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stupid crash

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I just crashed my HexaXl when descending fast from some 100m.
Pulling down the Gas also easily Yaws left.

It would be better to swap motors On and OFF. Then pulling the Gas down and accidentally pulling to the left at same time causes nothing.

Agree?

Hannu

PS the damage was less than 70€ from that 80m drop. Lucky me.
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no need to change that.
use the "motor safety switch" to prevent this next time !!!

http://www.mikrokopter.de/ucwiki/en/MK-Parameter/Channels
« Bearbeitet von helmar am 25.03.2013 00:49. »
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OK, thanks

I have done that already. However favoring natural behavior is allways the best solution.

Hannu
« Bearbeitet von salesh am 25.03.2013 09:23. »
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"...natural behavior..." ?! i dont understand what you mean.

i cant think of any reason, why one should put pitch down completely and yaw to the left at the same time unless one would want to spiral down very fast and crash it ;)
my "natural behavior" is that i put yaw on 45% or so and let it sink slowly, no yaw, only roll or nick if necessary. i never came in a situation where i accidentally
switch of the motors in flight...
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helmar meinte
"...natural behavior..." ?! i dont understand what you mean.

i cant think of any reason, why one should put pitch down completely and yaw to the left at the same time unless one would want to spiral down very fast and crash it ;)
my "natural behavior" is that i put yaw on 45% or so and let it sink slowly, no yaw, only roll or nick if necessary. i never came in a situation where i accidentally
switch of the motors in flight...


I mean that when pulling back the power rod, You simultaneuosly and unnoticed pull the rod to left. Human body is build that way. The meaning was just to get the hexa down as fast as possible, but not too fast. Sorry about my english.

Hannu
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np, my english it not the best either, thats why i was asking ;)

are you using a "pult"-remote (e.g. DC-16 or MC32 or similar) or a handheld remote as the MX-20
im using a DC-16 and i removed the spring from the pitch rod, so i can slide it down smoothly. (Mode 2)
If i would use a handheld and e.g. using the thumb for steering the pitch rod you'r right that might happen
it would be anatomically difficult not to yaw a little to the left, while pulling the pitch rod down

Best
Helmar
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salesh meinte
I mean that when pulling back the power rod, You simultaneuosly and unnoticed pull the rod to left. Human body is build that way.

Hannu


This does not sound like a human more than an elephant :-)
Sorry but when you pull the rod to the left so far, first you have to learn how to use the sticks more sensitive. I don`t wanna think about how you fly your kopter when this is a normal behaviour for you.

If you want to get your kopter down as fast as you can don`t forget that you don`t loose control. Descend while going forward and turn around in bigger circles. That is the best way to do it safely.

Matthias
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I Agree, that the combination of a low gas value (especially when you use Altitude Control) and yaw left is not the best and safest way to cut off the Motors, cause this can happen in flight as you may know now. But with the correct use of a Motor Safety switch this should be no longer a Problem. And to be honest, it will need more yaw than just a few degrees stick input. You have to pull the stick approximately half to the left. What i try to explain: you can't cut off the motors just by pulling down the gas stick, and unintentional yaw a bit.
« Bearbeitet von Marvin_0 am 25.03.2013 13:55. »
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I think an automatic safety switch would be nice. It could be accomplished by letting the software check the decrease of the altitude (So to say the derivation). When the negative derivation is lower than a certain threshold, the motors don't turn off.
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Simml meinte
I think an automatic safety switch would be nice. It could be accomplished by letting the software check the decrease of the altitude (So to say the derivation). When the negative derivation is lower than a certain threshold, the motors don't turn off.


This would be very nice feature. When browsing internet You can find many similar cases. I am a programmer and this kind of solution would take account of accelerations. This feature could be the default and option off to those who want it.

If we all were robots, this kind of properties would not be needed.

Hannu
« Bearbeitet von salesh am 25.03.2013 16:59. »
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My values from log. It would be very easy to prevent accidental motor cut value below minus 100 or last three values below it and growing.

elevation vertical speed
133,685 47
134,076 50
134,139 32
133,952 -10
133,506 -51
132,945 -36
132,952 -13
133,045 -25
132,839 -54
132,64 -37
132,803 5
133,469 64
133,792 38
134,377 77
135,006 48
135,142 14
135,606 6
135,485 5
135,085 -14
134,857 -14
134,618 -28
133,909 -53
133,859 -1
134,187 14
133,848 -26
132,583 -210
129,823 -303
125,364 -470
119,451 -563
114,152 -470
110,493 -377
107,062 -357
102,041 -400
97,097 -480
92,345 -473
88,181 -445
84,21 -437

values for rcstick

2,2,-11,-126,255,127,135,0,127,255,146,0
2,2,-11,-126,255,127,135,0,127,255,146,0
3,2,13,-126,255,127,135,0,127,255,146,0
3,2,127,-126,255,127,135,0,127,255,146,0

A disturbation in pilot's balance would have caused this /sudden glance to right.


Hannu
« Bearbeitet von salesh am 25.03.2013 23:34. »
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Sorry, but the functions for this already exists in the Motor Safety switch.

I must admit I see this as a user error because of several things:
- User didn't look into the motor-switch (hence, didn't read the manual).
- User didn't fly accordingly. Using a low min gas, the probability for a flip during descend is high, as the motor doesn't necessarily have enough power to correct movement or fight the reverse airflow.
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wizprod meinte
Sorry, but the functions for this already exists in the Motor Safety switch.

I must admit I see this as a user error because of several things:
- User didn't look into the motor-switch (hence, didn't read the manual).
- User didn't fly accordingly. Using a low min gas, the probability for a flip during descend is high, as the motor doesn't necessarily have enough power to correct movement or fight the reverse airflow.


Heh

of course this is the user error, I am not denying it. Manuals have been read. It is not question of that. Question is how to prevent user errors possibly leading to catastrophes.

Hannu
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easy question - easy answer: learn to fly like a sensitive and thinking human!
Hundreds of other pilots have learned, so you can too ( and they didn`t have the safety switch available). Only some did this stupid thing although they read all instructions and knew this problem. But they did it only once. After the crash they changed their behavior.
There is absolute no flight situation under full control who needs such stick position that cuts off the motors!
From now on use the safety-switch and this will never happen!
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no need to change that.
use the "motor safety switch" to prevent this next time !!!

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