17 replies to this topic

[glikar]

Tried it in linux and windows, and reflashed firmware with matching gcs.  The model spins while leveling, but ends up in a random position. Side ways, upside down, and changes every time I press the level button bar.  Gave up on BT in linux, works okay in windows, now this.  It started responding unpredictably earlier today as I was trying to set stabilization values.  Its worked for me several times in the past.

[glikar]

 glikar, on 21 February 2012 - 08:10 AM, said:

Tried it in linux and windows, and reflashed firmware with matching gcs.  The model spins while leveling, but ends up in a random position. Side ways, upside down, and changes every time I press the level button bar.  Gave up on BT in linux, works okay in windows, now this.  It started responding unpredictably earlier today as I was trying to set stabilization values.  Its worked for me several times in the past.

I should have added that it flew great the day before, hovered rock solid level all the way up to the tree tops. Unfortunately at that point I panicked and brought it down a little fast.  On the upside my quad landed on a mogul pine shrub, luckly its foliage is soft like a pillow, at least for a quad landing.

Edited by glikar, 21 February 2012 - 09:14 AM.

[agrath]

What are your gyro graphs showing before you press level (straight after boot)
They should all be < +- 1
If they are beyond this, please try locating the gyro chip (small black chips on the left hand side of the board with the USB down) and pressing on them

[mk1spitfire]

Did you erase settings before re-flashing, perhaps that may help.

[K Wells]

Glikar,

Temperature can cause this issue, taking the board from warm inside, to cold outside will affect the gyros... let the board stabilize in temperature before arming and flying....be cautious on condensation as well...no rapid temp changes. Also be sure to wait 10 seconds after arming before you touch your throttle

[Alec]

I think your just turning on your Multics wholile its not level.  Set it down as flat as you can and plug it in.  For the first 5-10seconds it is on the tyros are calibrating and can effect your flight angle.

[glikar]

Thanks for the suggestions fellows, I try them.

Edited by glikar, 21 February 2012 - 03:01 PM.

[glikar]

 agrath, on 21 February 2012 - 09:34 AM, said:

What are your gyro graphs showing before you press level (straight after boot)
They should all be < +- 1
If they are beyond this, please try locating the gyro chip (small black chips on the left hand side of the board with the USB down) and pressing on them

My scope range is +- 0.3 .  Pressing on the gyro produced different results, the graphs zeroed, then spiked and settled down.
Tried my backup board it worked fine.
I'm guessing the hard landing broke a solder joint.  The gyro are rated to 100k g's so it's unlikely the're damaged.   Don't think the quad did a free fall, but if it did the impact would only be around one g.   It was roughly 10 meters high.  Are my assumptions reasonable?

[K Wells]

Thats good news Glikar....are you able to reflow the board?

[2400rdr]

 K Wells, on 21 February 2012 - 05:16 PM, said:

Thats good news Glikar....are you able to reflow the board?

Out of curiosity- how should one of these boards be reflowed? I've reflowed HP printer formatter boards in a 350 oven for 8 minutes with good results. Would this work with a CC board?

Rick

[glikar]

Sorry, I wrote 100k g tolerant the gyro are 10k g tolerant - clarified just incase someone decides to throw one into a Black Hole. I can't even imagine 100k g impact.

 K Wells, on 21 February 2012 - 05:16 PM, said:

Thats good news Glikar....are you able to reflow the board?

K Wells that's a good question.  Haven't tried anything that small.  I have a microscope and replaced one eye piece with a Bevrc mini cam, which feeds a pair of MyVu  glasses, also have an inexpensive hot air rework station.  Not sure I'm ready to reflow the complete board.  Any tips on how to rework it would be appreciated.

[K Wells]

The boards are soldered using leaded solder..if...you have an old toaster oven..or even a new cheap one...you could add some flux,  place your board inside and take it to 195 -215 C for a few minutes....then let it cool...it may work for you...I have a digital IR thermometer I can open the door..check the temp of the board...just so I do not get too hot  

[glikar]

I've seen the Sparkfun tutorial and other video's, but didn't believe it was that easy.   I worry about the components on the bottom of the board falling off, do you use Kapton tape to secure them?

Back to the damage question. I'm perplexed, because nothing else was damaged not the frame nor landing gear.  CopterControl is in a case, it and camera sit on a sprung platform.


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[K Wells]

Yes I use Kapton tape

[glikar]

Thanks for the help!

[glikar]

These are pics of the ISZ500 Z axis gyro magnified 40X and 20X.  The dark line between the chip pin and solder looks like split in the pin itself.   Both gyro show the same split.

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[Rusty]

 glikar, on 22 February 2012 - 07:15 AM, said:

These are pics of the ISZ500 Z axis gyro magnified 40X and 20X.  The dark line between the chip pin and solder looks like split in the pin itself.   Both gyro show the same split.

It does look like they probably need to be resoldered.  It's somewhat deceiving to look at, but there are actually no pins on those chips.  The chip has a pad that wraps around from the bottom to the side, but no leg of any kind.  The solder is just on a pad on the board, and when it's all heated up properly, it should flow to the pads on the chips.

Cheers,
Rusty

[glikar]

Thanks Rusty,  it's hard to tell if the line is just the top of a solder mound.  Could be attached underneath.