600 Pimp my Chaos 600E Pro

Lee

Lee

Well-Known Member
Well one good thing about having the Castle Creations ESC is it has Logging. So i know everything that happened in the flight.
Voltage: ESC is set to cut off at 3.2V. log shows minimum of 3.5V and my battery checker read 3.8V straight after the crash.
Amps: Its a 100A esc with 150A burst and the log shows a max of 65A
It really did feel like low voltage cut off though. But with no power and inverted and low, I had no chance of a good auto. At least i kept it level and only broke the skids (reordered already) First time this heli has ever hit the ground in over a year and a half of flying.
The other great thing about the ESC is it tells you the head speed, which was 2300!!! it was 1900 with the other motor.
So i don't know why it did what it did.
 
stokke

stokke

Well-Known Member
I'll be waiting. Curious on what caused that crash...
It certainly looked strange - like it just died out.
 
Lee

Lee

Well-Known Member
I just spoke to a friend. He told me to drop the LVC to 3.0V instead of 3.2V. My sample rate was at its lowest, so may not have picked up a drop before cutting out. Will be back in the air asap. :)
 
Tony

Tony

Staff member
Definately looked like a voltage cut out to me. I have to say though, great save bro! :thumbsup. Make sure to check that feathering shaft as well. That was a solid hit and those blades are heavy.
 
Lee

Lee

Well-Known Member
Ok latest diagnosis,
Plugged in the battery today to check all is working. Funny thing was, the swash wasn't level? The elevator was tipped back.
So i know what happened, but i'm going to make this a quiz. WHAT HAPPENED??
If you watch the video, you will see me doing tic tocs. Just before the crash it flips out of the tic toc onto its back. That was not me.
So WHAT HAPPENED???
Answers on a postcard to...... Only joking. Answers here please. No prize for the winner.
 
stokke

stokke

Well-Known Member
Elevator servo brunt up, causing a short which in turn "rebooted" the ESC`s soft start mid air?
 
zenmetsu

zenmetsu

Member
Elevator ball link, the one with the shaft that fits into auto rotation device, came loose.

- - - Updated - - -

not auto-rotation device.. anti-rotation device.
 
stokke

stokke

Well-Known Member
Link have popped off the ball on elevator?
Bent elevator link?

Come on Lee, I hate this game!!
 
zenmetsu

zenmetsu

Member
Well, my first guess was that the anti-rotation shaft disconnected or got bent. So that is ruled out.

So provided that we are not dealing with a radio problem, i.e. you noobed and bumped some trim or fudged some setting while in the air, this kinda narrows it down.

If the elevator is stuck full up, I would assume that there is force being applied to keep it there since the natural tendency is for the blades to go to zero pitch while spinning. You already indicated that the servo did not fail. Only other thing I could see is if the ball in the swash jumped out and the swash is jammed.

You state that you did not give back cyclic, but that the heli went back for another tic-tock uncommanded. I can assume from this that the elevator could have been stuck high, and if you decreased collective (since your elevator seems to be in front), this would have caused the heli to flip over backwards. If you gave forward cyclic to right the heli, it would have required a lot of stick input to counteract an elevator stuck in the high position. You would have had very large positive pitch, likely with a low throttle, and this would have resulted in a drop in headspeed and noise, which I think I observed in the video.

So, is the elevator jammed in this position, or is the servo just "centering" in this position?

- - - Updated - - -

stokke said:
Come on Lee, I hate this game!!
Click to expand...

You would hate my job then. Failure analysis takes up probably 30% of my cycles. :) I actually like doing this sort of work, and it is one of the reasons that I picked up this hobby. Crashes will happen, the fun part is finding out why.
 
Lee

Lee

Well-Known Member
Ok i'll give in and tell you.
I did pull back for the tic toc but when i pushed forward again it kept going back because, The servo wheel stripped out the spine threads from the torque. So although the servo moved, the wheel (servo arm) stayed where it was. Need to buy the metal ones to replace them and we will be in business again. :thumbsup:
 
zenmetsu

zenmetsu

Member
Wow, that must be a lot of force on those servos.

My 500 build is going to use the Hyperion Atlas FMTs with the titanium gears. I realize that there is still plastic gears in the train, but as long as the part is cheap, the servo is easily fixed.

Good luck with the repair. I can't wait til I'm doing inverted stuff with a real heli, the sim just doesn't cut it for me. :)
 
Tony

Tony

Staff member
Lee, if that happened then your screw was not tightened down all the way. Friction plays a huge roll in holding that wheel along with the teeth. But lesson learned, every 10 flights you should check your servo arms as well.
 
Lee

Lee

Well-Known Member
It def wasn't the tightness of the screw Tony. To get it off took a lot of force with the screwdriver. It was on there nice and tight.
 
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