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Old Dec 23, 2013, 11:50 AM
Grumpy old git.. Who me?
JetPlaneFlyer's Avatar
Aberdeen
Joined Mar 2006
11,239 Posts
Help!
Ice 80HV - Sudden loss of RPM possibly related to data logging

I'm posting this here because I'm pretty sure it's an ESC issue:

I was flying yesterday with my Trex 600 DFC using the stock Castle Ice2 80HV. I'd put a battery through it and had been flying for a couple of minutes on the second pack. I was flying on governor and had used all the three governed head speeds the previous flight and they all worked fine.

I'm just hovering, doing nothing special when suddenly the headspeed sharply drops and even with full collective she comes down quite heavily. After checking for damage and checking the batteries (they have 4v per cell) I try to run her up again. The headspeed is still very low, not enough lift to get airborne. It was as if I'd set the governor at really low RPM. The motor started and ran smoothly enough, just at very low speed.
I repeated the test with fresh batteries with no change (the batteries are all just a few cycles old by the way). My telemetry showed battery voltage was good throughout.

I checked everything out when i got home and it all looks fine. No sign of bad connections and the motor is visibly fine with no smell of burning. The ESC programming is also still good with programmed headspeeds where I left them (1950, 2150, 2400).

The only thing that I did differently yesterday was that I'd set data logging (at 5Hz) for the flying session in question. On all previous flights I had logging disabled.
Now when i tried to download the log to see if it gave any clues to the problem the data appeared to be corrupt and would not 'parse'. Also and this could be coincidence but but the loss of RPM would seem to have occurred at about the same time as the data logger's memory became full (13 minutes of logging at the settings I used)

Anyway, after clearing the logger memory and disabling data logging (and making no other changes at all) I gave her another spin up and now everything is fine again, I'm getting full headspeed as confirmed by a tacho.

So the conclusion that I'm coming to is the problem was most likely caused by an ESC glitch that is related to data logging and possibly the logger memory.

Is this something anyone else has experienced?

My settup:
Trex 600DFC pro
12s, 3000mAh
Scorpion HKIII 4035 530kv
14t pinion, 118t main
Castle Ice2 80HV (latest firmware v4.19 beta)
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Old Dec 23, 2013, 12:48 PM
A man with too many toys
United States
Joined Feb 2001
17,377 Posts
Could you post the data log?
Just zip the .csv file, as that's the easiest to analyze.

.
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Old Dec 23, 2013, 01:04 PM
Grumpy old git.. Who me?
JetPlaneFlyer's Avatar
Aberdeen
Joined Mar 2006
11,239 Posts
Like I said, the data log file was corrupted. I got a warning saying the file could not be 'parsed' and the download failed.

All the more reason to conclude something was amiss.
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Old Dec 23, 2013, 06:15 PM
A man with too many toys
United States
Joined Feb 2001
17,377 Posts
This is what I would suggest.
1. Reload the firmware then clear the data log using the Castle Link. See if that is any better and save the data logs on all flights.
2. If that does not fix it call Tech Support.
3. Send it in to CC for a checkup.


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Old Dec 24, 2013, 02:19 AM
Grumpy old git.. Who me?
JetPlaneFlyer's Avatar
Aberdeen
Joined Mar 2006
11,239 Posts
Thanks, that all sounds sensible.

I already did clear the log and either that or disabling logging appeared to fix it. But I accept that it could be coincidence.

I have emailed Castle though I guess at this time of year it may take a while to get response.

What I might do is see if I can reproduce the problem on the ground. If I enable logging at highest frequency it will fill the logger memory in a few minutes. that will allow me to test on the ground to see if the problem repeats itself when the logger memory hits 'full'.

If the problem can be reliably reproduced then it will be easy enough to narrow down whet combination of circumstances caused it.
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Old Dec 24, 2013, 04:49 AM
A man with too many toys
United States
Joined Feb 2001
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Keep us updated.
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Old Dec 24, 2013, 09:01 AM
Grumpy old git.. Who me?
JetPlaneFlyer's Avatar
Aberdeen
Joined Mar 2006
11,239 Posts
ok, I did the ground test and could not simulate the loss of RPM problem. The test had to be done under no load conditions (running indoors with blades off) as we are in the middle of a storm with 60+MPH gusts so any running outside with blades on is impossible.

I tried to download the log file and again got the 'could not parse' error message.
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Old Dec 25, 2013, 04:52 AM
A man with too many toys
United States
Joined Feb 2001
17,377 Posts
Quote:
Originally Posted by JetPlaneFlyer View Post
I tried to download the log file and again got the 'could not parse' error message.

Have you tried using the Factory Defaults option under the Device Command menu? Then program our settings. If that does not do it you need to contact Tech Support or just send it in and have CC fix it for you. If it’s a hardware problem you probably don’t want to fly it until it’s repaired.



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Last edited by RC Man; Dec 25, 2013 at 04:58 AM.
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Old Dec 25, 2013, 08:56 AM
Michael
United States, ME, Wells
Joined May 2008
1,055 Posts
Cold Solder Joint on One Motor Leg?

I could be completely wrong, but it is also possible that your symptoms could be explained by a cold solder joint on one of the three motor leads from the ESC.

I purchased a used bird from a club member and experienced something similar, but it was intermittent.

In my case, I could get close to half-power when the joint "opened"; all ran smoothly, just not full power. The intermittent aspect became noticeable when I was examining all the wiring and the motor would run fine for a bit. Vibration during flight would cause the joint to reopen and back to greatly reduced power.

It took a while, but I found a cold solder joint; fixed it and problem solved.

Michael
Quote:
Originally Posted by JetPlaneFlyer View Post
I'm posting this here because I'm pretty sure it's an ESC issue:

I was flying yesterday with my Trex 600 DFC using the stock Castle Ice2 80HV. I'd put a battery through it and had been flying for a couple of minutes on the second pack. I was flying on governor and had used all the three governed head speeds the previous flight and they all worked fine.

I'm just hovering, doing nothing special when suddenly the headspeed sharply drops and even with full collective she comes down quite heavily. After checking for damage and checking the batteries (they have 4v per cell) I try to run her up again. The headspeed is still very low, not enough lift to get airborne. It was as if I'd set the governor at really low RPM. The motor started and ran smoothly enough, just at very low speed.
I repeated the test with fresh batteries with no change (the batteries are all just a few cycles old by the way). My telemetry showed battery voltage was good throughout.

I checked everything out when i got home and it all looks fine. No sign of bad connections and the motor is visibly fine with no smell of burning. The ESC programming is also still good with programmed headspeeds where I left them (1950, 2150, 2400).

The only thing that I did differently yesterday was that I'd set data logging (at 5Hz) for the flying session in question. On all previous flights I had logging disabled.
Now when i tried to download the log to see if it gave any clues to the problem the data appeared to be corrupt and would not 'parse'. Also and this could be coincidence but but the loss of RPM would seem to have occurred at about the same time as the data logger's memory became full (13 minutes of logging at the settings I used)

Anyway, after clearing the logger memory and disabling data logging (and making no other changes at all) I gave her another spin up and now everything is fine again, I'm getting full headspeed as confirmed by a tacho.

So the conclusion that I'm coming to is the problem was most likely caused by an ESC glitch that is related to data logging and possibly the logger memory.

Is this something anyone else has experienced?

My settup:
Trex 600DFC pro
12s, 3000mAh
Scorpion HKIII 4035 530kv
14t pinion, 118t main
Castle Ice2 80HV (latest firmware v4.19 beta)
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Old Dec 26, 2013, 10:18 AM
Grumpy old git.. Who me?
JetPlaneFlyer's Avatar
Aberdeen
Joined Mar 2006
11,239 Posts
ok guys, I've found the problem and it's nothing to do with the ESC. The problem turns out to be that the one way bearing is rotating in it's housing. It transmits enough power to spin the blades slowly but then slips when more power is applied. With the blades off it didn't slip which was why i couldn't simulate the problem in testing.

Fix is simple; the bearing has to be Loctited in it's housing.

Sorry for the 'wild goose chase'
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Old Dec 26, 2013, 03:13 PM
A man with too many toys
United States
Joined Feb 2001
17,377 Posts
Quote:
Originally Posted by JetPlaneFlyer View Post
ok guys, I've found the problem and it's nothing to do with the ESC. The problem turns out to be that the one way bearing is rotating in it's housing. It transmits enough power to spin the blades slowly but then slips when more power is applied. With the blades off it didn't slip which was why i couldn't simulate the problem in testing.

Fix is simple; the bearing has to be Loctited in it's housing.

Sorry for the 'wild goose chase'
What about the data log problem how did you fix that?

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Old Dec 27, 2013, 07:55 AM
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Long Valley, NJ, USA
Joined Dec 2001
1,689 Posts
Aberdeen,

Glad you found the real problem. It's funny how paranoid I can get about this sort of thing - after I read your initial posts I opened up my Mini Protos to access the ICE 50 Lite connector and turned off logging just in case!

I do not need the logging anymore on this heli now that it's set up, so all is well.

I did notice that the log, which had been running for about 10 flights since I last downloaded and cleared it, was full: It just ended in the middle of the last session. I suppose that means that the data recording just ends - it does not go back to the beginning and write over the earlier sessions.

Best luck,

Paul
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