll try and put Alex on this topic, maybe he has some insights. He's maintaining the models also for his brother Marik, if anyone knows, it's him
—Eddi
Born to fly ...
forced to work.
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Re: slow tail wag March 31, 2024 08:34PM |
Hi, i tested 13 tooth pinion and i was able to increase my tail gain like 20 points without any overspeeding and now is more stiff, also the motor has more torque. But i'm having a pwm too high now so after mid flight heli start to loose some rpm in some maneuvers and feels like less power as it gets close to the end of the flight.
Some advice to lower pwm scores?
Bigger blades and less rpm? lower gov gain? collective add?
Pics attached
Regards
Some advice to lower pwm scores?
Bigger blades and less rpm? lower gov gain? collective add?
Pics attached
Regards
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March 31, 2024 10:54PM |
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April 01, 2024 11:27AM |
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April 02, 2024 08:59AM |
Hi,
that, plus the fact that the motor kV are usually only a ballpark figure.
My calculation would be, for a 12s drive, 535 x 44.4 V / 10.46 * .9 (load factor) = 2044 1/min sustained max. head speed from battery full to battery empty.
With a 6s drive, my empirical load factor would even be .8
There seem to be two ways, the European way, set up so the governor can maintain the requested head speed throughout the flight/battery, and the U.S. way, go full throttle and forget about it, and who needs a governor anyway
In competition flying, there are, or must be, trade-offs, something in-between, for maximum performance as well as to get your three minutes' worth of flying time, as well as to protect the ESC, which has the least switching loss (and as a result, heat generation and dissipation) at full throttle.
Butt there are some given limits, like, you can not open throttle more than 100 % no matter if governed or if you set throttle manually.
And if the load becomes too high, collective/cyclic and tail combined, rpm has no other way than to drop.
Kind regards
Eddi
Born to fly ...
forced to work.
that, plus the fact that the motor kV are usually only a ballpark figure.
My calculation would be, for a 12s drive, 535 x 44.4 V / 10.46 * .9 (load factor) = 2044 1/min sustained max. head speed from battery full to battery empty.
With a 6s drive, my empirical load factor would even be .8
There seem to be two ways, the European way, set up so the governor can maintain the requested head speed throughout the flight/battery, and the U.S. way, go full throttle and forget about it, and who needs a governor anyway
In competition flying, there are, or must be, trade-offs, something in-between, for maximum performance as well as to get your three minutes' worth of flying time, as well as to protect the ESC, which has the least switching loss (and as a result, heat generation and dissipation) at full throttle.
Butt there are some given limits, like, you can not open throttle more than 100 %
no matter if governed or if you set throttle manually.
And if the load becomes too high, collective/cyclic and tail combined, rpm has no other way than to drop.
Kind regards
Eddi
Born to fly ...
forced to work.
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