I learned something last weekend.  The wingover is a very stressful manuever.  The two spikes in current that you see in the logged data are to be respected.  These are typically the largest current draw in the pattern.

I had my Ice 50 set to sensitive (60A).  I thought that this would be fine for most flights, and it was.  It should easily cover a prop strike.  But I decided to try one more prop the other day.  A large 13x6 3b was made from JXF pushers.  The motor was a Scorpion SII-3026-710 and had been working fine for the other props I had thrown at it.

But ..... a nice sharp pullup into the wingover, apparently is such a load on the system (even with piped systems this corner has caused problems) that the ESC decided to protect me from the surge of current needed to fly.  The motor shut off and the plane arced over and hit about 10 feet from the center of the circle. 

I think from now on I'll select the insensitive mode for current limiting. or should it be disabled?  This is the case of the transistor blowing to protect the fuse.

solution for such cases is slow down instead of cut off ... it saved many eirplanes so far

Igor,
Are you saying that one should ease into the wingover pullups for this very reason?  Have you seen this before?

Mark,
I thought the same thing about static loads, .... the three blade I know was a stretch for that motor ..... the motor was supported at both ends ...... I keep coming back to the fact that piped planes had a tendency to flame out at the same spot ..... don't think we ever solved that one.

Crist,
Yes I think now's the time to move up to the 75 or even the 100.

Igor,
Are you saying that one should ease into the wingover pullups for this very reason?  Have you seen this before?

I think Igor is saying there is a mode that in the event of an excess load slows down the motor for a moment instead of killing it.  There is a guy in our club that has the esc setup that way, it keeps his system from frying in the event of a prop strike but it gives at least partial power if overloaded in flight to prevent disaster.

This is a great discussion.  Thanks, guys.

Thanks Igor,
I understand what you are saying now. 

The plane was just a practice ship, but I think I've learned something real important here. 

The battery is a bit crunched on one end ..... it held its charge and didn't catch fire or anything ...not leaking anything..... do I dare try to use it again?

NO!!!  said simply - more due to Murphy than anything else - as sure as there's Sh*t in a cat - it will burn up or something when IN your plane..

For what it is worth, I have been using a battery that is crunched on one end for a couple of years with no problem --- but that is my battery and not yours. I use it on a junker practice plane because I do NOT have full confidence in the battery and I would not cry if I lost the model. I might cry if it took out my Castle creations ESC!!! 

Schuang

I think you may have hit on it - 3VDC per cell and maybe more Caps in the primary line.  Castle sells a board with four additional capacitors and very easy installation.  Could be worth a try.  The capacitors are for reducing ripple voltage and Castle recommends less than 10% ripple volts of the total battery so for a 4S, 1.48VDC and for a 5S, 1.85VDC.  I have normally seen .4-.7VDC on my logger but if it could hold the ESC input voltage for a milli second?  It seems a majority of the stoppages are on the way up the wingover.  This is also the most power demanding maneuver on the ESC other than start-up.
Norm

You can buy the proper Capacitors from www.digikey.com/

Part # P12411-ND @ .51 cents each (dirt cheap)!!!

Just remember that these are electrolytic capacitors and you need to match polarity when you solder them in to the battery leads on the ESC.

Well ....... nevermind ........ maybe its something else
I just looked closer at the output data ...... and I see that the throttle command went down to 1ms about one second before everything else shut down .....

Note that I did two wingovers and it was the second one that caused the problem ....

Could it be that the timer start/stop button is at fault here?  Its just a momentary switch contact I think.
Hummmm

Humm.. Timer shuts down exactly at 70 seconds.  Are you sure the timer was not tweaked prior to the flight?

I learned the hard way myself BTW...


Regards,

Sean

1.  Lower the cutoff voltage just like Igor mentioned. 

No, I mean just opposite, I mean to REPLACE high current cut off by setting low voltage cut off to 3.2 or 3.3V ... that is what we found with beginners in gym.

I'm certian that the flight time value was not changed.  It was a full flight.

The even second increment probably is from the data logging quantization due to being set to 1 set data rate. 

Could the little spring in the timer push button get weak and allow contact to be made during a hard manuever?  Why is it always the wingover?  Could the throttle data value being a second early just be an artifact of the data logging quantization and it all really is from the same time?

Hummmm?

Frank
So the motor shut down during the inverted “up line” on the second wingover. 
Frank, as you know I have had two of these occurrences.  The only common element of my two identical occurrences was the switch.  It was not Will Hubin’s switch but a cheap one from Radio Shack.  Switches of course are a high failure rate item when compared to IC's.
During the first incidence I did not have the data logging looking at the input pulse of the ICE Lite 50.  The second incidence was with a Phoenix 60 (without data logging capability).  I reused the same switch that was involved in the first incident as I did not suspect the switch.

BTW: For an ICE 50 you are operating very close to the line at about 48A - I know you know that but others should consider this when making ESC selections.

One other point.  I no longer use a switch to start my timer.   I use a 2 pin JST connector and a shorting plug to insert momentarily for start or stop.   

Norm

Yes, Frank,
I think it's best to ignore the slopes between points and just look at the values at the sampling points.
How often are you sampling? It looks like you are set 1 second per sample.

I'm with Norm and John on this, as it looks like the input went to zero and there was still full RPM at one point.

By the way, I like the bulletproof and lightweight solution, Norm!

Regards,
  Dean P.

I was going to say that it couldn't possibly be the switch, then I read Frank's post.

It may be the wires -- if you get a power glitch to the ESC it'll (presumably) reset.  I'd put the plane on the bench, take off the prop, install batteries, turn it on, and while it's running, wiggle every wire I could get my hands on.  In particular, I'd wiggle the wire from ESC to timer, and most particularly around the spot where it goes into the ESC and the connector to the timer.  With the prop off the load is going to be very low, so you should be able to do a 6-minute "flight" on the bench in still air and not have any cooling issues (and if you do it'll be the ESC or battery, and you can feel them.

This won't necessarily find a loose connection (nothing will -- I hate intermittent problems), but if wiggling a wire makes it misbehave, and if wiggling the wire didn't also wiggle the timer and hence the switch, then you've found the problem.

I'd also look at the way that the switch and/or timer is mounted, to make sure that the switch itself doesn't flop around in maneuvers and get actuated accidentally.

Come to think of it, if wiggling wires doesn't make it misbehave, try rattling the whole plane with motor on and prop off -- if that makes it cut out, you know you have a mechanical problem of some sort, not a motor loading issue.

And speaking of mechanical issues -- is the prop well balanced?  Does the plane stay vibration-free with it turning?  If you've got high vibration that'll cause no end of problems with wires and switches and whatnot.

Igor

I may not be understanding completely - are you saying turn off the "current cut-off" in the ESC and only use the voltage cutoff feature but set that to 3.3v ?

Regards
Norm

It not needs to be really "off" I mean that it should be safe enough. And in combination with current limit, it is good to use also high voltage limit. I can see what was the reason for cut off in my ESC (spin) and guy who crashed with his model and burned also motor and also ESC had setting for 2.8V ... while I am sure that 3.2V did safe cut off, and additionally it was clearly written in ESC that the reason for cut off was low voltage.

Some ESCs does not have adjustable current limit, and we found that voltage limit is safe also in those cheap ESC like this one: http://www.himodel.com/electric/HiModel_COOL_Series_11A_Brushless_Speed_Controller_6A_LBEC.html