Why I am done with the Brain 2 ( SW 3.1.001 )

[toadiscoil]

Have to admit has happened to me a lot as well. I usually start with a pissed-off thread. This is natural because after you crash you want to find what caused it and put a solution to it. Or if it grounds your heli.

But I am always turned around on my original anger thanks to the awesome and almost instant customer support and even immediate action if so required into the unit itself. I still can't believe the KST servos got included the day after it was brought up. Talk about a connected product group to their user base.

This is also why I stay with iKon/Brain.

Originally Posted by mulchi

Kudos to BrainDev for this thorough analysis. Those vibrations seem to be quite high, given that you were basically hovering around. Even if you were doing pitch pumps, what Rxpitch does not seem to support, such high vibrations are unusual and should go away immediately.

I personally would give the Brain another chance. I would suggest to not test rescue again until you have a few flights that are completely vibe free (always below 60) and you gained confidence that you have a model with good overall health

On a side note, good choice changing your original posting. This one gave much more constructive feedback than the original one would ever have.

[nflanagin]

Another thing to check, and this just happened to me, is the motor shaft, pinion and if the motor bell has play. I setup my Mikado for rescue, but it was the first time setting up trailing edge control - meaning swash down, pitch up. I messed up the setup, tested rescue and shot toward the earth - replaced skids, tail blades, tail grips, main blades, main gears. Totally my fault. Fixed it up and flew. I noticed the occasional vibe in the exact same spot. I thought it as from bad flying. Turned out I had knocked off the motor snap ring and damaged the motor bearing and I think the pinion may have been slipping too. So, check your pinion and motor.

Because I waited so long and damaged the motor bearings, I just ordered bearings and an new motor shaft. I do have to admit that the Brain2 was flying great - just the occasional bobble I was trying to tune out. Upright rescue worked, too.

[Guapo131]

Originally Posted by BrainDev

Obviously I have checked before send the post, and as you can see, the vibration that start at 117 start when pitch is at a fixed value from many seconds, similar for the others. So is not due to a pitch pump for sure. Check again because the problem is not generated by pitch pump.

Does anyone else see something really weird with the data on this plot?

It's basically showing that pitch is held almost exactly constant while his aileron is going back and forth. Yes, that's possible, but i find it unlikely. We are talking a full 30to 40 seconds of pitch being held very constant, and very weird steps. I haven't logged my RxPitch in my brain2, but I doubt it looks so flat and "steppy". Also, if you hold the pitch at one setting for 30 seconds, then increase it to whatever other setting for another 30 seconds, either you are now 1000' high, or you were descending for a long period, then go into a hover (or whatever variation - hopefully i got the message across).

On another subject, is it possible to look at the vibration history to find the exact time the crash occurred and then go back to this screen and correlate that to the pitch input? For example, to find out if the full negative pitch corresponds to after the crash, or before? It could be very possible that full negative pitch (from Tx) occurred after the crash and the OP pilot simply set the controller down. Other problems you could determine by knowing this: is throttle hold somehow tied to pitch and when you flip TH, the pitch goes full negative. That could explain the full negative pitch, and could also cause a problem in the air (for example, if you hit rescue and it starts to do something a little weird you don't like, then you hit TH as a precaution, then it somehow has negative pitch associated with TH, then it's still got full headspead and it shoots to the ground). Just spitballing here - seeing what sticks to the wall.

I'll also add, If the ikon is logging that the RxPitch is full negative (before the crash), then there's very likely something wrong with the TX and receiver setup - i.e. NOT the Ikon2. We may not know exactly when aux channel activated Rescue, but if the OP Pilot did not move the left stick all the way to the bottom, then there is something else going on between the TX stick and the input to the IKON. Because theoretically, the IKON is simply logging the input pitch value - no algorithms required - just logging it. It's a debugging step that allows you at least to know where in the signal path the problem is occurring.

Funny side story regarding TH pitch curves: A friend of mine was trouble shooting an issue and adjusted his normal mode pitch curve to be flat 50% (0pitch). He spun up the heli in normal mode, saw whatever it was he needed to see, then flipped TH. But TH still had the linear pitch curve, so the heli was full RPM and then all the sudden had XX% positive pitch. The heli shot up 20 feet instantly and came crashing down. No one was hurt. Heli crashed. Good cautionary story to laugh at.

[Xrayted]

Originally Posted by Guapo131

Does anyone else see something really weird with the data on this plot?

It's basically showing that pitch is held almost exactly constant while his aileron is going back and forth. Yes, that's possible, but i find it unlikely. We are talking a full 30to 40 seconds of pitch being held very constant, and very weird steps. I haven't logged my RxPitch in my brain2, but I doubt it looks so flat and "steppy". Also, if you hold the pitch at one setting for 30 seconds, then increase it to whatever other setting for another 30 seconds, either you are now 1000' high, or you were descending for a long period, then go into a hover (or whatever variation - hopefully i got the message across).

On another subject, is it possible to look at the vibration history to find the exact time the crash occurred and then go back to this screen and correlate that to the pitch input? For example, to find out if the full negative pitch corresponds to after the crash, or before? It could be very possible that full negative pitch (from Tx) occurred after the crash and the OP pilot simply set the controller down. Other problems you could determine by knowing this: is throttle hold somehow tied to pitch and when you flip TH, the pitch goes full negative. That could explain the full negative pitch, and could also cause a problem in the air (for example, if you hit rescue and it starts to do something a little weird you don't like, then you hit TH as a precaution, then it somehow has negative pitch associated with TH, then it's still got full headspead and it shoots to the ground). Just spitballing here - seeing what sticks to the wall.

I'll also add, If the ikon is logging that the RxPitch is full negative (before the crash), then there's very likely something wrong with the TX and receiver setup - i.e. NOT the Ikon2. We may not know exactly when aux channel activated Rescue, but if the OP Pilot did not move the left stick all the way to the bottom, then there is something else going on between the TX stick and the input to the IKON. Because theoretically, the IKON is simply logging the input pitch value - no algorithms required - just logging it. It's a debugging step that allows you at least to know where in the signal path the problem is occurring.

Funny side story regarding TH pitch curves: A friend of mine was trouble shooting an issue and adjusted his normal mode pitch curve to be flat 50% (0pitch). He spun up the heli in normal mode, saw whatever it was he needed to see, then flipped TH. But TH still had the linear pitch curve, so the heli was full RPM and then all the sudden had XX% positive pitch. The heli shot up 20 feet instantly and came crashing down. No one was hurt. Heli crashed. Good cautionary story to laugh at.

No, because sometimes it is what it is whether we want to agree with the facts or not. Conspiracy theories can be formed for anything under any situation. The log is what it is unless you have some other conclusive proof otherwise.

That is the entire point of logging the channels so that when things go wrong you can see conclusively what what really happening vs. assumptions, conjecture and theories otherwise.

[Guapo131]

Not sure where you thought i was implying that there was some sort of conspiracy theory on the part of the OP. I guess what i was implying was that there might have been something wrong with the log files, or the logging portion of the ikon software, or the pitch channel was in fact some other channel. And the only "proof" I had was exactly what was in the picture. It looks odd to me. It really doesn't look odd to anyone else? I'm completely alone here? And I'm crazy for even mentioning it? Perfectly straight constant pitch for 30-40 seconds? Do people fly and not touch that left stick for 30+seconds? I did say "Yes, that's possible, but i find it unlikely." I just wanted to see if anyone else looked closely enough at that data to see that and also thought that was weird, and if so had any thoughts on the matter.

I have personally experienced issues with the ikon logging where it would log nothing/jibberish for the first 60+sec after battery is plugged in, then it logs everything fine after that (and the good log data started after I was in the air). Another time, it showed data was downloading (300+seconds of data), then it wouldn't show anything on the log screen for any parameter. These anomalies happened after there were many changes to the logging frequency and parameters to save were changed back and forth (also weird stuff where the settings weren't being saved every time, even though i clicked off the page - that problem solved btw). Weird stuff in the software, but I just wrote it off as the software having a hiccup because all of the changes (especially the frequency). Once i stopped changing the settings every other flight, and cleared the log, it's been working as expected. Anyways, I absolutely believe that ikon logging can have "hiccups", and I've seen it myself. But I haven't seen this particular hiccup. I was bringing it up in case anyone had seen the software have this particular hiccup w.r.t. pitch.

Regarding your comment:
"when things go wrong you can see conclusively what what really happening vs. assumptions"
One section of my post discussed the following sequence: A) find crash time (sec), B) find if full neg pitch happened before or after that point, =C) gives some information on what was happening between TX and input to ikon. It may not be the entire picture or explicitly solve the problem, but it helps. No assumptions required. The data is right there. Or at least I was asking if someone would/could do that analysis.

Sure some of my other comments were theories and conjecture. But is throwing out theories and conjecture not allowed? Maybe the OP hadn't thought about some of the theories, or the theories reminded him of a different scenario that actually helps him find the answer. I would encourage other people to throw out some theories. This type of assistance helps me solve my problems. I guess we just fundamentally disagree on how to help someone on the forum.

Anyways, I was honestly just trying to help here. And not trying to "not agree with the facts". I apologize if I offended the OP. My post was not meant that way at all.

[Hobee]

I agree, that the logfile looks strange. Especially around the 118 second mark. I read the logfile as three short, consecutive aileron inputs into the ssame direction while keeping pitch completely unchanged. This does not feel like a natural flying manouver. But I must say I am no expert in reading logfiles.

But isn't it just great to have the Brain's logging capabilities? A year ago I would not have dreamed about the possibility to analyze a crash or just a regular flight in that detail!

Just an idea: It would be nice to have the ability to have the vibration levels and inputs/outputs on the same graph / screen.

[enied]

Sold the Brain 2 and I go ahead with the BD3SX, my third one now.

While the Brain 2 comes with a lot of bells and whistles, I prefer a FBL system which flies excellent and completely reliable. For me, the Brain 2 lacked in the areas of auto level and rescue which are fundamental basic functions a FBL system should be able to do in 2017.

My best wishes to the MSH Brain community.

Regards,
Eugen

[jsbach#1]

[TheBum]

I think it's time to close this thread.